Bigeye grunt

The bigeye grunt (Brachydeuterus auritus) is a marine fish from the grunt family Haemulidae, found along Africa's Atlantic coast. Its body is oblong and somewhat compressed, with a noticeably large eye, a snout shorter than the eye's diameter, and a large, protrusible mouth. The dorsal fin is deeply notched and has 10 to 13 spines, with the third (and sometimes fourth) being the longest. The anal fin has three spines and nine or ten soft rays, occasionally eight.

The caudal fin is deeply forked. The back is olive, while the sides and belly are silvery to white. A dark blotch sits on the upper edge of the gill cover, and small dark spots sometimes appear at the base of the dorsal fin. This species reaches a maximum total length of 30 cm (12 in), though 23 cm (9.1 in) is more typical.

Habitat and biology

In the eastern Atlantic, the bigeye grunt ranges from Morocco to Angola, but it is most common from Senegal southward. It lives at depths between 10 and 150 m (33 to 492 ft) over sandy and muddy bottoms, moving higher in the water column at night to feed near the surface on small fish and invertebrates. Spawning may occur year-round, with males reaching sexual maturity at about 8 months and females at 12 months; there are often two spawning peaks that coincide with upwelling events.

Systematics

First formally described in 1832 by French zoologist Achille Valenciennes as Larimus auritus, with the type locality given as Gorée, Senegal, it is the only species in the genus Brachydeuterus. The genus name combines brachy ("short") and deuterus ("second"), referring to the deep notch that nearly separates the lower, soft-rayed part of the dorsal fin from the spiny front section. The species name auritus means "eared," a reference to the blotch on the gill cover.

Utilisation

The bigeye grunt is commercially important in many parts of West Africa, especially Ghana and Côte d'Ivoire. It is caught with bottom trawls, gill nets, set nets, and push seines, and is sold fresh, smoked, or processed into fish meal. Its flesh is also mixed with cassava to make dish crackers.