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Shelf areas of the seas and oceans characterizing high productivity are the spawning sites of many aquatic organisms. However, they are strong impacted for anthropogenic pollution, including oil contamination, which negatively influence on marine organisms. The effects of mazut and diesel fuel in the concentrations of 0.05, 0.1 and 0.2 ml/l on the activity of antioxidant enzymes which are recognized as biomarkers of the oxidative stress namely superoxide dismutase (SOD), catalase (CAT), peroxidase (PER) and glutathione reductase (GR) in the developing embryos of two marine blennies Parablennius sanguinolentus and Salaria pavo (Perciformes: Blenniidae) on the V - VI developmental stages were studied. The results demonstrated higher mazut toxicity as compared with diesel fuel. In P. sanguinolentus embryos exposed to mazut the activity of key anti-oxidant enzymes SOD and CAT were significantly higher (+413% and +100% as compared with the control, p<0.05), while in the case of diesel fuel the enzymes level varied insignificantly. In the embryos of S. pavo SOD and CAT activities were also increased at mazut incubation (256% and 103% respectively, p<0.05), while the differences between enzymes level in embryos exposed to diesel fuel were lower. In contaminated S. pavo embryos enzyme activities varied less as compared with the embryos of P. sanguinolentus, therefore they are more resistant and adaptive to oil contamination. The possible mechanisms of fish embryos antioxidant system response to oil pollution are discussed. [ABSTRACT FROM AUTHOR]

Summary: The siganid production in the Philippines is continuously declining from 2007 up to present. In Palompon, Leyte, annual yield of siganids, particularly Siganus canaliculatus (Park, 1797) also showed a decreasing trend of total production. This is consistent that this stock is under heavy pressure, and when left unmanaged, this could lead to further overexploitation and the collapse of the stock in the long run. Regardless of this, detailed reproductive biology and potential of this species are very few in the Philippines. Therefore, this study was conducted to provide information on the reproductive biology and breeding cycle of S. canaliculatus in Palompon, Leyte where fishing pressure is high and sound management formulation is necessary. S. canaliculatus is a group‐synchronous, multiple spawners with skewed sex ratio where males predominates over females. Maturity stages based on macroscopic examinations identified four maturity stages (immature, developing, mature and spent) while six maturity stages (immature, developing, mature, spawning, spent and re‐developing) were identified through histological analysis. A single ovo‐testis was identified among the 669 specimens examined. Based on histological sections, the smallest size of mature male was 5.5 cm standard length, and the smallest mature female was 7.1 cm standard length. On the other hand, length at first maturity for mature fish were 8.1 cm standard length for males and 9.7 cm standard length for females. Two defined peaks of gonadosomatic index were identified in both sexes: a major peak from February to May and a minor protracted one from July to December. Mature and older ovaries and testes occurred throughout the year, an indication of your round breeding season of S. canaliculatus in Palompon. Implementing a fishing ban during the major and the minor breeding spawning peaks would allow the mature and older individuals to contribute first to the population; allowing the continuity of the stock. [ABSTRACT FROM AUTHOR]

Indonesia is an archipelago that has a wealth of marine fish resources, and the country with the second-longest coastline in the world. The improvement witnessed in the economy of Indonesia in recent years, is as a result of the growth experienced in various sectors, among which is the fisheries and marine. To overcome this problem, a portable conveyor system of moving equipment for fishermen’s catches was designed. It can be placed at the dock or port where the fishermen are anchored and unloading the fishermen’s catches from the sea. It designed to have the ability to move up and down in the moving frame, making this conveyor system can be used both in high tides and low tides of seawater level conditions. The advantage of this portable conveyor system is could be done continuously with a little human power. Other than that, from the results of the calculations, known that with increasing motor rotation, the required traveling time will only become shorter. The resulting conveyor capacity shows an increase. Also, it can use drive motors that are available on the market with a power capacity of 0.37 kW. Therefore, the process of this portable conveyor system can be more efficient.

Blue Growth is a relatively new term that is meant to realize economic growth based on the exploitation of marine resources, while at the same time preventing their degradation, overuse, and pollution. This article discusses the relevance and usefulness of this new concept for the development of capture fisheries, a sector where growth largely seems impossible without ecological devastation. An analytical distinction between intensive and extensive growth is used to argue that certain development trajectories of capture fisheries might qualify as Blue Growth. Such trajectories of growth are illustrated with the development of the Swedish bleak roe trawl fishery in the Bothnian Bay and Norwegian whitefish fishery in the Barents Sea. Comparison of the cases highlights aspects that Blue Growth advocates might want to include if they choose to consider capture fisheries as a relevant economic activity. These aspects include: a) adding value through certification; b) technological development to make more efficient use of resources used up in the fishing operation, and to upgrade their fish as commodity; and c) specialization. [ABSTRACT FROM AUTHOR]

Feeding copepods during early larval culture stages of marine fish has proven to be advantageous for growth and survival of marine finfish larvae. However, commercial availability of most copepods is limited; thus, there is an impetus to evaluate promising copepod species to meet the diverse dietary demands of various marine fish. The marine cyclopoid copepod, Oithona colcarva, was isolated out of zooplankton samples taken from waters within Tampa Bay, Florida. Once isolated, trials were conducted to determine the appropriate culture parameters for producing nauplii to feed marine fish larvae. The effects of temperature (22°C, 26°C and 30°C), salinity (15, 20, 25, 30 and 35 g L−1), stocking density (0.5, 1.0, 2.0, 4.0 and 8.0 individuals mL−1) and diet (Nanno 3600 microalgae paste, Colurella adriatica, Rhodomonas lens, Tisochrysis lutea, Chaetoceros gracilis and/or Tetraselmis chuii) on nauplii production during a single life cycle of reproducing individuals were examined. Results of those trials indicated that a culture temperature of 30°C and a salinity of 30 g L−1 were advantageous for maximum nauplii production. Furthermore, a diet containing a 1:1:1 mixture of T. lutea, C. gracilis and T. chuii and a stocking density of at least 8 individuals mL−1 were identified as beneficial. The results of these trials, the potential for large-scale culture and observations on the performance of marine fish larvae fed Oithona colcarva nauplii are discussed. [ABSTRACT FROM AUTHOR]

Marine fish populations exist in a complex environment, with oceanographic and fisheries factors affecting their dynamics. It has been shown that life history characteristics of marine fish vary in space and time. We examined spatial variability in growth of eight groundfish species in the Northeast Pacific Ocean to identify shared spatial patterns and hypothesize about common mechanisms behind them. Growth parameters were estimated in different areas over the latitudinal range of the species, and several hypotheses were tested as to how these parameters vary along the US west coast. Clear differences in spatial growth variability emerged among the species examined. Shelf species exhibit the highest growth rate between Cape Blanco and Cape Mendocino, which may, in part, be attributed to area-specific upwelling patterns in the California Current ecosystem, when nutrient-rich deep water is brought to the surface south of Cape Blanco and is uniquely distributed throughout this area, providing favourable conditions for primary productivity. Slope species showed a cline in asymptotic size (L∞), with L∞ increasing from south to north. This cline, previously attributed to fishery removals, also fits a specific case of the widely described Bergmann's rule, and we explore specific potential ecological mechanisms behind this relationship. [ABSTRACT FROM AUTHOR]

The effects of 2 currently used commercial pesticide formulations on Pacific sockeye salmon ( Oncorhynchus nerka), from fertilization to emergence, were evaluated in a gravel-bed flume incubator that simulated a natural streambed. Embryos were exposed to atrazine at 25 µg/L (low atrazine) or atrazine at 250 µg/L (high atrazine) active ingredient (a.i.), and chlorothalonil at 0.5 µg/L (low chlorothalonil) or chlorothalonil at 5 µg/L a.i. (high chlorothalonil) and examined for effects on developmental success and timing, as well as physical and biochemical growth parameters. Survival to hatch was reduced in the high chlorothalonil group (55% compared with 83% in controls), accompanied by a 24% increase in finfold deformity incidence. Reduced alevin condition factor (2.9-5.4%) at emergence and elevated triglyceride levels were seen in chlorothalonil-exposed fish. Atrazine exposure caused premature hatch (average high atrazine time to 50% hatch [H50] = 100 d postfertilization [dpf]), and chlorothalonil exposure caused delayed hatch (high chlorothalonil H50 = 108 dpf; controls H50 = 102 dpf). All treatments caused premature emergence (average time to 50% emergence [E50]: control E50 = 181 dpf, low chlorothalonil E50 = 175 dpf, high chlorothalonil E50 = 174 dpf, high atrazine E50 = 175 dpf, low atrazine E50 = 174 dpf), highlighting the importance of using a gravel-bed incubator to examine this subtle, but critical endpoint. These alterations indicate that atrazine and chlorothalonil could affect survival of early life stages of sockeye salmon in the wild. Environ Toxicol Chem 2017;36:1354-1364. © 2017 SETAC [ABSTRACT FROM AUTHOR]

We estimated the current level of knowledge concerning several biological characteristics of the Mediterranean marine fishes by carrying out a gap analysis based on information extracted from the literature, aiming to identify research trends and future needs in the field of Mediterranean fish biology that can be used in stock assessments, ecosystem modeling and fisheries management. Based on the datasets that emerged from the literature review, there is no information on any biological characteristic for 43% (n = 310) of the Mediterranean fish species, whereas for an additional 15% (n = 109) of them there is information about just one characteristic. The gap between current and desired knowledge (defined here as having information on most biological characteristics for at least half of the Mediterranean marine fishes) is smaller in length-weight relationships, which have been studied for 43% of the species, followed by spawning (39%), diet (29%), growth (25%), maturity (24%), lifespan (19%) and fecundity (17%). The gap is larger in natural mortality for which information is very scarce (8%). European hake (Merluccius merluccius), red mullet (Mullus barbatus), annular seabream (Diplodus annularis), common pandora (Pagellus erythrinus), European anchovy (Engraulis encrasicolus), European pilchard (Sardina pilchardus) and bogue (Boops boops) were the most studied species, while sharks and rays were among the least studied ones. Only 25 species were fully studied, i.e. there was available information on all their biological characteristics. The knowledge gaps per characteristic varied among the western, central and eastern Mediterranean subregions. The number of available records per species was positively related to total landings, while no relationship emerged with its maximum reported length, trophic level and commercial value. Future research priorities that should be focused on less studied species (e.g. sharks and rays) and mortality/fecundity instead of length-weight relationships, as well as the economy of scientific sampling (using the entire catch to acquire data on as many biological characteristics as possible) are discussed. [ABSTRACT FROM AUTHOR]

This study examines the relationships between first year growth of juvenile Prince William Sound herring, temperature and their food. We present time series of herring first year growth, determined from scale measurements as a proxy for herring length, water temperature and indices of multiple trophic levels of plankton obtained from Continuous Plankton Recorder (CPR) sampling on the adjacent Gulf of Alaska shelf. We show that there was a significant correlation between herring growth and water temperature, when the three warmest years were excluded (the mean July and August temperatures were greater than 12.5°C in 1989, 2004 and 2005). There were also strong, significant relationships between the abundance of appropriately sized (for first-feeding herring) planktonic prey groups and herring growth. First year herring growth was greater in years with higher abundances of diatoms, microzooplankton and small mesozooplankton but not related to variability in abundance of larger mesozooplankton (such as euphausiids and large copepods). Furthermore, the strong interannual relationship between diatoms and herring growth held true even in the warmest years where the relationship between temperature and growth broke down. We also found seasonal timing and abundance changes in the plankton in warm years that would make the prey more abundant during the summer months immediately after metamorphosis of the herring larvae. We thus conclude that young-of-the-year herring may grow better in warm years because the timing of key prey is a better match for their first feeding. [ABSTRACT FROM AUTHOR]

The fisheries sector is crucial to the Bangladeshi economy and wellbeing, accounting for 4.4% of national gross domestic product and 22.8% of agriculture sector production, and supplying ca. 60% of the national animal protein intake. Fish is vital to the 16 million Bangladeshis living near the coast, a number that has doubled since the 1980s. Here, we develop and apply tools to project the long-term productive capacity of Bangladesh marine fisheries under climate and fisheries management scenarios, based on downscaling a global climate model, using associated river flow and nutrient loading estimates, projecting high-resolution changes in physical and biochemical ocean properties, and eventually projecting fish production and catch potential under different fishing mortality targets. We place particular interest on Hilsa shad (Tenualosa ilisha), which accounts for ca. 11% of total catches, and Bombay duck (Harpadon nehereus), a low price fish that is the second highest catch in Bangladesh and is highly consumed by low-income communities. It is concluded that the impacts of climate change, under greenhouse emissions scenario A1B, are likely to reduce the potential fish production in the Bangladesh exclusive economic zone by ,10%. However, these impacts are larger for the two target species. Under sustainable management practices, we expect Hilsa shad catches to show a minor decline in potential catch by 2030 but a significant (25%) decline by 2060. However, if overexploitation is allowed, catches are projected to fall much further, by almost 95% by 2060, compared with the Business as Usual scenario for the start of the 21st century. For Bombay duck, potential catches by 2060 under sustainable scenarios will produce a decline of ,20% compared with current catches. The results demonstrate that management can mitigate or exacerbate the effects of climate change on ecosystem productivity. [ABSTRACT FROM AUTHOR]

An increasing number of studies have examined the effects of elevated carbon dioxide (CO2) and ocean acidification on marine fish, yet little is known about the effects on large pelagic fish. We tested the effects of elevated CO2 on the early life history development and behaviour of yellowtail kingfish, Seriola lalandi. Eggs and larvae were reared in current day control (450 µatm) and two elevated CO2 treatments for a total of 6 d, from 12 h post-fertilization until 3 d post-hatching (dph). Elevated CO2 treatments matched projections for the open ocean by the year 2100 under RCP 8.5 (880 µatm CO2) and a higher level (1700 µatm CO2) relevant to upwelling zones where pelagic fish often spawn. There was no effect of elevated CO2 on survival to hatching or 3 dph. Oil globule diameter decreased with an increasing CO2 level, indicating potential effects of elevated CO2 on energy utilization of newly hatched larvae, but other morphometric traits did not differ among treatments. Contrary to expectations, there were no effects of elevated CO2 on larval behaviour. Activity level, startle response, and phototaxis did not differ among treatments. Our results contrast with findings for reef fish, where a wide range of sensory and behavioural effects have been reported. We hypothesize that the absence of behavioural effects in 3 dph yellowtail kingfish is due to the early developmental state of newly hatched pelagic fish. Behavioural effects of high CO2 may not occur until larvae commence branchial acid-base regulation when the gills develop; however, further studies are required to test this hypothesis. Our results suggest that the early stages of kingfish development are tolerant to rising CO2 levels in the ocean. [ABSTRACT FROM AUTHOR]

Increased oceanic uptake of atmospheric carbon dioxide (CO2) is a threat to marine organisms and ecosystems. Among the most dramatic consequences predicted to date are behavioural impairments in marine fish which appear to be caused by the interference of elevated CO2 with a key neurotransmitter receptor in the brain. In this study, we tested the effects of elevated CO2 on the foraging and shelter-seeking behaviours of the reef-dwelling epaulette shark, Hemiscyllium ocellatum. Juvenile sharks were exposed for 30 d to control CO2 (400 µatm) and two elevated CO2 treatments (615 and 910 µatm), consistent with medium- and high-end projections for ocean pCO2 by 2100. Contrary to the effects observed in teleosts and in some other sharks, behaviour of the epaulette shark was unaffected by elevated CO2. A potential explanation is the remarkable adaptation of H. ocellatum to low environmental oxygen conditions (hypoxia) and diel fluctuations in CO2 encountered in their shallow reef habitat. This ability translates into behavioural tolerance of near-future ocean acidification, suggesting that behavioural tolerance and subsequent adaptation to projected future CO2 levels might be possible in some other fish, if adaptation can keep pace with the rate of rising CO2 levels. [ABSTRACT FROM AUTHOR]

Increased oceanic uptake of atmospheric carbon dioxide (CO2) is a threat to marine organisms and ecosystems. Among the most dramatic consequences predicted to date are behavioural impairments in marine fish which appear to be caused by the interference of elevated CO2 with a key neurotransmitter receptor in the brain. In this study, we tested the effects of elevated CO2 on the foraging and shelter-seeking behaviours of the reef-dwelling epaulette shark, Hemiscyllium ocellatum. Juvenile sharks were exposed for 30 d to control CO2 (400 µatm) and two elevated CO2 treatments (615 and 910 µatm), consistent with medium- and high-end projections for ocean pCO2 by 2100. Contrary to the effects observed in teleosts and in some other sharks, behaviour of the epaulette shark was unaffected by elevated CO2. A potential explanation is the remarkable adaptation of H. ocellatum to low environmental oxygen conditions (hypoxia) and diel fluctuations in CO2 encountered in their shallow reef habitat. This ability translates into behavioural tolerance of near-future ocean acidification, suggesting that behavioural tolerance and subsequent adaptation to projected future CO2 levels might be possible in some other fish, if adaptation can keep pace with the rate of rising CO2 levels. [ABSTRACT FROM AUTHOR]

This study investigated and compared asymmetry in sagittal otolith shape and length between left and right inner ears in four roundfish and four flatfish species of commercial interest. For each species, the effects of ontogenetic changes (individual age and total body length), sexual dimorphism (individual sex) and the otolith's location on the right or left side of the head, on the shape and length of paired otoliths (between 143 and 702 pairs according to species) were evaluated. Ontogenetic changes in otolith shape and length were observed for all species. Sexual dimorphism, either in otolith shape and length or in their ontogenetic changes, was detected for half of the species, be they round or flat. Significant directional asymmetry in otolith shape and length was detected in one roundfish species each, but its inconsistency across species and its small average amplitude (6·17% for shape and 1·99% for length) suggested that it has barely any biological relevance. Significant directional asymmetry in otolith shape and length was found for all flatfish species except otolith length for one species. Its average amplitude varied between 2·06 and 17·50% for shape and between 0·00 and 11·83% for length and increased significantly throughout ontogeny for two species, one dextral and one sinistral. The longer (length) and rounder otolith (shape) appeared to be always on the blind side whatever the species. These results suggest differential biomineralization between the blind and ocular inner ears in flatfish species that could result from perturbations of the proximal-distal gradient of otolith precursors in the endolymph and the otolith position relative to the geometry of the saccular epithelium due to body morphology asymmetry and lateralized behaviour. The fact that asymmetry never exceeded 18% even at the individual level suggests an evolutionary canalization of otolith shape symmetry to avoid negative effects on fish hearing and balance. Technically, asymmetry should be accounted for in future studies based on otolith shape. [ABSTRACT FROM AUTHOR]

Insulin-like growth factor (Igf) is the key regulator for development, growth, and reproduction. In most vertebrate species, the Igf family has two forms: Igf1 and Igf2. A novel form of Igf, termed Igf3, was recently discovered in fish. In the present study, we isolated igf3 from the orange-spotted grouper ( Epinephelus coioides ). The orange-spotted grouper igf3 consisted of a full-length cDNA of 1014 nucleotides with an open reading frame (ORF) of 597 bp, encoding for proteins of 199 amino acid residues in length. Tissue distribution analysis showed that igf1 widely expressed with the highest expression in the pituitary and liver. igf2 was expressed highly in all the tissues except the olfactory bulb, while igf3 showed the highest expression in the ovary, and moderate expression in brain areas. The expression profiles of three igf genes during the ovarian development and growth hormone (Gh) and human chorionic gonadotropin (hCG) treatment were also investigated. Three igf genes exhibited different expression patterns during the ovarian development, and showed different responses to the Gh and hCG treatments, appearing to play distinct roles in ovarian development. The present study provides further evidence for the existence of an intraovarian Igf system in orange-spotted grouper. [ABSTRACT FROM AUTHOR]

Estimated length-weight relationships are presented for 11 marine fish species representing six families, found above the continental shelf and in the pelagial of the Okhotsk Sea. A total of 13,841 specimens were caught by trawls that were equipped with a 1.0 by 1.2 cm mesh webbing inset. The period between 1974 and 2015 comprised mostly spring and autumn months. All length-weight relationships were highly significant ( r2 ≥ .95) on a log scale. None of the species had previous length-weight estimates, and two species had no previous length-length estimates in the FishBase. [ABSTRACT FROM AUTHOR]

The article reports presence of the fish Champsodon vorax in the Aegean Sea. Topics discussed include collection of specimen of C. vorax from the sea, morphological analysis revealing meristic counts on all fins, body color found to be dark brown with blotches on dorsal fin, increased colonization rate of Champsodon in the Mediterranean sea, water circulation pattern and ambient temperature of sea being responsible for increased growth of the fish.

Summary The world’s oceans are home to many fantastic creatures, including about 16,000 species of actinopterygian, or ray-finned, fishes. Notably, 85% of marine fish species come from a single actinopterygian subgroup, the acanthomorph or spiny-rayed fishes. Here, we review eight functional innovations found in marine acanthomorphs that have been instrumental in the adaptive radiation of this group in the marine realm. Jaw protrusion substantially enhances the suction feeding mechanism found in all fish. Fin spines serve as a major deterrent to predators and enhance the locomotor function of fins. Pharyngognathy, a specialization of the second pair of jaws in the pharynx, enhances the ability of fishes to process hard and tough prey. Endothermy allows fishes to function at high levels of physiological performance in cold waters and facilitates frequent movement across strong thermal gradients found in the open ocean. Intramandibular joints enhance feeding for fishes that bite and scrape prey attached to hard surfaces. Antifreeze proteins prevent ice crystal growth in extracellular fluids, allowing fish to function in cold waters that would otherwise freeze them. Air-breathing allowed fishes at the water’s edge to exploit terrestrial habitats. Finally, bioluminescence functions in communication, attracting prey and in hiding from predators, particularly for fishes of the deep ocean. All of these innovations have evolved multiple times in fishes. The frequent occurrence of convergent evolution of these complex functional novelties speaks to the persistence and potency of the selective forces in marine environments that challenge fishes and stimulate innovation. [ABSTRACT FROM AUTHOR]

Summary Sharks, rays, and chimaeras (Class Chondrichthyes; herein ‘sharks’) are the earliest extant jawed vertebrates and exhibit some of the greatest functional diversity of all vertebrates. Ecologically, they influence energy transfer vertically through trophic levels and sometimes trophic cascades via direct consumption and predation risk. Through movements and migrations, they connect horizontally and temporally across habitats and ecosystems, integrating energy flows at large spatial scales and across time. This connectivity flows from ontogenetic growth in size and spatial movements, which in turn underpins their relatively low reproductive rates compared with other exploited ocean fishes. Sharks are also ecologically and demographically diverse and are taken in a wide variety of fisheries for multiple products (e.g. meat, fins, teeth, and gills). Consequently, a range of fisheries management measures are generally preferable to ‘silver bullet’ and ‘one size fits all’ conservation actions. Some species with extremely low annual reproductive output can easily become endangered and hence require strict protections to minimize mortality. Other, more prolific species can withstand fishing over the long term if catches are subject to effective catch limits throughout the species’ range. We identify, based on the IUCN Red List status, 64 endangered species in particular need of new or stricter protections and 514 species in need of improvements to fisheries management. We designate priority countries for such actions, recognizing the widely differing fishing pressures and conservation capacity. We hope that this analysis assists efforts to ensure this group of ecologically important and evolutionarily distinct animals can support both ocean ecosystems and human activities in the future. [ABSTRACT FROM AUTHOR]