DISTRIBUTION AND BIOLOGY OF 5 GRENADIER FISH (PISCES, MACROURIDAE) FROM THE UPPER AND MIDDLE SLOPE OF THE NORTHWESTERN MEDITERRANEAN

Specimens of five Macrouridae species (Trachyrhynchus trachyrhynchus, Nezumia aequalis, Hymenocephalus italicus, Coelorhynchus coelorhynchus and Coelorhynchus labiatus) were obtained from 76 bottom trawls in th e Catalan Sea at depths between 147 and 1290 m. Abundance, biomass and length distribution by depth varied depending on the species. For T. trachyrhynchus, maximum abundance and biomass were found between 900 a nd 1000 m. In H. italicus, abundance and biomass decreased below 500-6 00 m, whereas abundance and biomass showed a bimodal trend for N. aequ alis. In these species, the mean length of the specimens increased wit h depth. The sex-ratio was 50% for intermediate sizes while larger fis h were predominantly females. Reproduction patterns were different for each species. Ripe females of N. aequalis and N. italicus were found all year round, while C. coelorhynchus and C. labiatus ripe females we re found in spring-summer and autumn-winter, respectively. No ripe fem ales of T. trachyrhynchus were found. Size at attainment of 50% maturi ty for N. aequalis and H. italicus was 4.5 and 2.7 cm pre-anal length (PAL), respectively. The PAL-otolith length (OL) and OL-otolith weight (OW) relationships showed a negative allometry, except for C. labiatu s whose GLOW relationship was isometric. Seasonal growth was detected in the otoliths of all five species; fast growth rings were laid down in summer. All the species reach ages of at least 9 years, and growth rates were relatively high and greater for females.