Identifying spawning events of greater amberjack using accelerometers

ABSTRACT

Direct observations of spawning events of large free-swimming migratory fish are difficult in nature. However, behavioural changes specific to spawning events of fish species, i.e. swimming depth or acceleration of body motion using data loggers attached to the body, have successfully been used to identify spawning. In this study, we observed the spawning behaviour in an experimental tank of a pair of greater amberjack Seriola dumerili, which were matured by injection of gonadotropin, by attaching an acceleration data logger, an accelerometer. The male and female were observed to vibrate their bodies during the moment of spawning. Analysis of the acceleration data showed the simultaneous appearance of a dominant cycle (cycle indicating the highest amplitude in 1 s) under 0.4 s continuing over 7 sand dominant amplitude over 0.4 indicating the time of the spawning in both sexes. These characteristics are useful for the development of an algorithm to detect the spawning behaviour, allowing us to develop a new data logger with an on-board algorithm for detection of spawning behaviour. Before development of this system, we need to develop new algorithms for separation of spawning behaviour from other similar large motion behaviours, particularly from feeding and prey avoidance behaviour.

SUBJECT EDITOR:

• Audrey Geffen

KEYWORDS:

• Migratory fish
• spawning event
• accelerometer
• vibration

Acknowledgements

We sincerely thank the staffs of the Komame Branch, which was discontinued in 2016, the National Research Institute of Aquaculture for their support of the experiment.

Disclosure statement

No potential conflict of interest was reported by the authors.