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The complexity of tropical reef habitats affects the occurrence and diversity of the organisms residing in these ecosystems. Quantifying this complexity is important to better understand and monitor reef community assemblages and their roles in providing ecological services. This study employed structure-from-motion photogrammetry to produce accurate 3D reconstructions of eight reefs in Guam and quantified the structural complexity of these sites using seven terrain metrics: rugosity, slope, vector ruggedness measure (VRM), multiscale roughness (magnitude and scale), plan curvature, and profile curvature. The relationships between terrain complexity, benthic community diversity, and coral cover were investigated with generalized linear models. While the average structural complexity metrics did not differ between most sites, there was significant variation within sites. All surveyed transects exhibited high structural complexity, with an average rugosity of 2.28 and an average slope of 43 degrees. Benthic diversity was significantly correlated with the roughness magnitude. Coral cover was significantly correlated with slope, roughness magnitude, and VRM. This study is among the first to employ this methodology in Guam and provides additional insight into the structural complexity of Guam's reefs, which can become an important component of holistic reef assessments in the future. [ABSTRACT FROM AUTHOR]

Past environmental changes are expected to have profoundly impacted diversity dynamics through time. While some previous studies showed an association between past climate changes or tectonic events and important shifts in lineage diversification, it is only recently that past environmental changes have been explicitly integrated in diversification models to test their influence on diversification rates. Here, we used a global reconstruction of tropical reef habitat dynamics during the Cenozoic and phylogenetic diversification models to test the influence of (i) major geological events, (ii) reef habitat fragmentation and (iii) reef area on the diversification of 9 major clades of tropical reef fish (Acanthuridae, Balistoidea, Carangoidea, Chaetodontidae, Haemulinae, Holocentridae, Labridae, Pomacentridae and Sparidae). The diversification models revealed a weak association between paleo-habitat changes and diversification dynamics. Specifically, the fragmentation of tropical reef habitats over the Cenozoic was found to be a driver of tropical reef fish diversification for 2 clades. However, overall, our approach did not allow the identification of striking associations between diversification dynamics and paleo-habitat fragmentation in contrast with theoretical model's predictions. [ABSTRACT FROM AUTHOR]

Green turtles are megaherbivores with a key role in the dynamics of tropical seagrass meadows, but little is known about their relevance as herbivores in tropical reef habitats. We conducted underwater censuses of green turtles, herbivorous fishes and sea urchins in two distinct tropical regions: Fernando de Noronha (Western Atlantic Ocean) and the Hawaiian Archipelago (Central Pacific Ocean), to assess the contribution of green turtles to the total herbivore biomass in shallow reef habitats of tropical oceanic islands. Juvenile green turtles ranging 40–60 cm were observed at most of the surveyed sites, and hence, could be considered typical components of the shallow reef fauna of tropical oceanic islands. Furthermore, they were usually one of the most abundant species of roving herbivores in many of the sites surveyed. However, the biomass of green turtles was usually much lower than the aggregated biomass of fishes or sea urchins, which usually constituted most of the total herbivore biomass. Green turtles made a major contribution to the total herbivore biomass only in sheltered sites with low rugosity, low coral cover and high algal cover. Further investigation on the trophic redundancy between herbivores is required to assess the actual relevance of green turtles in reef ecosystems of oceanic islands, compared to herbivorous fishes and sea urchins, because different herbivores may target different algal resources and complementarity may be needed to maintain ecosystem functioning across large, naturally varied reefscapes. [ABSTRACT FROM AUTHOR]

Background We have a limited understanding of genomic interactions that occur among partners for many symbioses. One of the most important symbioses in tropical reef habitats involves Symbiodinium. Most work examining Symbiodinium-host interactions involves cnidarian partners. To fully and broadly understand the conditions that permit Symbiodinium to procure intracellular residency, we must explore hosts from different taxa to help uncover universal cellular and genetic strategies for invading and persisting in host cells. Here, we present data from gene expression analyses involving the bioeroding sponge Cliona varians that harbors Clade G Symbiodinium. Results Patterns of differential gene expression from distinct symbiont states ("normal", "reinfected", and "aposymbiotic") of the sponge host are presented based on two comparative approaches (transcriptome sequencing and suppressive subtractive hybridization (SSH)). Transcriptomic profiles were different when reinfected tissue was compared to normal and aposymbiotic tissue. We characterized a set of 40 genes drawn from a pool of differentially expressed genes in "reinfected" tissue compared to "aposymbiotic" tissue via SSH. As proof of concept, we determined whether some of the differentially expressed genes identified above could be monitored in sponges grown under ecologically realistic field conditions. We allowed aposymbiotic sponge tissue to become re-populated by natural pools of Symbiodinium in shallow water flats in the Florida Keys, and we analyzed gene expression profiles for two genes found to be increased in expression in "reinfected" tissue in both the transcriptome and via SSH. These experiments highlighted the experimental tractability of C. varians to explore with precision the genetic events that occur upon establishment of the symbiosis. We briefly discuss lab- and field-based experimental approaches that promise to offer insights into the co-opted genetic networks that may modulate uptake and regulation of Symbiondinium populations in hospite. Conclusions This work provides a sponge transcriptome, and a database of putative genes and genetic pathways that may be involved in Symbiodinium interactions. The relative patterns of gene expression observed in these experiments will need to be evaluated on a gene-by-gene basis in controlled and natural re-infection experiments. We argue that sponges offer particularly useful characteristics for discerning essential dimensions of the Symbiodinium niche. [ABSTRACT FROM AUTHOR]

This article discusses learning that occurred during primary school visits to the UK National Marine Aquarium (Aquarium). Before visiting, children were asked to independently create a drawing of marine life off the Devon coast and a drawing of tropical reef marine life, allowing an assessment of prior knowledge. Post-visit, children created another drawing, with changes between the drawings indicating the degree of learning. Visiting children participated in the Aquarium's guided learning programmes, and children were observed to assess engagement and the contribution of provided information to post-visit drawings. Pre-visit drawings showed limited knowledge of local underwater habitats and less knowledge of tropical reef habitats. However, the comparison of post-visit drawings to pre-visit drawings showed that significant informal learning had occurred as a result of participating in a guided visit, demonstrating that the informal science programme at the Aquarium achieves the goal of enhancing knowledge and understanding of marine habitats. [ABSTRACT FROM PUBLISHER]

Objective: This paper highlights the complexity of marine fish spawner–recruit systems and how they vary across species and ecosystems while providing a universal terminology and framework to evaluate fish reproduction. We emphasize the gonadal development important to assess maturity, fecundity, where and when fish spawn, and transition and sex assignment in protogynous species. Methods: We review and compare reproductive traits in warmwater and coldwater fishes. Reproductive phases for both sexes and protogynous species are defined and histological micrographs presented. New methods are developed to assess maturity; spawning seasonality; peak spawning; and, for protogynous species, sex assignment. Result: Protogyny, extended spawning seasons, and indeterminate fecundity are more common in warmwater than coldwater systems. The following reproductive phases are defined as immature, transitional (sex change), early developing (the first stage of entrainment in the reproductive cycle), late developing (stages needed to complete maturational competence), spawning, regressing (spawning season termination), and regenerating (fish that are mature but outside of the spawning season). A method to assess the certainty of maturity assignment based on reproductive phase and the age and size range sampled is presented, as are best practices to estimate size and age at maturity. To remove the subjectivity from current methods to estimate spawning seasonality, we present a new quantitative method to identify the core spawning season and peak spawning months. Conclusion: A species' ability to adapt to fishing and climate change varies with their reproductive strategy. Improving our understanding of fish reproduction necessitates standardizing methodology and terminology. Impact statementWe demonstrate the complexity of fish reproductive strategies and how reproductive traits are species‐specific and differ between warmwater and coldwater systems, affecting population productivity. We present a unified framework and terminology to describe fish reproduction and new methods to assess key reproductive parameters. [ABSTRACT FROM AUTHOR]

The article presents a study of the role of herbivorous fishes in the families Acanthuridae or surgeonfishes and Scaridae or parrotfishes in the determination of the distributions and abundances of benthic species in tropical reef habitats in the Caribbean sea. Results demonstrate the significant influence of herbivorous fish on benthic species distributions and abundances within a number of tropical reef habitats.

Tropical reef communities contain spatial patterns at multiple scales, observable from microscope and satellite alike. Many of the smaller-scale patterns are generated physiologically (e.g., skeletal structures of corals at <1-m scale), while some of the larger patterns have been attributed to scale-dependent feedbacks (e.g., spur and groove reefs at 10–100-m scales). In describing the spatial patterning of reef benthic communities at landscape levels, we uncovered unique spatial patterning among living marine algae. Populations of the calcifying green alga Halimeda were observed to form a consistent polygonal pattern at a characteristic scale of 3–4 m. The pattern showed no clear evidence of having been formed through biologically created shifts in hydrodynamical conditions or related mechanisms. In considering the specifics of Halimeda growth patterns, a model of self-organization involving separation and patterned extension is proposed, a mechanism revealed in some geological pattern formation. This observation reinforces the diversity of pathways by which striking spatial patterns can occur in ecosystems. [ABSTRACT FROM AUTHOR]

Large gaps in reef distribution may hinder the dispersal of marine organisms, interrupting processes vital to the maintenance of biodiversity. Here we show the presence and location of extensive reef habitats on the continental shelf between the Amazon Reef System (ARS) and the Eastern Brazilian Reef System (ERS), two reef complexes off eastern South America. Formations located 20–50 m deep include both biogenic and geogenic structures. The presence of diverse reef assemblages suggests the widespread occurrence of rocky substrates below 50 m. These habitats represent an expansion of both the ARS and ERS and the closure of the only remaining large-scale gap (~ 1000 km) among West Atlantic reef environments. This indicates that the SW Atlantic harbors a single, yet heterogeneous, reef system that stretches for about 4000 km, and thus, represents one of the largest semi-continuous tropical marine ecosystems in the world. [ABSTRACT FROM AUTHOR]

Latitude and body size are generally considered key drivers of swimming performance for larval marine fishes, but evidence suggests that evolutionary relationships and habitat may also be important. We used a comparative phylogenetic framework, data synthesis and case study approach to investigate how swimming performance differs among larvae of fish species across latitude. First, we investigated how swimming performance changed with body length, and we found that temperate reef fishes have the greatest increases in swimming performance with length. Secondly, we compared differences in three swimming performance metrics (critical swimming speed, in situ swimming, and endurance) among post‐flexion larvae, whilst considering phylogenetic relationships and morphology, and we found that reef fishes have higher swimming capacity than non‐reef (pelagic and non‐reef demersal) fishes, which is likely due to larger, more robust body sizes. Thirdly, we compared swimming performance of late‐stage larvae of tropical fishes with oceanographic data to better understand the ecological relevance of their high‐capacity swimming. We found that reef fishes have high swimming performance and grow larger than non‐reef fish larvae, which we suggest is due to the pressures to find a specific, patchily distributed habitat upon which to settle. Given the current bias towards studies on percomorph fishes at low latitudes, we highlight that there is a need for more research on temperate reef fish larvae and other percomorph lineages from high latitudes. Overall, our findings provide valuable context to understand how swimming and morphological traits that are important for dispersal and recruitment processes are selected for among teleost fish larvae. [ABSTRACT FROM AUTHOR]

Sharks embody several major aspects of modern marine management: they are traditionally antagonized, exploited or by‐caught by humans, typically vulnerable to extirpation, pursued as luxury food, yet valued as wildlife and essential as top‐down regulators in marine food webs. Due to their generally large size, elusiveness, high mobility, and potentially dangerous nature, elasmobranchs pose substantial technical challenges to biodiversity monitoring, which prompted recent efforts to harness the power of environmental DNA (eDNA) as a noninvasive survey method for these taxa. Here we deployed an elasmobranch‐specific metabarcoding assay to characterize shark and ray diversity around Reunion Island, during the austral summer, detecting at least 14 species and a strong overall correlation between frequency of species detection and read abundance. Over 90% of sequence reads belonged to three large predators: scalloped hammerhead (Sphyrna lewini), tiger shark (Galeocerdo cuvier) and bull shark (Carcharhinus leucas). While the importance of tiger and bull sharks is well established in Reunion Island, and a major focus of the local shark control program, the prevalence and abundance of scalloped hammerhead has so far been grossly neglected. We also confirm the absence of typical "tropical reef sharks" around the island and reveal an important temporal fluctuation in tiger shark during the study period. Collectively, results show how eDNA can help circumvent barriers, bias and drawbacks associated with monitoring shark populations using visual and capture‐based techniques, and generate spatial and temporal biodiversity data on these species for rapid consideration by marine environmental managers. [ABSTRACT FROM AUTHOR]

Few studies have considered linkages of mobile predators across large spatial scales despite their significant and often critical role in maintaining ecosystem function and health. The bull shark (Carcharhinus leucas) is a large, widespread coastal predator capable of undertaking long-range movement, but there is still limited understanding of intra-regional differences in movement and habitat connectivity across latitudes within the same coastline. This study used acoustic telemetry data and network analyses to investigate long-range movements, residency patterns and seasonal habitat linkages of sub-adult and adult C. leucas along the east coast of Australia. Our results revealed that C. leucas tagged in Sydney Harbour were mainly present within this temperate estuary in summer and autumn; the rest of the year individuals were detected in tropical and subtropical habitats from southern and central Queensland. In contrast, the detection probability of C. leucas tagged in the Townsville Reefs (central Great Barrier Reef) peaked in spring, with a portion of the tagged population migrating south during the summer months. Differences in residency time between tagging locations were also detected, as all C. leucas tagged in Sydney Harbour were absent between June and November, but 35% of the tropical-reef tagged population remained resident year-round. Network analyses complemented these findings by revealing different seasonal habitat use between regions, thus highlighting complex seasonal-habitat linkages of C. leucas along the coast. Our findings support the hypothesis that the timing, duration, and drivers involved in the long-range movements and connectivity of sub-adult and adult C. leucas vary between latitudinal regions, most likely driven by the interaction between seasonal temperature changes, foraging and reproduction. [ABSTRACT FROM AUTHOR]

Species of the marine red algal family Gracilariaceae are distributed in tropical and warm temperate waters of the world where they are harvested for their agar content. In the Philippines, the level of exploitation of these species is low despite their high diversity and potentially large harvestable biomass. A taxonomic survey of the Gracilariaceae was conducted along the western corridor of Macajalar Bay in northern Mindanao for the first time. Six common species were found in three sampling sites. The findings of this study will contribute to the baseline marine biodiversity information, can promote the use of the various species among coastal inhabitants, and provide guidance towards better policy formulation for more effective resource management. [ABSTRACT FROM AUTHOR]

Recently, observations of black spot syndrome (BSS) in Caribbean fishes have been linked to infection by a digenean trematode parasite, Scaphanocephalus expansus. Recently, This study examined the distribution of BSS over multiple spatial and temporal scales: at the island scale in Bonaire, Dutch Caribbean, using field surveys of 4885 fish belonging to three species, and across the wider Caribbean through analysis of 2112 images from Google Images searches (1985–2013). The field surveys in Bonaire indicated that the prevalence (% of individuals affected with BSS) and intensity (severity of BSS measured in 3 stages) were highest in Acanthurus tractus (prevalence 61.8%, including 30.1% in stage 3) followed by Sparisoma aurofrenatum (prevalence 48.3%, 24.1% in stage 3) and lowest in Caranx ruber (prevalence 38.5%, 3.3% in stage 3). Prevalence and intensity of BSS decreased significantly with survey depth (e.g., 2 m: prevalence 68.0%, 22.0% in stage 3; 18 m: prevalence 36.2%, 4.0% in stage 3) and were significantly lower in 2012 than in 2017 (prevalence: 59.3% in 2012, 68.7% in 2017; stage 3: 16.3% in 2012, 25.1% in 2017). The Southeast of Bonaire had significantly lower prevalence of BSS (16.4%) than the other four regions and lower intensity (11.7% in stage 3) than all regions but the Southwest. The Google Images searches querying for ocean surgeonfish, A. tractus and A. bahianus, identified pictures from 26 wider Caribbean locations; BSS was detected in 14 locations of which 13 were new, with the first detection dating back to 1985 in Bonaire. The Southern Caribbean had significantly higher prevalence of BSS (78.1%) than other ecoregions (0–34.6%), and Bonaire was identified as a hotspot, highlighting the utility of mining websites for archival imagery to quantify spatial and temporal patterns in disease phenomena. This study demonstrates how visible signs of parasite infection can be used to find differences in parasite prevalence and loads on a reef, island and sea scale. [ABSTRACT FROM AUTHOR]

We develop a spatially explicit model of diversification based on palaeohabitat to explore the predictions of four major hypotheses potentially explaining the latitudinal diversity gradient (LDG), namely, the ‘time-area’, ‘tropical niche conservatism’, ‘ecological limits’ and ‘evolutionary speed’ hypotheses. We compare simulation outputs to observed diversity gradients in the global reef fish fauna. Our simulations show that these hypotheses are non-mutually exclusive and that their relative influence depends on the time scale considered. Simulations suggest that reef habitat dynamics produced the LDG during deep geological time, while ecological constraints shaped the modern LDG, with a strong influence of the reduction in the latitudinal extent of tropical reefs during the Neogene. Overall, this study illustrates how mechanistic models in ecology and evolution can provide a temporal and spatial understanding of the role of speciation, extinction and dispersal in generating biodiversity patterns. [ABSTRACT FROM AUTHOR]

Aim: Herbivorous reef fishes are considered to have difficulty digesting plant material at extratropical temperatures and are thus largely restricted to tropical waters where they are thought to have evolved. However, the herbivorous Kyphosidae, with both temperate and tropical species, provides an ideal opportunity to test this view. Previous studies have resolved the taxonomy and distribution patterns of all species. Here, we use a calibrated phylogeny to analyse the age, geographical origin and pattern of diversification of kyphosids to determine their origins in space and time, and thus refine hypotheses on the evolutionary origins of herbivory in reef fishes. Location: Pacific Ocean, Atlantic Ocean, Indian Ocean, Western Australia. Methods: The age and geographic origin of Kyphosidae were determined by incorporating fossil calibrations and species distributions onto a phylogeny of all extant species based on fragments from mitochondrial markers and three nuclear markers, and using Bayesian modelling to reconstruct ancestral distributions. Evolution of both diet and tooth shape was also examined using ancestral reconstruction. Results: Ancestral reconstruction suggested a subtropical, Southern Hemisphere Indo‐Pacific origin for the family. The chronogram indicates that Kyphosus originated in the early Miocene and that tropical diversity reflects very recent diversification. Main conclusions: Contrary to the general perception that herbivorous reef fishes invaded high latitudes from the tropics, herbivorous kyphosids evolved at intermediate latitudes in the Southern Hemisphere and subsequently diversified into low latitudes where several species dispersed recently to achieve circumglobal distributions. The southern temperate/subtropical reef environment appears to have generated episodes of diversification in several, well‐established, widespread reef fish taxa. Some of these reef fish taxa have remained restricted to southern temperate reef environments despite a long tenure in the Cenozoic (e.g. odacines and aplodactylids), and some such as the kyphosids which diversified very recently in both hemispheres resulting in both regional endemics and species with worldwide distributions. [ABSTRACT FROM AUTHOR]

Members of an ecological guild may be anticipated to show morphological convergence, as similar functional demands exert similar selective pressures on phenotypes. Nature is rife with examples, however, where such taxa instead exhibit 'incomplete' convergence or even divergence. Incorporating factors such as character displacement by other guild members or variation in ecological specialization itself may therefore be necessary to gain a more complete understanding of what constrains or promotes diversity. Cleaning, a behavior in which species remove and consume ectoparasites from "clientele," has been shown to exhibit variation in specialization and has evolved in a variety of marine habitats around the globe. To determine the extent to which specialization in this tropic strategy has affected phenotypic evolution, we examined the evolution of cleaning behavior in five marine fish families: Labridae, Gobiidae, Pomacanthidae, Pomacentridae, and Embiotocidae. We used a comparative framework to determine patterns of convergence and divergence in body shape and size across non-cleaning and cleaning members within these five clades. Highly specialized obligate cleaning, found in the Indo-Pacific and the Caribbean, evolved in the Labridae and Gobiidae at strikingly similar times. In these two regions, obligate cleaning evolves early, shows convergence on an elongate body shape, and is restricted to species of small body size. Facultative cleaning, shown either throughout ontogeny or predominately in the juvenile phase, exhibits a much more varied phenotype, especially in geographic regions where obligate cleaning occurs. Collectively, our results are consistent with varying extents of an ecological specialization constraining or spurring morphological evolution in recurrent ways across regions. [ABSTRACT FROM AUTHOR]

Despite a very strong El Niño Southern Oscillation in 2015/2016, no coral mortality associated with bleaching was observed at the northern Galapagos (Ecuador) Islands of Darwin and Wolf. From March 2016 to March 2018, coral cover and health as well as water chemistry (NO3− and PO43−) and temperature were recorded. A marked heat anomaly reached 30 °C at Wolf in February 2016, but peak temperatures were attenuated after 2 d by a 4 °C drop. Temperature patterns at three depths (10, 15, and 20 m) and a subsequent and persistent phytoplankton bloom suggest topographically driven upwelling as the source of colder water and dissolved inorganic nutrients—both of which helped corals endure the heating episode. Consequently, no mortality and only partial bleaching were recorded in March 2016. Partially bleached corals contained numerous healthy zooxanthellae in deeper tissue layers. A continuous temperature record from 2012 to 2014 suggests that such upwelling events are common, inducing temperature fluctuations of up to 6 °C within 24 h during the observation period. Events at Wolf in 2016 suggest local upwelling reduced coral stress by relieving heat and by delivering nutrients required by corals to retain their regular temperature tolerance. [ABSTRACT FROM AUTHOR]

Tropical reefs have been subjected to a range of anthropogenic pressures such as global climate change, overfishing and eutrophication that have raised questions about the prominence of macroalgae on tropical reefs, whether they pose a threat to biodiversity, and how they may influence the function of tropical marine ecosystems.We synthesise current understanding of the structure and function of tropical macroalgal reefs and how they may support various ecosystem goods and services. We then forecast how key stressors may alter the role of macroalgal reefs in tropical seascapes of the Anthropocene.High levels of primary productivity from tropical canopy macroalgae, which rivals that of other key producers (e.g., corals and turf algae), can be widely dispersed across tropical seascapes to provide a boost of secondary productivity in a range of biomes that include coral reefs, and support periodic harvests of macroalgal biomass for industrial and agricultural uses. Complex macroalgal reefs that comprise a mixture of canopy and understorey taxa can also provide key habitats for a diverse community of epifauna, as well as juvenile and adult fishes that are the basis for important tropical fisheries.Key macroalgal taxa (e.g., Sargassum) that form complex macroalgal reefs are likely to be sensitive to future climate change. Increases in maximum sea temperature, in particular, could depress biomass production and/or drive phenological shifts in canopy formation that will affect their capacity to support tropical marine ecosystems.Macroalgal reefs can support a suite of tropical marine ecosystem functions when embedded within an interconnected mosaic of habitat types. Habitat connectivity is, therefore, essential if we are to maintain tropical marine biodiversity alongside key ecosystem goods and services. Consequently, complex macroalgal reefs should be treated as a key ecological asset in strategies for the conservation and management of diverse tropical seascapes. A plain language summary is available for this article. [ABSTRACT FROM AUTHOR]

ABSTRACT: Teleost fishes are the most diverse group of vertebrates on Earth. On tropical coral reefs, their species richness exceeds 6000 species; one tenth of total vertebrate biodiversity. A large proportion of this diversity is composed of cryptobenthic reef fishes (CRFs): bottom‐dwelling, morphologically or behaviourally cryptic species typically less than 50 mm in length. Yet, despite their diversity and abundance, these fishes are both poorly defined and understood. Herein we provide a new quantitative definition and synthesise current knowledge on the diversity, distribution and life history of CRFs. First, we use size distributions within families to define 17 core CRF families as characterised by the high prevalence (>10%) of small‐bodied species (<50 mm). This stands in strong contrast to 42 families of large reef fishes, in which virtually no small‐bodied species have evolved. We posit that small body size has allowed CRFs to diversify at extremely high rates, primarily by allowing for fine partitioning of microhabitats and facilitation of allopatric reproductive isolation; yet, we are far from understanding and documenting the biodiversity of CRFs. Using rates of description since 1758, we predict that approximately 30 new species of cryptobenthic species will be described per year until 2050 (approximately twice the annual rate compared to large fishes). Furthermore, we predict that by the year 2031, more than half of the described coral reef fish biodiversity will consist of CRFs. These fishes are the ‘hidden half’ of vertebrate biodiversity on coral reefs. Notably, global geographic coverage and spatial resolution of quantitative data on CRF communities is uniformly poor, which further emphasises the remarkable reservoir of biodiversity that is yet to be discovered. Although small body size may have enabled extensive diversification within CRF families, small size also comes with a suite of ecological challenges that affect fishes' capacities to feed, survive and reproduce; we identify a range of life‐history adaptations that have enabled CRFs to overcome these limitations. In turn, these adaptations bestow a unique socio‐ecological role on CRFs, which includes a key role in coral reef trophodynamics by cycling trophic energy provided by microscopic prey to larger consumers. Although small in body size, the ecology and evolutionary history of CRFs may make them a critical component of coral‐reef food webs; yet our review also shows that these fishes are highly susceptible to a variety of anthropogenic disturbances. Understanding the consequences of these changes for CRFs and coral reef ecosystems will require us to shed more light on this frequently overlooked but highly diverse and abundant guild of coral reef fishes. [ABSTRACT FROM AUTHOR]

An essential suite of coral reef ecosystem engineers is coralline red algae. Among these, the smooth, encrusting Porolithon onkodes has historically been considered the most important and common reef building species worldwide. We assess P. onkodes biodiversity by performing a genomic analysis of the lectotype specimen collected in 1892 from the Tami Islands, Gulf of Huon, east of New Guinea. Comparisons of DNA sequences from the lectotype specimen to those deposited in GenBank and to newly generated sequences from both field‐collected and historical specimens demonstrate that at least 20 distinct species are passing under P. onkodes. We hypothesize that there were multiple evolutionary drivers including ecophysiology, hydrodynamic regimes, and biotic interactions as well as historical biogeography, which resulted in this high diversity of smooth, encrusting Porolithon species throughout the tropics. Our results emphasize the need to document the biodiversity, ecophysiology, and habitats of these tropical, reef‐building algae in light of climate change and ocean acidification. [ABSTRACT FROM AUTHOR]

Climate change and other anthropogenic disturbances are having dramatic impacts on tropical coral reefs and the ecosystem services they provide. Anticipating change in ecosystem services is a pressing challenge that requires understanding how species respond to an environmental change, and how they contribute to ecosystem services. Building on analogous efforts by plant ecologists, we propose a traitbased framework that aims to predict the resistance and recovery of coral ecosystem services against both pulse and press disturbances. The framework involves identifying effect, resistance, and recovery traits across coral species and using these to ascertain how species might (1) contribute to a service, (2) resist disturbance, and (3) recover after the disturbance. By identifying trait functional overlaps and quantifying correlations among the trait types, the framework can yield a better understanding of the potential mechanistic links between community assembly, ecosystem dynamics, and ecosystem functioning. We demonstrate the utility of the framework by applying it to a virtual scenario, implemented via simulation, in which habitat provisioning is the focal ecosystem service, and cyclones and bleaching events are the disturbances of interest. This demonstration required us to assemble an extensive dataset of relevant traits--a process that revealed key gaps in the coral trait database and in our understanding of coral functional ecology. The framework can provide predictive power for the resilience of ecosystem services and can also help identify crucial knowledge gaps, research objectives, and strategies for applying a trait-based approach to advancing coral reef science and conservation. [ABSTRACT FROM AUTHOR]

Abstract: Aim: The importance of quantifying the contribution of historical processes in shaping current biodiversity patterns is now recognized, but quantitative approaches that explicitly link speciation, extinction and dispersal processes to palaeo‐environmental changes are currently lacking. Here, we propose a spatial diversification model of lineages through time (SPLIT) based on the reconstruction of palaeo‐environments. We illustrate our approach using mangroves as a case study and evaluate whether habitat changes caused by plate tectonics explain the current biodiversity patterns of this group. Innovations: The SPLIT model allows one to simulate the evolutionary dynamics of species ranges by spatially linking speciation, extinction and dispersal processes to habitat changes over geological time periods. The SPLIT model provides a mechanistic expectation of speciation and extinction assuming that species are ecologically identical and not interacting. The likelihood of speciation and extinction is equivalent across species and depends on two dispersal parameters interacting with habitat dynamics (d a maximum dispersal distance and ds a distance threshold beyond which gene flow is absent). Beyond classical correlative approaches, this model tracks biodiversity dynamics under palaeo‐environmental changes and provides multiple expectations (i.e., α‐, β‐diversity, phylogenies) that can be compared to empirical patterns. Main conclusions: The SPLIT model allows a better understanding of the origin of biodiversity by explicitly accounting for habitat changes over geological times. The simulations applied to the mangrove case study reproduced the observed longitudinal gradient in species richness, the empirical pattern of β‐diversity and also provided inference on diversification rates. Future developments may include niche evolution and species interactions to evaluate the importance of non‐neutral mechanisms. The method is fully implemented in the InsideDNA platform for bioinformatics analyses, and all modelling results can be accessed via interactive web links. [ABSTRACT FROM AUTHOR]

The high diversity and distribution of Bathygobius Bleeker, 1878 makes it an excellent group to study evolution patterns within the Atlantic. Thus, the aims of this work were to investigate the taxonomic status, geographical distribution and evolutionary history of Bathygobius in the Atlantic and to examine the genetic structure and demographic and phylogeographic history of two species widely distributed in the Atlantic, Bathygobius soporator and Bathygobius geminatus. Our results indicate that a new insular species, Bathygobius brasiliensis sp. nov., can be found in the Western Atlantic, which diverged from its sister species, Bathygobius antilliensis, around 3.03 Mya [cytochrome c oxidase I (COI) d = 0.063; cytochrome b (cyt b) d = 0.074]. There are several old mitochondrial lineages and limited gene flow among major biogeographic provinces of both B. soporator and B. geminatus (COI: overall ΦST = 0.32, P < 0.05; overall ΦST = 0.31, P < 0.05, respectively). We discuss how the Atlantic biogeographical barriers appear to have influenced the formation of the sister species of Bathygobius, and we formulate hypotheses on how the intermittent nature of biogeographical barriers, coupled with the ecological and biological traits of species and ecological and hydrological characteristics of the provinces, shaped the genetic structure and phylogeography of B. soporator and B. geminatus. [ABSTRACT FROM AUTHOR]

Bacterial communities associated with marine invertebrates such as sponges and ascidians have demonstrated potential as sources of bio-medically relevant small molecules. Metagenomic analysis has shown that many of these invertebrates harbor populations of Actinobacteria, many of which are cultivable. While some populations within invertebrates are transmitted vertically, others are obtained from the environment. We hypothesized that cultivable diversity from sponges living in brackish mangrove habitats have associations with Actinobacterial populations that differ from those found in clear tropical waters. In this study, we analyzed the cultivable Actinobacterial populations from sponges found in these two distinct habitats with the aim of understanding the secondary metabolite potential. Importantly, we wanted to broadly evaluate the potential differences among these groups to guide future Actinobacterial collection strategies for the purposes of drug discovery. [ABSTRACT FROM AUTHOR]

Warming waters and changing ocean currents are increasing the supply of tropical fish larvae to temperature regions where they are exposed to novel habitats, namely temperate macroalgae and barren reefs. Here, we use underwater surveys on the temperate reefs of south-eastern (SE) Australia and western Japan (~33.5°N and S, respectively) to investigate how temperate macroalgal and non-macroalgal habitats influence recruitment success of a range of tropical fishes. We show that temperate macroalgae strongly affected recruitment of many tropical fish species in both regions and across three recruitment seasons in SE Australia. Densities and richness of recruiting tropical fishes, primarily planktivores and herbivores, were over seven times greater in non-macroalgal than macroalgal reef habitat. Species and trophic diversity ( K-dominance) were also greater in non-macroalgal habitat. Temperate macroalgal cover was a stronger predictor of tropical fish assemblages than temperate fish assemblages, reef rugosities or wave exposure. Tropical fish richness, diversity and density were greater on barren reef than on reef dominated by turfing algae. One common species, the neon damselfish ( Pomacentrus coelestis), chose non-macroalgal habitat over temperate macroalgae for settlement in an aquarium experiment. This study highlights that temperate macroalgae may partly account for spatial variation in recruitment success of many tropical fishes into higher latitudes. Hence, habitat composition of temperate reefs may need to be considered to accurately predict the geographic responses of many tropical fishes to climate change. [ABSTRACT FROM AUTHOR]

ABSTRACT Coral reefs are renowned for their spectacular biodiversity and the close links between fishes and corals. Despite extensive fossil records and common biogeographic histories, the evolution of these two key groups has rarely been considered together. We therefore examine recent advances in molecular phylogenetics and palaeoecology, and place the evolution of fishes and corals in a functional context. In critically reviewing the available fossil and phylogenetic evidence, we reveal a marked congruence in the evolution of the two groups. Despite one group consisting of swimming vertebrates and the other colonial symbiotic invertebrates, fishes and corals have remarkably similar evolutionary histories. In the Paleocene and Eocene [66-34 million years ago ( Ma)] most modern fish and coral families were present, and both were represented by a wide range of functional morphotypes. However, there is little evidence of diversification at this time. By contrast, in the Oligocene and Miocene (34-5.3 Ma), both groups exhibited rapid lineage diversification. There is also evidence of increasing reef area, occupation of new habitats, increasing coral cover, and potentially, increasing fish abundance. Functionally, the Oligocene- Miocene is marked by the appearance of new fish and coral taxa associated with high-turnover fast-growth ecosystems and the colonization of reef flats. It is in this period that the functional characteristics of modern coral reefs were established. Most species, however, only arose in the last 5.3 million years ( Myr; Plio- Pleistocene), with the average age of fish species being 5.3 Myr, and corals just 1.9 Myr. While these species are genetically distinct, phenotypic differences are often limited to variation in colour or minor morphological features. This suggests that the rapid increase in biodiversity during the last 5.3 Myr was not matched by changes in ecosystem function. For reef fishes, colour appears to be central to recent diversification. However, the presence of pigment patterns in the Eocene suggests that colour may not have driven recent diversification. Furthermore, the lack of functional changes in fishes or corals over the last 5 Myr raises questions over the role and importance of biodiversity in shaping the future of coral reefs. [ABSTRACT FROM AUTHOR]

As climate change continues to alter seawater temperature and chemistry on a global scale, coral reefs show multiple signs of degradation. One natural process that could facilitate the recovery of reef ecosystems is coral recruitment, which can be influenced by the benthic organisms in a local habitat. We experimentally tested both a global stressor (increased seawater temperature) and a local stressor (exposure to microcolin A, a natural product from a common marine benthic cyanobacterium) to determine how these stressors impacted coral larval sublethal stress, survival and settlement. Larvae of Porites astreoides had the same survival and settlement as the controls after exposure to increased temperature alone, but elevated temperature did cause oxidative stress. When exposed to natural concentrations of microcolin A, larval survival and settlement were significantly reduced. When larvae were exposed to these two stressors sequentially there was no interactive effect; but when exposed to both stressors simultaneously, there was a synergistic reduction in larval survival and an increase in oxidative stress more than in either stressor treatment alone. Increased seawater temperatures made larvae more susceptible to a concurrent local stressor disrupting a key process of coral reef recovery and resilience. These results highlight the importance of understanding how interactive stressors of varying spatial scales can impact coral demographics. [ABSTRACT FROM AUTHOR]

Subtropical reefs provide an important habitat for flora and fauna, and proper monitoring is required for conservation. Monitoring these exposed and submerged reefs is challenging and available resources are limited. Citizen science is increasing in momentum, as an applied research tool and in the variety of monitoring approaches adopted. This paper aims to demonstrate an ecological assessment and mapping approach that incorporates both top-down (volunteer marine scientists) and bottom-up (divers/community) engagement aspects of citizen science, applied at a subtropical reef at Point Lookout, Southeast Queensland, Australia. Marine scientists trained fifty citizen scientists in survey techniques that included mapping of habitat features, recording of substrate, fish and invertebrate composition, and quantifying impacts (e.g., occurrence of substrate damage, presence of litter). In 2014 these volunteers conducted four seasonal surveys along semi-permanent transects, at five sites, across three reefs. The project presented is a model on how citizen science can be conducted in a marine environment through collaboration of volunteer researchers, non-researchers and local marine authorities. Significant differences in coral and algal cover were observed among the three sites, while fluctuations in algal cover were also observed seasonally. Differences in fish assemblages were apparent among sites and seasons, with subtropical fish groups observed more commonly in colder seasons. The least physical damage occurred in the most exposed sites (Flat Rock) within the highly protected marine park zones. The broad range of data collected through this top-down/bottom-up approach to citizen science exemplifies the projects’ value and application for identifying ecosystem trends or patterns. The results of the project support natural resource and marine park management, providing a valuable contribution to existing scientific knowledge and the conservation of local reefs. [ABSTRACT FROM AUTHOR]

Plagioporus hageli n. sp. is described from the intestine of Oncorhynchus mykiss (Walbaum) collected from the River Yuba, California, USA. Of the accepted, nominal species of Plagioporus Stafford, 1904 from the Nearctic, the new species is morphologically similar to three intestinal species from the western USA parasitising diadromous fishes, including Plagioporus shawi (McIntosh, 1939), Plagioporus kolipinskii Tracey, Choudhury, Cheng & Ghosh, 2009 and Plagioporus siliculus Sinitsin, 1931, and is also similar to Plagioporus serotinus Stafford, 1904 from catostomids from eastern Canada. Plagioporus hageli n. sp. is distinguished from the former three species in lacking a dorsal vitelline field and from the latter species in having a consistent interruption in the distribution of the vitellarium at the level of the ventral sucker. The new species is also morphologically similar to an unnamed species of Plagioporus and a species misidentified as ' Plagioporus angusticolle' that were collected from California, but it is easily distinguished from both in its shorter body length. To estimate the placement of the new species within Plagioporus and within the Opecoelidae Ozaki, 1925, we conducted a Bayesian inference (BI) analysis of partial 28S rDNA sequence data that included sequences from Plagioporus hageli n. sp., five other species of Plagioporus, three species of Neoplagioporus Shimazu, 1990, including the type-species, Neoplagioporus zacconis (Yamaguti, 1934), two species of Urorchis Ozaki, 1927 (including the type-species, Urorchis goro Ozaki, 1927) and sequences of 42 opecoelid species obtained from GenBank. Our phylogenetic analysis revealed (i) plagioporines parasitising freshwater hosts form a monophyletic group; (ii) Plagiocirrus loboides Curran, Overstreet & Tkach, 2007 nested within the rest of the members of Plagioporus; (iii) the new species was closer to Plagiocirrus loboides than to Plagioporus shawi, the other salmonid parasite included in our analysis; (iv) P. shawi was the poorly supported sister to its congeners; (v) Neoplagioporus elongatus (Goto & Ozaki, 1930) Shimazu, 1990 was closer to the two species of Urorchis than to the other two species of Neoplagioporus; and (vi) the paraphyly of the Plagioporinae Manter, 1947 was reinforced. Based on 28S rDNA sequence data and our BI analysis, we propose Plagioporus loboides (Curran, Overstreet & Tkach, 2007) n. comb., and amend Plagioporus accordingly. This analysis represents the first phylogenetic study of the opecoelids that estimates the interrelationships of the Plagioporinae that includes a member of Plagioporus. [ABSTRACT FROM AUTHOR]

Understanding movement and connectivity of populations is increasingly important as human and climate change pressures become more pervasive, but can be problematic in difficult to observe species such as large marine predators. We examined the movements of bull sharks, Carcharhinus leucas, using acoustic telemetry arrays along the east coast of Australia. Approximately half of 75 individuals released in temperate waters moved into tropical reef regions, with both sexes undertaking long-range movements and multiple individuals making return trips. Only 3% of 39 individuals released in tropical reef habitats moved south to temperate waters, but approximately 25% moved to southern reef or subtropical coastal areas. These results reveal complex linkages along the east coast of Australia which suggest a tropical reef based population comprised of individuals that migrate to multiple regions. Connectivity between locations along the east coast of Australia creates important conservation challenges for resource managers in multiple jurisdictions.

Aim To combine a time-calibrated phylogeny with distributional, fossil and geomorphological data to infer the patterns of lineage origins and biogeography among gobies. Location Global marine areas (Indo-West Pacific, Western Indian Ocean, Mediterranean, Atlantic and Eastern Pacific) throughout the Cenozoic. Methods I inferred a molecular phylogeny using beast, simultaneously calibrating nodes for Gobiidae, Gobionellidae and their combined clade. I used that phylogeny, coupled with current range data, to reconstruct historical distributions with the R module BioGeo BEARS under both a dispersal, extinction and cladogenesis ( DEC) model and an augmented model including founder effect speciation ( DEC+J). I then compared model fits for placing the ancestral node of Gobiidae + Gobiidae at varying reef hotspots throughout the Cenozoic: the West Tethys (Mediterranean), Western Indian Ocean or Indo-West Pacific. Results Goby lineages arose over a 12-13 million year period in the late Eocene, followed by repeated invasions of the Eastern Pacific, Atlantic and Mediterranean from an ancestral Indo-West Pacific distribution. Optimization with DEC+J is preferred to DEC, but constraining the root of the phylogeny with a West Tethyan (Mediterranean) or Western Indian Ocean distribution does not result in significantly different model fits under DEC+J. Main conclusions In Gobiidae, several lineages migrated through the West Tethys to the Atlantic, followed by extinction in the Mediterranean. In contrast, lineages of Gobionellidae in the Mediterranean did not spread beyond the eastern North Atlantic. Gobionellidae invaded the Eastern Pacific by distinct routes in different lineages, either from the Caribbean through the open Isthmus of Panama or around the northern Pacific Rim. Eastern Pacific Gobiidae are younger and derived from tropical Atlantic clades. Although the reconstructed ancestral area of gobies is the Indo-West Pacific, fossils indicate that gobioids were present in the West Tethys region throughout the Oligocene and Miocene, including taxa that are not known from that area today. [ABSTRACT FROM AUTHOR]

Biodiversity patterns across the marine tropics have intrigued evolutionary biologists and ecologists alike. Tropical coral reefs host 1/3 of all marine species of fish on 0.1% of the ocean's surface. Yet our understanding of howmechanistic processes have underpinned the generation of this diversity is limited. However, it has become clear that the biogeographic history of the marine tropics has played an important role in shaping the diversity of tropical reef fishes we see today. In the last decade, molecular phylogenies and age estimation techniques have provided a temporal framework in which the ancestral biogeographic origins of reef fish lineages have been inferred, but few have included fully sampled phylogenies or made inferences at a global scale. We are currently at a point where new sequencing technologies are accelerating the reconstruction and the resolution of the FishTree of Life. How will a complete phylogeny of fishes benefit the study of biodiversity in the tropics? Here, I review the literature concerning the evolutionary history of reefassociated fishes from a biogeographic perspective. I summarize the major biogeographic and climatic events over the last 65 million years that have regionalized the tropical marine belt and what effect they have had on the molecular record of fishes and global biodiversity patterns. By examining recent phylogenetic trees of major reef associated groups, I identify gaps to be filled in order to obtain a clearer picture of the origins of coral reef fish assemblages. Finally, I discuss questions that remain to be answered and new approaches to uncover the mechanistic processes that underpin the evolution of biodiversity on coral reefs. [ABSTRACT FROM AUTHOR]

Molecular phylogenetic analyses based on plastid-encoded rbcL and mitochondrial cox3 gene sequences, in combination with morphological observations, revealed the existence of the following four bistratose Padina species previously unreported from Australian coasts: Padina calcarea Ni-Ni-Win, S.G.A. Draisma, W.F. Prudhomme van Reine & H. Kawai, characterised by its bright yelloworange inferior thallus surface and chalky white, heavily calcified superior surface, and the presence of hairlines only on the inferior surface; P. macrophylla Ni-Ni-Win, M. Uchimura & H. Kawai, characterised by a moderately calcified thallus with broad, depressed hairlines on the inferior surface and narrow, not depressed hairlines on the superior surface, those hairlines that are largely spaced on each surface; P. moffittiana I.A. Abbott & Huisman, characterised by lightly calcified thalli with narrow, slightly depressed hairlines that are distributed in alternate sequence between the two surfaces at unequal distances, and broad reproductive sori in one or two rows in the fertile zone; and P. okinawaensis Ni-Ni-Win, S. Arai, M. Uchimura & H. Kawai, characterised by heavily calcified thalli, except at the hairlines, which form an alternation of uncalcified furrows and calcified glabrous zones on the inferior surface. With the addition of these four species, 13 Padina species are known from Australia. [ABSTRACT FROM AUTHOR]

Species richness and abundance are biodiversity metrics widely used to describe and estimate changes in biodiversity. Studies of marine species richness and abundance typically focus on one, or just a few, taxa. Consequently, it is currently not possible to understand the performance of predictors of species richness and abundance across marine taxa. Using a taxonomically comprehensive dataset of twelve major taxa of flora and fauna from eight phyla sampled from the inter-reef seabed region of the Great Barrier Reef, Australia, we used boosted regression trees to test the performance of fourteen environmental and spatial predictors of species richness and abundance. Sediment composition predicted richness best for all taxa: gravel contributed up to 39% relative influence for one group and all taxa had low richness in muddy habitats. Sea surface temperature, seabed current shear stress, depth and latitude were also influential predictors for species richness for eight groups. Sediment was frequently an influential predictor for abundance also, while distance to domain (reef/coast) and longitude were relatively influential for six taxa. Within-site richness was correlated between nearly all pairs of taxa, as was within-site abundance, however ρ values were low. Overall, model performance was high, explaining up to 62% deviance of species richness, and 38% of abundance. Typically, deviance explained was greater for richness than abundance and may indicate that some drivers of species richness operate independently of any effects on species richness mediated by their effect on abundance. Deviance explained differed most between richness and abundance for bryozoans (23.3% difference) and soft corals (15.2% difference). While sediments were consistently the best predictors across all taxa, the inconsistent influence of all other predictors across taxonomic groups, as well as the low correlation of richness and abundance across taxonomic groups, cautions against predicting regional patterns of species richness and abundance from few taxa. [ABSTRACT FROM AUTHOR]

As the process of ocean acidification alters seawater carbon chemistry, physiological processes such as skeletal accretion are expected to become more difficult for calcifying organisms. The crustose coralline red algae ( Corallinales, Rhodophyta) form an important guild of calcifying primary producers in the temperate Northeast Pacific. The morphology of important ecological traits, namely, skeletal density and thallus thickness near the growing edge, was evaluated in Pseudolithophyllum muricatum ( Foslie) Steneck & R.T. Paine, the competitively dominant alga within this guild. P. muricatum shows a morphological response to increased ocean acidification in the temperate Northeast Pacific. Comparing historical (1981-1997) and modern (2012) samples from the field, crust thickness near the growing edge was approximately half as thick in modern samples compared with historical samples, while crust calcite density showed no significant change between the two sample groups. Morphological changes at the growing edge have important consequences for mediating competitive interactions within this guild of algae, and may affect the role of crustose coralline algal beds as hosts to infaunal communities and facilitators of recruitment in many invertebrate and macroalgal species. [ABSTRACT FROM AUTHOR]

Coral reefs are undergoing rapid changes as living corals give way to dead coral on which other benthic organisms grow. This decline in live coral could influence habitat availability for fish parasites with benthic life stages. Gnathiid isopod larvae live in the substratum and are common blood-feeding parasites of reef fishes. We examined substrate associations and preferences of a common Caribbean gnathiid, Gnathia marleyi. Emergence traps set over predominantly live coral substrata captured significantly fewer gnathiids than traps set over dead coral substrata. In laboratory experiments, gnathiids preferred dead coral and sponge and tended to avoid contact with live coral. When live gnathiids were added to containers with dead or live coral, significantly fewer were recovered from the latter after 24 h. Our data therefore suggest that live coral is not suitable microhabitat for parasitic gnathiid isopods and that a decrease in live coral cover increases available habitat for gnathiids. [ABSTRACT FROM AUTHOR]

Aim To use recently published phylogenies of three major reef fish families to explore global patterns of species origin and dispersal over the past 65 million years. The key questions are: when and where did reef fishes arise, and how has this shaped current biodiversity patterns? Location Biogeographic reconstructions were performed on globally distributed reef fish lineages. Patterns of lineage origination and dispersal were explored in five major biogeographic regions: the East Pacific, the Atlantic, the Indian Ocean, the Indo- Australian Archipelago hotspot, and the Central Pacific. Methods A dispersal, extinction and cladogenesis ( DEC) model implemented in Lagrange was used to infer the most likely biogeographic scenarios at nodes on chronograms of three diverse reef fish families ( Labridae, Pomacentridae, Chaetodontidae). For the terminal branches ANOVA was used to compare patterns of origination on a regional and global scale. Patterns of origination and dispersal were examined within discrete time periods for the five biogeographic regions. Results Temporal examination of hypothetical ancestral lineages reveal a pattern of increasing isolation of the East Pacific and Atlantic regions from the Eocene, and the changing role of the Indo- Australian Archipelago from a location of accumulating ranges in the Palaeo/ Eocene, a centre of origination in the Miocene, to extensive expansion of lineages into adjacent regions from the Pliocene to Recent. Main conclusions While the East Pacific and Atlantic have a history of isolation, the Indo- Australian Archipelago has a history of connectivity. It has sequentially and then simultaneously acted as a centre of accumulation ( Palaeocene/ Eocene onwards), survival ( Eocene/ Oligocene onwards), origin ( Miocene onwards), and export ( Pliocene/Recent) for reef fishes. The model suggests that it was the proliferation and expansion of lineages in the Indo- Australian Archipelago (the Coral Triangle) during the Miocene that underpinned the current biodiversity in the Indian and Pacific Oceans. [ABSTRACT FROM AUTHOR]

Presenting the science of global climate change is a challenge, particularly with the prevalence of climate denialism. Creative methods of communicating environmental science, such as visualizations, are needed to engage and inform the public. Art and science collaborations are therefore essential for climate change education. One such concept is Reefs on the Edge, an experimental hybrid between art and science that fuses marine biology, environmental science and multiple art forms to explore coral reef habitats and ecosystems threatened by the effects of climate change. Such cooperation encourages education, public discourse and critical discussion to promote conservation in changing climates. [ABSTRACT FROM AUTHOR]

The hypothesis that pelagic larval duration (PLD) influences range size in marine species with a benthic adult stage and a pelagic larval period is intuitively attractive; yet, studies conducted to date have failed to support it. A possibility for the lack of a relationship between PLD and range size may stem from the failure of past studies to account for the effect of species evolutionary ages, which may add to the dispersal capabilities of species. However, if dispersal over ecological (i.e. PLD) and across evolutionary (i.e. species evolutionary age) time scales continues to show no effect on range size then an outstanding question is why? Here we collected data on PLD, evolutionary ages and range sizes of seven tropical fish families (five families were reef-associated and two have dwell demersal habitats) to explore the independent and interactive effects of PLD and evolutionary age on range size. Separate analyses on each family showed that even after controlling for evolutionary age, PLD has an insignificant or a very small effect on range size. To shed light on why dispersal has such a limited effect on range size, we developed a global ocean circulation model to quantify the connectivity among tropical reefs relative to the potential dispersal conferred by PLD. We found that although there are several areas of great isolation in the tropical oceans, most reef habitats are within the reach of most species given their PLDs. These results suggest that the lack of habitat isolation can potentially render the constraining effect of dispersal on range size insignificant and explain why dispersal does not relate to range size in reef fishes. [ABSTRACT FROM AUTHOR]

Black band disease (BBD) of corals is a cyanobacteria-dominated polymicrobial disease that contains diverse populations of heterotrophic bacteria. It is one of the most destructive of coral diseases and is found globally on tropical and sub-tropical reefs. We assessed ten strains of BBD cyanobacteria, and ten strains of cyanobacteria isolated from other marine sources, for their antibacterial effect on growth of heterotrophic bacteria isolated from BBD, from the surface mucopolysaccharide layer (SML) of healthy corals, and three known bacterial coral pathogens. Assays were conducted using two methods: co-cultivation of cyanobacterial and bacterial isolates, and exposure of test bacteria to (hydrophilic and lipophilic) cyanobacterial cell extracts. During co-cultivation, 15 of the 20 cyanobacterial strains tested had antibacterial activity against at least one of the test bacterial strains. Inhibition was significantly higher for BBD cyanobacteria when compared to other marine cyanobacteria. Lipophilic extracts were more active than co-cultivation (extracts of 18 of the 20 strains were active) while hydrophilic extracts had very limited activity. In some cases co-cultivation resulted in stimulation of BBD and SML bacterial growth. Our results suggest that BBD cyanobacteria are involved in structuring the complex polymicrobial BBD microbial community by production of antimicrobial compounds. [ABSTRACT FROM AUTHOR]

Thirty-two species of cheilostomate Bryozoa are described and illustrated from 26 stations sampled by the United States Antarctic Research Program, including 29 new species and two new genera. A further new genus is introduced for two species formerly attributed to Osthimosia Jullien, 1888. One station was located in the Ross Sea and three in the cold temperate South Pacific; 14 stations were sampled in the region of the Scotia Arc, south of the Antarctic Convergence, and eight from the subantarctic southwest Atlantic, mostly in the vicinity of Tierra del Fuego. Nine new species were present in the Antarctic samples, whereas those from the southwest Atlantic yielded 18 new species and the two new genera. Three of the new subantarctic species are attributed to genera formerly considered to be Antarctic endemics, while the two newly assigned species of Osthimosia are presently known only from Antarctic localities. [ABSTRACT FROM AUTHOR]