Fish Identifier
Flathead Grey Mullet (Mugil cephalus) — saltwater, brackish, and freshwater
saltwater, brackish, and freshwater

Flathead Grey Mullet

Mugil cephalus

Elongated, torpedo-shaped body with a broad, flattened head. Large scales covering the body and head. They have two widely separated dorsal fins, the first having four spines. Coloration is typically olive-green to bluish-grey on the back with silvery sides and a white belly.…

Habitat
Circumglobal distribution in coastal tropical, subtropic…
Size & weight
Commonly ranges from 30 to 50 cm. Maximum recorded lengt…
Diet
Mainly detritivores and herbivores.…
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Physical characteristics

Elongated, torpedo-shaped body with a broad, flattened head. Large scales covering the body and head. They have two widely separated dorsal fins, the first having four spines. Coloration is typically olive-green to bluish-grey on the back with silvery sides and a white belly. Often shows thin dark longitudinal stripes along the sides.

Habitat & distribution

Circumglobal distribution in coastal tropical, subtropical, and temperate waters. Inhabits estuaries, lagoons, and can move far up into freshwater rivers. Prefers sandy or muddy bottoms in shallow waters.

Behavior

Highly social and known for schooling in large numbers. Famously known for jumping out of the water to increase oxygen intake or escape predators. Diurnal activity is most common.

Diet

Mainly detritivores and herbivores. They feed by sucking up the top layer of sediment to extract algae, diatoms, and organic detritus, filtering it through their gill rakers.

Reproduction

Catadromous life cycle; adults migrate from freshwater/estuaries to the open sea to spawn in large offshore schools during autumn and winter. Larvae then move back toward the coast.

Ecological role

Primary consumer that links detritus and algae to higher trophic levels. They are major prey for various coastal predators like sharks, barramundi, and dolphins.

Similar species

Thinlip Mullet (Liza ramada) which has a smaller, less flattened head and a dark spot at the pectoral fin base; Leaping Mullet (Liza saliens) which is more slender.

Identification tips

Look for the blunt, flattened head, large visible scales, and the characteristic gap between the first and second dorsal fins. The presence of dark lateral stripes is a key marker for this species.

Interesting facts

They possess a uniquely muscular, gizzard-like stomach to help grind up the sand and organic matter they ingest while feeding. They are also highly tolerant of broad ranges of salinity and temperature.