Emergence rhythms and first larval stage description of the crab Chiromantes boulengeri (Calman) from Shatt Al-Arab, Basrah, Iraq.

Abstract

Emergence rhythm and activity out of burrows of the crab  Chiromantes boulengeri was investigated at laboratory in three light regimes using 10 adult crabs transferred from field, for 5 consecutive days to each regime. In the natural day: dark experiment, an endogenic circadian rhythmic component was determined in the brackish water grapsid crab C. boulengeri, from Shatt Al-Arab River system, Basrah, Iraq, with no evidence of endogenic tidal rhythmic component obtained from the results of five consecutive days experiments in a condition of continuous light and continuous darkness experiments. The first larva stage of C. boulengeri, obtained from laboratory release of ovigerous females was described in details and drew microscopically as well as the new distinctive features were given.