Tamanho na primeira maturidade sexual das raias Dasyatis guttata E Dasyatis americana, no litoral do estado do Ceará

Abstract

The stingrays Dasyatis guttata and Dasyatis americana arespecies are important resources in small-scale fisheries off Ceará State, Brazil. The main objective of this paper was to estimate the mean length at the female’s first sexual maturity of those species, which should be enventually used in fishery management action. Sampling for size was carried out in Fortaleza, Caucaia and Aquiraz counties, Ceará State, Brazil, as by-catch material by the trawlnet and gillnet fisheries and landings from the hook-and-line fishery and harpooning fisheries, in years 1997, 1999, 2001 and 2003-2005. The data analysis produced the following results: (a) the onset of physiological reproduction is attained at length classes 50-60 cm DW and and 60-70 cm DW (male), and 60-70 cm DW e 80-90 cm DW (female), for D. guttata and D. americana, respectively; (b) and the mean length of the claspers was estimated as 11.2 cm (D. guttata) and e 11.8 cm (D. americana), with roughly equal proportions in both species, values which are supposed to define the mean size at first functional maturity