SUMMARY: In this study, the results obtained from three experimental trap shrimp (Plesionika edwardsi) fishing cruises in three different seasons are presented. They were carried out during a total of 50 days, of which 43 days were of effective fishing, covering the whole Spanish Mediterranean coast including the island of Alborán. On the whole, the fishing depth varied between 220 and 384 m, with a mean depth of 318 m. The target species appeared in 81% of the total samples carried out, with a mean yield (cpue) of 108.6 g/trap/day. The largest yields (cpue) of this species were from the Balearic islands, followed by Levant region, whereas the Alborán sea gave the lowest yields. The largest mean length was observed on the Levant zone, but on the contrary the smallest mean lengths were found towards the south, more specifically at Alborán island. Significant differences were found in both the relative and absolute growth, between males and females, with equilibrium in the ratio of the sexes (0.49). A total of 15 crustacean and 12 fish species were identified as accompanying fauna, with Conger conger, Plesionika narval and Scyliorhinus canicula being the most important, based on their mean cpue, although differences in the appearance and yields of the species were found in the different zones and depths. However, the mean yields of these species were very low, due to the high selectivity of the fishing gear used. The appearance of Heterocarpus ensifer, deserves a special mention, since it is the second documented record of the species in the Mediterranean.

SUMMARY:The hake (M. merluccius) is a target species of the Mediterranean trawl fleets. In this study, its growth was compared by two means: whole otolith readings and length frequency distribution analysis. Two growth hypotheses, fast and slow, were assumed using the results of otolith readings: (1) two rings were formed every year and (2) a single ring was formed every year. The monthly length distributions covered the period from 1992 to 1998, and the otoliths were obtained from monthly samplings between 1992 and 1995. The variability observed in the results for the number of rings counted was shown especially in the range of lengths for each group of individuals that had the same number of rings. A high correlation was found between the rings counted in the otoliths and the length of the individual in cm. The sex factor did not influence the relationship, unless the sexually undifferentiated individuals were included. The best fit with the growth data according to the length frequencies occurred in the two-ring hypothesis (Hypothesis 1), meaning faster growth rates than had been accepted till now, especially in females. We suggest the consideration of the hypothesis of faster growth in future studies.