Thick-lipped grey mullet
Otolith description
The general shape of the otolith is ovally rounded. The sulcus runs diagonally over almost the total length of the otolith, above the centre of the otolith. It is strongly curved and pointing down at the posterior. The sulcus is open at the ostium. A narrowing of the sulcus separates ostium and cauda. The ostium is wider but much shorter than the cauda. The otolith is slightly indented at the ostium. The surface of the inside is slightly irregular, while the outside is smooth. The margins are irregular. The ventral, dorsal and posterior margins are slightly rounded. The rostrum is small and rounded. The antirostrum is small and pointed. The inside is convex and the outside concave. The otolith is thin.
Otoliths of mugilidae, thick-lipped grey mullet, golden grey mullet Liza aurata and thin-lipped grey mullet L. ramada, are very difficult to determine to species level. The sulcus and ostium of golden grey mullet tend to be narrower than in thick-lipped or thin-lipped grey mullet. The ostium of thin-lipped grey mullet tends to be wider than in thick-lipped grey mullet. These differences are small and the variation between species is as large as within species. Though the fish are different in maximum total fish length, otoliths of all three species can reach a length of 12 mm, making size of the otoliths also useless for distinguishing between mugilidae.
When eroded the sulcus becomes indistinct and the margins are smoothed.
Fish length and distribution
Thick-lipped grey mullet can grow up to 75 cm. Thick-lipped grey mullet is a demersal schooling fish (CHELLABR.TIF) found in inshore and brackish waters. Spawning takes place in July and August (Wheeler, 1978, Nijssen and De Groot, 1987, Muus et al., 1999).
Thick-lipped grey mullet is common and found in the Eastern Atlantic and North Sea (in summer only).
Sample origin
Fyke.