Does variability in fish larvae behaviour affect the selection of their nursery habitat? | - CCMAR -

Does variability in fish larvae behaviour affect the selection of their nursery habitat?


Our reseachers with the collaboration of Claudio Carere from University of Tuscia (Italy), and researchers from IPMA/EPPO, tested the behaviour presented by fish larvae during their growth. 


Why we test the behaviour of temperate fish larvae? 
Animals as individual beings across all taxa differ in their behaviour, i.e., they show traces of their personalities. This variability between individuals has ecological and evolutionary consequences, since it affects a range of population processes. In this study, we focused on how the larvae of fish living in mild temperatures, i.e. temperate fish, select their nursery habitats. 

The research came from Sense Acuity And Behavioural Hypothesis which proposes that fish larvae can detect and follow environmental signs that allow them to choose the most suitable nursery habitats. We tested this hypothesis on individual larvae white sea bream (Diplodus sargus), where they were continuously tested at different ages through a two-channel choice-chamber apparatus, exposing them to a flow with different stimuli, such as nursery habitats (lagoon, coastal) and different temperatures or salinities and recording their exploratory activity and preference in different conditions. 


Fish larvae display some individuality that can affect the selection of their habitat  
We observed that most temperate fish larvae changed their behaviour during the transformations suffered since the fecundation of the egg until its complete development (ontogeny), but were also consistent in their behaviour, revealing a strong individuality. However, no significant preference emerged for the stimuli presented, nor was it related to individuality. The exploratory activity was higher when larvae presented non-responsive or inconclusive behaviours, which means that the larvae tried to find a different stimulus from the one we were offering or had a random selection of habitat. Thus, the individual variability could influence the process of searching for suitable nursery habitats and, consequently, dispersion and connectivity of white seabream populations.  

The final results  
This research demonstrated that characterizing the behaviour of temperate pelagic marine fish larvae and understanding active habitat selection may increase our understanding on fish recruitment variability and help refining larval dispersion models to understand the effects of climate changes and habitat degradation on fish distribution and population connectivity. Moreover, due to this new knowledge new aquaculture techniques may contribute to animal welfare. 


You can read the full article HERE.