PARENT SESSION
Oral Session 76: Biodiversity V: Marine.
Presiding: AA Sabor
Wednesday, August 4, 1:30 PM to 5:00 PM, Meeting Room B 110.
Cryptic density-dependence: Implications and sources of variation in coral reef fish.
Osenberg, Craig*,1, Shima, Jeffrey2, St. Mary, Colette1, 1 University of Florida, Gainesville, FL, USA2 Victoria University of Wellington, Wellington, New Zealand
ABSTRACT- Recent studies of reef fishes have demonstrated that the strength of post-settlement density-dependent and density-independent processes vary spatially. Because the strength of these processes and settlement rates can covary, resulting patterns may lead to biased estimates of the strength of density-independent and dependent processes and the relative importance of supply limitation. Here we review the data for this phenomenon, termed cryptic density-dependence. We then examine possible sources of spatial variation in post-settlement processes: traits of settling fish vs. the habitats into which they settle. Although there are few data to suggest that settler traits play an important role, this has not been well investigated. Our new data (collected for Thalassoma hardwicke in Moorea, French Polynesia) suggest that spatial variation in larval growth rates and post-settlement body composition (lipid, protein, and carbohydrate) are not correlated with variation in the strength of density-dependence. Instead, other studies suggest that habitat features and predator density may play primary roles.
Key words: fish, survival, density-dependence, settlement