Habitat structure influences the survival and predator-prey interactions of early juvenile red king crab Paralithodes camtschaticus


Highly structured nursery habitats promote the survival of juvenile stages of many
species by providing foraging opportunities and refuge from predators. Through integrated
laboratory and field experiments, we demonstrate that nursery habitat structure affects survival
and predator-prey interactions of red king crab Paralithodes camtschaticus. Crabs (<1 yr old
[Age 0]; 8 to 10 mm carapace length [CL]) preferred complex biogenic habitats formed by structural
invertebrates and macroalgae over structural mimics and sand in the absence of predators in
laboratory experiments, yet they associated with any available structural habitat when fish predators
were present. Survival was higher in the presence of complex habitat for Age 0 crabs (5 to
7.5 mm CL) with Pacific cod Gadus macrocephalus predators in the laboratory and for Age 0
(4 to 8 mm CL) and Age 1 (16 to 28 mm CL) crabs with fish and invertebrate predators in the field.
Crab activity and refuge response behavior varied with crab stage and habitat. Age 0 crabs were
cryptic, avoiding predators by associating with habitat structure or remaining motionless in the
absence of structure, and were less likely to respond to an attack. In contrast, Age 1 crabs were
more likely to respond to an attacking predator and were less likely to remain motionless in the
absence of structural refuge, suggesting an ontogenetic shift in behavior. Complex habitats, cryptic
behavior, and direct defense improve juvenile red king crab survival against certain predators,
including demersal fishes.


Center for Coastal and Ocean Mapping

Publication Date


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Marine Ecology Progress Series






Inter-Research Science Center

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Journal Article