A new species of armoured searobin, Peristedion nesium, has recently been described from the Isla del Coco off the Pacific coast of Costa Rica in Central America.
The armoured searobins (family Peristediidae) are part of the order Scorpaeniformes, which also includes the scorpionfishes well-known to marine aquarists. Unfortunately these heavily armoured fishes are generally found at depths of 100m/330ft or more, and collected by trawling; the photograph of the new species shown here was taken from a submersible and offers a rare glimpse of one of these fishes in life.
Peristedion nesium is only the fourth species known from the eastern coast of the Pacific, and the stronghold of the genus is the western Atlantic.
The new species is thought to be most closely related to one of the other Pacific taxa P. crustosum and perhaps an island derivative of it. The largest of the fairly numerous specimens collected measured just under 12cm/4.75in SL, so this would be an interesting aquarium fish if a way could be found to collect them alive at the depths where they live. None were found in trawls made in water shallower than 110m/362ft.
The name of the new species is derived from the Greek nesos meaning an islander, referring to its distribution, and is an adjective.
For further information see: Bussing, W. A. (2010) A new fish, Peristedion nesium (Scorpaeniformes: Peristediidae) from Isla del Coco, Costa Rica. Rev. Biol. Trop. 8 (44): 149-1156.