Reproductive biology of <i>Mugil curvidens</i> and <i>Mugil incílis</i> in the north coast of Alagoas

Abstract

The objective of the present paper was to study the reproductive biology of the mullets Mugil curvidens and Mugil incilis (Valenciennes, 1936), in the  north coast of Alagoas State. Four species were identified in the area: Mugil curema, M. curvidens, M. incilis and M. liza. From March 2003 to February 2004, 559 specimen were examined, including 326 M. curvidens (170 females and 156 males) and 233 M. incilis (106 females and 127 males). Male fork length (FL) for M. incilis varied from 24.0 to 35.0 cm, with a mode from 31.0 to 33.0 cm, while female FL ranged from 23.0 to 42.0 cm, with a mode from 31.0 to 35.0 cm. For M. curvidens, male FL ranged from 22.5 to 31.5 cm, with a mode from 23.0 to 25.0 cm, while female FL varied from 21.0 to 37.5 cm, with a modal class from 25.0 to 27.0 cm. The sex ratios (male: female) were 0.9: 1 and 1.2:1, for M. curvidens and M. incilis, respectively. Based on the Gonosomatic Index, M. curvidens spawns mainly during the 2^nd quarter of the year, while M. incilis spawning season happens in the 1^st quarter of the year.