ABSTRACT: Using data from bottom-trawl surveys conducted each summer, winter and spring on the Cretan shelf from 1988 to 1991, we examined the bathymetric distribution of red mullet Mullus surmuletus. Additionally, we used data from 3 yr (1991 to 1993) of monthly sampling in the Iraklion Gulf. Depth, temperature and salinity data were combined with biological data on abundance, biomass, fish size, age, sex and maturity. The ranges of bottom depth, temperature and salinity over which red mullet is distributed were established. In general, fish size increased with bottom depth, and smaller individuals tended to be found in shallower and warmer water. Abundance increased in mid-shelf waters during spring, indicating a movement across the shelf towards deeper water. The latter seemed to be associated with spawning behavior. The factor controlling the timing of that movement to deep water seemed to be the maturity of individual fish.

KEY WORDS: Red mullet · Distribution · Depth selection · Temperature selection · Migration

Published in MEPS Vol. 166 (1998) on May 28
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1998