Life cycle of Cymadusa filosa (Amphipod: Gammarids) under experimental laboratory conditions in the red Sea-Egypt

Abstract

Objective: The life cycle of Cymadusa filosa under experimental laboratory conditions in the Red Sea-Egypt. Methodology: Five of the ovigerous females collected from the coastal zone in front of the National Institute of Oceanography and Fisheries (NIOF) (27°17’09 N, 33E46’07 E) in Hurghada-Red Sea between summer, 2010 and middle of winter, 2011 were of a length that ranged between 8.0-9.0 mm. Each female was separated in a water tank with a capacity of 3 L and was fed different types of micro-algae. The water was changed daily (the rate of water changed was about 1/2 tank) and the follow-up process stages were from the hatching to the juvenile. Results: There are two identical periods throughout this experiment. The first period: The developing part after releasing juveniles; the aim of the experiment is to take care of juveniles to reach sexual maturity (ovigerous females) and then hatch directly into juveniles. The second period: The days taken between hatching (G0, 1) to (G0, 2) were 12-15 days, (G0, 2) to (G0, 3) were 7-10 days and (G0, 3) to (G0, 4) were 8-10 days of the ovigerous females. Conclusion: The total experimental period of the life cycle of C. filosa was (77-83 days). The fecundity of Cymadusa filosa was estimated by the number of juveniles released by a female. Females were able to carry eggs at a size of 6.50 mm. During the study, a curve linear represented the relationship between the number of juveniles and the size of ovigerous females C. filosa, it was a significant positive correlation.