Genomic Architecture of the Clownfish Hybrid Amphiprion leucokranos.

Natural hybridization is increasingly recognized as playing a significant role in species diversification and adaptive evolution. Amphiprion leucokranos, the naturally occurring clownfish hybrid between Amphiprion chrysopterus and Amphiprion sandaracinos, is found within the hybrid zone of the two parental species. Based on whole-genome sequencing of parental and hybrid individuals sampled in Kimbe Bay, Papua New Guinea, we found that most of the hybrids collected were first-generation hybrids, a few were first- and second-generation backcrosses with A.

Marine reserves contribute half of the larval supply to a coral reef fishery.

Marine reserves deliver impressive increases in the abundance and size of exploited species on protected reefs, but larval dispersal makes it difficult to estimate their wider benefits. Australia's Great Barrier Reef (GBR) contains an extensive network of marine reserves. By combining GBR-wide fish surveys, larval dispersal models, and commercial fishery catch data, we calculate the system-wide ecological and economic contributions of these reserves for coral groupers ( spp.

Strength of Sexual Selection and Sex Roles Vary between Social Groups in a Coral Reef Cardinalfish.

AbstractThe strength and direction of sexual selection can vary among populations. However, spatial variability is rarely explored at the level of the social group. Here we investigate sexual selection and sex roles in the paternally mouthbrooding, socially monogamous, and site-attached pajama cardinalfish, .

Physical, biological and anthropogenic drivers of spatial patterns of coral reef fish assemblages at regional and local scales.

Species abundance, diversity and community assemblage structure are determined by multiple physical, habitat and management drivers that operate across multiple spatial scales. Here we used a multi-scale coral reef monitoring dataset to examine regional and local differences in the abundance, species richness and composition of fish assemblages in no-take marine reserve (NTMR) and fished zones at four island groups in the Great Barrier Reef Marine Park, Australia. We applied boosted regression trees to quantify the influence of 20 potential drivers on the coral reef fish assemblages.

Contrasting hydrodynamic regimes of submerged pinnacle and emergent coral reefs.

Hydrodynamics on coral reefs vary with depth, reef morphology and seascape position. Differences in hydrodynamic regimes strongly influence the structure and function of coral reef ecosystems. Submerged coral reefs on steep-sided, conical bathymetric features like seamounts experience enhanced water circulation as a result of interactions between currents and the abrupt physical structure.

Life-history constraints, short adult life span and reproductive strategies in coral reef gobies of the genus Trimma.

Body size influences many life-history traits, with small-bodied animals tending to have short life spans, high mortality and greater reproductive effort early in life. In this study, the authors investigated the life-history traits and reproductive strategies of three small-bodied coral reef gobies of the genus Trimma: Trimma benjamini, Trimma capostriatum and Trimma yanoi. The authors found all Trimma species studied attained a small body size of <25 mm, had a short life span of <140 days and experienced high estimated daily mortality of 3.

Minimum size limits and the reproductive value of numerous, young, mature female fish.

Fisheries management relies on various catch and effort controls to preserve spawning stock biomass and maximize sustainable yields while limiting fishery impacts on marine ecosystems. These include species-specific minimum or maximum size limits to protect either small non-reproductive subadults, a portion of reproductively mature adults, or large highly fecund individuals. Protecting size classes of mature fish is expected to yield a viable source of larvae for replenishing populations and reduce the risk of recruitment overfishing, yet size-specific recruitment contributions have rarely been assessed empirically.

Species integrity, introgression, and genetic variation across a coral reef fish hybrid zone.

Hybridization and introgression are evolutionarily significant phenomena breaking down species boundaries. "Hybrid zones" (regions of species overlap and hybridization) enable quantification of hybridization frequency and examination of mechanisms driving and maintaining gene flow. The hybrid anemonefish is found where parent species () distributions overlap.

Ecological and social constraints combine to promote evolution of non-breeding strategies in clownfish.

Individuals that forgo their own reproduction in animal societies represent an evolutionary paradox because it is not immediately apparent how natural selection can preserve the genes that underlie non-breeding strategies. Cooperative breeding theory provides a solution to the paradox: non-breeders benefit by helping relatives and/or inheriting breeding positions; non-breeders do not disperse to breed elsewhere because of ecological constraints. However, the question of why non-breeders do not contest to breed within their group has rarely been addressed.

Sexual dimorphism in the horn size of a pair-forming coral reef butterflyfish.

Sexual dimorphism is a common in the animal kingdom and is often linked to mate choice or competition for mates in polygynous mating systems. However, sexual dimorphism is less common in species that form heterosexual pairs and has not been recorded in pair-forming coral-reef fish. Here we demonstrate a pronounced morphological difference between males and females in the humphead bannerfish (Heniochus varius)-a pair-forming coral reef butterflyfish.

A connectivity portfolio effect stabilizes marine reserve performance.

Well-managed and enforced no-take marine reserves generate important larval subsidies to neighboring habitats and thereby contribute to the long-term sustainability of fisheries. However, larval dispersal patterns are variable, which leads to temporal fluctuations in the contribution of a single reserve to the replenishment of local populations. Identifying management strategies that mitigate the uncertainty in larval supply will help ensure the stability of recruitment dynamics and minimize the volatility in fishery catches.

Natal philopatry increases relatedness within groups of coral reef cardinalfish.

A central issue in evolutionary ecology is how patterns of dispersal influence patterns of relatedness in populations. In terrestrial organisms, limited dispersal of offspring leads to groups of related individuals. By contrast, for most marine organisms, larval dispersal in open waters is thought to minimize kin associations within populations.

Strong habitat and weak genetic effects shape the lifetime reproductive success in a wild clownfish population.

The relative contributions of environmental, maternal and additive genetic factors to the Lifetime reproductive success (LRS) determine whether species can adapt to rapid environmental change. Yet to date, studies quantifying LRS across multiple generations in marine species in the wild are non-existent. Here we used 10-year pedigrees resolved for a wild orange clownfish population from Kimbe Island (PNG) and a quantitative genetic linear mixed model approach to quantify the additive genetic, maternal and environmental contributions to variation in LRS for the self-recruiting portion of the population.

Successful validation of a larval dispersal model using genetic parentage data.

Larval dispersal is a critically important yet enigmatic process in marine ecology, evolution, and conservation. Determining the distance and direction that tiny larvae travel in the open ocean continues to be a challenge. Our current understanding of larval dispersal patterns at management-relevant scales is principally and separately informed by genetic parentage data and biological-oceanographic (biophysical) models.

Extra-pair mating in a socially monogamous and paternal mouth-brooding cardinalfish.

Many vertebrates form monogamous pairs to mate and care for their offspring. However, genetic tools have increasingly shown that offspring often arise from matings outside of the monogamous pair bond. Social monogamy is relatively common in coral reef fishes, but there have been few studies that have confirmed monogamy or extra-pair reproduction, either for males or for females.

Marine reserves stabilize fish populations and fisheries yields in disturbed coral reef systems.

Marine reserve networks are increasingly implemented to conserve biodiversity and enhance the persistence and resilience of exploited species and ecosystems. However, the efficacy of marine reserve networks in frequently disturbed systems, such as coral reefs, has rarely been evaluated. Here we analyze a well-mixed larval pool model and a spatially explicit model based on a well-documented coral trout (Plectropomus spp.

Assessing the performance of artificial reefs as substitute habitat for temperate reef fishes: Implications for reef design and placement.

Artificial reefs (ARs) have been advocated and implemented as management tools for recreational fisheries, species conservation and habitat replacement. For ARs to function as substitute habitat for degraded natural reefs, they should perform as close as possible to local natural reefs, however this is seldom investigated. Here we evaluated the performance of new custom-designed reef structures (CDARs) as fish habitat.

Host anemone size as a determinant of social group size and structure in the orange clownfish ().

The size and structure of social groups of animals can be governed by a range of ecological factors and behavioral interactions. In small, highly site-attached coral reef fishes, group size is often constrained by the size of the habitat patch they are restricted to. However, group size may also be influenced by changes in abundance along important environmental gradients, such as depth or distance offshore.

Marginal sinks or potential refuges? Costs and benefits for coral-obligate reef fishes at deep range margins.

Escalating climate-related disturbances and asymmetric habitat losses will increasingly result in species living in more marginal habitats. Marginal habitats may represent important refuges if individuals can acquire adequate resources to survive and reproduce. However, resources at range margins are often distributed more sparsely; therefore, increased effort to acquire resources can result in suboptimal performance and lead to marginal populations becoming non-self-sustaining sink-populations.

Strong effects of coral species on the diversity and structure of reef fish communities: A multi-scale analysis.

While there is increasing evidence for habitat specialization in coral reef fishes, the extent to which different corals support different fish communities is not well understood. Here we quantitatively assess the relative importance of different coral species in structuring fish communities and evaluate whether sampling scale and coral colony size affect the perceived strength of fish-habitat relationships. Fish communities present on colonies of eight coral species (Porites cylindrica, Echinopora horrida, Hydnophora rigida, Stylophora pistillata, Seriatopora hystrix, Acropora formosa, A.

Loss of live coral compromises predator-avoidance behaviour in coral reef damselfish.

Tropical reefs have experienced an unprecedented loss of live coral in the past few decades and the biodiversity of coral-dependent species is under threat. Many reef fish species decline in abundance as coral cover is lost, yet the mechanisms responsible for these losses are largely unknown. A commonly hypothesised cause of fish decline is the loss of shelter space between branches as dead corals become overgrown by algae.

Site fidelity facilitates pair formation in aggregations of coral reef cardinalfish.

Colonial animals often form stable pair bonds, returning to the same site to breed with the same partner every year. Familiarity with both partner and breeding site has the potential to enhance an individual's reproductive success. However, it is often unknown whether the mating system arises because of site fidelity, mate fidelity or both.