The oval grouper ( Triso dermopterus) also known as the blackfin grouper, melon-seed grouper or oval rockcod, is a species of marine ray-finned fish, a grouper from the subfamily Epinephelinae which is part of the family Serranidae, which also includes the Anthiinae and sea basses. It is found in the Western Pacific Ocean.
Description
The oval grouper has a compressed, oval-shaped body and its depth is 2.0 to 2.8 times its
fish measurement. It has an oblique mouth and the lower jaw projects beyond the upper jaw.
The dorsal profile of the head is convex while the intraorbital area is rather wide and convex. The preopercle is not smoothly rounded, but is not sharply angled, and has fine serration on its margin which are enlarged at its angle. The gill cover has a convex upper edge and has three flat spines.
The
dorsal fin contains 11 spines and 19–21 soft rays while the
anal fin contains 3 spines and 9–12 soft rays.
[ The caudal fin is truncate to emarginate with rounded corners.][ The colouration is dark brown or violet-black on the body with darker fins. This species attains a maximum recorded fish measurement of .][
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Distribution
The oval grouper is found in the eastern Indian Ocean and Western Pacific Ocean where it has an anti-tropical distribution. In the Northern Hemisphere it has been recorded from Korea, Japan, Taiwan, Hong Kong and the Fujian.
Habitat and biology
The oval grouper has been recorded over on rocky or soft bottoms, consisting of sand or silty mud, at depths of . The juveniles are known to feed on zooplankton in the water column.[
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Utilisation
The oval grouper is frequently taken as by-catch by fishers using bottom trawls and it is valued as a food fish.[
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Taxonomy
The oval grouper was first formally described in 1842 as Serranus dermopterus in 1842 by the Dutch people zoologist Coenraad Jacob Temminck (1778-1858) and his student, the German people ichthyologist Hermann Schlegel (1804–1884), with the type locality given as Nagasaki.[ but Fishbase retains it within Triso.][
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