The behavioural pattern and variation in parental care of Aequidens rivulatus

Abstract

The study of fish parental care is important for understanding the social structure and improving the survival rate and welfare of fish populations in aquaculture. However, little is known about the parental care of fish at present, especially their attack patterns, behaviour patterns and spatiotemporal statistical characteristics. In this study, Aequidens rivulatus was taken as the research object and the parental care processes were recorded including the attacker, the attackee, and the start and end attack time. Then, the attack pattern, behaviour pattern and their changes over time were further analysed. The results were as follows: (1) no biting occurred most frequently (58%) and had the highest velocity and acceleration during the parental care period compared with lateral biting and frontal biting. (2) Male attacked intruder the most (52%) with the lowest velocity and acceleration, while female attacked male the least (7%) with the highest acceleration. (3) There was a shift in the role of protection of larvae from females to males. This shift occurred approximately 30 h after the first parental care action. These results suggested that A. rivulatus display a high degree of parental care and an obvious pattern of young protection when facing intruder, which is an important consideration when designing breeding and holding facilities.