Bigeye grunt

Lore & Background

The bigeye grunt has an oblong, somewhat compressed body with a large eye, a snout shorter than the diameter of its eye, and a large, protrusible mouth chin. Its dorsal fin is deeply notched and contains 10-13 spines, with the third spine (occasionally the fourth) being the longest. The anal fin has 3 spines and 9-10 soft rays, and the caudal fin is deeply emarginate. The back is olive, the flanks and abdomen are silvery to white, and there is a dark blotch on the upper edge of the gill cover, with small dark spots sometimes present on the base of the dorsal fin.

The species was first formally described in 1832 as Larimus auritus by French zoologist Achille Valenciennes, with the type locality given as Gorée in Senegal. It is the only species in the monotypic genus Brachydeuterus, a name that combines brachy meaning 'short' and deuterus meaning 'second', referring to the lower soft-rayed part of the dorsal fin nearly separated from the spiny part by a deep notch. The specific name auritus means 'eared', referencing the blotch on the gill cover.

The bigeye grunt is found in the eastern Atlantic Ocean along the western coast of Africa from Morocco to Angola, though it is most common from Senegal south. It inhabits sandy and muddy substrates at depths between 10 and 150 m, moving up the water column to feed near the surface at night on small fish and invertebrates. It may spawn throughout the year, with two possible peaks coinciding with upwellings, and becomes sexually mature at around 8 months for males and 12 months for females.

Reader's Guide

The bigeye grunt holds notable commercial significance in West Africa, particularly in Ghana and Côte d'Ivoire, where it is caught using bottom trawls, gill nets, set nets, and push seines. The fish is sold fresh, smoked, or processed into fish meal, and has also been used to make dish crackers when its flesh is mixed with cassava. This species attains a maximum total length of 30 cm, though 23 cm is more typical, and it is found at depths from 10 to 150 m over sandy and muddy substrates. Its biology includes nocturnal feeding near the surface on small fish and invertebrates, and it may spawn throughout the year with peaks tied to upwellings. The bigeye grunt is the sole member of the genus Brachydeuterus, first described in 1832 by Achille Valenciennes from a specimen collected at Gorée, Senegal. Its distinctive features include a large eye, a deeply notched dorsal fin, and a dark blotch on the gill cover. The species is most common from Senegal south along the African coast, ranging from Morocco to Angola.