Flathead Grey Mullet
Mugil cephalus
Type: saltwater, brackish, and freshwater
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.
Size & Weight
Commonly ranges from 30 to 50 cm. Maximum recorded length is 120 cm. They can weigh up to 8 kg (approx. 17.6 lbs).
Similar Looking 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.
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.
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.
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.
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.
Conservation Status
Least Concern (IUCN), with stable populations globally despite heavy use in commercial industries.
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.
Identified on: 6/7/2026
Mode: Standard