Reproductive cycle of Calamus brachysomus (Teleostei: Sparidae) in the Central Gulf of California, BCS, Mexico

Abstract

The Pacific porgy Calamus brachysomus (Lockington, 1880) is exploited for local consumption and commerce in Baja California Sur (BCS). Monthly samples to study its reproductive biology were obtained from the artisanal fishery operating in Santa Rosalía, BCS, Mexico, from July 2015 to July 2016. A total of 265 specimens were analyzed, including 147 females and 118 males. The sexual proportion (1.24F:1M) did not differ from the expected 1:1 proportion (P = 0.08). There were no significant differences between sexes in total length (P = 0.94). Variations in the hepatosomatic index and condition factor indicated that food constituted the main energy source during reproduction, with possible additional use of endogenous reserves originating in the liver during spawning. The gonads histological analysis indicated an asynchronous ovarian development and batch spawning strategy. There were spawning capable females during 11 of the 13 sampled months; the exceptions were February and September, coinciding with minimum and maximum sea surface temperature (SST) values. These results, along with the gonadosomatic index variations, allowed us to conclude that C. brachysomus reproduces over a large part of the year with an activity peak from May to July, in an SST interval of 21 to 28ºC.