Fisheries Behavioral Ecology - Abstracts
Lemke, J.L. and C.H. Ryer. 2006. Risk sensitivity in three juvenile (Age-0) flatfish species: Does
estuarine dependence promote risk-prone behavior? Journal of Experimental Marine Biology and Ecology 333:172–180.
Abstract
Pleuronectid flatfish are generally thought to use stereotypical anti-predator behavior to reduce encounters with potential predators, including burial, maintaining a low profile on the bottom, cryptic coloration, and reduced activity. However, a series of laboratory experiments demonstrate significantly different predation rates on juvenile (Age-0) English sole (Parophrys vetulus),
northern rock sole (Lepidopsetta polyxystra), and Pacific halibut (Hippoglossus stenolepis) by Age-2 Pacific halibut predators,
suggesting differing anti-predator strategies and/or capabilities among species. In this study, behavioral attributes that control how
conspicuous juvenile flatfish are to their predators, such as burial, body posture, and activity levels, were examined both in the
presence and absence of perceived predation risk. English sole exhibited risk-prone behavior; they tended to bury less, exhibit an
arched body posture (with head elevated off the bottom), and were more active in both the absence and presence of predators when
compared to the other two species. Conversely, rock sole exhibited risk-averse behavior, being buried, inactive, with a flat body
posture regardless of predation risk. Halibut demonstrated risk-sensitive behavior; behaving like English sole in the absence of
predation risk, and shifted to behavior similar to that of rock sole in the face of predation risk. As an estuarine dependent species,
English sole recruit to an environment that tends to be highly turbid reducing encounters with predators. As a result English sole,
may have “relaxed” anti-predator behaviors in comparison to northern rock sole and Pacific halibut which recruit to less turbid
coastal nurseries.
Last updated
26 April, 2007
FBE Webmaster
|
