Stress response gene family expansions correlate with invasive potential in teleost fish.

The bluegill sunfish Lepomis macrochirus and the closely related redear sunfish Lepomis microlophus have important ecological and recreational value and are widely used for research and aquaculture. While both species have been introduced outside of their native ranges, only the bluegill is considered invasive. Here, we report de novo transcriptome assemblies for these fish as a resource for sunfish biology.

A spatiotemporal comparison of length-at-age in the coral reef fish Acanthurus nigrofuscus between marine reserves and fished reefs.

Quantitative assessments of the capacity of marine reserves to restore historical fish body-size distributions require extensive repeated sampling to map the phenotypic responses of target populations to protection. However, the "no take" status of marine reserves oftentimes precludes repeated sampling within their borders and, as a result, our current understanding of the capacity of marine reserves to restore historical body-size distributions remains almost entirely reliant on independent, static visual surveys. To overcome this challenge, we promote the application of a traditional fisheries tool known as a "back-calculation", which allows for the estimation of fish body lengths from otolith annuli distances.

Temperature-induced physiological stress and reproductive characteristics of the migratory seahorse during a thermal stress simulation.

Inshore-offshore migration occurs frequently in seahorse species, either because of prey opportunities or because they are driven by reproduction, and variations in water temperature may dramatically change migratory seahorse behavior and physiology. The present study investigated the behavioral and physiological responses of the lined seahorse under thermal stress and evaluated the potential effects of different temperatures on its reproduction. The results showed that the thermal tolerance of the seahorses was time dependent.

Coral reef fishes exhibit beneficial phenotypes inside marine protected areas.

Human fishing effort is size-selective, preferentially removing the largest individuals from harvested stocks. Intensive, size-specific fishing mortality induces directional shifts in phenotypic frequencies towards the predominance of smaller and earlier-maturing individuals, which are among the primary causes of declining fish biomass. Fish that reproduce at smaller size and younger age produce fewer, smaller, and less viable larvae, severely reducing the reproductive capacity of harvested populations.

Body size shifts in philippine reef fishes: interfamilial variation in responses to protection.

As a consequence of intense fishing pressure, fished populations experience reduced population sizes and shifts in body size toward the predominance of smaller and early maturing individuals. Small, early-maturing fish exhibit significantly reduced reproductive output and, ultimately, reduced fitness. As part of resource management and biodiversity conservation programs worldwide, no-take marine protected areas (MPAs) are expected to ameliorate the adverse effects of fishing pressure.

Relating the ontogeny of functional morphology and prey selection with larval mortality in Amphiprion frenatus.

Survival during the pelagic larval phase of marine fish is highly variable and is subject to numerous factors. A sharp decline in the number of surviving larvae usually occurs during the transition from endogenous to exogenous feeding known as the first feeding stage in fish larvae. The present study was designed to evaluate the link between functional morphology and prey selection in an attempt to understand how the relationship influences mortality of a marine fish larva, Amphiprion frenatus, through ontogeny.

Morphological and biomechanical changes of the feeding apparatus in developing southern flounder, Paralichthys lethostigma.

The feeding biomechanics of premetamorphic, metamorphic, and postmetamorphic southern flounder, Paralichthys lethostigma, were investigated to better understand the origin and design of adult pleuronectiform feeding mechanisms. Larval P. lethostigma were sampled from culture tanks every day from first feeding through metamorphosis.

Ontogeny of suction feeding capacity in snook, Centropomus undecimalis.

The ontogeny of suction feeding performance, as measured by peak suction generating capacity, was studied in the common snook, Centropomus undecimalis. Suction pressure inside the buccal cavity is a function of the total expansive force exerted on the buccal cavity distributed across the projected area of the buccal cavity. Thus, the scaling exponent of peak suction pressure with fish standard length was predicted to be equal to the scaling exponent of sternohyoideus muscle cross-sectional area, found to be 1.

Morphology predicts suction feeding performance in centrarchid fishes.

Suction feeding fish differ in their capacity to generate subambient pressure while feeding, and these differences appear to relate to morphological variation. We developed a morphological model of force transmission in the fish head and parameterized it with measurements from individual fish. The model was applied to 45 individuals from five species of centrarchid fishes: Lepomis macrochirus, Lepomis punctatus, Lepomis microlophus, Micropterus salmoides and Pomoxis nigromaculatus.

The effects of opercular linkage disruption on prey-capture kinematics in the teleost fish Sarotherodon melanotheron.

The kinematics of prey capture in blackchin tilapia (Sarotherodon melanotheron) subjected to three experimental treatments (control, anesthetization, and opercular linkage disruption) were analyzed using high-speed video to explore the role of the opercular four-bar linkage in depressing the lower jaw in teleost fishes. A series of two-way mixed model analyses of variance (random effects=fish; fixed effects=treatment) revealed that maximum gape, lower jaw angle, gape cycle, and time to lower jaw depression differed among treatments. Tukey post-hoc comparisons revealed that the opercular linkage disruption treatment differed from the control and anesthetization treatments, suggesting that severing the opercular linkage affected the ability of fish to depress the lower jaw.

EVOLUTION OF PUFFERFISH INFLATION BEHAVIOR.

The evolution of the extraordinary inflation mechanism of pufferfishes was studied in the light of an independently derived phylogenetic hypothesis of tetraodontiform fishes. Inflation behavior is found in all members of the puffer sister taxa Tetraodontidae and Diodontidae. However, most other tetraodontiform fishes exhibit two functionally similar behaviors.

Interpopulation variation in prey use and feeding biomechanics in Caribbean triggerfishes.

The relationships between prey utilization and jaw biomechanics were explored in two Caribbean populations (La Parguera and Mona Island) of four trigger-fishes. The volumetric contribution of major prey types and six biomechanical features of the jaws that characterize biting strength were contrasted between populations. At Mona, Xanthichthys ringens ate 45% benthic organisms, whereas conspecifics at La Parguera fed exclusively on plankton.

Morphological and functional bases of durophagy in the queen triggerfish, Balistes vetula (Pisces, tetraodontiformes).

Tetraodontiform fishes are characterized by jaws specialized for powerful biting and a diet dominated by hard-shelled prey. Strong biting by the oral jaws is an unusual feature among teleosts. We present a functional morphological analysis of the feeding mechanism of a representative tetraodontiform, Balistes vetula.