Comparison of feeding behaviour characteristics between wild-caught and captive-reared Hippocampus kuda Bleeker

Abstract

The yellow seahorse, Hippocampus kuda Bleeker, an ornamental and pharmaceutical fish, is being artificially cultivated due to the insufficient commercial supply of wild resources. However, the artificial breeding is difficult due to the limited biological knowledge. To improve the breeding technology of H. kuda, we compared the feeding behaviour of wild-caught group (GW) and captive-reared group (GC). The feeding behaviour of the wild and cultured H. kuda included six steps: searching, locking, alerting, catching, swallowing, and withdrawing. However, differences existed in their behavioural parameters. The GC of H. kuda had a longer reaction time, lower feeding rate, smaller food intake of live food and a shorter feeding distance than the GW. Furthermore, compared with those single state, H. kuda in groups have a shorter reaction time and higher feeding rate of single food, but a slower reaction to batch food. Most of the changes had no effect on the artificial breeding of seahorse. However, there are two points need to be adjusted in feeding management. Firstly, the seahorses will likely lack the behaviour of looking up for food, and only look down at the bottom. They may eat spoiled residual food and develop gastroenteritis diseases and death. Secondly, appropriate stocking density of seahorse and feeding frequency can maintain a feeding competition, which can reduce residual food and improve food utilisation.