Mate Choice by the Male Convict Cichlid (Cichlasoma nigrofasciatum; Pisces, Cichlidae)

Abstract

AbstractThe influence of standard length (SL) and maximum body width on the attractiveness of female to male convict cichlids was examined in a choice apparatus. Preliminary experiments showed that maximum body width (abdominal swelling), ovary mass and ovary volume of females increased significantly over the 7‐d post spawning period. Variation in body width explained a moderate amount of the variation in ovary mass and volume. Therefore, body width is a suitable indicator of gravidity. Male convict cichlids were offered a simultaneous choice between two females that varied in standard length (SL) and/or gravidity. Choice was determined by amount of time the male spent near each female. Males chose the larger of two females when both were gravid but showed no choice when neither was gravid. In general, males chose the gravid female when one was gravid and the other was not, regardless of the difference in SL between them. Choice of female by males was not influenced by female behaviour in the test apparatus. We suggest that mate choice by convict cichlid males is based primarily on female gravidity and secondarily on female SL.