GROWTH AND REPRODUCTION OF FIVE SPECIES OF THE FAMILY MUGILIDAE PRESENT ON THE BEACHES OF THE CADIZ COAST

Resumen

Mugilids represent one of the most important commercial resources for estuarine and coastal fisheries in temperate, tropical and subtropical seas. They are also considered as potential fish in aquaculture. The aim of the project is to study the distribution, growth and reproduction of five species of the family Mugilidae: golden grey mullet (Chelon auratus), thinlip mullet (Chelon ramada), leaping mullet (Chelon salilens), thicklip grey mullet (Chelon labrosus) and flathead mullet (Mugil cephalus). Fish were caught monthly with a beach seine, coinciding with low tide (day and night). For fish growth, otoliths were analysed and growth rings were counted. Regarding fecundity, the volumetric method was used and eggs were counted and measured. Preliminary results show that the size range was between 15-48 cm for golden grey mullet, 20-33 cm for thinlip mullet, 18-22 cm for leaping mullet, 20-50 cm for thicklip grey mullet and 44-52 cm for flathead mullet. These size variations are related to ages from 1 to 6 years for golden grey mullet, between 2 and 4+ years for thinlip mullet, from 2 to 4 years for leaping mullet, thicklip grey mullet is between 2 and 7 years old and flathead mullet from 4 to 6+ years old. In terms of reproduction, egg diameters were generally between 0.2 and 0.8 mm, which varied according to the gonadal stage of the female. Moreover, in the same gonad, different stages can be found, characterised by the way in which the yolk is arranged and the variation in colour.