Salinity and temperature requirements for larviculture of the Monkey River prawn Macrobrachium lar (Fabricius, 1798) (Decapoda: Caridea: Palaemonidae).

摘要

The present study investigated the effects of salinity and temperature on the survival and development of larvae of the Monkey River prawn Macrobrachium lar. Larvae of specific morphological development stages (zoeae I, III, V and VII) were exposed to various salinities ranging from 0 to 30+or-0.5 per mil during salinity tolerance tests; while zoea I larvae were reared at temperatures of 26+or-0.5 degrees C, 28+or-0.5 degrees C, and 30+or-0.5 degrees C during temperature tolerance tests. The results of the salinity tolerance tests demonstrated that newly-emerged larvae of Macrobrachium lar are able to tolerate fresh or brackish-water of approximately 10 per mil, but require gradually increasing salinities post-hatch reaching 30-35 per mil; which probably needs to be maintained until metamorphosis into post-larvae (PL). Larval stages I-II required a range of 10-15 per mil, III-IV required 15-25 per mil and V-VI required 25-30 per mil. Stages VII to XIII required 30-35 per mil, following which salinity may be reduced after PL₁. Larval survival and growth were found to be significantly reduced when maintained outside these salinities. Larvae kept in freshwater (0 per mil) die within 4 days unless transferred to brackish-water. Results of the temperature tolerance investigations revealed that a temperature range of 30+or-0.5 degrees C produced optimal survival and growth. As a result of the current investigation, baseline data on the salinity and temperature requirements of M. lar larvae have been collected and will be useful in further larviculture research work with this species. A salinity acclimation protocol has also been developed that will be useful in developing a mass culture technique for hatchery production of PL.