Cyclic Male Reproductive Activities in the Dwarf Crawfishes Cambarellus shufeldti (Faxon) and Cambarellus puer Hobbs

Abstract

The male reproductive cycles of Cambarellus shufeldti and C. puer were com-pared. Although form I males in breeding condition and ovigerous females of each species can be found at almost any time throughout the year, 2 peaks of reproductive activity were shown; a major peak in Jan., Feb., and March and a lesser peak in July. C. shufeldti shows a strong tendency toward continuous, year-round breeding; while C. puer shows more clumping of reproductive activities into the 2 peak periods. Males of both species show 2 major cycles of sperm production as adults, the 1st occurring during the 1st breeding season following the one in which they were spawned. A 2nd cycle of sperm production occurs when the males are approximately 1 yr. old. Growth increment studies showed an average growth increment of approximately 0.45 mm in cephalothorax length/ molt for each species, with 12 to 13 molts required for reaching maturity in C. shufeldti and 13 to 14 for C. puer.