Speciation of the Starcki damselfish

[yikai]

Have you ever wondered how some fishes look similar to closely related species? Well, species divergence and speciation could account, and probably did, to why that is observed to be so. Let's take the argi angelfish, african flameback, caribbean flameback and resplendent angels for example. these four species probably came from a single ancestor thousands of years ago. after years and years, continental plates shifted and tidal currents change, and this single ancestor species was separated into different locations.

one populated africa, one maybe the carribean etc. over time, these isolated populations of that single ancestor fish evolved over time to suit that particular habitat, and eventually, speciated into different, but similarly marked species with distinct DNA, giving rise to the argi, flamebacks and resplendent.

now this may be going on in fishes currently as we speak, and many species are now being found out to be distinct from what was once considered only one species. but this usually have to occur with species that are found in quite different locations. for example, the most recent one, the splendid leopard wrasse. it was found that the red sea ones are a different species from the maldivian ones, as seen in the DNA. and what was once Macropharyngodon bipartitus from the red sea, it is now Macropharyngodon marisrubri. see here for more info - http://reefbuilders.com/2013/05/16/red-sea-leopard-wrasse-species-macropharyngodon-marisrubri/

today i observed a different between two damsels, of the same species, from different locations. this is the starcki damsel which everyone knows. the first picture shows one from the philippines, and the other, from australia.

The first picture is one that came from the former location, and has the blue coloration coloring the caudal peduncle completely, and also slightly encroaching the rays of the tail fin. The second individual from Australia, picture no. 2, has a yellow caudal peduncle with no blue on the tail. The shape of the tail is also different; it being round in the Philippine specimens and slightly forked in the Australia ones. These could be geographical variations but i'm quite sure in time to come, they will eventually speciate into different species. I found a journal online supporting this evidence as well, and it seems the difference have not gone unoticed by scientists.