Hi all just to put up here since its related. All info taken from Advanced Marine Aquarium Techniques by Jay F. Hemdal. I will not extract the everything from the book just summarize the necessary information to take care of the fish. Hope it helps anyone who is interested
Species name: STYGNOBROTULA LATEBRICOLA
Common name: Black Widow Brotula
Habitat: Carribean and Florida reef tracts
Reproduction: Livebearers
Reef compatibility: Reef safe
Tank mates: Prone to aggresion by tankmates
Water Temperature: 74 to 80 Farenheit
Feeding: Enriched live brine shrimp nauplii and larval mysid shrimp
Feeding style: This species has a unique feeding strategy, it slides on its side along smooth surfaces and into crevices and snaps up any food item clinging there. It is likely they do not use their sight at all in the feeding process. The black widow's high profile head means that they cannot see well directly in front of them, so they most likely just blindly snap their jaws whenever they bump into some food. It is possible that the "cleaning" behaviour noticed by others was simply the black widow using the side of a larger fish in the same manner. When the black widow is successful in capturing some food, it will keep moving forward. If it misses, you'll often see the fish shake its head and snap again or back up abit and snap, apparantly trying for the food a second time.
Reference:
Jay F. Hemdal. 2006. Advanced Marine Aquarium Techniques. T.H.F Publications, Inc. New Jersey.