Bioluminescent emissions of the deep-water pandalid shrimp, Heterocarpus sibogae De Man, 1917 (Decapoda, Caridea, Pandalidae) under laboratory conditions

Bioluminescent behaviour of deep-sea decapods is difficult to study under long-term laboratory maintenance, because most deep-sea organisms suffer from high mortality in such conditions. The objective of the present study was to determine the survival of the deep-water pandalid shrimp, Heterocarpus sibogae De Man, 1917 and its ability to produce bioluminescence when maintained in the laboratory. H. sibogae exhibited bioluminescence by emitting two streams of blue luminous secretions from the mouth when disturbed. The luminous material decayed rapidly and disappeared in seconds. Shrimps retreated from the luminous region immediately after secretion, suggesting that bioluminescence is a defence response. Under laboratory conditions, H. sibogae can produce luminous secretions for at least 43 days of maintenance. Maximum emission time was recorded in a non-ovigerous female that reached 634 seconds. Males and non-ovigerous females showed a similar average emission time of about 30 seconds. Ovigerous females, however, produced significantly longer emissions with an average of 103 seconds, suggesting that these may contain larger amounts of the key chemical for bioluminescence, coelenterazine, than males and non-ovigerous females do.