Fisheries Behavioral Ecology - Abstracts
Laurel, B.J., A.W. Stoner, and T.P. Hurst. 2007. Density-dependent habitat selection in marine
flatfish: the dynamic role of ontogeny and
temperature. Marine Ecology Progress Series 338:183-192.
Abstract
Changes in habitat use with increasing conspecific density are well-documented, but
such patterns are likely to be dynamic over the lifespan of the organism and responsive to changes in
the environment. In the laboratory, we examined how habitat selection was mediated by ontogeny (6,
8 and 12 mo) and temperature (4 and 9°C) in 2 juvenile, marine flatfish species: Pacific halibut Hippoglossus
stenolepis and northern rock sole Lepidopsetta polyxystra. In a set of initial trials at 9°C,
groups of same-aged juvenile flatfish (6, 8 or 12 mo) of either halibut or rock sole were given the
choice of 2 habitats—fine sand (preferred) and coarse gravel (unpreferred)—at 1 of 6 densities (0.4
to 12.2 fish m-2). A second set of trials was conducted at 4°C using 8 mo juvenile fish of both species
over the same range of densities. At 9°C, density-dependent habitat selection was observed among
all treatment groups. As juveniles increased in age in the 9°C treatments, both species began occupying
the less-preferred gravel habitat at lower densities. However, at 4°C, density-dependent habitat
selection varied between species. Sand habitat supported higher densities of juvenile Pacific halibut
at 4°C whereas no change was observed in northern rock sole. Juvenile Pacific halibut activity
was also lower than rock sole at 4°C, suggesting that competitive interactions (e.g. interference, territoriality
etc.) and/or physiological demands of halibut is sufficiently reduced at this temperature to
increase the carrying capacity of the preferred habitat. Together, these results indicate that temperature,
ontogeny and density interact to yield unique habitat selection patterns in fish, mechanisms
that may be important in area-abundance relationships.
Last updated
11 October, 2007
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