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Introduction: The coral reefs of Isla del Coco National Park are some of the most pristine ecosystems on Earth. The sea urchin Diadema mexicanum (Diadematoida: Diadematidae) is a common inhabitant with a pivotal role in the ecology of this unique ecosystem. Objective: In this study, we identified the predominant predators of D. mexicanum and estimated the predatory consumption rates. We also determined predation rates at different sea urchin sizes and at sites with contrasting refuge availability. Methods: We use field video recording observations and tethering experiments. Results: The balistid Sufflamen verres and the labrid Bodianus diplotaenia were identified as predators of small and medium size D. mexicanum; the labrids Thalassoma grammaticum and B. diplotaenia (juvenile) and the tetraodontid Arothron meleagris were attempted predators; and Canthigaster punctatissima and Holacanthus passer were scavengers. Larger sea urchins (> 30 mm) were also preyed upon during the tethering experiments. Furthermore, a clear effect of the site on survival of the different sea urchins' sizes was noted. No difference in the sea urchin predator biomass was found among sites, which highlights the importance of site complexity on survival. At high and medium complexity sites, large individuals had better survival, while at the low complexity site, there was almost no differences in survival rates among the three size classes. Our results also show that a high abundance of these predatory fishes, above 0.04 ind m-2, guarantees a low sea urchin density. Below this threshold, a higher variability in sea urchin density is observed Despite not being registered with the video recordings, lobsters were observed once preying upon a large sea urchin individual. Conclusions: This study identifies a keystone fish guild with high predation rate for Diadema in the National Park, which suggests that protective actions have positively benefited predatory fish and lobster populations. [ABSTRACT FROM AUTHOR]

Context: Balistes capriscus is relevant for fishing worldwide, but there is no consistent information on the maintenance of the species in a captive environment. Aims: Develop protocols for the reproduction of the species in aquaculture systems, contributing to the maintenance of the supply in the commerce through captive breeding. Methods: A Balistes capriscus couple was selected on the basis of behavioural observations. Nutritional and environmental stimuli were invested in obtaining natural spawning. After reproduction, the larvae were regularly observed under an microscope to monitor the ontogenic development. In larviculture, feeds based on Brachionus plicatilis (10 mL−1) and Nannochloropsis oculata (150 000 cells mL−1) and pate formulated with Artemia salina , Nannochloropsis oculata , sardines and commercial feed were evaluated. Key results: The eggs had a diameter of 667.5 μm (±21.66) and formed a mass adhered to the substrate. Newly hatched larvae had a total length of 1653.63 μm (±213.97). The first food intake was evidenced 72 h after hatching; however, larvae did not survive more than 6 days. Conclusions: The reproduction in laboratory of the species is viable; however, larviculture remains a limiting factor. Implications: The success in captive breeding is essential for the introduction of B. capriscus in aquaculture, and for the conservation of the species. This study observed the formation of a pair within a group of grey triggerfish (Balistes capriscus) in the laboratory, culminating in reproduction and enabling studies on the larviculture of the species. The results indicated that it is possible to keep small groups of breeders in captivity, but the individualisation of couples may be necessary, because of the aggressiveness towards other individuals. The hatchery phase is still a strong limiting factor for the artificial propagation of the species, because it demonstrates specificity regarding the first exogenous food. [ABSTRACT FROM AUTHOR]

A single specimen of the grey triggerfish, Balistes capriscus Gmelin, 1789, was caught by a speargun at 18 m water depth in the vicinity of the Çanakkale Strait in the Turkish Straits System, between the Aegean Sea and the Marmara Sea. Its total length was 57.8 cm and weight was 2270 g. The given size is the maximum observed length for the grey triggerfish, B. capriscus, in the Mediterranean Sea. In addition, this paper also documented the first confirmed record of the grey triggerfish, B. capriscus in the Çanakkale Strait (the Turkish Straits System). [ABSTRACT FROM AUTHOR]

Aquarium trade constitutes an important pathway for the introduction of non-indigenous aquatic organisms in several parts of the world. Here, based on a series of observations carried out along the Lebanese coasts, we document the first record of four non-indigenous fish species in the Mediterranean Sea. The paper discusses their occurrence as releases from home aquaria as the most plausible mean of introduction. [ABSTRACT FROM AUTHOR]

Presentamos cinco nuevos registros de peces para el área marina del Parque Nacional Sistema Arrecifal Veracruzano, con evidencia fotográfica y se proveen los datos morfométricos y merísticos básicos: el miraestrellas Gillellus greyae (70.3 mm, Longitud total), el góbido Oxyurichthys stigmalophius (36 mm, Longitud total), el cochito manchado Canthidermis maculata (342.4 mm, Longitud total) y el pez vela Istiophorus platypterus (≈1,800 mm, Longitud total) se distribuyen ampliamente en el Caribe; además del primer registro en el Golfo de México del lenguado manchado Bothus maculiferus (250 mm, Longitud total).

The feeding habits and reproductive biology of red-toothed triggerfish Odonus niger (Ruppell, 1836) was analysed from 449 specimens collected from the Karnataka coast of the south-eastern Arabian Sea. Of the total stomachs examined, only 54 (12%) were empty and 395 contained food remains. The diet comprised crustacean remains (48.0%), zooplankton (21.4%), algae (16.5%), fish remains (6.1%) and cephalopod remains (5.3%) along with partially digested matter (2.3%) and detritus (0.4%). The species was found to be a generalist feeder and an omnivore. The overall sex ratio between males and females (1: 0.44) was significantly (P < 0.05) different. Histological examination of the ovaries indicated asynchronous ovarian development in females, with males maturing earlier than females. The gonadosomatic index (GSI) patterns of males and females, and the presence of ripe ovaries and spermatozoids suggested that April–May is the peak spawning period. The absolute and relative fecundity estimates ranged from 16,464–312,420 eggs and 251–2812 eggs g−1 respectively. Fecundity was positively correlated with total length and body weight. The biological information on diet composition and reproductive traits provided for the first time in this study can facilitate conservation, management and sustainable exploitation of this species in the study area. [ABSTRACT FROM AUTHOR]

The present paper reports five ornamental triggerfishes (Tetraodontiformes: Balistidae) for the first time from the coastal waters of West Bengal. The five species namely, Balistapus undulatus (Park, 1797) Balistoides viridescens (Bloch & Schneider, 1801), Canthidermis maculata (Bloch, 1786), Odonus niger (Ruppell, 1836) and Sufflamen fraenatum (Latreille, 1804) are reported here for the first time from West Bengal coast with detailed morphometry. [ABSTRACT FROM AUTHOR]

This study evaluated the functional role of the highly generalist omnivore Melichthys niger in the remote St. Peter and St Paul's Archipelago (SPSPA), Brazil, where grazing herbivorous fishes are very scarce. We analysed patterns of distribution from zero to 30 m deep during three time intervals during the day and sampled different aspects of their feeding behaviour, including diel feeding rate, feeding substrate and diet. The density of M. niger increased with depth (26–30 m) and decreased by the end of the day. Although M. niger did not present a typical herbivore diel feeding pattern, they targeted the epilithic algal matrix as their primary feeding substrate, ingesting predominantly algae and detritus. The characteristic Caulerpa racemosa var. peltata from SPSPA was ingested only as detached fronds. We suggest that in the isolated SPSPA, the single species M. niger may perform a unique role as a link between benthic primary production and higher levels. Further studies on the trophic ecology of omnivorous species are necessary to better understand their roles in a reef system, especially in impoverished areas where they are likely to play a crucial role. [ABSTRACT FROM AUTHOR]

Movement is a central feature of the ecology of fish, yet the study of fish movement has been inhibited due to its multidimensional nature and technological and analytical limitations. We used a relatively new fine-scale acoustic tracking system to quantify movements of an economically valuable, demersal marine fish species (gray triggerfish Balistes capriscus) on a natural hardbottom reef on the continental shelf of North Carolina, USA. Overall, 30 fish were tagged and released, and 104,170 highly precise (˜1–3 m) spatial positions were estimated during the 43-d study. To quantify gray triggerfish movements, we used a combination of exploratory data analyses and hidden Markov models (HMM), the latter of which can identify and elucidate normally hidden behavioral states. Both methods suggested gray triggerfish movements varied by diel period and among individuals, and that some of the variation among individuals could be explained by fish size. Depending on model specification, HMMs identified two or three behavioral states, one of which was likely resting that occurred mostly at night and another was likely foraging or transit that occurred mostly during the day. Moreover, resting at night occurred in small, discrete patches within the study area, whereas foraging or transit behaviors occurred broadly throughout the study area. We encourage a wider use of acoustic telemetry and HMMs to shed light on the normally hidden behaviors of demersal fishes. [ABSTRACT FROM AUTHOR]

Abstract The present study aims to develop natural biopolymer bioactive edible films. Particularly, blend (F-Bl) and bilayer (F-Bi) films based on grey triggerfish skin gelatin (G) and agar (A), incorporated or not with vine leaves ethanolic extract (VLE), at 5 and 10 mg/mL, were prepared using the casting method. First, VLE presented an important antioxidant potential evaluated by the iron (Fe2+) chelating activity, ferric (Fe3+) reducing antioxidant power, β-carotene bleaching protection and DPPH•-radical scavenging activity. Furthermore, VLE presented interesting antibacterial and antifungal activities. On the other hand, the composite films were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR), physicochemical, and thermal analyses. SEM micrographs showed that agar and gelatin were compatible. Moreover, the mechanical properties results showed that F-Bl and F-Bi were mechanically stronger and more deformable than control films. This change in mechanical properties can be explained by the formation of a dense network after agar addition, due to the interactions with the gelatin matrix. After their incorporation into polymer network, VLE increased slightly the thermal stability, while it improved greatly the antioxidant activity of the composite films (gelatin and agar) in a dose dependent manner. Thus, results encourage the further use of gelatin/agar/VLE films as active food packaging material. Graphical abstract Image Highlights • Bio-based blend films based on fish gelatin and agar were prepared. • Addition of agar resulted in more resistant films. • Antioxidant power of the films increased with the incorporation of vine leaves extract. • Cross section micrographs demonstrated the good compatibility between both polymers. • Fish gelatin-agar/VLE films can act as a biodegradable and bioactive packaging film. [ABSTRACT FROM AUTHOR]

Colour vision mediates ecologically relevant tasks for many animals, such as mate choice, foraging and predator avoidance. However, our understanding of animal colour perception is largely derived from human psychophysics, and behavioural tests of non-human animals are required to understand how colour signals are perceived. Here, we introduce a novel test of colour vision in animals inspired by the Ishihara colour charts, which are widely used to identify human colour deficiencies. In our method, distractor dots have a fixed chromaticity (hue and saturation) but vary in luminance. Animals can be trained to find single target dots that differ from distractor dots in chromaticity. We provide MATLAB code for creating these stimuli, which can be modified for use with different animals. We demonstrate the success of this method with triggerfish, Rhinecanthus aculeatus, which quickly learnt to select target dots that differed from distractor dots, and highlight behavioural parameters that can be measured, including success of finding the target dot, time to detection and error rate. We calculated discrimination thresholds by testing whether target colours that were of increasing colour distances (ΔS) from distractor dots could be detected, and calculated discrimination thresholds in different directions of colour space. At least for some colours, thresholds indicated better discrimination than expected from the receptor noise limited (RNL) model assuming 5% Weber fraction for the long-wavelength cone. This methodology could be used with other animals to address questions such as luminance thresholds, sensory bias, effects of sensory noise, colour categorization and saliency. [ABSTRACT FROM AUTHOR]

Edges are salient visual cues created by abrupt changes in luminance and color and are crucial in perceptual tasks such as motion detection and object recognition. Disruptively colored animals exploit edge detection mechanisms to obscure their body outline and/or to conceal themselves against their background. Conversely, aposematic species may use contrasting patterns with well-defined edges to create highly salient, memorable warning signals. In this study, we investigated how the amount of internal pattern edge, colored area, pattern type, or shape repetition of warning signals influenced avoidance learning in the triggerfish, Rhinecanthus aculeatus. Using 6 different warning signals, we found that fish learnt to avoid aposematic signals faster when they featured more internal pattern edge. We found little evidence that the amount of colored area or pattern type affected learning rates. An optimal amount of pattern edge within a warning signal may therefore improve how warning signals are learnt. These findings offer important insights into the evolution of prey warning signal evolution and predator psychology. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate for the first time the wound healing and in vivo anti-inflammatory effects of glycosaminoglycans from skins of smooth hound (SHSG) and grey triggerfish (GTSG). Thermal analysis of GTSG and SHSG was evaluated using differential scanning calorimetry (DSC). The rheologie properties and water absorption capacity of two gels prepared from SHSG and GTSG were also studied. The application of GTSG and SHSG based gels on dermal full-thickness excision wounds in a mouse model, enhanced significantly wound healing activity and a total closure was achieved after eleven days of wound induction for SHSG. Further, histological examination of biopsies showed advanced tissue regeneration, characterized by the presence of well-organized stratum of both derma and epidermis. The anti-inflammatory evaluation of GTSG and SHSG in mice showed a significant inhibition of edema paw, after 5 h of carrageenan injection. The edema inhibition was 91.6% and 90% for SHSG and GTSG, respectively at the dose of 50 mg/kg. Furthermore, the histological evaluation and the superoxide dismutase, catalase and malondialdehyde level in muscle tissue were investigated. In summary, this work demonstrates that both GTSG and SHSG could be promising drugs with good wound healing and anti-inflammatory effects in animal model. [ABSTRACT FROM AUTHOR]

Abstract Urchins are ubiquitous components of coral reefs ecosystems, with significant roles in bioerosion and herbivory. By controlling urchin densities, triggerfishes have been identified as keystone predators. However, the functional linkages between urchins and triggerfishes, in terms of distributional patterns and concomitant effects on ecosystem processes, are not well understood, especially in relatively unexploited systems. To address this we censused urchins and triggerfishes on two cross-shelf surveys on the Great Barrier Reef (GBR) at the same times and locations. We also evaluated the role of urchins in bioerosion. Although urchin abundance and triggerfish biomass varied by 80% and nearly 900% across sites, respectively, this variability was driven primarily by shelf position with no evidence of top-down control on urchins by triggerfishes. Low urchin abundances meant urchins only played a minor role in bioerosion. We highlight the potential variability in functional links, and contributions to ecosystem processes, among regions. Graphical abstract Image 1 Highlights • Urchin and triggerfish densities were compared across the Great Barrier Reef. • Urchin bioerosion was compared with other bioeroders. • Triggerfish do not drive urchin distributions. • Urchins were generally rare and played a very minor role in bioerosion. • Factors other than top-down control mediate urchin densities. [ABSTRACT FROM AUTHOR]

This study evaluates the habitat characteristics, fishing effort, and production, as well as changes in the individuals, such as changes in size frequency, of the spawning aggregations of mutton snapper Lutjanus analis and grey triggerfish Balistes capriscus, caught in the Chinchorro Bank Biosphere Reserve (CBBR), Mexico. The mutton snapper aggregation was located in coral patches, while the spawning aggregation of grey triggerfish was located on the windward terrace of the reef flat. Fishery data was obtained for the duration of the spawning event in 2008, with a total of 5 days for mutton snapper and 4 days for grey triggerfish. The fishery recorded a total of 830 mutton snappers, with individual sizes ranging from 40 to 77 cm in fork length (FL). Individual size and catch per unit effort (CPUE) decreased through time, with the lowest values presented at the end of the 5 days. In contrast, a total of 665 grey triggerfish were recorded in the catch, ranging from 45 to 61 cm (FL) with the largest sizes caught at the end of the fishing period, concurrently with the lowest CPUE. A lack of governance allowed both species to be harvested during their spawning aggregations. The creation of an international body composed of fishers, managers, conservationists, and scientists from the countries belonging to the Mesoamerican Reef System is urgently required to look for agreements in conservation and management strategies of these commercially important species. [ABSTRACT FROM AUTHOR]

Field removal and laboratory studies examined competitive interactions between gray triggerfish (Balistes capriscus) and red snapper (Lutjanuscampechanus). In field studies, all gray triggerfish and red snapper were counted and sizes estimated on 24 reef sites. Gray triggerfish were then removed from half of these reef sites, resulting in significantly fewer gray triggerfish on the removal reefs at the start of the experiment. After 7 months the experiment ended and reef sites were resurveyed. Gray triggerfish decreased on both treatments, while the mean number of red snapper did not differ between treatments; however, there were significantly more small (<400 mm total length) red snapper on reefs where gray triggerfish were removed. In seven laboratory growth trials (30 to 35 days each), red snapper held with gray triggerfish had significantly lower growth rates and numerous bite marks compared with red snapper alone. These competitive interactions indicate that management efforts to rebuild and increase gray triggerfish populations may have unintentional negative effects on red snapper populations, particularly for smaller fish. [ABSTRACT FROM AUTHOR]

Despite high rates of photosynthetic oxygen production during the day, the warm waters of coral reefs are susceptible to hypoxia at night due to elevated respiration rates at higher temperatures that also reduce the solubility of oxygen. Hypoxia may be a challenge for coral-reef fish that hide in the reef to avoid predators at night. Triggerfishes (Balistidae) are found in a variety of reef habitats, but they also are known to find refuge in reef crevices and holes at night, which may expose them to hypoxic conditions. The critical oxygen tension (Pcrit) was determined as the point below which oxygen uptake could not be maintained to support standard metabolic rate (SMR) for five species of triggerfish. The triggerfishes exhibited similar levels of hypoxia tolerance as other coral-reef and coastal marine fishes that encounter low oxygen levels in their environment. Two species, Rhinecanthus rectangulus and R. aculeatus, had the lowest Pcrit (~ 3.0 kPa O2), comparable to the most hypoxia-tolerant obligate coral-dwelling gobies, while Odonus niger and Sufflamen bursa were moderately tolerant to hypoxia (Pcrit ~ 4.5 kPa), and Xanthichthys auromarginatus was intermediate (Pcrit ~ 3.7 kPa). These differences in Pcrit were not due to differences in oxygen demand, as all the species had a similar SMR once mass differences were taken into account. The results suggest that triggerfish species are adapted for different levels of hypoxia exposure during nocturnal sheltering within the reef. [ABSTRACT FROM AUTHOR]

Gelatins from grey triggerfish skin were extracted with different methods. The treatment by pepsin (PG) improved the yield of extraction when compared with untreated gelatin (UG) and acidic gelatin (AG). The outputs of gelatins AG, UG and PG, obtained respectively, with acitic acid, glycine buffer and glycine buffer added with 5 U of pepsin/g of the skin beforehand treated by alkali, were 6.9%, 7.9% and 9.7%, respectively. The enzymatic treatment of the alkali-pretreated skin of grey triggerfish altered the electrophoresis profile, biophysical, gellification, rheological and thermal properties of the prepared gelatins extracted under acidic condition. However, the untreated gelatin obtained without pepsin exhibited the highest transition and enthaply temperatures. In addition, the properties of the prepared films were interconnected to their microstructure as demonstrated by scanning electron microscopy. Furthermore, films with PG and UG had a regular surface and a more condensed structure, whereas films prepared with AG had rougher surface. [ABSTRACT FROM AUTHOR]

A feeding trial was designed to assess the effects of dietary protein and lipid content on growth, feed utilization efficiency, body composition, and hematological indices of juvenile filefish, Stephanolepis cirrhifer. Eight experimental diets were formulated with a combination of four protein (35, 40, 45, and 50%) and two dietary lipid levels (7 and 14%). Each diet was fed to triplicate groups of fish (3.2 ± 0.06 g) to apparent satiation for 8 wk. Fish growth performance and feed utilization were significantly affected by increasing dietary protein and lipid levels, with no significant interactions between factors. The highest growth performance value, in terms of weight gain, was observed in groups fed the diets with 50% protein (399%). However, fish fed the diet containing 45% protein had comparable growth (357%) while achieving relatively higher protein efficiency ratio. Hepatosomatic index was significantly affected by interaction of dietary lipid and protein with the highest values observed in those fish fed the highest protein (45-50%) and lipid (14%) diets. There was a significant increase in body lipid content (5.1 to 6.6%) and a decrease in body protein (15.8 to 14.8%) and ash (2.47 to 2.16%) with increasing dietary lipid levels from 7 to 14%. Muscle lipid content was significantly affected by both dietary protein and lipid levels and tended to increase with increasing dietary protein and lipid levels, ranging from 0.13 to 1.20%. Liver lipid content (65.9 to 68.7%) was significantly increased with the increase in dietary lipid levels while liver moisture content (28.9 to 25.9%) showed a clear decreasing trend. Hematological values were also altered with the increase in either dietary protein or lipid levels. These findings may suggest that a diet containing 45% protein and 7% lipid, with a protein to energy ratio of 23.8 mg/ kJ, could deliver sufficient nutrient and energy to support acceptable growth and feed utilization and avoid excessive fat deposition in juvenile filefish. [ABSTRACT FROM AUTHOR]

Fish stock assessments based solely on energy flow through the ecosystem are not good predictors of population dynamics. To accurately forecast the response of populations within one or more ecological regimes, consideration must be given to non-trophic mechanisms allowing interactions inside the system, and fish behaviour in response to changes in their habitats. The example of the grey triggerfish (Balistes capriscus) in West Africa shows that fisheries biology is unable to model satisfactorily the life of a fish population. The Ecosystem Approach to Fisheries improves the models but does not overcome this fundamental limitation. Data from direct observations of fish biology and behaviour must be added to the catch and environmental data to help to design energetic-cybernetic models in order to anticipate non-linear and chaotic dynamics. This requires adding data collected by fishers (e.g. underwater acoustics) to scientific data bases, conceiving environmental indicators (e.g. habitat), and using scenarios to anticipate the reactions of populations to regime shifts. It also requires a good understanding of the population structures and strategies. We developed the concept of "pelagic metapopulation" which, through comparative analysis with the jack mackerel (Trachurus murphyi), allowed us to propose a hypothesis explaining the history of the grey triggerfish population. [ABSTRACT FROM AUTHOR]

Warning signal variation is ubiquitous but paradoxical: low variability should aid recognition and learning by predators. However, spatial variability in the direction and strength of selection for individual elements of the warning signal may allow phenotypic variation for some components, but not others. Variation in selection may occur if predators only learn particular colour pattern components rather than the entire signal. Here, we used a nudibranch mollusc, Goniobranchus splendidus, which exhibits a conspicuous red spot/ white body/yellow rim colour pattern, to test this hypothesis. We first demonstrated that secondary metabolites stored within the nudibranch were unpalatable to a marine organism. Using pattern analysis, we demonstrated that the yellow rim remained invariable within and between populations; however, red spots varied significantly in both colour and pattern. In behavioural experiments, a potential fish predator, Rhinecanthus aculeatus, used the presence of the yellow rims to recognize and avoid warning signals. Yellow rims remained stable in the presence of high genetic divergence among populations. We therefore suggest that how predators learn warning signals may cause stabilizing selection on individual colour pattern elements, and will thus have important implications on the evolution of warning signals. [ABSTRACT FROM AUTHOR]

A baited videographic survey at Pitcairn Island has significantly extended the known range for two reef-fish species: blue-lined triggerfish Xanthichthys caeruleolineatus and greater amberjack Seriola dumerili, with an additional minor extension noted for giant trevally Caranx ignobilis. This highlights the importance of further research in this remote, poorly studied island group and provides evidence supplementing the understanding of oceanographic patterns in the South Pacific. [ABSTRACT FROM AUTHOR]

Following the 2010 Gulf of Mexico oil spill, concerns were raised regarding exposure of fish to crude oil components, particularly polycyclic aromatic hydrocarbons (PAHs). This three year study examined hepatic enzymes in post-mitochondrial supernatant fractions from red snapper ( Lutjanus campechanus ) and gray triggerfish ( Balistes capriscus ) collected in the north central Gulf of Mexico between 2011 and 2014. Biomarker activities evaluated included benzo( a )pyrene hydroxylase (AHH), ethoxyresorufin O -deethylase (EROD), glutathione transferase (GST), and glutathione peroxidase (GPx). Mean EROD activity was higher in gray triggerfish (12.97 ± 7.15 pmol/min/mg protein [mean ± SD], n = 115) than red snapper (2.75 ± 1.92 pmol/min/mg protein, n = 194), p < 0.0001. In both species, EROD declined over time between 2011 and 2014. Declines in GST and GPx activities were also noted over this time period for both species. Gray triggerfish liver was fatty, and heptane extracts of the liver fat contained fluorescent substances with properties similar to known PAHs, however the origin of these PAHs is unknown. [ABSTRACT FROM AUTHOR]

Few data exist to evaluate the performance or assess the potential impacts of hook regulations on catchability or selectivity of recreational fisheries in the northern Gulf of Mexico. The purpose of this study was to test the effects of hook type (circle vs. J hook) and hook size (1/0, 4/0, and 7/0) on catch composition, traumatic hooking, species-specific catches, and size-selectivity of red snapper, Lutjanus campechanus, and grey triggerfish, Balistes capriscus. Selectivity was estimated by conditioning size distributions from hook-specific catches against in situ size distributions observed with a remotely operated vehicle. Deep hooking (hook set in gills or beyond) was low in all hook treatments for red snapper (<10%) and grey triggerfish (<6%), but was generally higher with J hooks, especially for other fishes caught with the largest J hook (34%). Hook type did not significantly affect catches, but catches decreased significantly with increasing hook size in all groups except red snapper. Selectivity curves were dome-shaped for both focus species in all hook treatments and selection peaks were similar among treatments for red snapper. Peak selectivity was 78.1mm larger for J hooks than circle hooks for grey triggerfish. Overall, study results indicate that the circle hook regulation may have reduced traumatic hooking mortality by up to 50%, and that catchability is similar between hook types for both red snapper and grey triggerfish when controlling for hook size. Strong dome-shaped selection estimated for nearly all selectivity curves suggest logistic size-selectivity assumptions in assessment models are likely inappropriate for recreational sectors targeting red snapper or grey triggerfish. [ABSTRACT FROM AUTHOR]

Abstract: Intraocular pressure, a major modifiable risk factor for glaucoma, has been shown to fluctuate throughout the day in patients with glaucoma. The detection and measurement of this fluctuation may help guide the clinical management of glaucomatous individuals. The Sensimed Triggerfish contact lens sensor (CLS), which has recently gained approval for marketing in the USA, is designed to detect intraocular pressure-related changes in an eye over a 24-hour period. This review will provide an overview of the Triggerfish CLS, as well as summarize current clinical data pertaining to the device. Overall, the current evidence suggests that the Triggerfish CLS is safe and well tolerated, and provides reproducible results. One challenge of using the Triggerfish CLS is that it may only provide data on relative changes in intraocular pressure rather than absolute intraocular pressure. In addition, its validity at estimating intraocular pressure compared to other methods is still controversial. Despite these limitations, recent studies suggest a myriad of potential indications for the Triggerfish CLS, including predicting glaucomatous progression and predicting efficacy of glaucoma treatment. With further research, the Triggerfish CLS may become a useful tool for eye care practitioners. [ABSTRACT FROM AUTHOR]

In diverse tropical webs, trophic cascades are presumed to be rare, as species interactions may dampen top-down control and reduce their prevalence. To test this hypothesis, we used an open experimental design in the Galápagos rocky subtidal that enabled a diverse guild of fish species, in the presence of each other and top predators (sea lions and sharks), to attack two species of sea urchins grazing on benthic algae. Time-lapse photography of experiments on natural and experimental substrates revealed strong species identity effects: only two predator species–blunthead triggerfish (Pseudobalistes naufragium) and finescale triggerfish (Balistes polylepis)–drove a diurnal trophic cascade extending to algae, and they preferred large pencil urchins (Eucidaris galapagensis) over green urchins (Lytechinus semituberculatus). Triggerfish predation effects were strong, causing a 24-fold reduction of pencil urchin densities during the initial 21 hours of a trophic cascade experiment. A trophic cascade was demonstrated for pencil urchins, but not for green urchins, by significantly higher percent cover of urchin-grazed algae in cages that excluded predatory fish than in predator access (fence) treatments. Pencil urchins were more abundant at night when triggerfish were absent, suggesting that this species persists by exploiting a nocturnal predation refuge. Time-series of pencil urchin survivorship further demonstrated per capita interference effects of hogfish and top predators. These interference effects respectively weakened and extended the trophic cascade to a fourth trophic level through behavioral modifications of the triggerfish-urchin interaction. We conclude that interference behaviors capable of modifying interaction strength warrant greater attention as mechanisms for altering top-down control, particularly in speciose food webs. [ABSTRACT FROM AUTHOR]

The potential of aqueous two-phase system (ATPS) for the purification and recovery of proteinase from albacore tuna (Thunnus alalunga) liver was explored. Influence of phase compositions such as type of phase forming salts, PEG molecular weight, concentration of salt and PEG, pH of the system, and NaCl addition on partitioning of proteinase was investigated. ATPS comprising PEG1000 (25%, w/w) and NaH2PO4(20%, w/w) at pH 7.0 provided the best condition for the maximum partitioning of proteinase into the top phase and gave the highest purification factor (5.58-fold) and specific activity (20.65 unit/mg protein). The yield of 89.99% was obtained. The addition of NaCl up to a final concentration of 6% (w/w) decreased the degree of purification and enzyme recovery of proteinase. Based on electrophoresis and activity staining, the fractionated proteinases had the MW 21, 24, 30, and 34 kDa. The effect of fractionated proteinases on starry triggerfish (Abalistes stellaris) muscle hydrolysis was also studied. Fractionated proteinases were able to hydrolyze triggerfish muscle in a dose-dependent manner. Overall, results demonstrated the feasibility of ATPS for the recovery and purification of proteinase without the need for multiple steps, and the obtained proteinase can be further in preparation of protein hydrolysate. [ABSTRACT FROM AUTHOR]

Chondroitin sulfate/dermatan sulfate GAGs were extracted and purified from the skins of grey triggerfish (GTSG) and smooth hound (SHSG). The disaccharide composition produced by chondroitinase ABC treatment showed the presence of nonsulfated disaccharide, monosulfated disaccharides ΔDi6S and ΔDi4S, and disulfated disaccharides in different percentages. In particular, the nonsulfated disaccharide ΔDi0S of GTSG and SHSG were 3.5% and 5.5%, respectively, while monosulfated disaccharides ΔDi6S and ΔDi4S were evaluated to be 18.2%, 59% and 14.6%, 47.0%, respectively. Capillary elecrophoresis analysis of GTSG and SHSG contained 99.2% and 95.4% of chondroitin sulfate/dermatan sulfate, respectively. PAGE analysis showed a GTSG and SHSG having molecular masses with average values of 41.72 KDa and 23.8 KDa, respectively. HCT116 cell proliferation was inhibited ( p < 0.05) by 70.6% and 72.65% at 200 μg/mL of GTSG and SHSG respectively. Both GTSG and SHSG demonstrated promising antiproliferative potential, which may be used as a novel, effective agent. [ABSTRACT FROM AUTHOR]

The ability to produce sound has been known for decades in Balistidae. Sounds of many species have been recorded and a variety of sound-producing mechanisms have been proposed, including teeth stridulation, collision of the buccal teeth and movements of the fins. The best-supported hypothesis involves movements of the pectoral fin against the lateral part of the swimbladder, called a drumming membrane. In this study, we describe for the first time the sounds made by the blackbar triggerfish Rhinecanthus aculeatus, which are like short drum rolls with an average duration of 85 ms, 193 Hz dominant frequency and 136 dB SPL level at 3 cm distance. The sounds are a series of pulses that result from alternate sweeping movements of the right and left pectoral fins, which push a system of three scutes that are forced against the swimbladder wall. Pulses from each fin occur in consecutive pairs. High-speed videos indicate that each pulse consists of two cycles. The first part of each cycle corresponds to the inward buckling of the scutes, whereas the second part of the cycle corresponds to an apparent passive recoil of the scutes and swimbladder wall. This novel sound production mechanism is probably found in many members of Balistidae because these peculiar scutes occur in other species in the family. Comparison of sound characteristics from fishes of different sizes shows that dominant frequency decreases with size in juveniles but not in adults. [ABSTRACT FROM AUTHOR]

The present study aimed to characterize and evaluate the in vitro and in vivo anticoagulant activity of sulfated glycosaminoglycans from the skins of smooth hound (SHSG) and grey triggerfish (GTSG). The analysis of SHSG and GTSG with acetate cellulose electrophoresis in Zn-acetate revealed the presence of hyaluronic acid (HA), chondroitin sulfate (CS) and dermatan sulfate (DS). Both glycosaminoglycans were evaluated for their in vitro anticoagulant activities using activated partial thromboplastin time (aPTT), thrombin time (TT) and prothrombine time (PT) tests. SHSG and GTSG and calciparin were tested as in vivo anticoagulants by subcutaneous (s.c) injection to adult female Wistar rats in a concentration of 75 mg/kg of body weight. The administration of SHSG, GTSG and calciparin to rats induced a significant decrease of platelet rates compared to the control. The aPTT assay of SHSG and GTSG was prolonged 1.3 and 1.23-fold respectively compared with the control. Toxicity studies were performed to investigate whether or not SHSG and GTSG can cause pathological changes in the liver, proteins and DNA. The concentration and catalytic activity of liver oxidative stress markers and enzymes, respectively, as well as the observed hepatic morphological changes indicated that calciparin induced hepatic toxicity and oxidative damage in the liver. The higher activity and lower toxicity of SHSG and GTSG recommended these compounds as a better drug candidate than calciparin. [ABSTRACT FROM AUTHOR]

Xanthichthys greenei sp. n. is described from six specimens, 97-154 mm standard length (SL) collected from mesophotic coral ecosystems (90-100 m) at Kiritimati (Christmas Island), Line Islands, part of the Republic of Kiribati in the Central Pacific. Of the six species of Xanthichthys, it is most similar to the Atlantic X. ringens and the Indo-West Pacific X. lineopunctatus, sharing with these species the character of three pigmented cheek grooves. It is distinctive in its low body scale row count (33-35, other Xanthichthys species with 39 or more), small size (maximum SL 154 mm, other species over 225 mm), and color pattern of scattered dark spots sub-dorsally and no other spots or lines on body.

Little is known about the movement patterns of gray triggerfish, Balistes capriscus Gmelin, in the northern Gulf of Mexico. To examine fine-scale movements, gray triggerfish ( n = 17) were tagged with transmitters and tracked with the VR2W Positioning System from 17 October 2012 to 9 December 2013. Most (76%) tagged fish survived and were tracked for 1-57 weeks. Tagged fish showed significantly larger home ranges and core areas in autumn than winter-spring and during day than night. Seasonal movement patterns were positively correlated with water temperature. Gray triggerfish stayed close to the reef (mean ± SD distance = 35.9 ± 28.4 m) and showed high site fidelity (64%) and high residency (>57 weeks). These patterns emphasise the importance of structured habitat for this species and suggest that artificial reef building in the northern Gulf of Mexico has enhanced this population. [ABSTRACT FROM AUTHOR]

Sulfated polysaccharides were isolated from two Tunisian fish skins grey triggerfish ( Balistes capriscus) (GTSP) and smooth hound ( Mustelus mustelus) (SHSP). Their chemical and physical characteristics were investigated. The Analysis of surface morphology by scanning electron microscopy of both sulfated polysaccharides displayed the same shape with netted structure. The antioxidant activities of GTSP and SHSP were evaluated using various in vitro antioxidant assays: 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, reducing power, β-carotene bleaching inhibition assay (IC = 0.5 mg mL and IC = 0.6 mg mL) and DNA nicking assay. Both sulfated polysaccharides exhibited good antioxidant activities. The sulfated polysaccharides showed strong angiotensin I-converting enzyme inhibitory activities (IC = 0.16 mg mL and IC = 0.18 mg mL). These results revealed that GTSP and SHSP exhibited significant antihypertensive activities. Overall, the results indicated that grey triggerfish and smooth hound skins can be used to generate high value-added products, thus offering a valuable source of bioactive sulfated polysaccharides for application in wide range of biotechnological applications. [ABSTRACT FROM AUTHOR]

This study investigated the effects of different doses of UV-C light at 253.7 nm (0–18 kJ/m2) on the reduction of Escherichia coli, Staphylococcus aureus and Bacillus cereus in contaminated seasoned dried filefish (Thamnaconus modestus) and sliced squid (Todarodes pacificus) surfaces and sensory quality. The counts of all three bacteria were significantly (P < 0.05) reduced by the increase of UV-C dosage. E. coli, S. aureus and B. cereus on filefish with 18 kJ/m2 of UV-C maximally reduced by 2.70, 2.55 and 2.57 log CFU/g, respectively; however, on the sliced squid using the same UV dose reduced the same bacteria by 1.35, 0.54 and 1.05 log CFU/g, respectively. However, the results suggest that 6 to 9 kJ/m2 of UV-C could be used for the inactivation of E. coli and B. cereus in these dried fishery products without any changes in sensory quality. However, S. aureus levels on sliced squid will require a combination of UV-C light and chemical treatment. [ABSTRACT FROM AUTHOR]

Single specimens of Finescale Triggerfish ( Balistes polylepis) and Louvar ( Luvarus imperialis) were found in British Columbia's coastal waters in 2014. Both B. polylepis and L. imperialis normally are found off southern-most California and Baja California. Although a stray B. polylepis was caught as far north as Metlakatla, Alaska, during the 1982-1983 El Niño event, and L. imperialis is known to stray north along the Washington coastline, these 2 new specimens represent 1st records for British Columbia. Both probably moved north during the warm-water anomaly that has persisted along the North American coast since 2013. [ABSTRACT FROM AUTHOR]

This study tested the potential for 27 artificial reefs, which were deployed in the northeastern Gulf of Mexico (nGOM) but not reported to the public, to serve as refuges from fishing mortality for reef fishes. Red SnapperLutjanus campechanus(n= 2,114) and Gray TriggerfishBalistes capriscus(n= 267) were tagged at a subset (n= 9) of the study reefs from winter 2005 to fall 2007 to estimate their site fidelity and mortality rates. Mortality was also estimated from catch curves fit to Red Snapper and Gray Triggerfish age distributions that were estimated at the study reefs both before (2005–2007) and after (2007–2008) the GPS coordinates of the above subset were advertised to the public. Red Snapper site fidelity (f), estimated by fitting Burnham's (1993) joint encounter model to tagging data, was 12.8% per year; while estimated instantaneous total mortality (Z) of Red Snapper ranged from 0.08 per year during the closed recreational fishing seasons to 1.31 per year during the open seasons. Similar estimates were not available for Gray Triggerfish due to inadequate model structure. Prior to reporting of reef coordinates to the public, estimatedZfrom the catch curve analysis was 1.04 per year for Red Snapper and 0.56 per year for Gray Triggerfish. After reporting, estimatedZincreased from 0.56 to 0.69 per year for Gray Triggerfish and from 1.04 to 1.14 per year for Red Snapper. The low site fidelity and high fishing effort in the region resulted in no discernible refuge effects for Red Snapper. A modest refuge effect occurred for Gray Triggerfish, fish which have been shown to display high site fidelity (>80% per year) to reefs; however, Gray Triggerfish mortality from fishing quickly increased following the reporting of the study reef coordinates. Our study results indicate that unreported artificial reefs that are deployed in areas of the nGOM where fishing is otherwise allowed are not likely to offer protection to reef fishery species. Received November 14, 2014; accepted August 12, 2015 [ABSTRACT FROM AUTHOR]

The triggerfishes (family Balistidae) and filefishes (family Monacanthidae) comprise a charismatic superfamily (Balistoidea) within the diverse order Tetraodontiformes. This group of largely marine fishes occupies an impressive ecological range across the world's oceans, and is well known for its locomotor and feeding diversity, unusual body shapes, small genome size, and ecological and economic importance. In order to investigate the evolutionary history of these important fish families, we used multiple phylogenetic methods to analyze molecular data from 86 species spanning the extant biodiversity of Balistidae and Monacanthidae. In addition to three gene regions that have been used extensively in phylogenetic analyses, we include sequence data for two mitochondrial regions, two nuclear markers, and the growth factor gene bmp4, which is involved with cranial development. Phylogenetic analyses strongly support the monophyly of the superfamily Balistoidea, the sister-family relationship of Balistidae and Monacanthidae, as well as three triggerfish and four filefish clades that are well resolved. A new classification for the Balistidae is proposed based on phylogenetic groups. Bayesian topology, as well as the timing of major cladogenesis events, is largely congruent with previous hypotheses of balistid phylogeny. However, we present a novel topology for major clades in the filefish family that illustrate the genera Aluterus and Stephanolepis are more closely related than previously posited. Molecular rates suggest a Miocene and Oligocene origin for the families Balistidae and Monacanthidae, respectively, and significant divergence of species in both families within the past 5 million years. A second key finding of this study is that, relative to the other protein-coding gene regions in our DNA supermatrix, bmp4 shows a rapid accumulation of both synonymous and non-synonymous substitutions, especially within the family Monacanthidae. Overall substitution patterns in bmp4 support the hypothesis of stabilizing selection during the evolutionary history of regulatory genes, with a small number of isolated examples of accelerated non-synonymous changes detected in our phylogeny. [ABSTRACT FROM AUTHOR]