Showing papers by "Donald L. DeAngelis published in 1985"
TL;DR: An age-structured two-species predator-prey model was developed to explore the possible role of selective predation by naticid gastropods in the evolution of the energy allocation of their bivalve prey.
Abstract: An age-structured two-species predator-prey model was developed to explore the possible role of selective predation by naticid gastropods in the evolution of the energy allocation of their bivalve prey. The model describes prey fitness in terms of the amount of energy available for reproduction over a lifetime and describes predator fitness in terms of the net energy intake rate of the adult predator. Both species are considered to be age- and size-structured. Predation is size-dependent, and the predator is assumed to select prey in a manner that maximizes its net energy intake. Two evolutionary traits of the prey are considered: the age-dependent allocation of energy between reproduction and growth (X1) and the allocation of energy between overall growth and extra growth in shell thickness (X2). The results of the model are described in terms of prey phenotypic fitness landscapes as functions of predation intensity. These landscapes consist of prey fitness plotted as a function of the parameters, X1 and...
56 citations
TL;DR: The role of disturbance is dependent on the temporal and spatial characteristics of the system as discussed by the authors, and disturbances act primarily in a destructive way, reducing the ecological structure that can be maintained, whereas in other categories disturbances promote species diversity and richness of spatial pattern.
45 citations
TL;DR: In this paper, a study of the life cycle of the smallmouth bass Micropterus dolomieui was conducted in the Baie du Dore, Lake Huron during six summers to determine growth after dispersal from nests.
Abstract: As part of a study of the life cycle of the smallmouth bass Micropterus dolomieui, young of the year were sampled in the Baie du Dore, Lake Huron, during six summers to determine growth after dispersal from nests. Length-frequency distributions were plotted approximately weekly each of the summers. The changes through time of the mean size of fish in each cohort were described by a mathematical model that assumed a size-dependent growth rate and no size-dependent mortality for the fish. The constraint on the model to fit the empirical mean fish sizes through the growing season automatically produced time-varying standard deviations of the size distributions that compared closely to the empirical standard deviations for 5 out of the 6 years. The poor fit to the standard deviations of the sixth year was explicable in terms of unusual data on one sampling date. These results suggest that size dependence of the growth rate was an important mechanism in the spread in the length-frequency distribution ...
17 citations