VALIDATION OF DAILY INCREMENT DEPOSITION IN OTOLITHS - AGE AND GROWTHDETERMINATION OF APHIA-MINUTA (PISCES, GOBIIDAE) FROM THE NORTHWEST MEDITERRANEAN

The transparent goby Aphia minuta (Risso, 1810) is one of the main tar get species of the small-scale fishery off the Island of Majorca. Otol ith microstructure and length-frequency analysis were used to study th e age and growth of this species during the 1982/1983 and 1992/1993 fi shing seasons. Daily periodicity of increment formation was determined by experiments with marked otoliths in individuals maintained in capt ivity. The length range of the catches during the 11 yr period was bet ween 12 and 49 mm, with a main distribution (89%) between 24 and 40 mm . Otolith age-readings indicate that the population exploited in the c ommercial fishery consists of seven age-groups (2 to 8 mo old), with a very high proportion of individuals (95%) between 3 and 6 mo old. Pop ulation growth-curves revealed no differences between males and female s. The growth parameters for the whole population are: asymptotic leng th, L-infinity = 53.69 mm; growth coefficient, K = 2.23 yr(-1); theore tical age at length zero, t(0) = -0.005 yr. Those individuals of A. mi nuta caught in Majorca during the winter period reached a maximum age of 7 or 8 mo.