Harlequinmania

Click through to see the images. From the California Academy of Sciences 2014 Philippines Expedition blog: Keeping animals healthy in the field—and then healthy while en route back to Manila for a 14-hour flight to their new home in Golden Gate Park—entails an entire slew of life-support equipment (LSS). We have that stuff at the Academy, obviously, but right now we’re out in the field. Where it’s too hot. Where there isn’t a store to buy what we need. Where we have to constantly battle a continually moving colony of fire ants that appeared right where we set up our equipment. Fortunately, all the pre-planning we did to prepare for this is paying off. Want the laundry-list of what came with us on the plane? Two 200-gallon inflatable kiddie pools (plus a third, just in case), 220-bolt air and water pumps, rolls of tubing, nets, containers, coral-holding devices, fish-holding cups, seeded biofilters, and an assortment of valves, glue, patch kits, rubber bands, cable ties, etc. We knew we’d need to keep water temperatures down in the pools so the animals could survive (from 94 degrees to a reasonable 82), so our original plan was to give the pools water-changes every few hours, which would have required many trips hauling 5-gallon buckets of water 30 feet back-and-forth from the shore. Luckily, our hosts were able to find a powerful sump pump and modify it so it could stay in the ocean while plugged in. We were also able to connect the two pools via four siphon hoses, basically turning them into one body of water. Then we able to fabricate drains in the pools, which gave us not just cooler temps, but also stronger water flow—much better for the shallow-water corals (which are, as the kids say “money”), two coconut octopuses, and selection of fish we’re caring for (which includes ghost pipe fish and white mushroom coral pipefish). And today we’re going to attempt to collect pigmy seahorses. Many of the fish collected deeper than 300 feet have a gas-filled swim bladder. When they’re brought to the surface, the pressure on them decreases and the gas in the swim bladder expands in the same way a sealed bag of chips does when you take it on an airplane. When the bladder expands, it can damage the internal organs of the fish—which is, well, very bad for the fish. Traditionally, collectors have used a hypodermic needle to relieve pressure from the swim bladder, but that’s a less-than-optimal solution, resulting in unreliable survival. To combat this problem, we designed and built a fish decompression hyperbaric chamber based on some larger designs that have been used for collecting cold-water rock fish. Our design is light, relatively portable, and the collection chamber itself doubles as the decompression chamber. The deepwater team collect the first deepwater fish yesterday, and our chamber is working very well. Tomorrow morning, Aquarium Team One heads home to the Academy with the live animals we’ve collected. Packing and shipping them is a story in and of itself, which I’ll try to write up on the plane. Next week, Aquarium Team Two arrives for more collecting with a focus on the deep-water fishes. I’m looking forward to getting home, unpacking the animals, and seeing what the second aquarium team achieves next week. View the full article

Click through to see the images. Visit www.oceanshutter.com for more reef photography and videos by husband-and-wife team Dustin and Tyra Adamson. Trust us. It's worth your while; their photos and videos are absolutely top notch. " height="383" type="application/x-shockwave-flash" width="680"> "> "> View the full article

Click through to see the images. One of the most oft-discussed - if not the single most commonly mentioned - elements in the home aquarium is nitrogen. Although far from being the only element of interest to the typical reef aquarist, nitrogen is among the first elements the burgeoning aquarist learns about, and the canonical nitrogen cycle often lies at or near the center of most aquarium husbandry techniques. This attention is well deserved, of course, for the various nitrogen compounds, nitrate (NO3) especially, can have a controlling impact on the function of both natural and home reef ecosystems. Of particular interest to most reef hobbyists is the effect that nitrate concentrations can have on algae growth, with many hobbyists focusing on controlling nitrate concentration as a way to limit the growth of nuisance microalgae. On a global scale, nitrogen is often considered the limiting nutrient controlling primary productivity, and although many home aquaria may deviate from this rule, nitrate control remains one of the single most effective ways to influence primary productivity in our own systems. Despite the importance of nitrogen in the home aquarium, among many aquarists there exists only a basic understanding of the dynamics that control the speciation and concentration of nitrogen. For many aquarists, our knowledge of the nitrogen cycle consists simply of the oxidation of ammonium (NH4) to nitrate and then reduction to nitrogen gas (N2). Although this is not an inaccurate understanding of aquarium nitrogen dynamics, what it fails to capture is the intricacy of the nitrogen cycle, especially in terms of how it is influenced by additional factors within our aquaria. Many of these additional factors may seem relatively unimportant at first glance, but I will argue that understanding them and the effect they have on nitrogen cycling can not only yield insight into how our systems work, but also make us better aquarists. In this paper, I hope to shed light on to the home aquarium nitrogen cycle while providing additional insight into the factors that control the speed and magnitude of these processes. I will focus especially on factors that control the rates of denitrification, given the importance of this process as a sink for the removal of nitrogen from the system. In so doing, I will also present the relationship the nitrogen cycle has with the sand bed in an aquarium, as well as the twin concepts of bioirrigation and bioturbation that I argue are critical considerations when designing a natural and healthy reef aquarium. Finally, I will discuss the importance of carbon in this whole picture, with practical suggestions on ways to remove persistent high levels of nitrate and the broader implications for the aquarium ecosystem. The Nitrogen Cycle In its simplest form (presented below in figure 1), the nitrogen cycle is taught as a simple linear progression from ammonia (NH3), which is oxidized to nitrite (NO2) and then nitrate, which is then reduced to nitrogen gas, (N2) which bubbles out of the aquarium and acts as a sink for the removal of nitrogen. The last step occurs under anoxic conditions (i.e. in areas where oxygen has been depleted), but other than that requirement the activity of the nitrogen cycle is essentially a given. While this is certainly only a basic understanding of complicated marine nitrogen dynamics, for the vast majority of home aquarists this simple concept has proven sufficient for typical husbandry practices. The whole picture, however, is more detailed, and in truth can not be considered in isolation from other elements; for instance, the basic premise that denitrification occurs in anoxic zones implies that we must also consider oxygen dynamics in the aquarium. Furthermore, in addition to transitions between the dissolved inorganic nitrogen (DIN) species listed above, we must also consider the organic sources and potential organic sinks of nitrogen. Figure 1: The classical nitrogen cycle as known by most aquarists consists of ammonium being oxidized by two groups of bacteria (Nitrosomonas and Nitrobacter are pictured) into nitrate, which is then reduced by a number of different species (Azomonas is pictured) into nitrogen gas, which then bubbles out of the aquarium. Sources of Nitrogen One of the main sources of nitrogen in the home aquarium is in the form of organic nitrogen, either particulate organic nitrogen (PON) or dissolved organic nitrogen (DON). The sole difference between those two sources is whether the organic substance has been broken down from large solid particles such as proteins to smaller dissolved ones such as amino acids. For our purposes we can consider both groups to be essentially interchangeable; not only is the conversion from PON to DON relatively fast, but also PON can be directly acted upon by the microbes responsible for nitrogen cycling (Kristensen et al. 1987, Berg et al. 2003). Organic nitrogen can enter the aquarium in a number of ways. Every commonly available food (whether for fish, invertebrates, or the entire tank) contains large amounts of proteins, amino acids, etc. which contribute to this pool. While some of this food directly and immediately enters the nitrogen cycle, most enters as digestion by-products in the form of organic waste (or whole cells in the case of microbes). These wastes are then broken down in the process of diagenesis, of which the nitrogen cycle is a part and which will be discussed below. In addition to direct input in the form of food, organic nitrogen can also enter the system as a product of nitrogen fixation. Nitrogen fixation is the process whereby a select group of organisms (collectively called diazatrophs) convert nitrogen gas into ammonium, which is then usually used by the nitrogen-fixing organism to support its own growth. Of course, when the organism dies this nitrogen enters the system, making this a crucially important source of N. Nitrogen fixation is a globally very important process that controls production in many ocean systems (Gruber et al. 1997), but unfortunately it is currently unknown to what extent N-fixation occurs in the home aquarium. The process is known to occur on coral reefs (Larkum et al. 1988), but it is not known whether cyanobacteria in the home aquarium undertake the process under normal conditions. Anecdotally, I have personally observed heterocysts (the N-fixing "organ" in these cyanobacteria) in microscopic samples obtained from my own aquarium, so it is a safe assumption that N-fixation is a source of nitrogen in the aquarium. Once it has entered the system in the form of either PON or DON, nitrogen in the home aquarium is invariably consumed in some form or another, which will be discussed below. In nature, a significant chunk of PON is buried, but our aquaria lack both the sedimentation rate and thick sediment beds necessary for burial. Instead, all organic nitrogen in our systems will undergo the processes called diagenesis, which is the breakdown and eventual fate of organic material. Remineraliztion and nitrification Compounds that contain organic nitrogen - as a rule - also contain organic carbon, collectively termed particulate or dissolved organic carbon (POC or DOC). Although all heterotrophic organisms feed on these compounds (and many autotrophs need at least some of their components), the cellular machinery can work only with the small building blocks that make them up, such as amino acids. So, the first step in diagenesis is the breakdown of large, complex organic molecules into their building blocks, the process called remineralization, the general form of which is: (CH2O)x(NH3)y + xTER + yH+ --> xCO2 + yNH4+ + xH2O Where I have used "TER" to indicate the terminal electron acceptor and x and y are subscripts indicating the makeup of the organic matter. Usually, these values are 106 and 16, respectively, indicating the famous Redfield ratio of these elements in plankton. However, many aquarium foods deviate from this ratio, so I have left the equation in general form. What we are most concerned with right now, though, is the ammonium that is produced by this reaction. This ammonium is the first substance that then enters the classical nitrogen cycle. It should be noted that - unlike the other processes we have discussed and will discuss - remineralization is carried out by every organism present in the aquarium (and ourselves, using O2 as the terminal electron acceptor), which means that this process is always going on in our aquarium, typically producing a lot of ammonium. Thankfully, a great deal of this ammonium is incorporated into new growth (Herbert 1999, Fennel et al. 2006), but a large portion also does enter the nitrogen cycle via nitrification. Nitrification is a process by which the ammonium produced in remineralization is oxidized to nitrate. This is a two-step process with nitrite (NO­2) as an intermediate, and is typically performed by a consortium of bacteria, with one group excreting nitrite that is consumed and oxidized by the second group. Of these two steps, it is the first (oxidation of ammonium) that is very slow, which is why nitrite levels are rarely detected in the home aquarium after the bacterial populations have been established. The nitrate that is produced in this process can be incorporated into biomass, but the majority of it enters the process that aquarists are most often concerned with: denitrification. Denitrification Denitrification is a heterotrophic process (meaning the organisms involved must consume their carbon, rather than producing it themselves) that reduces nitrate into nitrogen gas, and follows the general equation: (CH2O)106(NH3)16 + 85NO3 + 100H+ --> 106CO2 + 16NH4+ + 43N2 + 149H2O (Please Note that the equation is very slightly imbalanced, as I have rounded the decimal points in the stoichiometric coefficients). The net result of this equation is the relatively large removal of nitrogen in the form of dinitrogen gas. Globally, this represents a major control on primary productivity (which requires nitrogen), and in the aquarium this represents one of the most effective ways we can remove nitrogen that may reach excessive levels. Although this process has been discussed at great length in the primary literature, I think the most important thing we can take from it right now is that this process requires organic material. This is a crucially important point I will return to later. Additional processes affecting nitrogen Although the processes described above constitute a fairly complete list of what can happen in our own systems, the picture in nature is more complex. Specifically, there are a couple of additional processes that can take place, which are worth mentioning in the spirit of completeness. It should be noted that these processes are relatively new to the scientific community, and so our understanding of them is unfortunately not entirely clear as of yet. One relatively newly-discovered process impacting nitrogen in the natural ecosystem is anaerobic ammonium oxidation, better known as annamox. In this process, certain anaerobic bacteria and archaea are able to essentially short-circuit the typical nitrogen cycle and react ammonium with nitrite to produce nitrogen gas. This represents a potentially very important alternative sink of nitrogen (Engstrom et al. 2005), but it is still not entirely clear under what conditions this process becomes important. It is most often noted in areas of the ocean with low oxygen levels combined with low levels of organic carbon, which is almost certainly not representative of the typical aquarium. In conditions more similar to those expected in our systems, annamox is much less frequent and so is likely not an important issue (Porubsky et al. 2009). Another relatively "new" process is called dissimilatory reduction of nitrate to ammonium, or DNRA. Although energetically very similar to traditional denitrification, this processes represents a way for organisms to recycle nitrate rather than allow it to leave the system. Thankfully for our purposes, DNRA predominates almost exclusively in highly sulfidic sediments (Porubsky et al. 2009), which do not reflect the conditions found in most reef systems. Figure 2: An expanded version of the nitrogen cycle, including sources of nitrogen as well as the relatively newly discovered processes DNRA and annamox. Nitrogen and the Sand Bed A discussion of nitrogen cycling is nearly impossible to separate from a discussion of the sand bed in our aquaria, because it is in the sand bed where most of the processes take place. Of course, the carbonate matrix of live rock is also the site of a very active microbial community, and I will be discussing that in line with this discussion of the sand bed. Although at times the presence of a sand bed is a contentious issue, I would argue that having a sand bed is a necessity for natural nitrogen cycling (please note, however, that I am not claiming that natural nitrogen cycling is the only valid aquarium husbandry method). Many aquarists might disagree with me on this point, and many in the hobby have argued that sand beds do more harm than good in the long run. This is often in part due to a fairly poor understanding of the processes that take place in marine sediments, but there are legitimate issues that must be considered in sand bed maintenance that I will discuss below. First, however, I must discuss the actual processes that take place in sediments, especially the ways in which they are connected to nitrogen cycling. The Redox Cascade Worldwide and especially in coastal areas including coral reefs, benthic sediments are the primary site of the diagenesis and remineralization that have been discussed above (Galloway et al. 2004). One reason for their primacy is the simple fact that organic wastes (which consist of dead organisms, feces, and nutrient-rich marine snow) end up in and make up the sediment layer; the majority of organic matter decomposition is simply where the organic matter ends up. When organic matter ends up being deposited to the sediment, it immediately begins to undergo diagenesis. First and foremost, organic matter is consumed and metabolized using aerobic respiration, which uses oxygen as the terminal electron acceptor ("TER" in equation 1). However, the amounts of organic matter typically exceed the levels of oxygen, so organisms then begin to use "substitute" electron receptors in place of oxygen. The first of these is nitrate, via denitrification, which is thermodynamically not as "profitable" for organisms as aerobic respiration. This is why denitrification is always associated with anoxic sediments or water: oxygen is thermodynamically a favorable electron acceptor, and nitrate is only used as a last resort. Once both nitrate and oxygen have been consumed, any remaining organic material continues to be broken down by energetically less favorable terminal electron acceptors according to a well-established cascade, continuing next with iron reduction, and finally with sulfate reduction. In most cases, organic matter is consumed long before sulfate is depleted, so our discussion can end with that step. Collectively, all of these metabolic pathways are termed the redox cascade, referring to the cascade of less desirable terminal electron acceptors as heterotrophic organisms consume organic matter in the sediment. For most aquarists, our interest in the redox cascade can end with nitrate reduction, but as a side note I think it necessary to briefly discuss sulfate reduction. One potential argument that is used against sand beds is that it can potentially lead up to the buildup of toxic sulfides. However, this argument ignores the fact that iron reduction takes place before sulfate reduction. That fact is important for two reasons: 1) iron is plentiful in marine sediments and thus highly unlikely to be depleted in the relatively low nutrient loading we have in our aquaria and 2) any sulfide that is produced in the sediments will react to precipitate with the iron produced in iron reduction to form insoluble iron sulfide (FeS), thus acting to remove any of the potential sulfide. Of course, this is a complex subject worthy of its own article, so I will leave it with only this brief discussion. Live Rock As I mentioned above, live rock is also a major site for microbial activity including nitrogen cycling. Unfortunately, the particular dynamics are not as well studied as those specific to the sand bed, but the same basic principles apply in terms of the redox cascade. The primary difference between the live rock and sand bed is simple structure, which has pronounced effects on the speed of diffusion, the process that supplies most of the nitrate and other compounds that are metabolized in the redox cascade. One other major difference between the two sites of metabolism is one I have not yet mentioned: the possibility of bioturbation and bioirrigation. Critters in the Mud To me, one of the most fascinating aspects of the aquarium hobby isn't the livestock that I purchase and add to my system, it's the unintended occupants, the hitchhikers that end up in my tank either on purchases or as hitchhikers on the original live rock. However, the importance of these organisms goes beyond simple curiosity: these organisms are typically responsible for a pair of intricately related processes that play a pivotal role in the nitrogen cycle: bioturbation and bioirrigation. Although these two are technically distinct processes, they are nearly impossible to extricate from one another, and are often performed simultaneously by the same organisms. Darwin's Last Idea Although certainly less well known than his theory of evolution, bioturbation as a phenomenon was actually first described by Charles Darwin in one of his last works (Meysman et al. 2006). In short, "bioturbation" is the term for the collective action of burrowing organisms that causes or enhances the physical mixing of sediments. Related to this is "bioirrigation," which is the term for any active ventilation of burrows or surrounding sediments by the organisms that live within them. Together these processes play a vital role in coastal and benthic systems, to the point where such organisms are considered "ecosystem engineers," organisms whose presence has a formative effect on the ecosystem around them (Jones et al. 1994). One of the most important ways that these infauna (organisms that live within sediments) structure their environment is the formation of burrows within the sediment (see figure 3 for examples). These burrows represent a dramatic increase in the surface area of the sediment-water interface (SWI), the surface across which solutes such as nitrogen are exchanged between sediment and the overlying water. This exchange process is known as benthic-pelagic coupling, and serves as an important avenue of "communication" between coastal waters and the sediment that serves as their natural filter. More importantly, these burrow structures usually extend into the anoxic zone, and thus serve as important sources of oxygen to be used in nitrification. Further down the nitrogen cycle, the presence of oxic zones caused by burrows in otherwise anoxic sediments stimulates what is called "coupled denitrification", which is simply denitrification that is "powered" by nitrate that has just been generated in nitrification (Kristensen et al. 1987). In addition to simply extending the surface area for diffusive exchange, the active irrigation of burrows often actively supplies both oxygen and nitrate to be used in both nitrification and denitrification at a rate much faster than could be supported by molecular diffusion (Henriksen et al. 1983, Huettel 1990 among many others). This can result in rates of denitrification that are orders of magnitude higher than those in "barren" sediments, and these organisms can in fact be responsible for ecosystem recovery after periods of nitrogen eutrophication (Bartoli et al. 2000). On a more physical basis, the action of bioirrigating and bioturbating organisms can actually control the physical makeup of the sediment (Volkenborn et al. 2007), preventing the type of "clogging" that is often raised as a potential long-term issue with sand beds. Bioturbation in the home aquarium Although the vast majority of bioturbating organisms that have been studied are relatively large and unlikely to be encountered in the aquarium (such as the lugworm, Arenicola marina, which many European aquarists might be familiar with from the Wadden Sea), there are a number of organisms that are responsible for sediment mixing and burrow formation that can be found within the home aquarium. Chief among these are the numerous polychaete species that can usually be found actively burrowing in most aquaria (Figure 3 has an example). Yes, believe it or not, those bristleworms many of us once feared can actually be responsible for enhancing nitrate removal from our systems! Another group of organisms responsible for bioturbation in the home aquarium are the amphipods. Indeed, large amphipod burrows can often be seen against the side of the aquarium glass (see Figure 3 for a possible example), and these organisms can be responsible for moving very large volumes of overlying water through their burrow as they ventilate it to provide oxygen. Sadly, there is currently little to no direct study of bioturbation in the home aquarium, but there is no reason to believe it does not play as important a role in the hobbyist's tank as it does in nature. In fact, it is distinctly possible that one factor that leads to the stability of a mature aquarium is the development of a healthy population of sediment infauna. Furthermore, one possible explanation of "old tank syndrome" is the decline of the infaunal population, with a subsequent decline in rates of nitrification and denitrification. Of course, this possible explanation is at this point just speculation, and would need rigorous experimentation to move beyond conjecture. One thing that I have not yet mentioned is the role of bioirrigation within live rock. Although the solid nature of the rock prevents bioturbation (mixing) from playing any sort of role, the organisms that live within live rock must still ventilate burrows to provide oxygen, and so they can have many of the same effects as their relatives that live in the sand bed. Unfortunately, bioirrigation within solid structures such as live rock is entirely uninvestigated, though that does provide an exciting possible area of study. What we do have, however, is the observation that our systems seem to mature and stabilize at the same time as populations of polychaetes and microcrustaceans become well established and visible on both live rock and the sand. Figure 3: Evidence of bioturbation in the home aquarium. TOP shows a polychaete worm within its burrow and BOTTOM shows multiple burrow traces, including one extending down into the anoxic zone (seen as darker sediment, though the author's use of black sand makes this difficult to see) Carbon Matters Having introduced what I hope is a more comprehensive picture of nitrogen cycling and examined the roles that both the sand bed and sand bed organisms play in the nitrogen cycle, I have one final aspect of this whole picture that I wish to discuss: carbon. If there has been one overall trend in the 20 years I've been a hobbyist that has promised to enhance the viability of our captive systems, it has been the movement from relatively restricted nutrient input to active supplementation of carbon via a number of methods. On its surface the argument is clear: carbon is the basic food for the ecosystem, and more food enhances growth. Although this is a deliberate oversimplification of the idea to save space, I hope to expand on this idea by directly linking carbon to the nitrogen cycle in two distinct ways. Carbon and Nitrogen removal When I was first introduced to the idea of adding carbon, the basic science supporting the idea was that of the Redfield ratio. In this justification, it is posited that our aquaria have an excess of nitrogen compared to carbon, which in nature typically exist at a C:N ratio of 106:16. While not an untrue statement, the Redfield ratio indicates the elemental makeup of plankton, and so invoking the ratio as an argument assumes that nitrate is consumed and incorporated as biomass. Although this is certainly the fate of some of the nitrate in the system, the vast majority of natural removal is through the process of denitrification rather than assimilation. This is not, however, to suggest at all that carbon and the C:N ratio are unimportant, but rather that the reasoning has less to do with the Redfield ratio, and much more to do with the redox cascade. As I present above, carbon is the overall fuel that powers the redox cascade that takes place within sediments and live rock, and of which denitrification is one major step. What this means is that in order for denitrification to take place, there must be sufficient organic material to not only consume oxygen, but also to be used in denitrification itself. In most aquaria, the former condition is usually met, and the formation of anoxic zones can be assessed easily by judging the color of the sediment. However, especially in cases of very large excesses of nitrate, there may be insufficient carbon to fuel enough denitrification to remove all nitrates present. In these cases, addition of carbon provides the essential fuel for this process, which is what leads to the reduction of nitrate in cases where carbon is limited. This is one way that carbon addition can impact nitrogen cycling, but I wish to propose an additional mechanism that directly invokes the bioturbation discussed above, but is significantly more complex and related more to our system ecology. Carbon and bioturbation As I describe above, the presence and activity of infauna can have a profound impact on nitrogen cycling, directly enhancing rates of nitrification and especially denitrification. In many cases, the impact of infauna is directly linked to diversity (Norling et al. 2007) and/or organism density (Waldbusser et al. 2004), such that increasing diversity and density either linearly or even exponentially increases the rates of denitrification. In all cases, these infauna are heterotrophic, so increasing the supply of nutrients such as carbon directly impacts the availability of their food. The increased food availability then supports larger populations, directly increasing the density of these beneficial organisms. In addition to simply supporting larger populations, increased flow of energy in the form of carbon (and nitrogen, though that is a subject worthy of an article on its own) supports more diversity, in part due to decreased competitive pressures (though the particular mechanism is not entirely known, even if the relationship is well documented). Because faunal diversity is positively correlated with the sediment's ability to remove nitrogen via denitrification, this is another way that carbon enhances our system's ability to remove and control nitrogen levels. So although it's not new advice, hopefully this gives some added scientific impetus to the growing trend of carbon and nutrient supplementation to our systems. Conclusion Although most home aquarists have a basic understanding of the nitrogen cycle from almost the very first day of aquarium keeping, the understanding of many is fairly limited. The classical nitrogen cycle is not incorrect, but the nuances of the cycle and especially the factors that control it are largely unreported in common aquarium literature. In addition to details of the nitrogen cycle itself, I have provided what I hope is valuable insight into the different factors that control the ways and speeds with which nitrogen moves through our systems. I have also introduced the concepts of bioturbation and bioirrigation, the ways in which all the miscellaneous and often unexpected organisms that find their way into our tanks contribute to their overall health. It is my hope that this information will not only foster an appreciation for organisms that in the past have been considered pests, but also foster an understanding of aspects of ecology that we as aquarists can use to our advantage. Finally, I have discussed the importance of carbon in this entire big-picture discussion of nitrogen cycling, and I hope that I have provided additional encouragement to - if not exactly actively dose carbon - move away from the old paradigm of essentially starving our reefs. Literature Cited Bartoli, M., D. Nizzoli, D.T. Welsh, and P. Viaroli. 2000. Short-term influence of recolonisation by the polychaete worm Nereis succina on oxygen and nitrogen fluxes and denitrification: a microcosm simulation. Hydrobiologia 431: 165-174 Berg, P., S. Rysgaard, and B. Thamdrup. 2003. Dynamic modeling of early diagenesis and nutrient cycling. A case study in an arctic marine sediment. American Journal of Science 303: 905-955 Engstrom, P., T. Dalsgaard, S. Hulth, and R.C. Aller. 2005. Anaerobic ammonium oxidation by nitrite (annamox): implications for N2 production in coastal marine sediments. Geochimica et Cosmochimica Acta 69: 2057-2065 Fennel, K., J. Wilkin, J. Levin, J. Moisan, J. O'Reilly, and D. Haidvogel. 2006. Nitrogen cycling in the Middle Atlantic Bight: results from a three-dimensional model and implications for the North Atlantic nitrogen budget. Global Biogeochemical Cycles 20: GB3007 doi: 10.1029/2005GB002456 Galloway, J.N., F.J. Dentener, D.G. Capone, E.W. Boyer, R.W. Howarth, S.P. Seitzinger, G.P. Asner, C.C. Cleveland, P.A. Green, E.A. Holland, D.M. Carl, A.F. Michaels, J.H. Porter, A.R. Townsend, and C.J. Vorosmarty. 2004. Nitrogen cycles: past, present, and future. Biogeochemistry 70: 153-226 Gruber, N. and J.L. Sarmiento. 1997. Global patterns of marine nitrogen fixation and denitrification. Global Biogeochemical Cycles 11: 235-266 Henriksen, K., M.B. Rasmussen, and A. Jensen. 1983. Effect of bioturbation on microbial nitrogen transformations in the sediment and fluxes of ammonium and nitrate to the overlying water. Environmental Biogeochemistry 35: 193-205 Herbert, R.A. 1999. Nitrogen cycling in coastal marine ecosystems. FEMS Microbiology Reviews 23: 563-590 Huettel, M. 1990. Influence of the lugworm Arenicola marina on porewater nutrient profiles of sand flat sediments. Marine Ecology Progress Series 62:241-248 Jones, C.G., J.H. Lawton, and M. Shachak. 1994. Organisms as ecosystem engineers. Oikos 29: 373-386 Kristensen, E. and T.H. Blackburn. 1987. The fate of carbon and nitrogen in experimental marine sediment systems: influence of bioturbation and anoxia. Journal of Marine Research 45: 231-257 Larkum, A.W.D., I.R. Kennedy, and W.J. Muller. 1988. Nitrogen fixation on a coral reef. Marine Biology 98: 143-155 Meysman, F.J.R., J.J. Middelburg, and C.H.R. Heip. 2006. Bioturbation: a fresh look at Darwin's last idea. Trends in Ecology and Evolution 21: 688-695 Norling, K., R. Rosenberg, S. Hulth, A. Gremare, and E. Bonsdorff. 2007. Importance of functional biodiversity and species-specific traits of benthic fauna for ecosystem functions in marine sediment. Marine Ecology Progress Series 332: 11-23 Porubsky, W.P., N.B Weston, and S.B. Joye. 2009. Benthic metabolism and the fate of dissolved inorganic nitrogen in intertidal sediments. Estuarine, Coastal and Shelf Science 83: 392-402 Volkenborn, N., L. Polerecky, S.I.C. Hedtkamp, J.E.E. van Beusekom, and D. de Beer. 2007. Bioturbation and bioirrigation extend the open exchange regions in permeable sediments. Limnology and Oceanography 52: 1898-1909 Waldbusser, G.G., R. L. Marinelli, R.B. Whitlach, and P.T. Visscher. 2004. The effects of infaunal biodiversity on biogeochemistry of coastal marine sediments. Limnology and Oceanography 49:1482-1492 About the Author Tommy Dornhoffer is currently (as of Spring 2014) a fifth-year marine sciences PhD student at the University of Georgia in Athens, GA, as well as an avid aquarist with nearly two decades of aquarium experience. He specializes in benthic ecology (the study of the organisms in sediments and their effects) and nitrogen cycling, and loves doing anything he can to further our understanding of these fields. He is also an active instructor at UGA, and loves teaching almost as much as he loves his tanks. View the full article

Click through to see the images. From the California Academy of Sciences 2014 Philippines Expedition blog: There are two Academy groups currently in the Philippines for the 2014 Biodiversity Expedition: one from Research, and the other from the Aquarium. Though we’re staying at different locations, we collaborate when we can, like tonight. It all started with a 90-minute night dive at Anilao Pier to try to collect a Bobbitt worm—a creature that lives in the sand, has jaws like a bear trap, and might be several meters long. It shoots up with lightning speed to catch fish and other animals, yanking them down into the muck like something out of a nightmare. In the 1990s, Academy Senior Curator Terry Gosliner named the Bobbitt worm after Lorena Bobbitt (and her legendary attack on her husband), and Academy crews have been trying to collect this animal both for display and for our preserved collection ever since. One look at the photo shows you why catching this animal isn’t easy, but take a look at this video for an even better demonstration. 19200b4655acd38b0c02289eb742623f

Click through to see the images. Innovative Marine supplied Advanced Aquarist with the following information: " height="383" type="application/x-shockwave-flash" width="680"> "> "> Unseen. Unheard. Unrivaled Performance SkimMate Ghost – Protein Skimmer Drop in, ready to skim. Completely re-engineered to push the limits of All-In-One skimmers, the SkimMate Ghost Series is packed with a plethora of performance driving features that propels organics out of your aquarium water. These user-friendly, recirculating protein skimmers are equipped with bubble plates, integrated air silencers, and needle wheel impellers, all housed in a pearl white body that embodies a fresh modern look on its’ exterior and an array of performance features on its’ interior. Features: 1. Recirculating Design – Passively recirculates bubbles for maximum dwell time 2. Drop-In Convenience – Preset to optimal water level and eliminates the need for extra accessories. 3. Enlarged Air Silencer Box– integrated into the skimmer’s body for a seamless look while reducing noise. 4. Bubble Plate Diffuser – Reduces turbulence inside skimmer to improve skimmate production 5. Adjustable Air Valve – Provides air intake control 6. Needle Wheel Impeller – Produces dense micro bubbles 7. Cup Drain Elbow – Prevents overflows 8. Airline Management – Keeps airline organized and “kink free” 9. Suspended Pump Design – Reduces vibration by suspension 10. Self-Draining – Eliminate messy maintenance 11. Low Profile Cup Design – Keeps your skimmer hidden from view Available in three models: MODEL 7203—Desktop DIMENSIONS: 3.58” x 2.28” x 9.84” TANK CAPACITY: 20 GALLON DESIGNED FOR: Nano 16 POWER: 110-120V/60HZ PUMP WATTS: 6.5 WATTS FLOW RATE: 158 GPH PRICE: $150 MODEL 7204—Midsize DIMENSIONS: 3.62” x 3.07” x 11.22” TANK CAPACITY: 40 GALLON DESIGNED FOR: Fusion 30L & 40 POWER: 110-120V/60HZ PUMP WATTS: 6.5 WATTS FLOW RATE: 158 GPH PRICE: $250 MODEL 7205—Fullsize DIMENSIONS: 5.39” x 3.74” x 14.57” TANK CAPACITY: 60 - 120 GALLON DESIGNED FOR: SR-60, 80 & 120 POWER: 110-120V/60HZ PUMP WATTS: 24 WATTS FLOW RATE: 370 GPH PRICE: $300 View the full article

Click through to see the images. The cute and photogenic need their beauty rest. The two flapjack octopus (photo right) that became the darlings of Monterey Bay Aquarium's Tentacles exhibit have been moved into private aquariums. MBA has announced that the Japetella octopus and vampire squid will take their place in the public spotlight. What the two replacements lack in cuteness they more than make up for in wonderful bizarreness. The Japetella octopus (Japetella sp.) is a beautiful animal that lives in the midwater realm, hundreds of feet below the surface but well above the sea floor. It has chromatophores that enable it to go from see-through with spots to almost a solid orange color. MBARI’s remotely operated vehicles have observed them on video both in Monterey Bay and—even more often—on expeditions to the Gulf of California. " height="360" style="width: 640px;" type="application/x-shockwave-flash" width="640"> "> The vampire squid (Vampyroteuthis infernalis) is an ancient animal that lives in deep tropical and temperate waters—like the Monterey submarine canyon. Despite its sinister appearance—and its name, which means “vampire squid from hell”—this animal is a scavenger. It lives on “marine snow” that rains down from above: a mixture of poop, dead animal parts and mucus. Interestingly enough, the vampire squid is neither really a squid nor an octopus. It's a sort of frankenstein with characteristics of both, and scientists have placed it in its own order: Vampyromorphida. View the full article

Click through to see the images. Cairns Marine is Australia’s largest supplier of live ornamental marine life. Last week, during a trek out to Holmes Reef (approximately 150 miles northeast of Cairns, Australia), divers equipped with rebreathers spotted the first ever Pseudanthias aurulentus (commonly known as the Central Pacific or Golden Anthias) within Australian waters. The divers were able to bring up approximately 70 specimens. Pseudanthias aurulentus was officially described in 1982 by Randall & McCosker. Until last week, this lovely deepwater anthias species was only known from the Eastern Central Pacific around Line Islands and Fanning Island, occurring at depth around 50m. Cairns' divers discovered the first known population of P.aurulentus outside of the Eastern Central Pacific at similar depths at Holmes Reef. The expansion of distribution ranges for deepwater fish is a fairly common occurrence because much of the ocean depth remains unexplored. Still, the discovery of P.aurulentus over 3,500 miles from its previously only known range is quite remarkable. If the species originated from the Eastern Central Pacific, larvae or breeding populations were likely carried thousands of miles by the N.Equatorial ocean down to the E.Australian current. Who knows what other locations in between P.aurulentus may be eventually found. [via Cairns Post via Cairns Marine facebook page] View the full article

Click through to see the images. What this frog was doing is anyone's guess. Hitching a ride? Strange love? Isopod impersonation? The frog was so determined to cling tightly to his new friend that Andree ultimately had to pull it off the fish. Read the Daily Mail for more photos of a frog getting frisky with a goldfish. View the full article

Click through to see the images. What this frog was doing is anyone's guess. Hitching a ride? Strange love? Isopod impersonation? The frog was so determined to cling tightly to his new friend that Andree ultimately had to pull it off the fish. Read the Daily Mail for more photos of a frog getting frisky with a goldfish. View the full article

Click through to see the images. From the American Society for Biochemistry and Molecular Biology via Eureka Alert: Discovery raises hope for new methods to prevent the spread of HIV The proteins, called cnidarins, were found in a feathery coral collected in waters off Australia's northern coast. Researchers zeroed in on the proteins after screening thousands of natural product extracts in a biorepository maintained by the National Cancer Institute. "It's always thrilling when you find a brand-new protein that nobody else has ever seen before," said senior investigator Barry O'Keefe, Ph.D., deputy chief of the Molecular Targets Laboratory at the National Cancer Institute's Center for Cancer Research. "And the fact that this protein appears to block HIV infection—and to do it in a completely new way—makes this truly exciting." In the global fight against AIDS, there is a pressing need for anti-HIV microbicides that women can apply to block HIV infection without relying on a man's willingness to use a condom. Koreen Ramessar, Ph.D., a postdoctoral research fellow at the National Cancer Institute and a member of the research team, said cnidarins could be ideally suited for use in such a product because the proteins block HIV transmission without encouraging the virus to become resistant to other HIV drugs. "When developing new drugs, we're always concerned about the possibility of undermining existing successful treatments by encouraging drug resistance in the virus," said O'Keefe. "But even if the virus became resistant to these proteins, it would likely still be sensitive to all of the therapeutic options that are currently available." The research team identified and purified the cnidarin proteins, then tested their activity against laboratory strains of HIV. The proteins proved astonishingly potent, capable of blocking HIV at concentrations of a billionth of a gram by preventing the first step in HIV transmission, in which the virus must enter a type of immune cell known as the T-cell. "We found that cnidarins bind to the virus and prevent it from fusing with the T-cell membrane," said Ramessar. "This is completely different from what we've seen with other proteins, so we think the cnidarin proteins have a unique mechanism of action." The next step is to refine methods for generating cnidarins in larger quantities so the proteins can be tested further to identify potential side effects or activity against other viruses. "Making more of it is a big key," said O'Keefe. "You can't strip the Earth of this coral trying to harvest this protein, so our focus now is on finding ways to produce more of it so we can proceed with preclinical testing." The scientists discovered cnidarins while screening for proteins, a largely understudied component of natural product extracts found in the National Cancer Institute's extract repository. The institute maintains a large collection of natural specimens gathered from around the world under agreements with their countries of origin. The specimens are available to researchers across the United States. "The natural products extract repository is a national treasure," said O'Keefe. "You never know what you might find. Hopefully, discoveries like this will encourage more investigators to use this resource to identify extracts with activity against infectious disease." View the full article

Click through to see the images. Yin & Yang A few of us have the good fortune of keeping multiple aquariums, but rarely do we see two of the more advanced subtypes set up side by side; The combination definitely makes for one dynamic presentation! James' two 20L rimless aquariums highlight the diverse disciplines and aesthetics within our hobby. The slower-growing reef has some catching up to do to match the beauty and maturity of its planted counterpart (which is the focal point of the video*), but we have no doubt it'll get there. " height="383" type="application/x-shockwave-flash" width="680"> "> "> *For those interested in the rundown for the planted aquarium, James shared a summary in his video's description: Lighting: 4x39w T5HO ( FNI 10k, Wavepoint Tropical Sun, FNI Pink, Giesemann Midday CO2: 3bps, 5lb Tank, Milwaukee Reg Substrate: EcoComplete, White sand Hardscape: Seiryu Stone, Malaysian Driftwood Plants (Rear, Left to right): Ludwigia Tornado, Pearlweed, Ludwigia Rubin, Limno Aromatica, Rononculus Inundatus, Rotala sp Green, Stargrass Plants (Front): Dwarf baby tears, riccia Fish & Shirmp: Boraras Urophthalmoides, Panda Corydoras, True SAE, Ottos, Fire Red Shrimp, Blueberry Shrimp, Farlowella Cat, 2 Neon Tetra (kept because they were spawning in old tank but discus and harlequins would eat all eggs) View the full article

Click through to see the images. From the ARC Centre of Excellence in Coral Reef Studies More coral babies staying at home on future reefs Researchers have found that increasing ocean temperatures due to climate change will soon see reefs retaining and nurturing more of their own coral larvae, leaving large reef systems less interconnected and potentially more vulnerable. “We found that at higher temperatures more coral larvae will tend to stay on their birth reef,” says the lead author of the study published today, Dr Joana Figueiredo from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University. Right: Colony of Acropora valenciennesi in Alor, Indonesia. Credit: Andrew Baird “This is good news in an otherwise cloudy picture for isolated reefs, because in the future they will be able to retain more of their own larvae and recover faster from severe storms or bleaching events,” she adds. Professor Sean Connolly, also from the Coral CoE, explains that while more coral larvae will stay close to their parents, fewer will disperse longer distances, leaving reefs less connected. “The loss of connectivity can make reef systems such as the Great Barrier Reef more vulnerable,” he said. “So interconnected reef systems that depend on the recruitment of coral larvae may take more time to recover after a disturbance, such as a cyclone, because fewer larvae will disperse from other reefs to the disturbed reef.” Professor Connolly adds that weaker connections between reefs means warm-adapted corals, such as those in the northern Great Barrier Reef, may take longer to expand their ranges to the south. Similarly for isolated reefs, Dr Saki Harii from the University of the Ryukyus says, “While isolated reefs can retain more of their own larvae, this also leaves them with fewer possibilities to change their species composition to adjust to climate change.” Professor Andrew Baird from the Coral CoE says the implications of the research present management with both challenges and opportunities. “Our results demonstrate that global warming will change patterns of larval connectivity among reefs. On a positive note, the stronger link between adults and recruits means an even greater benefit if we reduce local threats such as dredging and fishing methods that can damage corals,” Professor Baird says. Nevertheless, he explains, “This does not reduce the need for global action on climate change.” Increased local retention of reef coral larvae as a result of ocean warming by Joana Figueiredo, Andrew H. Baird, Saki Harii and Sean R. Connolly appears in Nature Climate Change. View the full article

Click through to see the images. I'm sure whale watching is exhilarating when observed the old-fashioned way from a boat. However, these two divers took it a step further and decided to swim out with the whales while they were feeding and almost became lunch! Do not try this one on your next whale watching expendition. c81a4deedbe5596b17e4021cba86b20b

Click through to see the images. The Air They Breath ... The fact is many city health departments conduct similar "preventative" procedures throughout the year. The elevated concentration of chlorine is safe for human consumption, but it may harm or kill aquarium life. The additional chlorine, after all, is meant to kill biological organisms. Between regular maintenance and accidental contamination in centralized water systems (read about how city water caused mass fish mortalities), this is another reminder to get an reverse osmosis water filter if you aren't yet using one. It's one of the best investments any aquarist can make for their animals. It's good for your own health too. To quote one of our previous reports: This [...] should remind aquarists about the importance of using high quality water for their water changes and top-off. While our hobby preaches the value of reverse osmosis systems, we know many aquarists still use dechlorinated tap water. [...] Need more convincing? Read Randy Holmes-Farley's article about the risky business of using tap water in the home aquaria. View the full article

Click through to see the images. Garrett plans to stock his aquarium with Lamprologus ornatipinnis "Kigoma", a small African cichlid endemic to alkaline waters of Lake Tanganyika. Lamprologus spp. are one of several cichilds known as "shell dwellers" because these fish spawn in empty shells. After selecting a suitable shell, Lamprologus will "use propeller-like motions of the tail to bury the shells that they reside in." (Wiki) Fascinating dwelling for a fascinating little fish makes for a fascinating biotope exhibit. By using some rocks in your backyard, a few pounds of sand, and a bag of shells, you can create a exhibit so simple yet so beautiful. Here is a photo of a trio of captive-bred F1 Lamprologus ornatipinnis "Kigoma" photographed by Ray Quennelle. At Lake Tanganyika, L.ornatipinnis naturally occurs in single, pairs, or trios. View the full article

Click through to see the images. To be honest, I'm not sure I see the resemblance to fish in any of these shoes other than perhaps the pair above (called Scorpionfish, though your guess is as good as mine why they called a pure silver shoe Scorpionfish). But I admit they are rather snazzy designs that I wouldn't mind sporting on my 10Ks. For $99.99, you can own one of these limited-edition New Balances that come with the tagline: "Mysterious. Hypnotic. Deadly tempting. When you step out in the Limited Edition Tropical Fish 574s, you’ll shine in a sea of boring." Lionfish (apparently it's a military camo phenotype) Dragonfish (whatever that is) View the full article

Click through to see the images. From Standford University: Some corals adjusting to rising ocean temperatures, Stanford researchers say By Rob Jordan To most people, 86-degree Fahrenheit water is pleasant for bathing and swimming. To most sea creatures, however, it's deadly. As climate change heats up ocean temperatures, the future of species such as coral, which provides sustenance and livelihoods to a billion people, is threatened. Through an innovative experiment, Stanford researchers led by biology Professor Steve Palumbi have shown that some corals can – on the fly – adjust their internal functions to tolerate hot water 50 times faster than they would adapt through evolutionary change alone. The findings, published April 24 in Science, open a new realm of possibility for understanding and conserving corals. "The temperature of coral reefs is variable, so it stands to reason that corals should have some capacity to respond to different heat levels," said Palumbi, director of Stanford's Hopkins Marine Station and a senior fellow at the Stanford Woods Institute for the Environment. "Our study shows they can, and it may help them in the future as the ocean warms." Coral reefs are crucial sources of fisheries, aquaculture and storm protection. Overfishing and pollution, along with heat and increased acidity brought on by climate change, have wiped out half of the world's reef-building corals during the past 20 years. Even a temporary rise in temperature of a few degrees can kill corals across miles of reef. American Samoa presents a unique case study in how corals might survive a world reshaped by climate change. Water temperatures in some shallow reefs there can reach 95 degrees Fahrenheit, enough to kill most corals. To find out how native corals survive the heat, researchers in Palumbi's lab transplanted colonies from a warm pool to a nearby cool pool and vice versa. The researchers found that, over time, cool-pool corals transplanted to the hot pool became more heat-tolerant. Although these corals were only about half as heat-tolerant as corals that had been living in the hot pool all along, they quickly achieved the same heat tolerance that could be expected from evolution over many generations. Corals, like people, have adaptive genes that can be turned on or off when external conditions change. The corals Palumbi's group studied adjusted themselves by switching on or off certain genes, depending on the local temperature. These findings make clear that some corals can stave off the effects of ocean warming through a double-decker combination of adaptation based on genetic makeup and physiological adjustment to local conditions. "These results tell us that both nature and nurture play a role in deciding how heat-tolerant a coral colony is," Palumbi said. "Nurture, the effect of environment, can change heat tolerance much more quickly – within the lifetime of one coral rather than over many generations." Palumbi cautioned that corals' heat-adaptive characteristics do not provide a magic bullet to combat climate change. They can't respond to indefinite temperature increases and they could be compromised by stressors such as acidification and pollution. Still, if it holds true for most corals, this adaptive ability could provide a "cushion" for survival and might give coral reefs a few extra decades of fighting back the harsh effects of climate change, Palumbi said. Journal Reference: Stephen R. Palumbi, Daniel J. Barshis, Nikki Traylor-Knowles, and Rachael A. Bay. Mechanisms of Reef Coral Resistance to Future Climate Change. Science, 24 April 2014 View the full article

Click through to see the images. Like most fishkeepers, I started with common freshwater fish like bettafish, goldfish, mollies, danios, tetras, and gouramis won at fairs and easily purchased at local mom-and-pop pet shops. However, it wasn't until I saw my first discus that my past-time became an obsession. There's just something about the discus body form, docile demeanor, and (of course) colors that really speak to me. Discus breeding is an addiction in and of itself. A few years later, I saw my first nicely aquascaped planted aquarium (before the days nature aquariums became a well-studied discipline), and by happenstance it contained a school of beautiful pigeon blood discus. From that day on, fishkeeping grabbed a hold of me and has never let go. This heavily planted 65 gallon discus aquarium by Zachary Braverman really brought me back to my first love. Every now and then, it's good to go back to our personal beginnings to remind us where our passion began. A big reason why discus aren't commonly displayed in modern nature aquariums is because large fish ruin the sense of scale within meticulously aquascaped planted tanks. Siddhartha Saive solved this problem by going big ... REALLY big ... 600 GALLONS BIG! " height="383" type="application/x-shockwave-flash" width="680"> "> "> View the full article

Click through to see the images. Like most fishkeepers, I started with common freshwater fish like bettafish, goldfish, mollies, danios, tetras, and gouramis won at fairs and easily purchased at local mom-and-pop pet shops. However, it wasn't until I saw my first discus that my past-time became an obsession. There's just something about the discus body form, docile demeanor, and (of course) colors that really speak to me. Discus breeding is an addiction in and of itself. A few years later, I saw my first well-aquascaped planted aquarium (before the days nature aquariums became a well-studied discipline), and by happenstance it contained a school of beautiful pigeon blood discus. From that day, fishkeeping grabbed a hold of me and has never let go. This heavily planted 65 gallon discus aquarium by Zachary Braverman really brought me back to my first love. Every now and then, it's good to go back to our personal beginnings to remind us where our passion began. A big reason why discus aren't commonly displayed in modern nature aquariums is because large fish ruin the sense of scale within meticulously aquascaped planted tanks. Siddhartha Saive solved this problem by going big ... REALLY big ... 600 GALLONS BIG! " height="383" type="application/x-shockwave-flash" width="680"> "> "> View the full article

Click through to see the images. From the University of California, Riverside: " height="383" type="application/x-shockwave-flash" width="680"> "> "> Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, have developed a design structure for composite materials that is more impact resistant and tougher than the standard used in airplanes. “The more we study the club of this tiny crustacean, the more we realize its structure could improve so many things we use every day,” said David Kisailus, a Kavli Fellow of the National Academy of Science and the Winston Chung Endowed Chair of Energy Innovation at the UC Riverside’s Bourns College of Engineering. David Kisailus, an associate professor of chemical engineering, in his lab. Photo credit: Carlos Puma The peacock mantis shrimp, or stomatopod, is a 4- to 6-inch-long rainbow-colored crustacean with a fist-like club that accelerates underwater faster than a 22-calibur bullet. Researchers, led by Kisailus, an associate professor of chemical engineering, are interested in the club because it can strike prey thousands of times without breaking. The force created by the impact of the mantis shrimp’s club is more than 1,000 times its own weight. It’s so powerful that Kisailus needs to keep the animal in a special aquarium in his lab so it doesn’t break the glass. Also, the acceleration of the club creates cavitation, meaning it shears the water, literally boiling it, forming cavitation bubbles that implode, yielding a secondary impact on the mantis shrimp’s prey. Previous work by the researchers, published in the journal Science in 2012, found the club is comprised of several regions, including an endocuticle region. This region is characterized by a spiraling arrangement of mineralized fiber layers that act as shock absorber. Each layer is rotated by a small angle from the layer below to eventually complete a 180-degree rotation. In a paper “Bio-Inspired Impact Resistant Composites,” just published online in the journal Acta Biomaterialia, the researchers applied that spiraled, or helicoidal, layered design when creating carbon fiber-epoxy composites. Composites with this design structure could be used for a variety of applications, including aerospace and automotive frames, body armor and football helmets. In experiments outlined in the paper, the researchers created carbon fiber-epoxy composites with layers at three different helicoidal angles ranging from about 10 degrees to 25 degrees. They also built two control structures: a unidirectional, meaning the layers were placed directly on top and parallel to each other, and a quasi-isotropic, the standard used in the aerospace industry, which has alternating layers stacked upon each other in an orientation of 0 degrees (first layer), -45 degrees (second layer), +45 degrees (third layer), 90 degrees (fourth layer) and so on. Helicoidal structure of the mantis shrimp club. The goal was to examine the impact resistance and energy absorption of the helicoidal structures when they were struck and to quantify the strength after the impact. The researchers used a drop weight impact testing system with a spherical tip that on impact creates 100 joules of energy at USC with their collaborator, Professor Steven R. Nutt. This replicates testing done by the aircraft industry. Following the tests, they measured external visual damage, depth of the dent and internal damage by using ultrasound scans. In the external damage category, the unidirectional samples split and completely failed. The quasi-isotropic samples were punctured through the backside and had significant fiber damage. Although the helicoidal samples showed some splitting of fibers, they were not punctured completely through. In fact, the dent depth damage to all of the helicoidal samples was 20 percent to 50 percent less than the quasi-isotropic samples. The ultrasound tests showed that with the helicoidal samples the damage spread laterally within the structure, rather than catastrophically rupturing through, as the quasi-isotropic samples did. The researchers then compressed the samples until they broke. Their results showed that the helicoidal samples, in general, displayed a significant increase, about 15 percent to 20 percent, in residual strength after impact compared to the quasi-isotropic samples. Finite element modeling work done by Kisailus’ collaborator, Pablo Zavattieri, an associate professor at Purdue University, provided unique insights into the failure modes within these structures and potential modifications for future designs. Future research by the team will incorporate a variety of new materials as well as potential insights from this and other organisms they study. Kisailus recently learned he has been selected to receive a $7.5 million Department of Defense grant to continue this work. “Biology has an incredible diversity of species, which can provide us new design cues and synthetic routes to the next generation of advanced materials for light-weight automobiles, aircraft and other structural applications,” Kisailus said. In addition to Kisailus, Nutt and Zavattieri, authors of the paper are: Lessa Grunenfelder, Christopher Salinas, Garrett Milliron, Steven Herrera, Nick Yaraghi, all current or former UC Riverside students; Nobphadon Suksangpanya, a graduate student in Zavattieri’s lab; and Kenneth Evans-Lutterodt, a physicist at Brookhaven National Laboratory The research was funded by the Air Force Office of Scientific Research and the National Science Foundation. View the full article

Click through to see the images. In an exhibit dedicated to some of the world's coolest animals including prehistoric chambered nautilus, flamboyant cuttlefish, giant octopus, the master-of-disguise wunderpus, and pigment-shifting squids, you have to be quite special to stand out in this crowd. But one eight-legged citizen has done just that. The ultra-deepwater and ultra-bizarre (if not ultra-cute) flapjack octopus has stolen the spotlight at Monterey Bay Aquarium's newest exhibit, Tentacles. Why? The video below speaks for itself. Crowds flock to the special tall, columnar tank located in the dark corner of the exhibit (lit only by red lights) to oooooh and awwww at this pint-sized natural wonder with webbed tentacles, dumbo-like "ears" (actually fins), and big piercing red eyes. There are currently fourteen known species of flapjack octopus (genus Opisthoteuthis, suborder Cirrina) that inhabit the Pacific deep seafloor from California to Japan. We're talking pitch-black depths in excess of 350 meters to nearly 600 meters. Monterey Bay Aquarium Research Institute believes the flapjack octopus they have on exhibit is a new, undescribed species. Taxonomic work is currently underway to give this little fella an official scientific name (if it is indeed determined a new species). If you're considering a family vacation this Spring, the flapjack octopus at Monterey Bay Aquarium welcomes you with all eight of his adorable webbed arms. View the full article

Click through to see the images. Kerry's instructions actually include patterns for ages 3-6 months to adult, so mom and dad can rock matching clownfish hats with their baby (just imagine the family photo!). All you need is $4.99 to purchase the pattern, some yarn, crocheting skills, and a wacky sense of fashion. If you lack the time or talent, you might try to contact Kerry on her facebook page, Hats & What Knots, to see if she can create something special for you. View the full article

Click through to see the images. AA: We've attended several Reef-A-Paloozas (RAP) on the West Coast, so we were happy to see the successful reefkeeping event head out East. Can you describe the history of RAP for those who have never attended? RAP: Reef-A-Palooza (RAP) is an annual event every October and is promoted by the Southern California Marine Aquarium Society (SCMAS). Now in its tenth year, the show originally started in the founder's back yard as a club frag swap. From its humble beginnings to what it has become ... RAP can be best described as an indoor marketplace where sellers, exhibitors, and hobbyists of all types can buy, sell, trade, and showcase their products to the marine hobbyist community. Reef A Palooza Orlando is being run with the same standards that we are accustom to from the original event run by SCMAS. However, they are not directly running the RAP Orlando event. AA: Why Orlando? Why now? RAP: Victor first dropped the seed in Greg & Marc's (SCMAS) ear way back in 2008. Since MACNA was in Orlando in 2010, Florida’s entire reefkeeping community has grown rapidly. Plus with the demand by others on the East Coast who wanted a Reef-A-Palooza-type show, the time was right and so was the plan to make it happen. Now we have RAP for the first time ever outside of Southern California. AA: What can attendees expect at RAP Orlando? RAP: New gadgets and products will be released along with some of the best of the best that the hobby has to offer in live corals & livestock. Reef-A-Palooza mainly caters to the exhibitor and hobbyist rather than as an educational conference. Most attendees come specifically for the purpose of viewing and seeing all the different exhibitor’s booths (corals…corals…corals) and displays. With the addition of educational speakers and a great raffle, attendees will want to stick around for most of the day. The promotional and marketing efforts that have been put forth are nearly guaranteed to attract high participation and attendance. Expect heavy foot-traffic throughout the building. AA: Will RAP Orlando become an annual event? RAP: Yes; that is what we are striving for! AA: Open mic time! Is there anything else you'd like to tell our readers? RAP: Make sure you make plans to take tours of all the fish stores in and around the Orlando area. Each one has plenty to offer and most are ready to cater to customers who are in from out of town in need of shipping home live stock. Last but not least ... Please bring the whole family and make it a family vacation. The theme parks, Walt Disney World, Universal Studios Florida (directly across the street), SeaWorld Orlando, and many others are in close proximity to the event. There's beautiful beaches either direction of Orlando. We are also surrounded by shopping opportunities for every budget, all-season golf courses, and some of the most enticing dining opportunities on the planet. Less known but equally inviting are the downtown sections of Orlando itself and many nearby towns in Central Florida – places that celebrate public art and take pride in offering a myriad of cultural opportunities. Come to Orlando, and bring the family. There's plenty to do for all! About Reef-A-Palooza, Orlando For more information, visit: http://www.raporlando.com Saturday, April 26th, 2014 11AM-6PM Sunday, April 27th, 2014 11AM- 4PM $15 per day Admission - Tickets sold at door FREE - Seniors 60 and over FREE - Children 12 years and younger 5780 Major Blvd Orlando, FL 32819 (407) 351-1000 Reef-A-Palooza (RAP) is an annual event in Southern California now in its tenth year. For the first time ever RAP is coming to Orlando, FL! RAP can best be described as an indoor marketplace where sellers, exhibitors, and hobbyists of all types can buy, sell, trade, showcase their products to the marine hobbyist community. The main purpose of Reef-A-Palooza is to provide an enjoyable, positive atmosphere that is conducive to education and trade of both product and knowledge. As such, participating exhibitors range from large manufacturers, to retailers, to small livestock sellers, and participating hobbyists range from the beginner to the elite, rare-species coral farmer. It is the perfect venue to showcase new products in the marine aquarium industry. We strive to rally a diverse range of participants into the two-day event so as to present the best value and interest to everyone involved. View the full article

Click through to see the images. Vanderhorstia lepidobucca is a new shrimpgoby from Sulawesi (Indonesia) described by Gerald R. Allen, Teguh Peristiwady and Mark V. Erdmann. Maratecoara gesmonei is a new Amazon (Brazil) rivulid killifish described by Dalton Tavares Bressane Nielsen, Mayler Martins and Ricardo Britzke. Aphyosemion mengilai is a new African killifish from Massif du Chaillu (Republic of Congo) described by Stefano Valdesalici and Wolfgang Eberl. To purchase the full peer-reviewed papers, visit AQUA, International Journal of Ichthyology. View the full article

Click through to see the images. From the Florida Fish and Wildlife Conservation Commission: Lionfish invasion: FWC moves forward with management changes The lionfish is an invasive species that threatens Florida’s native wildlife and habitat. With that in mind, the Florida Fish and Wildlife Conservation Commission (FWC) on April 16 moved forward with steps to combat the spread of invasive lionfish. Changes proposed by FWC staff at today’s meeting near Tallahassee will be brought back before the Commission at its June meeting in Fort Myers for final approval. Changes include: Prohibiting the importation of live lionfish; Prohibiting the development of aquaculture of lionfish; Allowing the harvest of lionfish when diving with a rebreather, a device that recycles air and allows divers to remain in the water for longer periods of time; and Increasing opportunities that will allow participants in approved tournaments and other organized events to spear lionfish or other invasive species in areas where spearfishing is not allowed. This will be done through a permitting system. Staff has been working with the Florida Legislature on a bill in support of the initiatives to prohibit the importation of live lionfish and the aquaculture of lionfish. “By targeting the importation of lionfish to our state, we can limit the number of new lionfish that find their way into Florida waters and, at the same time, encourage further harvest to reduce the existing invasive population,” said State Rep. Holly Raschein, sponsor of the House bill. “These fish pose a significant threat to Florida’s ecosystem, and I am proud to stand in support of the proposed ban. Anything we can do to limit new lionfish introductions and further facilitate the development of a commercial market for this invasive species is a step in the right direction.” Changes like these will make it easier for divers to remove lionfish from Florida waters and will help prevent additional introductions of lionfish into marine habitats. Lionfish control efforts, from outreach and education to regulatory changes, have been a priority for FWC staff. In 2013, they hosted the first ever Lionfish Summit, which brought together various stakeholders from the public as well as management and research fields to discuss the issues and brainstorm solutions. The changes proposed at today’s meeting came from ideas that were discussed at the Lionfish Summit. To learn more about these changes, visit MyFWC.com/Commission and “Commission Meetings.” To learn more about lionfish, visit MyFWC.com/Fishing and click on “Saltwater,” “Recreational Regulations” and “Lionfish.” View the full article