Effect of temperature on survival and developmental period of coconut crab (Birgus latro) larvae reared in the laboratory

Populations of the coconut crab, Birgus latro, have been severely depleted on most inhabited islands throughout Indo-Pacific regions because of overharvesting and environmental degradation. To assist in the development of artificial propagation technologies for restocking/stock enhancement of this species, this study was designed to elucidate the effect of rearing temperature on survival and developmental period of zoeae through a laboratory experiment testing six constant temperatures levels (18.9, 21.3, 24.6, 27.0, 29.8, and 32.4 °C). Mortality of all first stage zoeae occurred at 18.9 °C. In contrast, the survival rate to the megalopal stage was significantly higher (85.6 and 82.2%) at 27.0 and 29.8 °C, respectively, than all other treatments. Temperature also had marked effects on larval developmental periods. The number of days from hatching required to reach each larval stage (D) significantly decreased with increasing temperature (T). The mean duration from hatching to the megalopal stage ranged between ~ 19 and 23 days at appropriate temperatures for larval survival (27.0 and 29.8 °C).