Life Cycle of the Fairy Shrimp, Phallocryptus spinosa Milne Edwards, ۱۸۴۰ (Crustacea: Anostraca) at Different Temperatures

This study was conducted to evaluate a temperature regime ranged from ۱۵ to ۳۰°C on survival, growth, life span and reproductive traits (reproductive period, clutch number, offspring number) of Phallocryptus spinosa from Iran. Newly hatched nauplii (N= ۲۰۰ and ۳ replicates per each treatment) were allocated into containers and maintained at various temperature regimes (at ۱۵, ۲۰, ۲۵ and ۳۰˚C). During trial, the larvae were fed with unicellular algae Dunaliella tertiolecta and Lansy PZ (lipid-enriched yeast). Survival and growth rate of P. spinosa with an interval of ۳ days to ۱۸ days were examined. After attaining adulthood, ۱۶ pairs of adult P. spinosa were transferred from all culture vessels into separate containers supplied with ۳۰۰ ml of brackish water (۵ ppt) and similar temperatures to compare their life span and reproductive traits. Based on results obtained, maximum growth at shortest period (۱۳.۲±۲.۰ mm on day ۱۲) was observed at ۳۰°C; whereas, all P. spinosa died before reaching sexual maturity by day ۱۵. Maximum survival (۸۶%) was observed at ۱۵°C; however, minimum growth also was obtained at the same temperature with none of P. spinosa reaching sexual adulthood. On the ۱۸th day, P. spinosa reached sexual adulthood only at ۲۰ and ۲۵°C. Furthermore, a significant difference was observed in most of the reproductive traits especially in total egg production per female at ۲۰°C. Thus, it seems that ۲۰°C is the suitable temperature to rear this fairy shrimp. Future studies should be focused on the feasibility of mass production of this species as a valuable live feed in the aquaculture industry.

Keywords:

Fairy shrimp , Growth , Survival , Life span , Reproductive characteristics