Reproductive biology of dolphinfish, Coryphaena hippurus (Actinopterygii: Coryphaenidae), in Saint Peter and Saint Paul Archipelago, Brazil

Abstract

In order to elucidate the main aspects related to dolphinfish reproduction around Saint Peter and Saint Paul Archipelago, 862 individuals caught in that area by commercial handline fishing were examined between 2007 and 2011. From those specimens, it was possible to assess the sex in 782 specimens (271 males and 511 females) and the levels of gonadal maturation in 536 of them (175 males and 361 females). The fork length (FL) of the examined specimens varied between 27 and 150 cm. Sex ratio found was 1.0 male: 1.9 females, but the difference was not statistically significant in April (χ2=0.08), August (χ2=0.82) and October (χ2=3.63). However, by size interval, sex ratio was 1.0 male: 1.0 female for FL between 120 and 130 cm. The gonadal index showed the highest values in February for males and in April for females. Most spawning-capable specimens were found in February (males 36.4%) and in May (females 42.2%). The length of size-at-50%-maturity (L50) was estimated at 70.66 cm FL for males and 68.60 cm FL for females. The results suggest that the period of highest reproductive activity occurs between April and June.