ELSEVIER Fisheries Research 30 (1997) 67-76 Life history and fishery of the common dentex ( Dentex dentex) in Mallorca ( Balearic Islands, western Mediterranean) Beatriz Morales-Nin *, Joan Moranta zyxwvutsrqponmlkjihgfedcbaZYXW CSIC-Institut M editerrani de Estudis Auaqats, Campus Uniuersituri, 07071 Palma de M allorca, Spuin Accepted 7 September 1996 Abstract Age, growth, mortality, maturity and diet were analysed for 210 common dentex from 17 to 83 cm TL collected off the island of Mallorca from 1993 to 1995. The length composition by sex showed no differences between females and males. The length-weight relationship was identical for both sexes: W = 0.01 I TL3.06. Age at 50% maturity was reached between 2 and 4 years old. The reproductive period was centred in the second quarter of the year. Ages were estimated from whole sagittal otoliths. Marginal-increment analysis showed that a single annuli formed each year during autumn-winter. Common dentex ages ranged from 0 to 28 years. The von Bertalanffy growth equation for males was TL = 844 (1 - e(-“.‘(‘+2s54)) and for females was TL = 856(1 - e(-“.‘(“22.874)). Th e estimate of the instantaneous rate of total mortality (Z) was 0.24. Empirically derived estimates of natural mortality were similar to total mortality estimates su ggesting that fishing mortality is low. 0 1997 Elsevier Science B.V. Keywords: Age; Growth; Reproduction; Diet; Fishery; Drnrex denrex 1. Introduction The common dentex, Dentex dentex (L., 1758) is a littoral species which lives on rocky bottoms and Posidonia oceanica beds. Although common down to a depth of 50 m it is also found down to 100 m. It is a highly valued table fish in the Mediterranean region and elsewhere in the tropics. Common dentex inhabit the Mediterranean Sea most frequently south of 40”, although rarely in the Black Sea. They also occur in the Atlantic from the Bay of Biscay to Cape Blanc and Madeira, but not around the British Isles (Bauchot and Hureau, 1986). In the Mediterranean * Corresponding author. Sea the abundance of this species changes depending on the area. Whereas in the northern part (Catalonia, France, Ligurian Sea and Northern Adriatic) its fre- quency is low, it is relatively abundant in the central and southern areas (Ramos-Espla and Bayle- Sempere, 1991). In the Balearic Islands it is rela- tively frequent, being caught by means of bottom long-lines between a depth of 30 and 60 m. Juveniles are caught by trammel net and surface trolling. The total catches registered in the central fish market of Palma (the only market of the island) for 1994 were 4023 kg. Given its high commercial value, the fish- ing of common dentex is important for the artisanal fleet of the island (Iglesias et al., 1994). This species has been scarcely investigated, with most of the studies being centred on its distribution 016% 7836/97/$17.00 0 1997 Elsevier Science B.V. All rights reserved. P/I SO 165.7836(96)00560-7