Poster Presentation Australian Society for Fish Biology Conference 2022

The development of survival behaviour in hatchery reared Murray cod  (#220)

Leia Rogers 1 , Paul Humphries 1 , R Keller Kopf 2 , Raf Freire 1
  1. School of Agricultural, Environmental and Veterinary Sciences, Charles Sturt University, Albury, NSW, Australia
  2. Charles Darwin University, Darwin

The exposure to artificial environments with low-risk conditions has caused a domesticated behavioural trait seen in adult hatchery-reared Murray cod. Domesticated fish are bold in behaviour compared to their wild conspecifics and have lower chances of survival in wild situations. Stocking programs release hatchery-reared Murray cod at 10 weeks of age into the Murray-Darling Basin (MDB) with the behaviour of these fish being crucial to their survival. This project aims to identify if there is a significant behavioural shift to a domesticated behavioural trait in the early developmental stages of hatchery-reared Murray cod that are destined for release in MDB stocking programs. We collected 247 Murray cod at various ages significant in early development and hatchery procedures (1, 3, 6, 10, 16 and 20 weeks old). Fish were observed through four behavioural tests; latency to emerge from a shelter, exploration of a novel area, suitable habitat preference and predator avoidance. Our results display various behavioural changes across the ages of rapid development, with fish of 6 and 16 weeks of age displaying traits most suitable for survival. There is no evidence from these findings that the domesticated phenotype of hatchery-reared Murray cod develops in the stages of early development.