ASPECTS OF THE BIOLOGY AND GILLNET SELECTIVITY OF THE AXILLARY SEABREAM (PAGELLUS-ACARNE, RISSO) AND COMMON PANDORA (PAGELLUS-ERYTHRINUS, LINNAEUS) FROM THE ALGARVE (SOUTH PORTUGAL)

Two species of seabreams, Pagellus acarne and Pagellus erythrinus, fro m the Algarve coast (south Portugal) were studied to obtain informatio n on these fisheries. This study presents results on first maturity, l ength-weight relationships and gillnet selectivity curves, which may b e used to provide a scientific basis for management proposals. Spawnin g lasts from May to August, and length at first maturity was 20.95 cm for P. acarne and 18.03 cm for Pagellus erythrinus. Males reached firs t maturity at smaller lengths than females. The relationships between length and weight were W=0.0085TL(3.153) for P. acarne and W=0.0189TL( 2.881) for P. erythrinus. The Sechin method was used to determine gill net selectivity curves. The estimated selectivity curves correspond cl osely to the catch curves, but were narrower. P. acarne will be caught in the following length ranges: 15-25 cm, 18-27 cm and 20-29 cm, and P. erythrinus in the length ranges 15-25 cm, 16-27 cm and 19-30 cm, re spectively, by the 60 mm, 70 mm and 80 mm mesh sizes.