Using external morphology as a proxy for stomach size in .

Stomach morphology can provide insights into an organism's diet. Gut size or length is typically inversely related to diet quality in most taxa, and has been used to assess diet quality in a variety of systems. However, it requires animal sacrifice and time-consuming dissections.

Shift from income breeding to capital breeding with latitude in the invasive Asian shore crab Hemigrapsus sanguineus.

Organisms vary in the timing of energy acquisition and use for reproduction. Thus, breeding strategies exist on a continuum, from capital breeding to income breeding. Capital breeders acquire and store energy for breeding before the start of the reproductive season, while income breeders finance reproduction using energy acquired during the reproductive season.

Past energy allocation overwhelms current energy stresses in determining energy allocation trade-offs.

Regeneration of lost appendages is a gradual process in many species, spreading energetic costs of regeneration through time. Energy allocated to the regeneration of lost appendages cannot be used for other purposes and, therefore, commonly elicits energetic trade-offs in biological processes. We used limb loss in the Asian shore crab to compare the strength of energetic trade-offs resulting from historic limb losses that have been partially regenerated versus current injuries that have not yet been repaired.

Latitudinal and temporal variation in injury and its impacts in the invasive Asian shore crab Hemigrapsus sanguineus.

Nonlethal injury is a pervasive stress on individual animals that can affect large portions of a population at any given time. Yet most studies examine snapshots of injury at a single place and time, making the implicit assumption that the impacts of nonlethal injury are constant. We sampled Asian shore crabs Hemigrapsus sanguineus throughout their invasive North American range and from the spring through fall of 2020.

Polymorphism promotes edge utilization by marsh crabs.

Understanding how habitat edges affect ecological processes is crucial given widespread and increasing modifications to natural landscapes. Resource specialization is a key factor affecting among-species edge responses, but we know little about how intraspecific resource use variation mediates edge utilization. Here, we integrate stomach content analysis, geometric morphometrics and feeding experiments to explore the role of resource polymorphism in mediating marsh crab (Panopeus obesus) foraging within the marsh-oyster reef boundary.

Developmental Change in Predators Drives Different Community Configurations.

AbstractTheoreticians who first observed alternative stable states in simple ecological models warned of grave implications for unexpected and irreversible collapses of natural systems (i.e., regime shifts).

Cannibalism and Intraguild Predation Community Dynamics: Coexistence, Competitive Exclusion, and the Loss of Alternative Stable States.

Predators often exert strong top-down regulation of prey, but in many systems, juvenile predators must compete with their future prey for a shared resource. In such life-history intraguild predation (LHIGP) systems, prey can therefore also regulate the recruitment and thus population dynamics of their predator via competition. Theory predicts that such stage-structured systems exhibit a wide range of dynamics, including alternative stable states.

Deadly competition and life-saving predation: the potential for alternative stable states in a stage-structured predator-prey system.

Predators often undergo complete ontogenetic diet shifts, engaging in resource competition with species that become their prey during later developmental stages. Theory posits that this mix of stage-specific competition and predation, termed life-history intraguild predation (LHIGP), can lead to alternative stable states. In one state, prey exclude predators through competition (i.

Personality, foraging behavior and specialization: integrating behavioral and food web ecology at the individual level.

Behavioral traits and diet were traditionally thought to be highly plastic within individuals. This view was espoused in the widespread use of optimality models, which broadly predict that individuals can modify behavioral traits and diet across ecological contexts to maximize fitness. Yet, research conducted over the past 15 years supports an alternative view; fundamental behavioral traits (e.

Trait-mediated functional responses: predator behavioural type mediates prey consumption.

The predator functional response (i.e. per capita consumption rate as a function of prey density) is central to our understanding of predator-prey population dynamics.

Parasite modification of predator functional response.

Parasite alteration of the host (predator) functional response provides a mechanism by which parasites can alter predator-prey population dynamics and stability. We tested the hypothesis that parasitic infection of a crab (Eurypanopeus depressus) by a rhizocephalan barnacle (Loxothylacus panopei) can modify the crab's functional response to mussel (Brachidontes exustus) prey and investigated behavioral mechanisms behind a potential change in the response. Infection dramatically reduced mussel consumption by crabs across mussel densities, resulting in a decreased attack rate parameter and a nearly eightfold reduction in maximum consumption (i.

The role of individual behavior type in mediating indirect interactions.

Trait-mediated indirect interactions (TMII) play an important role in structuring natural communities, and numerous studies have experimentally demonstrated their presence in a variety of systems. However, these studies have largely examined the presence or absence of traits that are responsible for these interactions, without considering natural variation between individuals in the extent to which these traits are manifested. We used a well-documented TMII to investigate the importance of individual behavior type for determining the strength of the TMII.