Some Aspects of the Biology of two Copepods: Apocyclops dengizicus and Mesocyclops isabellae from a Pool in Garmat - Ali, Basrah, Iraq

Some biological aspects of the copepods Apocyclops dengizicus and Mesocyclops isabellae were studied at a pool in Garmet-Ali during the period between August 1998 and July 1999. The laboratory sex ratio was in favour of the females: 3.6:1 and 2.06:1 in the two species respectively. The females of the two species showed faster growth during the copepodites IV, V and the adult. The males reached the adult stage at a shorter time than the females. All stages of life of A. dengizicus appeared in August 1998 and then disappeared. In February 1999 a few copepodites and adults were present, peaked in March and disappeared during April. M. isabellae appeared during August 1998 - December 1998, then disappeared and reappeared in April 1999. It is suggested that predation and cannibalism may be the causes of diapause in the two species.