SEXUAL MATURITY IN THE VELVET SWIMMING CRAB NECORA-PUBER (BRACHYURA, PORTUNIDAE) - MORPHOMETRIC AND REPRODUCTIVE ANALYSES

Relative growth and morphometric maturity of males and females of Neco ra puber in soft-bottom mussel raft areas of the Ria de Arousa (Galici a, north-west Spain) were analysed. A study was made of the changes in the allometric growth of cheliped size, abdominal width of females, a nd length of the first pleopod in males, related to the onset of matur ity. Multivariate analysis and different bivariate regression methods were employed to compare one- and two-phase growth models. Heterochely and allometric changes related to sexual maturity were the main facto rs determining the variability of the relative growth in both sexes. I n males, the length of the first pleopod and the length of the right c hela showed a change in allometry. In females, the abdominal width was characterized by two phases of growth. Morphometric maturity size was similar for both sexes (53.3-mm carapace width in males and 52.3-mm i n females). Complementary information from the same population on sexu al maturity (based on percentage of ovigerous females, presence of spe rm plugs, and sperm in the spermathecae and gonad development) indicat ed a maturity size of 54.8-mm carapace width in males and 49.8-mm in f emales. The size at onset of maturity based in morphometric and reprod uctive criteria coincided with a decrease in growth rate at moult in f emales (transition point 50.5-mm carapace width).