Impact of the Sex Ratio in the Breeding Aspects of the Crayfish Cambarellus montezumae

Abstract

Background: The exploitation of aquaculture resources, such as the freshwather crayfish C. montezumae (Mexican endemic crustacean), is related with fertility of females due to the available number of postlarvae that can be cultivated. Goals: To evaluate the impact on reproductive aspects of the sex ratio C. montezumae in relation to obtained postlarvae. Methods: The impact of three sex ratio of males and females in the number of ovigerous females, fertility, fecundity, hatching time and the relation between these variables was determinate under laboratory conditions. Results: The analysis of variance shows that sex ratio 1:1 produced the highest number of ovigerous females (61) and a higher number of postlarvae (2451). When comparing the average fecundity (37 eggs per female) and the mean hatching percentage (97.96%), no significant differences between treatments were obtained. Females of first reproduction influenced the absence of linear relationships between size (weight and length) and reproductive aspects evaluated (fecundity and fertility). Conclusions: The sex ratio 1:1 is set as the optimum to get the highest number of postlarvae. The absence of linear relationship between size and studied variables provides the opportunity to study the influence of second breeding females to determine the technical conditions of higher postlarvae production in this specie.