Estimation of length at maturation and spawning time and determination of fishing prohibition time and optimum length for catch are of important information about a fish species. Seasonal samplings were conducted over a year to study population dynamic of Carasobarbus luteus in Shadegan wetland. Samples were collected from five sampling stations in Shadegan wetland (Salmane, Rogabe, Khoroosi, M...

This paper deals with a discrete-time predator–prey system with Allee effect. We obtain asymptotically stable conditions of the equilibrium points which are subject to the Allee effect. The stabilizing effect of Allee effect on prey and predator populations is studied, respectively. The Allee effect which occurs on both of predator and prey populations is also discussed by stability analysis, p...

We review the results obtained using the Penna model for biological ageing (T.J.P. Penna, J. Stat. Phys. 78 (1995) 1629) when di erent strategies of parental care are introduced into evolving populations. These results concern to: longevity of semelparous populations; self-organization of female menopause; the spatial distribution of the populations and nally, sexual delity. c ©1999 Elsevier Sc...

Models of population dynamics have been the subject of much study in biology. The essay of Malthus (1798) rst suggested exponential growth. The idea of quantitative limits on growth is usually attributed to Verhulst (1838), who pioneered the use of the logistic equation (LE), and to Lotka (1920) and Volterra (1926), who considered models of predators and prey. Typically these early studies of p...

In classical games that have been applied to ecology, individual fitness is either density independent or population density is fixed. This article focuses on the habitat selection game where fitness depends on the population density that evolves over time. This model assumes that changes in animal distribution operate on a fast time scale when compared to demographic processes. Of particular i...

Induced plant resistance may contribute to regulating or driving fluctuations in insect herbivore populations. However, experimental demonstrations of induced resistance affecting long-term herbivore population dynamics are lacking, and few models find that induced resistance drives cycles in herbivore populations. Here a simulation model is used to explore the influence of characteristics of t...

In size-structured predator–prey systems, capture success depends on the sizes of both predator and prey. We study the population-dynamic consequences of sizedependent predation using a model of a size-structured, cannibalistic fish population with one shared, alternative resource. We assume that a prey can be captured by a predator if the ratio of prey length to predator length is within a spe...

The use of fish closures as a management tool to protect juvenile fish habitat and adult spawning grounds has become increasingly popular, although knowledge of the direct effects of marine closures on juvenile fish populations is limited. Given that monkfish landings account for a considerable percentage of the monetary value derived from the groundfish fishery in new England, investigating th...

Simulation models are becoming increasingly popular in the analysis of important policy issues including global warming, population dynamics, energy systems, and urban planning. The usefulness of these models is predicated on their ability to link observable patterns of behavior of a system to micro-level structures. This paper argues that structural validity of a simulation model -right behavi...

Different discrete models of population dynamics of certain insects have been investigated under various feasible conditions within the framework of nonlinear dynamics. Evolutionary phenomena are discussed through bifurcation analysis leading to chaos. Some tools of nonlinear dynamics, such as Lyapunov characteristic exponents (LCE), Lyapunov numbers, correlation dimension, etc. are calculated ...