Growth and behaviour of juvenile European eel (Anguilla anguilla) in sandy and stony bottom substrates

Understanding how the physical habitat influences growth and behaviour is essential for developing effective habitat restoration programmes of threatened and endangered fish species. In our study, we compared the growth and behaviour of juvenile European eel during 13 weeks in aquaria with either sa...

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Bibliographic Details
Published in:Ecology of Freshwater Fish
Main Authors: Motyka, Roman, Calles, Olle, Lind, Lovisa, Watz, Johan
Format: Article in Journal/Newspaper
Language:English
Published: Karlstads universitet, Institutionen för miljö- och livsvetenskaper (from 2013) 2023
Subjects:
SGR
Online Access:http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-94372
https://doi.org/10.1111/eff.12716
Description
Summary:Understanding how the physical habitat influences growth and behaviour is essential for developing effective habitat restoration programmes of threatened and endangered fish species. In our study, we compared the growth and behaviour of juvenile European eel during 13 weeks in aquaria with either sand (0.8-2 mm) or pebbles (25-40 mm) as bottom substrate. In aquaria with the pebble substrate, eel grew significantly faster than in aquaria with sand (specific growth rate 0.15 vs. 0.11% day(-1)). Moreover, growth rates varied more for individuals inhabiting aquaria with sand than in those with pebbles (coefficient of variation 1.26 vs. 0.67). Habitat-dependent growth rates may partly be explained by the observed differences in behavioural patterns. In aquaria with sand, eel left the substrate more often and moved close to the bottom or freely in water column. In aquaria with pebbles, eel remained hidden in the substrate to a high degree, also during feeding. These results may be important for prioritising connectivity- and habitat-restoring measures and for optimization of restocking programmes.