Shoaling behaviour of Lates japonicus revealed through a digital camera logger

Abstract

Protecting endangered species is one of the main targets of conservation biology, but the study of these species is often a sensitive issue. The need to risk, and often take, the life of some specimens during the experiments is not easily justified. Technological advances provide scientists with tools that can reduce damage to studied species, while increasing the quality of the data obtained. Here, we analyse the social behaviour of an endangered Japanese fish, Akame (Lates japonicus), using an attached underwater camera. Social behaviour, especially concerning aggregations, is a key factor in conservation plans and fisheries management to avoid by-catch and to establish coherent protected areas. In this experiment, a fish-borne underwater still-camera logger was attached to a captured Akame, recording the individual in its natural environment in July, 2009. The images obtained from the camera revealed several groups of large adults moving together, showing for the first time in this species an aggregative behaviour. This discovery opens the door for initiation of protective measures to preserve these groups, which in turn, can help to ensure continuity of this fish in the Shimanto River by protecting the specific areas where these shoals gather.

Keywords

• Lates japonicus
• Digital still-camera logger
• Shoaling behaviour
• Protected area