Use of Melanophore Patterns On The Ventral Side Of The Head To Identify Fry Of Grey Mullet (Teleostei: Mugilidae)

Abstract

Examination of fry of five species of grey mullet revealed that the shape of the lower jaw and the melanophore patterns along the edge of the lower jaw and the ventral side of the head are species-specific. Mugil cephalus is characterized by an acute angle of the dentary symphysis and lightly pigmented ventro-opercular and gular regions of the head. In Liza aurata, the mandibular region has spots of pigment at the corners of the mouth, the gular region is lightly pigmented with a single row of melanophores, the ventro-opercular region of the head has two rows that form a distinct arch and, in specimens over 20 mm TL, at least one of these rows extends to the posterior ventro-opercular region. In Liza ramada, the pigmentation is darkest in the mandibular and gular regions of the head, the melanophores in the mandibular region in specimens of 30-40 mm TL are concentrated around the anterior tip of the jaw and the corners of the mouth, and the anterior ventro-opercular region usually has a single row of melanophores that may extend into the posterior ventro-opercular region. In Chelon labrosus, there are two rows of melanophores in the ventro-opercular region and one or two rows in the gular region which usually extend beyond the eye into the posterior sector. In Liza saliens, there are two rows of melanophores in the ventro-opercular region and two in the gular region which rarely extend beyond the eye to the posterior sector. These observations were used to create a key which may be useful for identifying fry of grey mullet species grown in aquaculture in the Mediterranean region.