News / Species Spotlight / Species Spotlight - Giant Jewel Damselfish (Microspathodon dorsalis) (08/02/17)

Species Spotlight - Giant Jewel Damselfish (Microspathodon dorsalis)

Species Spotlight - Giant Jewel Damselfish (Microspathodon dorsalis)
The Giant Jewel Damselfish comes with a caveat it gets big and mean. As long as youre cool with that, lets continue.

Fully grown, Microspathodon dorsalis is a monster of a damselfish, tipping the scales at nearly a foot in length. And, pound for pound, there are few fish in the sea which can rival its pugnacity. These are naturally solitary and territorial creatures. Even divers are not immune from their fishy wrath when entering into their domain. So you can imagine how that translates in the confines of a small glass box. Tankmates must be chosen with care and precision. Think big, think mean groupers, eels, scorpionfishes or, alternatively, try fishes small enough to go unnoticed, like itty bitty gobies and blennies and such.

For all its viciousness, the beauty of the Giant Jewel Damselfish makes it worth the hassle. Juveniles are an inky black, highlighted with row upon row of bright blue scales, further accentuated by a series of larger caerulean dots along the back. As it matures, this fish turns a deep slaty blue throughout, with a crisp, contrasting white along the edges of the fins. Breeding males are more remarkable still, boasting a whitened forebody that stands in stark relief to the darkened rear. Combined with the elegantly attenuated finnage and the stately body profile, there should be no questioning its bona fides as a truly spectacular reef fish.

Microspathodon is a small group, with just four species to its credit. Theres one off in West Africa (M. frontatus) which is fairly dull and all but unobtainable to aquarists... as well as the familiar Caribbean species M. chrysurus, whose speckled juveniles are a common sight in captivity. And in the Eastern Pacific Ocean we find the Bumphead Damselfish (M. bairdii), which, admittedly, is a bit on the ugly side, especially in comparison to its compatriot M. dorsalis, which abounds in shallow rocky reefs from Baja south to Ecuador.

The genus makes a living gleaning algae from the substrate in these productive waters, and, as tends to be the case with the herbivorous pomacantrids, they are quite particular with who they let pass into their territories. Algae is a precious and finite resource, and woe be to the fish (or diver) foolish enough to come too close. Since aquariums seldom produce enough algal biomass to satiate a fish of this sort, be sure to offer a diverse diet full of vegetarian cuisine. Herbivorous dry foods and sheets of nori are recommended, alongside meatier fare like frozen mysis.