Alopias Superciliosus Research Articles

Fishery, population characteristics and stock status of the bigeye thresher Alopias superciliosus Lowe, 1841 off Thoothukudi, south-east coast of India

Fishery, population parameters and stock estimates of the bigeye thresher Alopias superciliosus Lowe, 1841 from the Thoothukudi coast of Gulf of Mannar Marine Biosphere Reserve (GoMMBR) was studied during the period 2015 to 2019. Results of the study reveals that the estimated annual average production of sharks from Thoothukudi region was 105 t of which the dominant shark species was A. supercilious (52.70%). The length of the sampled A. supercilious ranged between 108 and 265 cm. Results of the length-weight relationship showed negative allometric growth with b value of 2.66. The growth parameters viz, asymptotic length (L∞), growth co-efficient (K) and arbitrary origin of growth (t0 ) were estimated at 367 cm, 0.39 y-1 and 0.12 respectively. The mortality parameters viz, total mortality (Z), fishing mortality (F) and natural mortality (M) rates were estimated at 1.20, 0.70 and 0.50 y-1, respectively. In Thoothukudi, the recruitment season of A. superciliosus was found during March and October showing optimal exploitation with exploitation rate (E) of 0.58 and the estimated exploitation ratio (U) was 0.54. The virtual population analysis (VPA) showed a fishing pressure on the 240 to 320 cm length group. The estimated annual catch and maximum sustainable yield (MSY) were 58 and 68 t respectively. The present study gives valuable baseline information on the fishery and population characteristics of this vulnerable and data deficit resource A. superciliosus off Thoothukudi. Keywords: Growth and mortality parameters, Maximum sustainable yield, Recruitment overfishing, Virtual population analysis

Identifikasi Hiu yang Diperdagangkan di Bali Menggunakan Metode DNA Barcoding dan Analisis Filogenetik

Sharks are one of the keys for ecosystems balance in the ocean. Sharks as top predators have an important role to maintain the stability of the food chain in the ocean. The loss of sharks will have a major impact on the marine ecosystem, so the presence of sharks in the ocean must be protected from extinction. However, there are some activities such as sharks hunting and trading going on because of the high demand of sharks processed products. Bali is one of the locations of shark fishing and trading activities. The problem is the trade-in sharks have gone through the finning process, leaving only the body parts or fins which resulted in the difficulty of morphological identification process. An alternative method that can be used if molecular identification cannot be done is DNA Barcoding. DNA Barcoding means identifying all the animal species with an effective molecular approach applied to identify species. The identification results of DNA Barcoding of shark’s trade in Bali shows that there are four species of sharks have been sold, which is hammerhead sharks (Sphyrna lewini), thresher sharks (Alopias pelagicus), big eye thresher shark (Alopias superliciosus), silky sharks (Carcharinus falciformis). These sharks registered in the IUCN red list, Sphyrna lewini classified as threatened species, while the others (Alopias pelagicus, Alopias superciliosus and Carcharinus falciformis) classified as vulnerable species. In the international trade regulations on CITES, these four species come under the Appendix II. In national regulations, Alopias pelagicus, Alopias superciliosus, Sphyrna lewini have been regulated by the Ministerial regulations, while for Carcharinus falciformis, there are no national regulations yet.

Blue sharks (Prionace glauca) by-catch in the Indonesian industrial tuna longline fishery in the eastern Indian Ocean

The Indonesian tuna longline fisheries in Indonesia have been targetting four main tuna, including yellowfin tuna, bigeye tuna, albacore, and southern bluefin tuna. In reality, there are many by-catch species, including blue sharks. This study aims to provide integrated information on blue shark species as by-catch species in Indonesian industrial tuna longline fisheries, including nominal and standardized CPUE and biomass of blue shark exploited by Indonesian longliners in the eastern Indian Ocean. This research is expected to become a reference point in shark management in the Indian Ocean. The scientific observer collected 2951 set-by-set longline fishing data based on Research Institute For Tuna Fisheries (RITF) from January 2006 to December 2018, on which the present analysis was made. The result indicated that there were eighteen shark species caught by Indonesian longliner were dominated by a blue shark (Prionace glauca) (60%) followed by crocodile shark (Pseudcarcharias kamoharai) (23.84%), bigeye thresher shark (Alopias superciliosus) (3%) and other species (<3%). Nominal CPUE was fluctuating and needed to be standardized in GLM analysis. The results of CPUE standardization can then be used as a reference in calculating the biomass blue sharks exploited by Indonesian Longliners. By considering several aspects, including the average of hook/set/fleet, an average of size (length and weight), the total number of set/year, reported the number of vessels, it is obtained that the estimated catch of blue sharks ranges from 366.3-2,616 tons per year with an average of about 1,282 tons.

Vulnerability Assessment of Pelagic Sharks in the Western North Pacific by Using an Integrated Ecological Risk Assessment.

Simple SummaryA new integrated ecological risk assessment (ERA) including the IUCN Red List category, the body weight variation trend of 1989–2011 with large sample size (n > 678,000), and the inflection point of population growth curve coupled with the ERA was developed to assess the impact of longline fishery on the pelagic sharks in the western North Pacific. The intrinsic rate of population growth was used to estimate the productivity, and the susceptibility was estimated by the multiplication of the catchability, selectivity, and post-capture mortality. Five groups were identified based on the cluster analysis coupling with non-parametric multi-dimensional scaling. Rigorous management measures are recommended for the scalloped hammerhead, silky, and spinner shark at highest risk, setting total allowable catch quota is recommended for the bigeye thresher, and sandbar shark, and a consistent monitoring scheme is suggested for the smooth hammerhead, shortfin mako, pelagic thresher, oceanic whitetip, and dusky shark.The vulnerability of 11 pelagic shark species caught by the Taiwanese coastal and offshore longline fisheries in the western North Pacific were assessed by an ecological risk assessment (ERA) and 10 of the 11 species was assessed by using an integrated ERA developed in this study. The intrinsic rate of population growth was used to estimate the productivity of sharks, and the susceptibility of sharks was estimated by the multiplication of the catchability, selectivity, and post-capture mortality. Three indices namely, the IUCN Red List category, the body weight variation trend, and the inflection point of population growth curve coupled with ERA were used to conduct an integrated ERA. The results indicated that the scalloped hammerhead is at the highest risk (group 1), followed by the silky shark, and the spinner shark at high risk (group 2). The bigeye thresher, and sandbar shark fall in group 3, the smooth hammerhead falls in group 4, and the shortfin mako, pelagic thresher, oceanic whitetip, and dusky shark fall in group 5. Rigorous management measures for the species in groups 1 and 2, setting total allowable catch quota for group 3, and consistent monitoring schemes for groups 4 and 5 are recommended.

Occurrence of the bigeye thresher shark, Alopias superciliosus (Lowe, 1841) (Elasmobranchii, Alopiidae) in the southwestern Gulf of Mexico

The bigeye thresher shark Alopias supeciliosus is a large epipelagic and mesopelagic species, and it has a wide distribution in the Atlantic. However, its record in the Gulf of Mexico is sporadic. A single adult female of A. superciliosus, measuring 360 cm total length and about weight 165 kg, was caught by artisanal fishers in Salinas Roca Partida, Veracruz, Mexico, on July 14, 2020. This study reports the first occurrence of this species in the southwestern of the Gulf of Mexico, which extends its geographical distribution in Mexico.

Species composition and conservation status of shark from fishery landings and fish markets in Sri Lanka revealed by DNA barcoding

Sharks are considered to be top predators in marine ecosystems. Due to the high market value of shark fins, fishing pressure on these top predators has increased significantly and they are currently considered to be a threatened marine vertebrate group. Sri Lanka is an island nation with 21 major fish harbours in operation and one of the top 20 shark fishing countries. With an increasing local and global demand for shark meat and fins, the species consumed by Sri Lankans as well as species composition of the landing are in question because the identification of processed shark is difficult (e.g. fish filet) and there is a lack of species-specific landing data. In the present study, we applied a DNA barcoding approach to identify species composition of the shark catch in Sri Lanka. Shark tissue samples were collected in 2018 and 2019 from 10 fishing harbours and fish markets around Sri Lanka. In total, 330 out of 353 tissue samples were successfully barcoded and the results revealed 17 shark species corresponding to five families including Alopias superciliosus, Carcharhinus amblyrhynchoides, C. falciformis, C. leucas, C. limbatus, C. longimanus, C. melanopterus, C. sorrah, Chiloscyllium griseum, Hemipristis elongate, Loxodon macrorhinus, Paragaleus randalli, Prionace glauca, Rhizoprionodon oligolinx, R. acutus, Sphyrna lewini and Galeocerdo cuvier. Among them, C. falciformis (silky shark) is the most dominant (39.4 %). Variation in fishing area and fishing gear used could be the main determinants of species composition across localities. The results showed 62 % of shark species identified in this study are threatened globally based on IUCN categories. Surprisingly, two banned species, A. superciliosus and C. longimanus, were found with low abundance. The results of this study provide crucial information for improving the Sri Lankan shark management plan in the future. In addition, we suggest a regular assessment of shark landing species composition be implemented to monitor the efficiency of current management.

A direct multiplex loop‐mediated isothermal amplification method to detect three CITES‐listed shark species

Abstract Species identification of sharks under catch or trade regulations is important for law enforcement and species conservation. Rapid detection of Convention on the International Trade in Endangered Species (CITES)‐listed species is needed for on‐site screening. Species‐specific primers were designed to target three mitochondrial genes (ND2, COI, and CytB) in both the simplex and multiplex loop‐mediated isothermal amplification (LAMP) assay for the pelagic thresher shark (Alopias pelagicus), the bigeye thresher shark (Alopias superciliosus), and the scalloped hammerhead shark (Sphyrna lewini), respectively. Another primer set designed to target S. lewini was used for detection‐limit testing of the LAMP assay. The refined direct multiplex LAMP was used to detect the three CITES‐listed shark species and omitted the lengthy DNA extraction process. A homogenizer was used to release the DNA from the shark tissues, and a simplex or multiplex LAMP reaction was conducted for 30 min in an incubator at 65°C using species‐specific primer sets. Positive LAMP reactions showed a colour change from pink to yellow, whereas negative reactions showed no colour change. Multiplex LAMP assays were performed using 84 samples, which successfully identified the target and non‐target species and provided a fast (&lt;1 h), simple, and reliable method to distinguish three CITES‐listed shark species from the other non‐target species, for either fresh or dry fin products. Results of this study and the method developed will play a critical role in assisting fishery agencies and customs officials in identifying the illegal catch and trade of CITES‐listed shark species.

NEW RECORDS AND PRELIMINARY REPRODUCTIVE ASPECTS OF ELASMOBRANCHS OF THE TRINDADE-MARTIN VAZ INSULAR COMPLEX

Here we presented records of elasmobranchs obtained during a longline pelagic fishing monitoring around the Trindade-Martin Vaz insular complex, including one new record. New information on the reproductive aspects of the blue shark (Prionace glauca) and pelagic stingray (Pteroplatytrygon violacea) suggest the use of this area as mating and parturition ground for these species. The most abundant species was the P. glauca (N = 65), followed by shortfin mako shark Isurus oxyrinchus (N = 12). We also recorded for the first time the smooth hammerhead shark Sphyrna zygaena (N = 3) and the bigeye thresher shark Alopias superciliosus (N = 2), and other shark species previous reported for the insular complex, including the oceanic whitetip Carcharhinus longimanus (N = 2), and the tiger shark Galeocerdo cuvier (N = 1). Our findings highlight the importance of further studies at the Trindade-Martin Vaz insular complex considering the pelagic biodiversity and reproductive aspects of elasmobranchs.

Concentrations and stable isotopes of mercury in sharks of the Galapagos Marine Reserve: Human health concerns and feeding patterns

The human ingestion of mercury (Hg) from sea food is of big concern worldwide due to adverse health effects, and more specifically if shark consumption constitutes a regular part of the human diet. In this study, the total mercury (THg) concentration in muscle tissue were determined in six sympatric shark species found in a fishing vessel seized in the Galapagos Marine Reserve in 2017. The THg concentrations in shark muscle samples (n = 73) varied from 0.73 mg kg-1 in bigeye thresher sharks (Alopias superciliosus) to 8.29 mg kg-1 in silky sharks (Carcharhinus falciformis). A typical pattern of Hg bioaccumulation was observed for all shark species, with significant correlation between THg concentration and shark size for bigeye thresher sharks, pelagic thresher sharks (Alopias pelagicus) and silky sharks. Regarding human health concerns, the THg mean concentration exceeded the maximum weekly intake fish serving in all the studied species. Mass-Dependent Fractionation (MDF, δ202Hg values) and Mass-Independent Fractionation (MIF, Δ199Hg values) of Hg in whitetip sharks (Carcharhinus longimanus) and silky sharks, ranged from 0.70‰ to 1.08‰, and from 1.97‰ to 2.89‰, respectively. These high values suggest that both species are feeding in the epipelagic zone (i.e. upper 200 m of the water column). While, blue sharks (Prionace glauca), scalloped hammerhead sharks (Shyrna lewini) and thresher sharks were characterized by lower Δ199Hg and δ202Hg values, indicating that these species may focus their foraging behavior on prey of mesopelagic zone (i.e. between 200 and 1000 m depth). In conclusion, the determination of THg concentration provides straight-forward evidence of the human health risks associated with shark consumption, while mercury isotopic compositions constitute a powerful tool to trace the foraging strategies of these marine predators. CapsuleA double approach combining Hg concentrations with stable isotopes ratios allowed to assess ontogeny in common shark species in the area of the Galapagos Marine Reserve and the human health risks concern associated to their consumption.

Bigeye thresher shark Alopias superciliosus movements and post-release survivorship following capture on linked buoy gear

Off the US west coast, fishery development efforts have led to the recent recommendation for authorization of deep-set buoy gear (DSBG) and linked buoy gear (LBG), two commercial gear types for targeting swordfish at depth during the day. Because the new deep-set configurations interact with bigeye thresher sharks (Alopias superciliosus), a large pelagic species that is not typically retained for sale, this work has focused on documenting the fate of released catch. Bigeye thresher sharks (BETS) were captured and outfitted with pop-up satellite archival tags (Wildlife Computers sPATs and miniPATs) to assess movement trends and acute (30-d) post-release survival during exempted fishing trials authorized by National Marine Fisheries Service (NMFS) and the Pacific Fisheries Management Council (PFMC). Post-release survivorship was based on 14 BETS (∼157−230 cm LF) caught on LBG between August 2016 and December 2019 following fight times ranging from 17−300 min. Thirteen BETS survived the acute effects of capture, and one immediate mortality was documented following heavy entanglement in the monofilament leader. BETS were resilient to the acute effects of handling stress following capture on LBG, with an observed post-release survival rate of 93 %. Surviving BETS exhibited consistent diurnal dive patterns with sharks remaining well below the thermocline during the daytime (mean = 386 ± 62 m) and within the mixed layer at night (mean = 65 ± 25 m). With the exception of one tag that reported within close proximity of the SCB tagging location, BETS exhibited extensive southward movements (mean = 1235 ± 235 km) towards a potentially relevant migratory corridor for large pelagic sharks.

Evaluation of Biological Reference Points for Conservation and Management of the Bigeye Thresher Shark, Alopias superciliosus, in the Northwest Pacific

Full stock assessment of sharks is usually hindered by a lack of long time-series catch and effort data. In these circumstances, demographic and per-recruit analyses may provide alternate approaches to describe population status because these methods can be applied to estimate biological reference points (BRPs) for shark stocks. However, the appropriate level of BRPs for sharks is difficult to determine, given the expected low reproductive rates. To determine which BRPs are most appropriate for the CITES-listed species—bigeye thresher shark, Alopias superciliosus, a stochastic demographic model with Monte Carlo simulations and per-recruit models were used to estimate BRPs in this study. The results indicated that conventional fishing mortality-based BRPs (FBRPs) derived from per-recruit models may result in a clear population decline. Our analyses also demonstrated that the bigeye thresher population in the Northwest Pacific will stabilize only if demographic-based FBRP is implemented. The FBRP estimated based on the stochastic demographic model was 0.079–0.139 y−1, which was equivalent to SPR = 50–70%. The findings strongly suggested that more conservative threshold FBRPs should be implemented to ensure sustainable utilization of the bigeye thresher stock. The present study provides new and strategically important information on the population dynamics of the bigeye thresher in the Northwest Pacific, which can be used to help fishery managers to adopt more efficient management measures for this stock. It is also suggested that this approach can be applied to other shark species with limited catch and effort data.

Deadly interaction between a swordfish Xiphias gladius and a bigeye thresher shark Alopias superciliosus.

Deadly interaction between a swordfish Xiphias gladius and a bigeye thresher shark Alopias superciliosus.

Occurrence of the Young Thresher Shark Alopias superciliosus Lowe, 1841 (Lamniformes: Alopiidae) in the Northeastern Mediterranean Sea

The Bigeye Thresher Shark Alopias superciliosus Lowe, 1841 is one of the largest shark species found in the Pacific, Atlantic, and Indian oceans. They also have started to be seen in the Mediterranean Sea since the 1980s. The presence of two different species of Thresher sharks in Turkish waters is known, which are A. vulpinus and A. superciliosus. Thresher sharks can easily be distinguished from other shark species with their big tails. A juvenile female specimen of A. superciliosus with a total length of 240 cm was caught incidentally in Mersin Bay in January 2020. Essential measurements of the fish were fulfilled and the specimen was deposited in the Museum of the Systematic, Faculty of Fisheries, Mersin University (catalog number: MEUFC-20-11-127). This study is the first record of A. superciliosus in Mersin Bay.

Thermal effects on red muscle contractile performance in deep-diving, large-bodied fishes.

Bigeye thresher sharks (Alopias superciliosus) and swordfish (Xiphias gladius) are large, pelagic fishes, which make long-duration, diurnal foraging dives from warm, surface waters (18-24°C) to cold waters beneath the thermocline (5-10°C). In bigeye thresher sharks, the subcutaneous position of the red, aerobic swimming muscles (RM) suggests that RM temperature mirrors ambient during dives (i.e., ectothermy). In swordfish, the RM is closer to the vertebrae and its associated with vascular counter-current heat exchangers that maintain RM temperature above ambient (i.e., RM endothermy). Here, we sought to determine how exposure to a wide range of ambient temperatures (8, 16, 24°C) impacted peak power output and optimum cycle (i.e., tailbeat) frequency (0.25, 0.5, 1Hz) in RM isolated from both species. Bigeye thresher shark RM did not produce substantial power at high cycle frequencies, even at high temperatures; but it did produce relatively high power at slow cycle frequencies regardless of temperature. Swordfish RM produced more power when operating at a combination of fast cycle frequencies and higher temperatures. This suggests that swordfish RM benefits considerably more from warming than bigeye thresher shark RM, while the RM of both species was able to produce power at cold temperatures and slow cycle frequencies. Despite different thermal strategies (i.e., ectothermy vs. RM endothermy), the ability of the RM to power sustained swimming during foraging-related search behaviors may contribute to the unique ability of these fishes to successfully exploit food resources in deep, cold water.

Integument-based inferences on the swimming ability and prey hunting strategy of the bigeye thresher shark, Alopias superciliosus (Lamniformes: Alopiidae)

Alopias is a group of lamniform sharks characterized by a highly elongate caudal fin with three known extant species: Alopias pelagicus (pelagic thresher shark), Alopias superciliosus (bigeye thresher shark), and Alopias vulpinus (common thresher shark). Alopias pelagicus and A. vulpinus are considered fast swimmers and use their caudal fin to hunt for small schooling fish by stunning them, but this feeding behavior has never been directly observed for A. superciliosus. In this study, we examined four integumentary variables of selected fast swimming (e.g. A. pelagicus, A. vulpinus, and Lamna) and slow swimming (e.g. Mitsukurina and Megachasma) lamniform sharks to determine whether A. superciliosus is a fast swimmer or a slow swimmer. Our data indicate that A. superciliosus is a slow swimming lamniform, but it probably employs a simple laterally directed tail slap to capture its prey. Overall, our study points to an interpretation that A. superciliosus is an ambush predator, rather than an active prey-pursuing hunter. Mapping of scale data onto previously published phylogenetic trees indicate that slow swimming is a plesiomorphic condition in the order Lamniformes. Our work represents the most extensive comparative study of the morphology and variation of integumentary structures, especially placoid scales, conducted so far for Lamniformes.

Preliminary report on an artisanal fishery for thresher sharks (Alopias spp) in Tawi-Tawi, Southern Philippines

Thresher sharks (family Alopiidae) are highly migratory pelagic predators whose populations have drastically declined due to extensive fishing for their fins. There are only three species of thresher sharks worldwide. The International Union for Conservation of Nature (IUCN) has listed pelagic (A. pelagicus) thresher sharks as endangered while bigeye (Alopias superciliosus) and common (A. vulpinus) thresher sharks as vulnerable to extinction. There is limited scientific information about thresher shark fisheries in the Philipines. In this study we described a thresher shark fishery in Tawi-Tawi, Southern Philippines which has been existing for more than 20 years now. The fishery is generally small-scale, using simple hook and line and 13-hp inboard motorized boats with a capacity of one to two fishers per boat. Fishing is year-round with peak season occurring from March to May. Fishers spend about 10 days per month fishing during neap tide when the currents are weak. All three species of thresher sharks are caught in Tawi-Tawi. They are generally hunted for their fins and meat which are sold to local buyers. About 50 boats fish per day with about half of them catching one to two sharks. Our study suggests that monthly production of thresher sharks during the peak season in 2018 was about 15.3 mt or valued at about US$19,886.39. Our study is the first to report that the Sibutu Passage is an important fishing grounds for thresher sharks which must be put under immediate protection for effective conservation of these valuable species.

Thresher sharks (Alopiidae) catch in the pelagic fisheries of Western Indonesia

Thresher sharks (family Alopiidae) are an evolutionarily distinct and globally endangered species group. Indonesia is the world’s largest shark fishing nation, and a global priority for reducing the capture of threatened shark species. Kutaradja port is one of Indonesia’s largest fishing ports, located in the capital of Aceh Province, Banda Aceh, Western Indonesia. Kutaradja is a large oceanic port serving a variety of fisheries, from small scale to industrial fleets. One of the main fisheries operating from Kutaradja port is an industrial purse seine fleet targeting valuable pelagic fish, particularly tuna. Pelagic sharks such as threshers are vulnerable to capture in these fisheries, due to their co-occurrence with stocks of valuable pelagic species. Here we describe the volume and composition of shark catch in Kutaradja’s purse seine fleet, based on daily landing monitoring conducted in January 2017 to May 2019. Our results show that the dominant species caught are thresher sharks (Alopiidae), which make up 51% of all shark landings. A total of 627 thresher sharks were landed during the monitoring period, consisting of 558 individuals of pelagic threshers shark (Alopias pelagicus) and 69 individuals of bigeye thresher shark (Alopias superciliosus). The catch is dominated by mature females, which could be particularly detrimental to the reproductive capacity of the population. Fishers in purse seine vessels often catch these threshers with hand-lines, which are used as a secondary gear while the main fishing gear is soaking. Based on these findings, we proposed recommendations for reducing thresher shark fishing mortality, including restricting the use of secondary fishing gears and releasing incidentally captured sharks.

New Mediterranean Biodiversity Records 2019

This paper is a collection of novel distributional records of 20 species belonging to 8 phyla (Chlorophyta, Rhodophyta, Cnidaria, Ctenophora, Annelida, Mollusca, Arthropoda and Chordata) from 11 Mediterranean countries, namely, Spain: an additional record of the Canary dentex Dentex canariensis is reported from Spain (Valencia), this is the northernmost record of this species in the Mediterranean; Algeria: the first documented record of Caulerpa chemnitzia is reported from the Algerian coast; France: the first record of the Spotted sea hare Aplysia dactylomela is reported from the eastern coast of Corsica; Italy: the first records of the Lessepsian polychaete Dorvillea similis and the alien bivalve Isognomon legumen are reported from Italian waters while additional records of Mnemiopsis leidyi in the south Adriatic are provided; Libya: the first record of an alien mollusc Crepidula fornicata is reported from Libyan waters; Malta: multiple sightings of gelatinous species Apolemia uvaria, Phacellophora camtschatica and Physophora hydrostatica are reported for the first time from Maltese waters, as well as the first tentative record of the Orange-spotted grouper Epinephelus cfr. coioides; Greece: an occurrence of a rare Bigeye thresher shark Alopias superciliosus is reported from Hellenic Ionian waters, while the first records of the alien Mertens’ prawn-goby Vanderhorstia mertensi, the recently described cyclopoid copepod Oithona davisae and the alien red seaweed Asparagopsis armata are reported from the Aegean Sea. The presence of the micromollusc Euthymella colzumensis is confirmed for Greece; Cyprus: the first record of the red cornetfish Fistularia petimba is reported from Cyprus; Turkey: the first record of the alien jellyfish Marivagia stellata is reported from south-eastern Turkey; Israel: the first records of the sea nettle Chrysaora sp. in the Levant are reported.

Elasmobranch species in the artisanal fishery of Sucre State, Venezuela

A wide diversity of elasmobranch species has been reported for waters off Venezuela; however, information regarding this group is lacking for most coastal regions. This study aimed to determine the species composition in catches made by the artisanal fishery of Sucre State, Venezuela, and to analyze size structure by sex for the most common species. During the study period (January 2016–September 2017), visits were made to the main fish markets in the city of Cumaná, Sucre State, and a total of 2,167 elasmobranchs belonging to 24 species (15 sharks and 9 rays) were quantified. The most frequently captured elasmobranch species were Mustelus higmani (36.2%), Mustelus canis (18.0%), Hypanus guttatus (15.1%), and Hypanus americanus (7.1%). The size ranges for these species were 29.3–73.7 cm total length (TL), 34.0–86.0 cm TL, 17.0–138.0 cm disc diameter (DD), and 48.0–108.0 cm DD, respectively. Considering national conservation assessments (following International Union for Conservation of Nature criteria), 7 of the species reported for the study area (M. higmani, Carcharhinus limbatus, Carcharhinus falciformis, Isurus oxyrinchus, Alopias superciliosus, Prionace glauca, and Aetobatus narinari) are listed as vulnerable, and the remaining species (n = 17) have not been assessed. Current conservation efforts in Venezuela are deficient given the collapse of government institutions responsible for the management of fisheries. This has led to noncompliance with fishing regulations designed for elasmobranchs. In the future, great effort must be made to continue generating information; however, future advances in scientific research and conservation will depend largely on the recovery of the economic and political stability in Venezuela.

Informing CITES Parties: Strengthening science‐based decision‐making when listing marine species

AbstractInternational trade in vulnerable marine species is regulated once they are listed in CITES Appendices (the Convention on International Trade in Endangered Species of Wild Fauna and Flora). Parties to the Convention submit proposal(s) 150 days prior to the CITES Conference for voting on the inclusion of new species in Appendices I and II, making a case for why CITES listing criteria are met in each case. Before the vote, Parties receive advice from (a) the Food and Agriculture Organization of the United Nations, (b) the International Union for Conservation of Nature—TRAFFIC and (c) the CITES Secretariat, among others. This paper offers an expert review of listing processes, which are the subject of much debate in fishery and environment‐protection communities, looking at two specific cases: silky shark (Carcharhinus falciformis, Carcharhinidae) and bigeye thresher shark (Alopias superciliosus, Alopiidae). The reviewers determine that the evidence made available to voting Parties is substantial, but suffers from non‐standard presentation across assessments. The best available data are not always presented or described transparently in relation to CITES criteria. An extension of the assessment period, as well as the opportunity to refute evidence, has been suggested as ways to support more informed and effective decision‐making by CITES Parties, whose composition of delegations varies greatly in their experience of marine species management and trade. Experts welcomed a greater coherence of advice between fishery and non‐fishery sources in the long term, and proposed a range of suggested improvements for the delivery of information and advice to CITES Parties.