Bigeye Emperor

Monotaxis grandoculis, commonly referred to as the humpnose big-eye bream, is a marine ray-finned fish within the Lethrinidae family. It inhabits the 🇮🇳 Indian and 🌊 Pacific Oceans. Originally described as Sciaena grandoculis in 1775 by Finnish naturalist Peter Forsskål, its type locality is Jeddah. The specific name "grandoculis" highlights its notably large eyes, which mirror its common name "large-eye bream."

The species features an oblong body with a depth ranging from 2.1 to 2.7 times its standard length. Its head has a distinct hump in front of the eyes and a steeply sloping snout. The fish possesses large eyes, with a diameter approximately equivalent to the snout length, and a finely serrated rear preoperculum. Its jaw structure includes canine-like teeth at the front, transitioning to smaller side teeth and molar-like teeth at the back. The dorsal fin comprises 10 spines and 10 soft rays, while the anal fin has 3 spines and 9 soft rays. The body is silvery-grey with thin dark scale margins and a prominent black blotch at the axil of the pectoral fin. It typically displays 3-4 black vertical bands on the back, punctuated by thinner white bands. Juveniles have 3 broad dark bars resembling saddles and exhibit a black eye stripe and a reddish caudal fin band. The species can grow up to 60 cm (24 in) in length and weigh as much as 5.9 kg (13 lb), though it usually reaches around 40 cm (16 in).

Monotaxis grandoculis is widely distributed across the Indo-Pacific, from the 🌊 Red Sea and eastern African coast to Hawaii (🇺🇸 United States) in the East Pacific, north to southern 🇯🇵 Japan, and south to 🇦🇺 Australia, specifically around Christmas Island, the Cocos (Keeling) Islands, Ningaloo Reef, and the Great Barrier Reef. It resides near reefs in sand and rubble at depths between 3 and 150 meters.

This species is typically solitary, although larger adults can form schools of up to 50 individuals. Its diet consists of benthic invertebrates and fish. Monotaxis grandoculis is known to host several parasites, including Haliotrema angulocirrus and Proctoeces hawaiiensis.

Economically, Monotaxis grandoculis is significant for both commercial and artisanal fisheries and is commonly targeted by recreational anglers. Fishing methods include gill netting, fish traps, spearfishing, and handlining, with the catch primarily marketed fresh. In the 🇲🇭 Marshall Islands, its consumption has been associated with Ciguatera fish poisoning.