Biologia reprodutiva dos budiões-batata, Sparisoma axillare e Sparisoma frondosum (Actinopterygii : Scaridae), capturados na costa Central do Estado de Pernambuco

Abstract

The parrotfishes, Sparisoma axillare and S. frondosum (Family: Scaridae), are reef fish species frequently caught as bycatch on the trap fishery for lobster and goatfishes in the State of Pernambuco. Between 2002 and 2005, the total of parrotfish caught by the marine fisheries in Pernambuco State, varied from 136.5 to 280.5 t. These numbers show a growing fishing pressure on this important zoological group, with a significant impact on coral reef ecosystems, highlighting the importance of biological and ecological studies on these species. In this context, the present study intends to generate information regarding the main reproductive parameters of S. axillare e S. frondosum, with the purpose of supporting the management of their fisheries in the region. For the study of the reproductive biology, the stages of gonad maturation were defined through microscopic analysis of 283 specimes of S. axillare and 185 specimes of S. frondosum. The standard length (SL) varied between 13.8 and 33.4 cm, for S. axillare, and from 12.6 to 29.5 cm, for S. frondosum. The sex ratio between male and female was 1:6.4, for S. axillare, and 1:1.2, for S. frondosum. The average values of Gonad Index (G.I.) for S. axillare were higher during the second semester of the year, with the largest values for females occurring in July, August, September and November and for males, in September. For S. frondosum, females presented the highest average GI in February and males in April. The size of first sexual maturity (L50) for females of S. axillare was estimated at 20.2 cm of SL. It was not possible to determine the L50 for males. The L50 for females of S. frondosum was estimated at 17.0 cm of SL and for males at 17.7 cm. The average fecundity was 50.075 oocytes for S. axillare and 80.276 oocytes for S. frondosum. These results indicate that both species present multiple or batch spawning, with reproduction occurring all year.