FISH MOUTH DIMENSIONS AND SIZE-SELECTIVITY IN A PORTUGUESE LONGLINE FISHERY

The relationship between fish total length (TL) and mouth size in six species was investigated in light of the implications for the modellin g of size selectivity of hooks. Significant non-linear relationships w ere found in three species, suggesting that optimal size at capture is not a linear function of hook size. These results strongly support th e choices made in modelling skew-normal selectivity with optimal size at capture as a function of hook size.