November 18, 2016


Research: Fish personality linked to reproductivity


A group of university-based aquaculture experts have discovered how the fish Senegalese sole, which is much valued in Europe, can be produced more effectively and abundantly.


The aquaculturists, based in the University of Stirling in the UK, found that the way the Senegalese sole cope with stress has a bearing on how reproductive they are. Their personality remains consistent regardless of the situation they are in, they said.


The researchers hope that the first study to test stress copying styles in mature Senegalese sole will help farmers screen fish from a young age to help the species reproduce in captivity and improve aquaculture production.


When faced with confinement, restraint or a new environment, the younger fish-known as juveniles-and the older fish-known as breeders-were found to have similar behavioural patterns and levels of activity, showing consistent responses in animals of different ages.


There was a correlation between the personality of the fish and how they acted across the various tests, suggesting that those that are reactive and fearful, on the one hand, and those that are proactive and curious, on the other, consistently maintain their respective behaviour.    


"Senegalese sole is a very valuable fish farmed across Europe; however, first-generation males' failure to reproduce is still a problem affecting production of the species. Animals who are proactive and try to explore are likely to reproduce in captivity so it's important these fish can be identified at a young age", said Dr Sonia Rey Planellas, research fellow at the Institute of Aquaculture.


She added, "The three tests we used to simulate life in captivity was easy to apply and required no special equipment. We hope this can be replicated by fish farmers, large and small, to help establish selection-based breeding programmes and easily identify fish that deal best with stress and will be able to reproduce more successfully in a variety of environments".


Planellas said these operational behavioural screening tests (OBST) could also be used for other species of interest facing similar problems on domestication and production.


Around 120 Senegalese sole were used in the conduct of five individual behavioural tests and two grouping tests. Cortisol, glucose and lactate in the blood were measured at the end of the tests to measure the stress response.


The study was part of Zohar Ibarra-Zatarain's doctoral thesis who is now working in the Nayarit Centre of Technology Innovation and Transfer (CENIT2) in Tepic, México.


The research also involved experts from the Institute for Food and Agricultural Research and Technology (IRTA) in Catalonia and the Spanish Institute of Oceanography. It is published in Royal Society Open Science journal.