A dorsal valve of an Upper Cambrian lingulate brachiopod exhibits a repair scar on the anterior lateral edge of its larval shell. This species is characterized by an abrupt change in ornamentation from larval to postlarval growth. Shell material secreted in the injured area after the damage occurred exhibits ornamentation that is characteristic of postlarval growth, although equivalent growth e...

Many animals respond to predation risk by altering their morphology, behavior, or life-history. We know a great deal about the cues prey respond to and the changes to prey that can be induced by predation risk, but less is known about how plastic responses to predators may be affected by separate plastic responses occurring earlier in life, particularly during the embryonic period. Embryos of a...

In this study, it was tried to determine the amount of prey consumed by Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) at varying densities and its potency in reducing population pest. Aphids used as nutrients [Aphis fabae Scopoli Acyrthosiphon pisum Harris (Hemiptera: Aphididae)] were given each larval stage (InstarI, InstarII, InstarIII) predator certain numbers (5, 10, 20, 40, 80, 1...

The predator Chrysoperla externa (Hagen, 1861) (Neuroptera: Chrysopidae) is a polyphagous species that has, among its wide range of acceptable prey, the aphid Macrosiphum rosae (Linnaeus, 1758) (Hemiptera: Aphididae), an important pest rose plants. We assessed consumption nymphs and adults M. by C. larvae, predatory efficiency, larval survival under different predator:prey ratios, densities aph...

The relationships between a predator population's mortality rate and its population size and stability are investigated for several simple predator-prey models with stage-structured prey populations. Several alternative models are considered; these differ in their assumptions about the nature of density dependence in the prey's population growth; the nature of stage-transitions; and the stage-s...

In this paper, a new stage structured prey-predator model with linear functional response is proposed and studied. The stages for prey have been considered. The proposed mathematical model consists of three nonlinear ordinary differential equations to describe the interaction among juvenile prey, adult prey and predator populations. The model is analyzed by using linear stability analysis to ob...

Exposure to olfactory cues during embryonic development can have long term impacts on birds and amphibians behaviour. Despite the vast literature on predator recognition and responses in fishes, few researchers have determined how fish embryos respond to predator cues. Here we exposed four-day-old rainbowfish (Melanotaenia duboulayi) embryos to cues emanating from a novel predator, a native pre...

Larval mortality is an important component of recruitment variability. To understand the mechanisms affecting larval mortality, it is necessary to take into account the nonlinear interactions involved in density-dependent population dynamics and the physical environment at scales of motion comparable with larval feeding scales. This paper develops a framework for further analysis by describing ...

1. The life stage suffering the highest predation rate is expected to have the highest escape performance unless developmental or functional constraints interfere. Peak aquatic escape performance in ephemeral pond-breeding amphibians is expected to develop early in the larval period, and metamorphosis is expected to reduce or completely disrupt aquatic escape performance. In anurans, exceptiona...