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The Amazon basin, spanning approximately 540,000 km2, exhibits distinct fluviometric surfaces that differentiate between the dry and rainy seasons. This seasonality, along with hydrological connectivity and the creation of new habitats during the rainy season, significantly promotes the migration, reproduction, and feeding of potamodromous fishes. To estimate the realized niches of species, species distribution models (SDMs) employ the extrapolation of environmental predictors and species occurrence data. Our objective was to compare the spatial distribution of migratory fish species in the Amazon basin using SDMs based on variables characterizing the dry season, rainy season, and a combination of both. All evaluated treatments demonstrated high performance and exhibited different distribution ranges in the applied SDMs, particularly when combining environmental variables with occurrence data during the rainy season. These findings support the hypothesis that spatial distribution is influenced by seasonality. The increased fluviometric surface and enhanced connectivity of the rainy season favor both longitudinal and lateral migrations of Amazonian migratory catfishes. Moreover, the spatial distribution reveals four critical spatial overlap (CSO) regions with higher population densities regardless of the season. These CSOs primarily coincide with the Amazon alluvial plain, which exhibits the highest rates of endemism, species richness, and abundance of organisms. Considering the discontinuous and heterogeneous nature of fluviometry when performing niche modeling processes is pivotal, although SDMs applied in the Amazon generally ignore such regional seasonality. [ABSTRACT FROM AUTHOR]

Fish biologists have long assumed a link between intestinal length and diet, and relative gut length or Zihler's index are often used to classify species into trophic groups. This has been done for specific fish taxa or specific ecosystems, but not for a global fish dataset. Here, we assess these relationships across a dataset of 468 fish species (254 marine, 191 freshwater, and 23 that occupy both habitats) in relation to body mass and fish length. Herbivores had significantly relatively stouter bodies and longer intestines than omni- and faunivores. Among faunivores, corallivores had longer intestines than invertivores, with piscivores having the shortest. There were no detectable differences between herbivore groups, possibly due to insufficient understanding of herbivorous fish diets. We propose that reasons for long intestines in fish include (i) difficult-to-digest items that require a symbiotic microbiome, and (ii) the dilution of easily digestible compounds with indigestible material (e.g., sand, wood, exoskeleton). Intestinal indices differed significantly between dietary groups, but there was substantial group overlap. Counter-intuitively, in the largest dataset, marine species had significantly shorter intestines than freshwater fish. These results put fish together with mammals as vertebrate taxa with clear convergence in intestine length in association with trophic level, in contrast to reptiles and birds, even if the peculiar feeding ecology of herbivorous fish is probably more varied than that of mammalian herbivores. [ABSTRACT FROM AUTHOR]

The understanding of the role of fishes in the trophic functioning of estuaries has increased in stages over many decades. It began with qualitative and quantitative dietary studies, mainly from the 1970s onwards, and progressed to more sophisticated stable isotope work towards the end of the 20th Century and into the present. Building on an initial wide array of predominantly single species rather than community dietary studies, our global knowledge of the food and feeding ecology of fishes in estuaries has now progressed to a stage where we can begin to discern patterns and make generalised statements on the nature and role of fish assemblages in the trophic functioning of these systems. In this review we summarize the dominant aspects relating to the trophic ecology of fishes in estuaries, including ontogenetic changes in fish diet and food provision for the nursery function of estuaries, detritus as a direct and indirect driver of the food web, the influence of latitude and habitat type on trophic structuring, predator prey relationships with an emphasis on the importance of invertebrates in fish food chains, the role of stable isotopes in combination with dietary analyses in understanding trophic functioning, and the effects of environmental change and fishing and other human activities on fish food webs in estuaries. Apart from providing an overview of information on the current status of our knowledge on fish trophic ecology in estuaries, this review also identifies important research gaps that need to be filled. [ABSTRACT FROM AUTHOR]

Animals need to move between different habitats to successfully complete their life cycle. Anthropogenic activities and infrastructure impact animal movement, especially in the aquatic realm, due to habitat alteration (including fragmentation), pollution, overexploitation, the spread of invasive alien species and climate change. Gaining knowledge on the complex phenomenon of fish movement is essential to understand the diverse ways in which anthropogenic activities may influence the spatial ecology of fish, which can inform management. The four main methods to study fish movement are through observation and interception, electronic tracking, otolith chemistry and environmental DNA. We discuss the strengths and shortcomings of these methods and suggest effective management can be aided by combining these and other methods. Often the weaknesses of one technique can be met by the strengths of the others. Also, cross-boundary collaboration is essential for the successful management of fish that move over jurisdictional boundaries to complete their life cycle. Data analyses on interdisciplinary datasets obtained at spatial scales relevant to the movement ecology of a given population can yield a more holistic understanding of fish movement. This knowledge may help for the appropriate selection of cost-efficient, evidence-based and effective management actions that balance the needs of fishes and human activities. [ABSTRACT FROM AUTHOR]

Disentangling the causes and consequences of ontogenetic niche shifts has been a pivotal challenge in ecology, aiming to enhance the understanding of biological processes that function at the individual, population, and community levels. Studies on ontogenetic dietary shifts have traditionally focused on short time scales, mostly including sampling covering just one or a few consecutive years, thus neglecting possible aspects of temporal variation and ecosystem stability that can only be revealed on long-term scales. We address ontogenetic dietary shifts of two fish predators in an intraguild system (Arctic charr and brown trout) using a long-term dataset spanning 20 consecutive years. Our study revealed distinct ontogenetic niche shifts of the two intraguild predators and demonstrated that these patterns were stable over time, suggesting large stability in prey acquisition and resource partitioning despite changes in their abundances and relative species composition. Some interannual variation was observed, but this was primarily due to sampling bias from low observation numbers for some ontogenetic stages, reflecting a common methodical challenge for ontogenetic niche shift studies. The persistent patterns in the trophic ontogeny of intraguild predators likely facilitate population and community stability by reducing inter- and/or intraspecific competition, thereby having important consequences for ecosystem functioning and resilience. Our study provides a strong rationale for performing ontogenetic niche shift studies over several consecutive years, enabling important insights into temporal variation, enhancement of observation numbers by merging data from multiple years, and the facilitation of a less intrusive sampling scheme for more vulnerable populations. [ABSTRACT FROM AUTHOR]

A mechanistic understanding of how environmental change affects trophic ecology of fish at the individual and population level remains elusive. To address this, we conducted a space-for-time approach incorporating environmental gradients (temperature, precipitation and nutrients), lake morphometry (visibility, depth and area), fish communities (richness, competition and predation), prey availability (richness and density) and feeding (population niche breadth and individual trophic specialisation) for 15 native fish taxa belonging to different thermal guilds from 35 subarctic lakes along a marked climate-productivity gradient corresponding to future climate change predictions. We revealed significant and contrasting responses from two generalist species that are abundant and widely distributed in the region. The cold-water adapted European whitefish (Coregonus lavaretus) reduced individual specialisation in warmer and more productive lakes. Conversely, the cool-water adapted Eurasian perch (Perca fluviatilis) showed increased levels of individual specialism along climate-productivity gradient. Although whitefish and perch differed in the way they consumed prey along the climate-productivity gradient, they both switched from consumption of zooplankton in cooler, less productive lakes, to macrozoobenthos in warmer, more productive lakes. Species with specialist benthic or pelagic feeding did not show significant changes in trophic ecology along the gradient. We conclude that generalist consumers, such as warmer adapted perch, have clear advantages over colder and clear-water specialised species or morphs through their capacity to undergo reciprocal benthic–pelagic switches in feeding associated with environmental change. The capacity to show trophic flexibility in warmer and more productive lakes is likely a key trait for species dominance in future communities of high latitudes under climate change. [ABSTRACT FROM AUTHOR]

The opening of the Panama Canal ~ 100 years ago created a migration pathway between the Caribbean Sea and the Pacific Ocean for euryhaline marine organisms that can cope with passage through 65 km of freshwater. The Atlantic Tarpon, Megalops atlanticus, a prized recreational-fishery species in its native geographic range, where it is considered "Vulnerable" by the IUCN Red List, is one species that has swum through the canal to the Tropical Eastern Pacific (TEP). Since Tarpon were first seen in the Pacific locks of the Panama Canal in the late 1930′s, ~ 25 y after the opening of the canal, and large adults were subsequently observed in Panama Bay over many years, it has remained unclear whether this species has become established and is reproducing in the TEP. Here we review evidence showing that the Tarpon's TEP geographic range now extends along ~ 2600 km of the coastline (Guatemala to the Colombia/Ecuador border), and that adults are moderately common in the southern parts of that area. General ichthyoplankton surveys in the TEP over the last 50 year have not detected any Tarpon larvae. Small juveniles have been found throughout the main part of its TEP range, up to 700 km from the Panama Canal. As such fish typically are sedentary and have never been seen inside the Panama Canal, they most likely were spawned in the TEP. At present, nothing is known about the basic ecology of Tarpon in the TEP and possible effects it might have on native ecosystems there. [ABSTRACT FROM AUTHOR]

The mahseer fishes (Tor spp.) represent an iconic genus of large-bodied species of the Cyprinidae family. Across the 16 recognised species in the genus, individual fish can attain weights over 50 kg, resulting in some species being considered as premier sport fishes. Tor species also generally have high religious and cultural significance throughout South and Southeast Asia. Despite their economic and cultural importance, the status of Tor fishes has been increasingly imperilled through their riverine habitats being impacted by anthropogenic activities, such as hydropower dam construction and exploitation. Moreover, conservation efforts have been constrained by knowledge on the genus being heavily skewed towards aquaculture, with considerable knowledge gaps on their taxonomy, autecology, distribution and population status. Whilst taxonomic ambiguity has been a major constraint on conservation efforts, this has been partially overcome by recent, robust taxonomic revisions. This has enabled revision of the IUCN Red List status of Tor fishes; three species are now assessed as 'Near Threatened', one 'Vulnerable', three 'Endangered' and one 'Critically Endangered'. However, eight species remain 'Data deficient'. Here, information on these 16 Tor fishes is synthesised for the first time, outlining the current state of knowledge for each species, including their known distributions and population status. For each species, the outstanding gaps in knowledge are also identified, and their population threats and conservation prospects outlined. Consequently, this review provides the basis for researchers to challenge and enhance the knowledge base necessary to conserve these freshwater icons in an era of unprecedented environmental changes. [ABSTRACT FROM AUTHOR]

Large epipelagic fishes (> 30 kg maximum size) are known to display a variety of patterns of vertical movement. Although advances in the affordability and sophistication of electronic tags now allows researchers to routinely document these patterns, there is no standardised approach to classify these behaviours and investigate their physical and biological drivers. This paper reviews the existing knowledge of the vertical movements of large, epipelagic fishes and the evidence for the underlying factors that structure this behaviour. The review focuses on behaviours occurring at a range of temporal scales, from seconds to years. We propose that patterns of vertical movement in gill-breathing animals of the epipelagic are best characterised by the need to move continuously in a three-dimensional environment while optimising food encounter and energy expenditure, avoiding predators, searching for mates and remaining within the limits imposed by the physical environment on their physiology (notably water temperature and oxygen). Modern biologging technologies that record both the internal (body temperature, heart rate) and external physical environment coupled with direct recording of behaviour from tri-axial sensors and animal-borne cameras offer a new approach to the analysis of drivers of vertical movement. Ultimately, this can provide insights into the evolution of the behaviour and morphology of these animals. [ABSTRACT FROM AUTHOR]

Flooding regulates the amount and quality of habitat available for fish populations in river-floodplains. Although previous studies assessed fish population responses to river hydrology, the processes by which flooding affects fish abundance and catch remain unclear. Here, we investigated whether degree of flooding affects abundance and catch of Colossoma macropomum, a long-lived, overexploited fish population of the central Amazon Basin. We computed the degree of flooding corresponding to the feeding area of young-of-the-year C. macropomum as the annual magnitude of the moving littoral zone (ML). We estimated abundance of age classes one, two, and three of C. macropomum using a modeling program based on catch, fishing effort, and fish length frequency data from the principal commercial fishery. We found that flooding positively and non-linearly affected abundance of the age-one cohort but not of older age classes. ML data corresponding to a late rising water phase in which zooplankton, seeds, and fruits dominated the diet provided the strongest effect on age-one abundance. However, flooding effects on total catch were not found, likely due to catches comprising several age classes. These results provide support to existing evidence that the magnitude of the moving littoral zone regulates abundance of juvenile fish. Because the ML quantifies food and habitat availability for various other fish species, it may constitute an important control of fish abundance in these systems. Management of these fisheries may be improved by adjusting fishing effort based on hydrology. More generally, the information also serves to assess the impacts of hydrological alterations (e.g., dams) on fish recruitment. [ABSTRACT FROM AUTHOR]

Insects have been identified as an economically sustainable high-value, and safe protein-rich alternative to fishmeal in compound feeds for farmed fish. Accordingly, the present study aimed to evaluate the effects of substitution of fishmeal with insect meal from Hermetia illucens in the diet of rainbow trout (Oncorhynchus mykiss), on fish growth performance, and gut microbiota composition. For this purpose, three diets, with increasing levels of insect prepupae meal inclusion (10%, 20% and 30%) in partial substitution of fishmeal and a control diet without insect meal were tested in a 12-weeks feeding trial. Fish growth and feed conversion ratio were evaluated. The Illumina MiSeq platform for high-throughput amplicon sequencing of 16S rRNA gene and QIIME pipeline were used to analyse and characterize the whole microbiome associated to aquafeeds, and fish gut. The number of reads taxonomically classified according to the Greengenes database was 1,140,534. We identified 450 OTUs at 97% identity in trout fecal samples; 62 OTUs constituted the core gut microbiota. Actinobacteria, Firmicutes and Proteobacteria represented the dominant phyla in both experimental groups. Among them, the abundance of Actinobacteria and Proteobacteria was significantly influenced by including insect meal in the diet. In summary, our findings clearly indicated that insect meal positively modifies fish gut microbiota, increasing its richness and diversity and in particular, increasing the amount of beneficial lactic acid-and butyrate-producing bacteria, which contribute to the global health of the host. In addition, based on our present and previous studies, we believe that the prebiotic effect of insect meal is principally due to fermentable chitin. [ABSTRACT FROM AUTHOR]

Migratory fishes are one of the groups most threatened by the interruption of river connectivity caused by reservoirs and dams. The downstream displacement of eggs and larvae of these species implies overcoming the barrier presented by the reservoir and passage through the hydraulic structures of the dam. Although a low water renewal time attenuates the drift constraints on eggs and larvae in the reservoir, these organisms still require safe passage through these structures, which represents an additional challenge that demands methodological tools for impact assessment and management evaluation to subsidise operational decision making. This paper presents a protocol to help fill current gaps in knowledge of the impact of hydropower dams on the survival of fish larvae travelling through the hydraulic components of dams. A sampling and analysis design capable of in situ assessment of the effects of passage by the larvae through dams is presented and discussed along with potential alternatives to support hydraulic structure management and mortality reduction as well as inferences on the effectiveness of fish translocation strategies. The proposed approach is a new possibility for the in situ assessment of downstream ichthyoplankton passage through dams. The proposed sampling design is relatively simple, easily executed and affordable compared to those demanding more sophisticated technologies or that combine field and lab studies to associate fish injuries and mortality with the downstream passage through dams operating under different regimes. Its rapid diffusion is important given the accelerated expansion of the hydroelectric sector, especially in the main tropical basins. [ABSTRACT FROM AUTHOR]

Cephalopods, especially squids, are believed to have a structuring role in marine ecosystems as a link between different trophic levels, primarily due to their voracious prey consumption and high production rate. Cephalopod ecology, however, is still poorly understood as observational studies often give highly uncertain and variable results due to the peculiarities of cephalopod behaviour and biology, and their responsiveness to external drivers. This review evaluates our representation of cephalopods in ecosystem models and the insights given by these models on the role of cephalopods in our oceans. We examined ecosystem models from 13 regions to analyse the representation of cephalopods and compared their results to local trophic studies. Our analysis indicated that most ecosystem models inadequately include cephalopods in terms of model structure and parametrization; although some models still have the capacity to draw valuable conclusions regarding the impact and role of cephalopods within the system. Oceanic squid species have a major role linking trophic levels and food webs from different habitats. The importance of neritic species varies locally, but generally cephalopods have a substantial impact via their consumer role. To better understand the ecological role of cephalopods, improved representation of these species in ecosystem models is a critical requirement and could be achieved relatively easily to more accurately articulate the mechanisms regulating the ecological role of cephalopods. [ABSTRACT FROM AUTHOR]

Telemetry is an increasingly common tool for studying the ecology of wild fish, with great potential to provide valuable information for management and conservation. For researchers to conduct a robust telemetry study, many essential considerations exist related to selecting the appropriate tag type, fish capture and tagging methods, tracking protocol, data processing and analyses, and interpretation of findings. For telemetry-derived knowledge to be relevant to managers and policy makers, the research approach must consider management information needs for decision-making, while end users require an understanding of telemetry technology (capabilities and limitations), its application to fisheries research and monitoring (study design), and proper interpretation of results and conclusions (considering the potential for biases and proper recognition of associated uncertainties). To help bridge this gap, we provide a set of considerations and a checklist for researchers to guide them in conducting reliable and management-relevant telemetry studies, and for managers to evaluate the reliability and relevance of telemetry studies so as to better integrate findings into management plans. These considerations include implicit assumptions, technical limitations, ethical and biological realities, analytical merits, and the relevance of study findings to decision-making processes. [ABSTRACT FROM AUTHOR]

Elasmobranch populations face worldwide declines owing to anthropogenic stressors, with lethal and sub-lethal consequences. Oxygen uptake rates ( M ˙ O2, typically measured in mg O2 kg−1 h−1) can be quantified as proxies of whole-organism aerobic metabolic rates and are relevant to fisheries management and conservation through aerobic performance's relationship with fitness and spatial ecology. The purpose of this review was to better understand how M ˙ O2 has been and can be applied to predict how elasmobranch populations will respond to current and future anthropogenic stressors. We identified 10 studies spanning 9 elasmobranch species that quantified M ˙ O2 to understand elasmobranch populations' responses to exposure to anthropogenic stressors. Studies measuring responses to climate change stressors (ocean warming and acidification, declining oxygen content, increasing storm frequency) were most common. Studies with relevance to fisheries stressors used M ˙ O2 to approximate energetic costs of capture and estimate recovery times in bycatch scenarios. Ecotourism encounters were investigated in the context of increases in energetic requirements owing to anthropogenic disruption of diel activity cycles. Furthermore, we discuss how an understanding of M ˙ O2 in elasmobranchs has been and can be applied to predict populations' responses to anthropogenic stressors with deliverables for improving species management and conservation. Specifically, M ˙ O2 can be applied to predict population-level responses to stressors by quantifying associations between M ˙ O2 and fitness-related processes, spatial ecology, and impact on ecosystem function (via bioenergetics modelling). This review is meant to serve as a call-to-action to further bridge the gap between experimental biology and elasmobranch conservation in the "good Anthropocene". [ABSTRACT FROM AUTHOR]

Research effort is unevenly distributed across species, which can cause important biases in our understanding of evolutionary and ecological processes and affect conservation decisions. For example, many shark species remain understudied, despite the fact that sharks play fundamental roles in marine ecosystems and are particularly affected by fisheries. Assessing and acknowledging these differences in research effort across shark species is a key step to improving our knowledge and management of shark populations as it allows researchers to both target species in need of research and control for potential biases when performing comparative analyses. I provide here an index of research effort (the number of articles published between 1978 and 2014 listed in the Zoological Record database) for 509 shark species that can be downloaded and utilized in future comparative analyses. I then show that research effort is not randomly distributed across species within the clade, but is significantly predicted by taxonomy, geography, ecology, life history and extinction risk. For example, large species that occur across a large range of latitudes and at shallow minimum depths have attracted considerably more research. The consequence is a strong bias in our knowledge of sharks towards species that are not an unbiased representative sample of the clade. The database and the patterns demonstrated here call for more awareness of the biases in research effort and their potential consequences, not only for practical considerations such as the interpretation of the results of comparative analyses and the assessment of extinction risk, but also for our basic understanding of the ecological roles of sharks. [ABSTRACT FROM AUTHOR]

Fisheries bycatch is one of the biggest threats to marine mammal populations. A literature review was undertaken to provide a comprehensive assessment and synopsis of gear modifications and technical devices to reduce marine mammal bycatch in commercial trawl, purse seine, longline, gillnet and pot/trap fisheries. Successfully implemented mitigation measures include acoustic deterrent devices (pingers) which reduced the bycatch of some small cetacean species in gillnets, appropriately designed exclusion devices which reduced pinniped bycatch in some trawl fisheries, and various pot/trap guard designs that reduced marine mammal entrapment. However, substantial development and research of mitigation options is required to address the bycatch of a range of species in many fisheries. No reliably effective technical solutions to reduce small cetacean bycatch in trawl nets are available, although loud pingers have shown potential. There are currently no technical options that effectively reduce marine mammal interactions in longline fisheries, although development of catch and hook protection devices is promising. Solutions are also needed for species, particularly pinnipeds and small cetaceans, that are not deterred by pingers and continue to be caught in static gillnets. Large whale entanglements in static gear, particularly buoy lines for pots/traps, needs urgent attention although there is encouraging research on rope-less pot/trap systems and identification of rope colours that are more detectable to whale species. Future mitigation development and deployment requires rigorous scientific testing to determine if significant bycatch reduction has been achieved, as well as consideration of potentially conflicting mitigation outcomes if multiple species are impacted by a fishery. [ABSTRACT FROM AUTHOR]

This review compiles, summarizes and provides new analytical insights on large amounts of fragmented information on the diets and feeding behaviours of syngnathids (Family Syngnathidae). This review is broken down into two distinct sections that address two central questions: (1) How, where, when and what do syngnathids eat? And (2) How does diet differ with feeding morphology? For (1) we summarized both qualitative and quantitative information on the diets and feeding behaviours of syngnathids found in the published and grey literature. This section includes a narrative summary of syngnathid feeding events and foraging behaviours (e.g. body mechanics and feeding morphologies, habitat use, seasonal and diurnal timing of feeding, energetics) and a tabulated summary of what syngnathids eat. For (2) we performed a comparative analysis on the diets of 41 species of syngnathid, comprising 15 genera from 39 sources in peer-reviewed and grey literature. Redundancy analyses on bulk, numeric, and frequency of occurrence data, analyzed separately, all show large unexplained dietary variation, which we hypothesize is the result of large differences in prey availability. Of the explained variation, syngnathid diets were most strongly correlated with head characteristics: most notably relative snout lengths and gape sizes. Syngnathid feeding morphologies also showed high phylogenetic signal; this suggests that dietary differences across genera were largely explained by how syngnathids differed with respect to these feeding morphologies. This review identifies new taxonomic patterns, and expands on previous generalities, improving our ecological understanding of this diverse group of fishes. [ABSTRACT FROM AUTHOR]

This paper revises detailed data on hooking (at-haulback) mortality of swordfish captured and discarded by pelagic longlines, using as a case study the shallow night setting Portuguese pelagic longline fishery that targets manly swordfish, in the Atlantic Ocean. The overall at-haulback mortality for swordfish was very high, specifically 85.2% for all sample/sizes combined, and even higher for the smaller sizes classes. Specifically, observed at-haulback mortality was 87.8% for specimens smaller than 125 cm lower jaw fork length (LJFL) and 88.1% for specimens smaller than 119 cm LJFL, corresponding to the minimum landing size options currently in place in the Atlantic Ocean. The mortality was modeled with logistic generalized linear models, showing that specimen size, sea surface temperature (SST) and mode of operation were significant variables, and with the hooking mortality decreasing with specimen size while increasing with SST. Even though this study only focuses one fishery, the data is widespread and covers a wide Atlantic area, being representative of most modern shallow setting longlines targeting swordfish, and including both fresh and freezer operating vessels. Additionally, this study only focuses hooking mortality, with a note that the overall mortality rates are likely higher due to post-release mortality of released specimens. Overall, this work presents new and important information on swordfish mortality and opens the discussion on the efficiency of the minimum landing sizes for swordfish currently in place in the Atlantic that were established mainly to protect juvenile swordfish. [ABSTRACT FROM AUTHOR]

Modern lampreys (Petromyzontiformes) are one of two lineages of surviving jawless fishes (agnathans), and are thus of critical importance to understanding the evolution of the vertebrates. Although their fossil record is meager, it appears they have remained morphologically conserved for at least 360 million years, but the origin of their multi-stage life history is unclear. Unlike hagfishes, the other extant group of jawless fishes, which exhibit direct development, all modern lampreys possess a complex life cycle which includes a long-lived freshwater larval (or ammocoete) period, followed by a true metamorphosis into a sexually-immature juvenile and then mature adult which differ dramatically in their morphology and ecology from the larva. Because of their basal position, it is critical to understand when the extant lamprey life history evolved, and if such a life history was present in the last common ancestor of agnathans and gnathostomes. Recent discoveries in paleontology, genomic analyses, and developmental biology are providing insights into this problem. The current review synthesizes these findings and concludes that the ancestral lamprey life cycle followed a direct development. We suggest that the larval period was short and relatively limited if present at all, but that the juvenile included modern larval traits; over the course of evolution, differential selection pressures throughout the lifetime produced distinct larval and juvenile/adult periods. Each period required the dramatically different morphologies seen in modern lampreys, ultimately requiring a true metamorphosis to accommodate the large changes in the body plan and to maximize the efficiency of each life period. As a result, modern lamprey life histories are a patchwork of ancestral and derived characters. [ABSTRACT FROM AUTHOR]

In laboratory fish research, the zebrafish Danio rerio (Cyprinidae) represents the equivalent of the mouse in mammalian research. This species has become a major model for studies in developmental and behavioural genetics, neurophysiology, biomedicine, ecotoxicology, and behavioural and evolutionary ecology. To meet the need for accurate and reproducible data in both fundamental and applied sciences, it is of primary importance to be able to tag and/or recognize individual zebrafish. However, classic methods used in fish ecology and aquaculture are generally difficult to apply to such small fish. Recently, various new tagging methods have been developed. This paper presents a first review of current identification and marking methods applied to zebrafish, from external observation methods (such as skin pattern recognition, fin clipping, scale regeneration, colour and transgenic methods) to the most advanced technological developments in electronic (low- and high- radio-frequencies PIT tags, microchip) and image analysis methods (video tracking). This review aims to help researchers and zebrafish facility managers select the identification method (ID) best adapted to their needs. The main characteristics of each ID method are examined (including detection range, durability, speed and repetitiveness, ID code combination, size dependence and ethical considerations), and their pros and cons are summarized in a decision table to help select the most appropriate option for a research or management program. Finally, contextual applications of these ID methods and future developments are discussed. [ABSTRACT FROM AUTHOR]

Salmonid fish are an ecologically important and extensively studied group of fish which concern many interest groups in our society. The aim of this paper is to discuss and suggest solutions to the multifaceted problems associated with studying behavioural variation in salmonids, with focus on designing behavioural studies that are ecologically relevant. Many of the general problems and solutions discussed can be applied to other animals as well. First, the importance of asking clear questions when conceiving behavioural studies is addressed, using Tinbergen’s four questions and associated theories as stepping stones towards generating testable hypotheses about behavioural variation. We then address a range of methodological challenges encountered when attempting to study behavioural variation in salmonids and suggest solutions to overcome these problems. A range of approaches is discussed, from highly controllable laboratory experiments to monitoring studies of behaviour in the wild. The importance of combining lab- and field approaches to evaluate the ecological relevance of behavioural variation is highlighted. Finally, we suggest a general framework using a multi-faceted research approach to address questions about the behavioural ecology of salmonids (and other animals) so that knowledge can progress, and the ecological relevance of behavioural studies can be validated. [ABSTRACT FROM AUTHOR]

Fisheries stock assessments are essential for science-based fisheries management. Inland fisheries pose challenges, but also provide opportunities for biological assessments that differ from those encountered in large marine fisheries for which many of our assessment methods have been developed. These include the number and diversity of fisheries, high levels of ecological and environmental variation, and relative lack of institutional capacity for assessment. In addition, anthropogenic impacts on habitats, widespread presence of non-native species and the frequent use of enhancement and restoration measures such as stocking affect stock dynamics. This paper outlines various stock assessment and data collection approaches that can be adapted to a wide range of different inland fisheries and management challenges. Although this paper identifies challenges in assessment, it focuses on solutions that are practical, scalable and transferrable. A path forward is suggested in which biological assessment generates some of the critical information needed by fisheries managers to make effective decisions that benefit the resource and stakeholders. [ABSTRACT FROM AUTHOR]

Anthropogenic impacts have shifted aquatic ecosystems far from prehistoric baseline states; yet, understanding these impacts is impeded by a lack of available long-term data that realistically reflects the organisms and their habitats prior to human disturbance. Fish are excellent, and largely underused, proxies for elucidating the degree, direction and scale of shifts in aquatic ecosystems. This paper highlights potential sources of qualitative and quantitative data derived from contemporary, archived and ancient fish samples, and then, using key examples, discusses the types of long-term temporal information that can be obtained. This paper identifies future research needs with a focus on the Southern Hemisphere, as baseline shifts are poorly described relative to the Northern Hemisphere. Temporal data sourced from fish can improve our understanding of how aquatic ecosystems have changed, particularly when multiple sources of data are used, enhancing our ability to interpret the current state of aquatic ecosystems and establish effective measures to safeguard against further adverse shifts. The range of biological, ecological and environmental data obtained from fish can be integrated to better define ecosystem baseline states on which to establish policy goals for future conservation and exploitation practices. [ABSTRACT FROM AUTHOR]

Current-mediated downstream dispersal by the early developmental stages of fish in rivers is a common phenomenon. Knowledge of patterns and processes in the dispersal, or 'drift', of young fishes provides important information on spawning location and spawning success, habitat use, movement paths and flow-ecology relationships more generally, all of which are critical for effective river conservation and management. But despite the importance of such information, our understanding of the patterns and processes of the drift of the early life stages of riverine fishes is limited. Furthermore, riverine fish drift research has tended to occur in isolation from movement studies of other organisms, limiting its integration with higher level concepts and theory. This manuscript reviews the literature on the dispersal of young fishes in running waters. Relevant studies from all climatic zones and geographical regions are investigated, with particular attention given to the types and life history stages of fishes that drift and the seasonal and diel patterns of drifting. We then consider how fish enter the drift and their mode of drifting, attempting to reconcile a long-running discussion, under what we call the 'active-passive conundrum'. We argue that, aside from eggs, the early stages of fish are not exclusively either passive or active drifters, but usually a mixture of the two, which we term 'actipassive' drift. Finally, we evaluate existing knowledge in the context of a general conceptual framework for movement ecology, identifying gaps in our understanding of the roles of internal state, navigation capacity, motion capacity, external factors and internal factors in influencing the dispersal process. [ABSTRACT FROM AUTHOR]

Conservation efforts, environmental planning, and management must account for ongoing ecosystem alteration due to a changing climate, introduced species, and shifting land use. This type of management can be facilitated by an understanding of the thermal ecology of aquatic organisms. However, information on thermal ecology for entire taxonomic groups is rarely compiled or summarized, and reviews of the science can facilitate its advancement. Crayfish are one of the most globally threatened taxa, and ongoing declines and extirpation could have serious consequences on aquatic ecosystem function due to their significant biomass and ecosystem roles. Our goal was to review the literature on thermal ecology for freshwater crayfish worldwide, with emphasis on studies that estimated temperature tolerance, temperature preference, or optimal growth. We also explored relationships between temperature metrics and species distributions. We located 56 studies containing information for at least one of those three metrics, which covered approximately 6 % of extant crayfish species worldwide. Information on one or more metrics existed for all 3 genera of Astacidae, 4 of the 12 genera of Cambaridae, and 3 of the 15 genera of Parastacidae. Investigations employed numerous methodological approaches for estimating these parameters, which restricts comparisons among and within species. The only statistically significant relationship we observed between a temperature metric and species range was a negative linear relationship between absolute latitude and optimal growth temperature. We recommend expansion of studies examining the thermal ecology of freshwater crayfish and identify and discuss methodological approaches that can improve standardization and comparability among studies. [ABSTRACT FROM AUTHOR]

Deep-water tropical fishes support locally significant commercial fisheries, high value recreational fisheries, and culturally and economically important artisanal and subsistence fisheries throughout the Indo-Pacific region. The main species captured by these fisheries are deep-water snappers (Lutjanidae), groupers (Epinephelidae), and emperors (Lethrinidae). Quantitative assessments of deep-water tropical fisheries have been limited by a lack of adequate biological and fisheries data. We review the biology and ecology of deep-water tropical fishes, discuss the implications for assessment and management of tropical deep-water fisheries, and provide perspectives on future research priorities. We found that biological and fisheries information is lacking for the majority of deep-water tropical fishes. Furthermore, many studies were constrained by low samples sizes and the use of methods that have not been validated or verified. Most species for which reliable information was available were reported to have extended longevities (>20 years), low rates of natural mortality ( M < 0.15), and slow to modest growth rates ( K = 0.12-0.25). These life history traits indicate a low production potential for many deep-water tropical fishes, and suggest that sustainable exploitation rates and potential yields may be low. There is a need for more representative and adequate studies of deep-water tropical fishes and for improved fisheries data collection and the use of consistent methods in addition to information sharing to facilitate the development of robust data-poor assessment techniques for these species. [ABSTRACT FROM AUTHOR]

Despite increasing concern that climate change may negatively impact trout-a globally distributed group of fish with major economic, ecological, and cultural value-a synthetic assessment of empirical data quantifying relationships between climatic variation and trout ecology does not exist. We conducted a systematic review to describe how temporal variation in temperature and streamflow influences trout ecology in freshwater ecosystems. Few studies ( n = 42) have quantified relationships between temperature or streamflow and trout demography, growth, or phenology, and nearly all estimates (96 %) were for Salvelinus fontinalis and Salmo trutta. Only seven studies used temporal data to quantify climate-driven changes in trout ecology. Results from these studies were beset with limitations that prohibited quantitatively rigorous meta-analysis, a concerning inadequacy given major investment in trout conservation and management worldwide. Nevertheless, consistent patterns emerged from our synthesis, particularly a positive effect of summer streamflow on trout demography and growth; 64 % of estimates were positive and significant across studies, age classes, species, and locations, highlighting that climate-induced changes in hydrology may have numerous consequences for trout. To a lesser degree, summer and fall temperatures were negatively related to population demography (51 and 53 % of estimates, respectively), but temperature was rarely related to growth. To address limitations and uncertainties, we recommend: (1) systematically improving data collection, description, and sharing; (2) appropriately integrating climate impacts with other intrinsic and extrinsic drivers over the entire lifecycle; (3) describing indirect consequences of climate change; and (4) acknowledging and describing intrinsic resiliency. [ABSTRACT FROM AUTHOR]

Better knowledge of food search behaviour in fish is essential for studies that aim to improve longline fishing, particularly through bait development. This review provides an overview of our understanding of how fish detect and locate sources of food odour, focusing on the stimuli and sensory modalities involved, and on factors that affect feeding activity. Studies that identify feeding attractants and efforts to develop alternative longline baits are presented. The review reveals that such studies are few in number, and that to date there are no alternatives to traditional baits in commercial longlining despite the growing demand for these resources, which are also used for human consumption. The chemical compounds that elicit food search behaviour differ from species to species, and species selectivity could be improved by incorporating specific feeding attractants in manufactured baits. The unique properties of chemical stimuli and odour dispersal form the basis for improving longline efficiency through the development of a long-lasting bait. Vision is important in prey capture, and manufactured baits can be made more visible than natural baits by increasing the contrast (e.g. via fluorescent or polarising coatings) and creating motion through buoyancy. Physical properties such as size, shape, texture and strength can also be manipulated in a manufactured bait to improve catch efficiency. Knowledge obtained from studies of various aspects of food search behaviour is of paramount importance for future research aimed at alternative bait development and improving longline fishing. [ABSTRACT FROM AUTHOR]

The common dentex Dentex dentex (Linnaeus, 1758) is an iconic marine coastal fish in the Mediterranean Sea. It is a demersal sparid fish (0-200 m), that grows to a maximum length of 100 cm and a weight of 13 kg, with a relatively long life span (more than 20 years). As a high trophic level predator, it holds a key position in coastal marine food webs. The common dentex is of great economic importance for both artisanal (small-scale coastal fisheries) and recreational fishing. Despite its economic and ecological importance, scientific data on this species in its natural environment are still very scant. The global commercial catch of common dentex has fluctuated over the last 60 years on an interannual time scale, and has declined significantly since the 1990s. There are few data regarding fishing effort and total catch from recreational fishing for common dentex, but it appears that this species is particularly targeted by this activity. The common dentex is now classified as 'vulnerable' in the Red List of Threatened Species in the Mediterranean Sea. This review summarizes the current literature on D. dentex in regard to biology, ecology, parasitology, population structure, commercial and recreational fishing, and management regulations. Future research directions to fill gaps in current knowledge are suggested. [ABSTRACT FROM AUTHOR]

Any attempt to describe the spatial ecology of sharks and rays should consider the drivers responsible for movement. Research has shown fluctuations in the environment (abiotic factors) can trigger movement and changes in behaviour and habitat use for many elasmobranch species. Most studies to date have selectively focused on a small number of abiotic factors (i.e. temperature, salinity); however, other factors such as dissolved oxygen, tide, photoperiod, barometric pressure and pH have also been documented to act as drivers of movement in shark and ray species. Although usually examined individually, abiotic factors rarely act in isolation and often differ in their level of influence between species, sex, ontogenetic stage, season and geographic location. This paper reviews the role of abiotic factors as a driver of movement and changes in behaviour and habitat use in elasmobranchs. In the context of a changing climate, insight into how sharks and rays may respond to fluctuating environmental conditions projected under future scenarios is required. [ABSTRACT FROM AUTHOR]

Recruitment of the three northern hemisphere eel species (European eel Anguilla anguilla, American eel Anguilla rostrata and Japanese eel Anguilla japonica) has reduced significantly over the past thirty-five years. The stock of the European eel is described as being outside safe biological limits, with urgent action required by European Union Member States to assist recovery of the panmictic stock. Stock recruitment models and estimates of silver eel output from a river catchment are strongly influenced by the degree of certainty in estimating key population parameters of each life history stage. Therefore, management decisions aimed at enhancing eel populations rely on sound scientific evidence, based upon a fundamental understanding of the complex anguillid eel life cycle. This review paper focuses on the estuarine entry phase of the eel life cycle and synthesises the current scientific knowledge with regard to glass eel migratory behaviour, sampling methods and abundance estimates within estuaries. Although the behavioural and environmental processes modulating glass eel migration patterns are reasonably well understood, site specific factors play a significant role in determining fine scale distribution patterns at an individual estuary level. Given the large resource commitment required to adequately sample this key life history stage, behavioural studies of migration patterns on a local scale are crucially important to aid the design of robust sampling programmes aimed at quantifying seasonal abundance and annual recruitment. [ABSTRACT FROM AUTHOR]

Coral reef fishes differ in their intrinsic vulnerability to fishing and rates of population recovery after cessation of fishing. We reviewed life history-based predictions about the vulnerability of different groups of coral reef fish and examined the empirical evidence for different rates of population recovery inside no-take marine reserves to (1) determine if the empirical data agree with predictions about vulnerability and (2) show plausible scenarios of recovery within fully protected reserves and periodically-harvested fishery closures. In general, larger-bodied carnivorous reef fishes are predicted to be more vulnerable to fishing while smaller-bodied species lower in the food web (e.g., some herbivores) are predicted to be less vulnerable. However, this prediction does not always hold true because of the considerable diversity of life history strategies in reef fishes. Long-term trends in reef fish population recovery inside no-take reserves are consistent with broad predictions about vulnerability, suggesting that moderately to highly vulnerable species will require a significantly longer time (decades) to attain local carrying capacity than less vulnerable species. We recommend: (1) expanding age-based demographic studies of economically and ecologically important reef fishes to improve estimates of vulnerability; (2) long term (20-40 years), if not permanent, protection of no-take reserves to allow full population recovery and maximum biomass export; (3) strict compliance to no-take reserves to avoid considerable delays in recovery; (4) carefully controlling the timing and intensity of harvesting periodic closures to ensure long-term fishery benefits; (5) the use of periodically-harvested closures together with, rather than instead of, permanent no-take reserves. [ABSTRACT FROM AUTHOR]

Sharks are traditionally classified as generalists that use a diverse range of habitats and prey. While this is an accurate description of some species, sharks exhibit a range of resource use strategies that affect their influence on communities. These strategies also influence resilience in the face of environmental and anthropogenic effects. Identifying resource use patterns is critical to understanding sharks in aquatic environments. However, despite the rapid increase in studies focused on measuring the dietary and habitat selection patterns of sharks, discussion on how to define the ecological specialisation of sharks has been limited. This is an impediment to communication and research as definitions of specialisation and how to measure it vary based on context. This review presents a conceptual framework within which to define the specialisation of sharks that can be applied to different environmental scales and goals. We present examples of species with varying degrees of specialisation at large and small scales within the proposed context. The effects of specialisation on population stability are also briefly discussed. Specialists are more sensitive to environmental fluctuations and thus more susceptible to population depletion following environmental changes. Therefore identifying specialised species is key to understanding species vulnerabilities and advancing ecological discussions. [ABSTRACT FROM AUTHOR]

The shoal bass ( Micropterus cataractae) is a black bass species native to the Apalachicola-Chattahoochee-Flint Basin of the southeastern U.S. Damming in the basin has created extensive habitat loss; consequently, shoal bass have been extirpated from several areas of their native range. Early shoal bass research focused on age and growth, spawning habits, and distribution. The formal recognition of the species in 1999 increased interest in research and restoration. Recent research has described critical habitat, movements, and systematic information about shoal bass. As researchers continue to investigate the life history of the species, several threats have become apparent including habitat modification, interactions with non-native black basses, and the effects of angling. Currently, management needs include basic population assessments and investigation of factors causing population declines. Despite increased interest in the species, the outlook for the long-term conservation of the shoal bass is uncertain. [ABSTRACT FROM AUTHOR]

Great Bear Lake, Northwest Territories, Canada supports important sport and aboriginal-subsistence fisheries and is among the last remaining pristine great lakes of the world. The lake's unique ecology is characterized by a harsh subarctic climate, low productivity and species diversity, and high intraspecific diversity of lake trout. These aspects in combination with geographical remoteness present special challenges to the management of two exceptionally different fisheries. The history of its management has not been well documented or reviewed; therefore, our objectives in this paper were to summarize the history and status of Great Bear Lake's fisheries and their management, and to identify gaps in knowledge, future challenges, and actions required to meet those challenges. Prior to 1970, management goals for the lake had not been established formally, and harvest numbers and biological characteristics of fish were unknown. To reduce data gaps, creel surveys, gillnet assessments, fish tagging, and subsistence monitoring were implemented. During the 1980s, Canada established the management goal of conserving a high quality sport fishery, while protecting aboriginal access to the subsistence fishery. On the basis of assessment data, lodge harvest quotas, lodge guest capacity limits, individual angler harvest limits, and angler licensing were among the management actions taken to achieve that goal. Since 2005, decision making has been guided by the 'water heart,' a management plan for Great Bear Lake. Management has since evolved into a complex co-management system among aboriginal, territorial, and federal governments. Changes in regulations, sport trophy and tourism industries, subsistence resource use, and social and cultural norms and practices contributed to changes in the Great Bear Lake fishery and its management. In the future, anthropogenic and climate change are the two main challenges facing co-management of the lake's resources. We recommend the adoption of an ecosystem approach to management, establishment of a fishery technical committee, reformulation of the current plan, explicit commitment to evaluation, conducting community-based monitoring, and development and use of a joint strategic plan among co-managers to describe how to interact and implement the Great Bear Lake management plan. [ABSTRACT FROM AUTHOR]

The two great rivers of India the Ganga and the Brahmaputra form their estuary at the lower part of West Bengal and most of the part of this estuarine system is surrounded by Sundarban mangrove forest. This mangrove based estuarine ecosystem harbors a large number of fin fishes i.e. more or less 267 species of fishes which belong under 81 families. Estuary's own ecological characters and mangrove's all beneficial features support this high species diversity here. But due to continuously increasing natural and anthropogenic stresses, nowadays this entire species community faces a tremendous problem of extinction. 82 species under 24 families loss their juveniles in a significant number regularly due to wild harvest of lucrative prawn seeds. The present article aims to review the roles of estuary and mangroves in enrichment of finfish diversity and the possible threats causing harm to the same. [ABSTRACT FROM AUTHOR]

Small freshwater fish species (SFFs) (length <25 cm) are highly rich in vitamin A, calcium, iron etc. and hence, can contribute to social health through nutrient supplement to rural communities. Under the pressure of extensive modern agricultural practices and indiscriminate harvesting, stocks of SFFs are gradually declining and their habitats and breeding grounds are also being deteriorated at faster rate. A better conservationist approach could be carp-SFFs integration which will reduce indiscriminate mass capture fishing of SFFs and will ensure conservation of natural SFFs stocks in their habitats providing economic benefit to stakeholders. Different studies have already showed success story of SFF polyculture through carp-SFFs integration. This production cum conservation practice leads to sustainability-a better term in fishery is 'social fishery'. However, the part which needs attention is the feeding ecology of SFFs to understand within and between species (with carps) food partitioning and habitat preference as better culture cum conservational approach. [ABSTRACT FROM AUTHOR]

Parachanna obscura is the most common African Channidae. Various studies are being conducted on its biology and ecology. It lives in fresh water in quiet and muddy areas. It has accessory respiratory organs allowing it to live in hypoxic environment. It has a varied diet and feeds on fish, remains of fish, insects, other invertebrates and plant detritus. It is a species with iteroparous asynchronous oogenesis which breeds throughout the year but much more during and just after the flood. It size at first maturity is 24.5 cm. Eggs and larvae of P. obscura are yellow and guarded by one or both parents. Hardiness, rapid growth, high tasty flesh and commercial value of this species represent significant aquaculture potentiality. Natural stocks of P. obscura are overexploited and are not sufficient to met local demands. Its extensive farming system has already started in some African countries. Successful farming of this species in intensive systems and semi-intensive can help not only to preserve and enhance natural stocks of P. obscura but also to continuously produce fingerlings remediation technologies for direct human consumption. [ABSTRACT FROM AUTHOR]

Oreochromis mossambicus (Peters 1852) are native to the eastward flowing rivers of central and southern Africa but from the early 1930s they have been widely distributed around the world for aquaculture and for biological control of weeds and insects. While O. mossambicus are now not commonly used as an aquaculture species, the biological traits that made them a popular culture species including tolerance to wide ranging ecological conditions, generalist dietary requirements and rapid reproduction with maternal care have also made them a 'model' invader. Self-sustaining populations now exist in almost every region to which they have been imported. In Australia, since their introduction in the 1970s, O. mossambicus have become established in catchments along the east and west coasts and have the potential to colonise other adjacent drainages. It is thought that intentional translocations are likely to be the most significant factor in their spread in Australia. The ecological and physical tolerances and preferences, reproductive behaviour, hybridization and the high degree of plasticity in the life history traits of O. mossambicus are reviewed. Impacts of O. mossambicus on natural ecosystems including competitive displacement of native species, habitat alteration, predation and as a vector in the spread of diseases are discussed. Potential methods for eradicating or controlling invasive populations of O. mossambicus including physical removal, piscicides, screens, environmental management and genetic technologies are outlined. [ABSTRACT FROM AUTHOR]

Hydrokinetic devices generate electricity by capturing kinetic energy from flowing water as it moves across or through a rotor, without impounding or diverting the water source. The Tanana River in Alaska, a turbid glacial system, has been selected as a pilot location to evaluate the effects of such a device on fish communities that are highly valued by subsistence, sport, and commercial users. The basic ecology and habitat use of fishes in turbid glacial systems are poorly understood; therefore it is necessary to study the species composition of the fish community and the spatial and temporal patterns of mainstem river use by these fishes to evaluate impacts of a hydrokinetic device. In this document, we provide an overview of existing knowledge of fish ecology in the Tanana River and impacts of hydrokinetic devices on fishes in other river systems. Seventeen fish species are known to inhabit the Tanana River and several may utilize the deepest and fastest section of the channel, the probable deployment location for the hydrokinetic device, as a seasonal migration corridor. Previous studies in clearwater river systems indicate that mortality and injury rates from turbine passage are low. However, the results from these studies may not apply to the Tanana River because of its distinctive physical properties. To rectify this shortcoming, a conceptual framework for a comprehensive fish ecology study is recommended to determine the impacts of hydrokinetic devices on fishes in turbid, glacial rivers. [ABSTRACT FROM AUTHOR]

Relatively little is known about the biology and ecology of the world's largest (heaviest) bony fish, the ocean sunfish Mola mola, despite its worldwide occurrence in temperate and tropical seas. Studies are now emerging that require many common perceptions about sunfish behaviour and ecology to be re-examined. Indeed, the long-held view that ocean sunfish are an inactive, passively drifting species seems to be entirely misplaced. Technological advances in marine telemetry are revealing distinct behavioural patterns and protracted seasonal movements. Extensive forays by ocean sunfish into the deep ocean have been documented and broad-scale surveys, together with molecular and laboratory based techniques, are addressing the connectivity and trophic role of these animals. These emerging molecular and movement studies suggest that local distinct populations may be prone to depletion through bycatch in commercial fisheries. Rising interest in ocean sunfish, highlighted by the increase in recent publications, warrants a thorough review of the biology and ecology of this species. Here we review the taxonomy, morphology, geography, diet, locomotion, vision, movements, foraging ecology, reproduction and species interactions of M. mola. We present a summary of current conservation issues and suggest methods for addressing fundamental gaps in our knowledge. [ABSTRACT FROM AUTHOR]

A correction to the article "Ecological and evolutionary patterns of freshwater maturation in Pacific and Atlantic salmonines" that was published in the previous issue is presented.