Bioenergetic modeling of the blue crab (Callinectes sapidus) using the fish bioenergetics (3.0) computer program

To understand better the ecology and growth dynamics of the blue crab (Callinectes sapidus). we developed a bioenergetic model based upon the Fish Bioenergetics 3.0 computer program. We summarized and analyzed existing data from published studies on the ecology and physiology of both blue crab and closely related species to parameterize the model. The respiration and excretion components were estimated directly from published studies. Parts of the consumption component were estimated indirectly. The resulting model was evaluated for applicability against known growth trajectories from field and laboratory studies. The model predicted observed growth and consumption to a first approximation. Inspection of model results suggest that improvements in our knowledge of temperature- and size-dependant consumption are required before a more predictive model can be developed. However, at this point the model is sufficiently accurate to explore some fishery-related questions

Mating opportunities, paternity, and sexual conflict: Paternal care in northern and southern temperate house wrens

Males are generally predicted to care less for their young when they have more additional mating opportunities, lower paternity, or when their mates care more. We tested these predictions using male provisioning as a proxy for paternal care in two temperate populations of house wrens (Troglodytes aedon) with divergent life histories. Males in the migratory, occasionally socially polygynous New York, USA (northern) population provisioned less when more local females were fertile. A similar relationship was only weakly supported in the resident, socially monogamous Buenos Aires Province, Argentina (southern) population, possibly due to the higher density of house wrens there. A relationship between male provisioning and level of paternity within the brood was supported in both populations, but in opposite directions: while males in the southern population provisioned less at broods containing more extra-pair young, males in the northern population provisioned such broods more, contradicting predictions. Males provisioned less when their mates provisioned more in both populations, in agreement with sexual conflict theory. Additionally, the populations both exhibited a positive relationship between male provisioning and nestling age, but differed in the direction of the relationships of male provisioning with date and brood size. Our results suggest that even within a species, life history differences may be accompanied by differences in the determinants of behavior such as paternal care.Fil: LaBarbera, Katie. Cornell Lab Of Ornithology; Estados Unidos. University of California at Berkeley; Estados UnidosFil: Lovette, Irby Jhon. Cornell University; Estados UnidosFil: Llambias, Paulo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin