Preliminary observation of mantis shrimp breeding success in captivity

Abstract

Mantis shrimps (Crustacea: Stomatopoda) are potential aquaculture species as they are constantly fished from the wild to satisfy demands of the seafood industry. Breeding capacity of mantis shrimps in captivity is scarce and implies a gap in this area to achieve successful aquaculture practices for this species. A preliminary observation was conducted with locally obtained mantis shrimps Miyakella nepa (n=42) and Oratosquillina interrupta (n=22) to elucidate their breeding behaviour in laboratory settings. The ratio of female to male were kept to 1:1 and females kept together are either all mature or immature. Mature females were selected based on the ovary development and males from similar size group were selected to respective females for the breeding observation. The mantis shrimps were placed in either group comprising of 6 females and 6 males, 3 females and 3 males or 1 female paired to 1 male in an aquarium. The observation was conducted for 2 months and daily observation of spawning, egg brooding, mortality, moulting occurence were recorded. For M. nepa within the group breeding, a total of 2 spawning activities occurred, however all egg clutches were unfertilized. Breeding of pairs was more successful comparatively, with the fertilization rate of 66.7% (n=6) for M. nepa. More studies are needed for O. interrupta as results obtained were insufficient, with only 2 spawning and only 1 fertilized egg mass for both group and pair breeding. High mortality rate was the main cause of unsuccessful breeding within the group breeding as aggression and cannibalistic behaviour was displayed among conspecifics even though ample artificial shelters were provided in the tanks. This preliminary observation indicated that pair settings is more favourable compared to group settings for successful mantis shrimps breeding.