Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Effects of food supply on the reproduction of the convict cichlid, Cichlasoma nigrofasciatum.

Abstract

Cichlasoma nigrofasciatum, the convict cichlid, is a biparental, substrate-spawning, Central American cichlid. Male-female pairs were kept for 4 months on 1 of 3 rations: high, 1 g food daily; medium, 1 g 3 times per week; low, 1 g per week. The number of spawnings was directly related to the food ration. Fecundity of the females on the low and medium rations declined. At all rations the inter-spawning interval and egg size increased during the experiment. Egg size was positively related to ration and the length of the inter-spawning interval, but the latter was inversely related to ration. Females on the high ration grew in weight whereas those on the low ration lost weight. Histological examination of the ovaries at the end of the experiment suggested that low rations reduced the proportion of oocytes that become vitellogenic. At the end of the experiment, the total, gonad and liver weights of females at a given length were significantly related to ration. No similar, significant effect was found for the males, although growth in length of the males was related to ration. Ration had no detectable effect on the histological appearance of the testes.