title: Hierarchical analysis of taxonomic variation in intraspecific competition across fish species.
abstract: The nature and intensity of intraspecific competition can vary greatly among taxa, yet similarities in these interactions can lead to similar population dynamics among related organisms. Variation along the spectrum of intraspecific competition, with contest and scramble competition as endpoints, leads to vastly different responses to population density. Here we investigated the diversity of intraspecific competition among fish species, predicting that functional forms of density-dependent reproduction would be conserved in related taxa. Using a hierarchical model that links stock-recruitment parameters among populations, species, and orders, we found that the strength of overcompensation, and therefore the type of intraspecific competition, is tightly clustered within taxonomic groupings, as species within an order share similar degrees of compensation. Specifically, species within the orders Salmoniformes and Pleuronectiformes exhibited density dependence indicative of scramble competition (overcompensation) while the orders Clupeiformes, Gadiformes, Perciformes, and Scorpaeniformes exhibited dynamics consistent with contest competition (compensation). Maximum potential recruitment also varied among orders, but with less clustering across species. We also tested whether stock-recruitment parameters correlated with maximum body length among species, but found no strong relationship. Our results suggest that much of the variation in the form of density-dependent reproduction among fish species may be predicted taxonomically due to evolved life history traits and reproductive behaviors.
authors.affiliation: University of Maryland Department of Biology, College Park, Maryland, 20742, USA.
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Foss-Grant
authors.affiliation: Michigan State University Department of Integrative Biology, Michigan State University Ecology, Evolutionary Biology and Behavior Program, East Lansing, Michigan, 48864, USA.
authors.forename: Elise F
authors.initials: EF
authors.lastname: Zipkin
authors.affiliation: Fisheries Resources Assessment and Monitoring Division, Northwest Fisheries Science Center, National Marine Fisheries Service, NOAA, Seattle, Washington, 98112, USA.
authors.forename: James T
authors.initials: JT
authors.lastname: Thorson
authors.affiliation: Rutgers University Department of Marine and Coastal Sciences, New Brunswick, New Jersey, 08901, USA.
authors.forename: Olaf P
authors.initials: OP
authors.lastname: Jensen
authors.affiliation: University of Maryland Department of Biology, College Park, Maryland, 20742, USA.
authors.forename: William F
authors.initials: WF
authors.lastname: Fagan
mesh_terms: D000818:Animals; D044822:Biodiversity; D002965:Classification; D005399:Fishes / Q000502:physiology*; D011156:Population Density; D011157:Population Dynamics
keywords: Shepherd stock-recruitment model; density-dependence; hierarchical model; intraspecific competition; meta-analysis; recruitment compensation; stock assessment; stock-recruitment