Developmental Stages, Growth and Sex Ratio in <i>Pseudodiaptomus binghami</i> Sewell (Copepoda: Calanoida)

Abstract

Larval stages of a calanoid copepod P. binghami have been reared in the laboratory. The life history comprising altogether 11 instars; 5 naupliar and 6 copepodid stages, the last stage being the adult, takes about 25 days at ambient temperature (27.5-29° C) and salinity of 10 + or – 2%. Nauplii are asymmetrical, the asymmetry disappearing with naupliar development. Copepodid stages follow the general pattern of calanoid development. Growth rate in nauplii varies from 0.018 to 0.02 mm/day and for copepodid stages, it is 0.065 mm/day in females and 0.069 mm/day in males. Ratio of adult females to adult males is 6:1 for the natural population and 2:1 for the laboratory reared individuals. The possibility of mass culture of this species for feeding the shrimp larvae in aquaculture is suggested.