Latin name

Mugil cephalus

Other names

Flathead mullet, striped mullet, black mullet, bully mullet, common mullet, grey mullet, sea mullet, mullet

Identification

Body elongate, thick, semi-cylindrical, covered with large ctenoid scales. There are 39-45 transverse rows of scales along the lateral side of the body, and 13-15 longitudinal rows. Head broad, flattened dorsoventrally, width of head less than its height. Head covered with scales almost to the end of the snout. The length of the blunt snout is equal to or less than the diameter of the eye. The upper jaw is straight, its posterior edge not curved downwards. The posterior margin of the maxilla reaches a vertical line passing through the anterior margin of the eye. The symphysis of the lower jaw is at an acute angle to the bone. The mouth is transverse and short. The lips are thin with the lower lip pointing forward. The upper lip has 1 or 2 outer rows of closely set single incisors and 1 to 5 inner rows of small double incisors. The lower lip has an outer row of close fitting unicuspid teeth and one or more inner rows of small bicuspid teeth (inner rows may be absent). There are no teeth on the jaws or scutellum. In adults, the fatty eyelid is well developed and reaches the pupil. There are 50-90 gill stamens on the lower half of the first gill arch. The suprajabral organ is not divided. The lateral line is absent. There are two pyloric appendages. There are 24 vertebrae.

Features of fish fins

The two dorsal fins are separated by a large gap. The first dorsal fin with 4 rigid rays is located almost in the centre of the back. The base of the second dorsal fin is on a vertical line just behind the beginning of the anal fin. The second dorsal fin has 9 soft rays. The anal fin has 3 hard and 8-9 soft rays in adults and 2 hard and 9-10 soft rays in juveniles less than 3 cm long. The pectoral fins have 1 barbed and 15-17 soft rays, the ends of which do not reach the beginning of the base of the first dorsal fin. Above the base of the pectoral fin is a long, pointed axillary plate. The anterior part and bases of the second dorsal and anal fins are covered with scales. The caudal fin is forked.

Fish colouring

The flathead grey mullet in the sea has an olive green back, silvery sides and a whitish belly. There are 7 longitudinal brownish stripes along the body, weakly expressed on the belly. In estuaries, the sides of the fish are less brightly coloured and the back is dark blue or light brown. Dorsal fins are greyish blue, anal and caudal fins are yellowish green. Pectoral fins are yellowish with a whitish edge and a distinct blue spot above the base. Pelvic fins are pale yellow.

Distribution

Widespread in tropical, subtropical and temperate waters of all oceans from 51°N to 42°S. In the western Atlantic it is found from Nova Scotia, Canada along the east coast of the USA, including the Gulf of Mexico. It is not found off the Bahamas or in the West Indies. In the eastern Atlantic it is known from the coastal waters of France, the Mediterranean and the Black Sea; and along the coast of western Africa to southern Africa, including the oceanic archipelagos. In the Indo-Pacific, from the Red Sea along the coast of East Africa to Southern Africa, the Persian Gulf, Mauritius, Madagascar, India, Seychelles, New Caledonia, Australia, New Zealand, Japan, Hawaii. It is rare off the Philippines. In addition to the Black Sea, it is found in Russian waters off the coast of Primorye and further north to the Tatar Strait and the mouth of the Amur River. In the eastern Pacific it is found from California to Chile, including the Galapagos Islands.

Habitat

Marine, freshwater, brackish, benthopelagic, catadromous, subtropical fish. Depth range 0-120 m, usually 0-10 m. Occupies lagoons, estuaries and river mouths. Can tolerate wide variations in salinity, occurring in both hypersaline and freshwater environments.  Maximum life span is 16-18 years.

Size

Maximum length 100 cm, usually up to 50 cm. Maximum body weight 12 kg, commercial catches are dominated by fish up to 50 cm long and weighing up to 2 kg.

Behavior

They live in small schools near the shore. During the spawning season they migrate to the open sea. One spawning school was observed in detail. It consisted of five fish, one female and four males. The males were clinging to the female, which happened as the whole group moved slowly forward, encountering a fairly strong tidal current.

Food and feeding habits

In summer it feeds intensively on detritus, periphyton, and less frequently on algae, worms, crustaceans and mollusc larvae. In autumn, at the end of October-November, it enters the brackish waters of estuaries and bays.

Reproduction

They do not mature until 3-4 years of age, with males usually maturing a year earlier than females.  

In the Black Sea they spawn from the end of May until the end of August-September. During the spawning season they form small groups of one female and several males. The eggs are pelagic, spherical in shape, 0.7 mm in diameter, with a fat droplet 0.26 mm in diameter. Fecundity increases as the fish grows and ranges from 3 to 13 million eggs. The duration of embryonic development depends on the water temperature and is 1.5-5 days. The length of the larvae at hatching is about 2.5 mm. The larvae are pelagic.

They spawn from February to September in various areas of Australia's coastal waters. Mature lobsters migrate along the coast or concentrate in estuaries before moving into open waters to spawn in the surface water layers above the continental shelf. Lobster fecundity in Australian waters ranges from 300,000 to 7.2 million eggs. Eggs have an average diameter of 0.89 mm with a fat droplet diameter of 0.39 mm. Larvae average 2.68 mm in length at hatching. Larvae switch to external feeding 3-5 days after hatching and spend 2-3 months in open pelagic waters, after which juveniles return to coastal waters, estuaries and river mouths to feed.

Fishing

Valuable commercial fish. It is the subject of sport and recreational fishing.

Relationship with a person

It is consumed in almost all parts of the world. The meat of the Flathead grey mullet is superior in flavour to that of other fish in the Mugilidae family. It is moderately fatty, has a dense texture and a mild odour.