Breeding antarctic krill in captivity

Antarctic krill were maintained in large aquaria at Port of Nagoya Aquarium, Japan, under controlled photoperiod and were fed on phytoplankton and enriched animal feed. Maturation and spawning were induced after the light : dark (L : D) cycle was increased from 8 : 16 or 12 : 12 to 24 : 0, or when the L : D cycle was held constant at 14 : 10. This study is one of the first studies that demonstrate initiation of maturation and spawning events of krill under controlled photoperiod. Out of three experimental batches of krill, a total of 28 spawning events were observed. The mean number of eggs per event was 1424 with a range between 139 and 3458. The mean hatching success per batch was 19.1%. The relation between photoperiod and maturity/spawning is discussed. Furthermore, hatching is compared to previous studies and the reason for the low success is discussed.