Displaying publications 1 - 20 of 27 in total

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  1. Exploring shark VNAR antibody against infectious diseases using phage display technology
    Lim HT, Kok BH, Leow CY, Leow CH
    Fish Shellfish Immunol, 2023 Sep;140:108986.
    PMID: 37541634 DOI: 10.1016/j.fsi.2023.108986
    Antibody with high affinity and specificity to antigen has widely used as a tool to combat various diseases. The variable domain of immunoglobulin new antigen receptor (VNAR) naturally found in shark contains autonomous function as single-domain antibody. Due to its excellent characteristics, the small, non-complex, and highly stable have made shark VNAR can acquires the antigen-binding capability that might not be reached by conventional antibody. Phage display technology enables shark VNAR to be presented on the surface of phage, allowing the exploration of shark VNAR as an alternative antibody format to target antigens from various infectious diseases. The application of phage-displayed shark VNAR in antibody library and biopanning eventually leads to the discovery and isolation of antigen-specific VNARs with diagnostic and therapeutic potential towards infectious diseases. This review provides an overview of the shark VNAR antibody, the types of phage display technology with comparison to the other types of display system, as well as the application and case studies of phage-displayed shark VNAR antibodies against infectious diseases.
    Matched MeSH terms: Sharks*
  2. Widespread diversity deficits of coral reef sharks and rays
    Simpfendorfer CA, Heithaus MR, Heupel MR, MacNeil MA, Meekan M, Harvey E, et al.
    Science, 2023 Jun 16;380(6650):1155-1160.
    PMID: 37319199 DOI: 10.1126/science.ade4884
    A global survey of coral reefs reveals that overfishing is driving resident shark species toward extinction, causing diversity deficits in reef elasmobranch (shark and ray) assemblages. Our species-level analysis revealed global declines of 60 to 73% for five common resident reef shark species and that individual shark species were not detected at 34 to 47% of surveyed reefs. As reefs become more shark-depleted, rays begin to dominate assemblages. Shark-dominated assemblages persist in wealthy nations with strong governance and in highly protected areas, whereas poverty, weak governance, and a lack of shark management are associated with depauperate assemblages mainly composed of rays. Without action to address these diversity deficits, loss of ecological function and ecosystem services will increasingly affect human communities.
    Matched MeSH terms: Sharks*
  3. Tropical sharks feasting on and swimming through microplastics: First evidence from Malaysia
    Matupang DM, Zulkifli HI, Arnold J, Lazim AM, Ghaffar MA, Musa SM
    Mar Pollut Bull, 2023 Apr;189:114762.
    PMID: 36870137 DOI: 10.1016/j.marpolbul.2023.114762
    Plastic can be degraded into microplastic (<5 mm) and has been polluting worldwide marine environment and negatively impact human health. Microplastics in marine organisms are still understudied in Malaysia, let alone from a subclass Elasmobranchii. Five tropical shark species (Carcharhinus dussumieri, Carcharhinus sorrah, Chiloscyllium hasseltii, Chiloscyllium punctatum, and Scoliodon laticaudus) were examined for the presence of microplastics. 74 sharks were sampled from the local wet market and 100 % of samples contained microplastics. A total of 2211 plastic particles were found in gastrointestinal tracts (GIT) and gills, where 29.88 ± 2.34 particles per shark (mean ± SEM). Black (40.07 %) and fiber (84.44 %) microplastics were the most dominant. Extracted microplastic sizes ranged from 0.007 mm to 4.992 mm. This study suggests that microplastic uptake is gender-related for some shark species. A subsample of microplastics (10 %) was used for polymer type identification, where polyester was recorded the highest (43.95 %).
    Matched MeSH terms: Sharks*
  4. Half a century of rising extinction risk of coral reef sharks and rays
    Sherman CS, Simpfendorfer CA, Pacoureau N, Matsushiba JH, Yan HF, Walls RHL, et al.
    Nat Commun, 2023 Jan 17;14(1):15.
    PMID: 36650137 DOI: 10.1038/s41467-022-35091-x
    Sharks and rays are key functional components of coral reef ecosystems, yet many populations of a few species exhibit signs of depletion and local extinctions. The question is whether these declines forewarn of a global extinction crisis. We use IUCN Red List to quantify the status, trajectory, and threats to all coral reef sharks and rays worldwide. Here, we show that nearly two-thirds (59%) of the 134 coral-reef associated shark and ray species are threatened with extinction. Alongside marine mammals, sharks and rays are among the most threatened groups found on coral reefs. Overfishing is the main cause of elevated extinction risk, compounded by climate change and habitat degradation. Risk is greatest for species that are larger-bodied (less resilient and higher trophic level), widely distributed across several national jurisdictions (subject to a patchwork of management), and in nations with greater fishing pressure and weaker governance. Population declines have occurred over more than half a century, with greatest declines prior to 2005. Immediate action through local protections, combined with broad-scale fisheries management and Marine Protected Areas, is required to avoid extinctions and the loss of critical ecosystem function condemning reefs to a loss of shark and ray biodiversity and ecosystem services, limiting livelihoods and food security.
    Matched MeSH terms: Sharks*
  5. Fulltext Tiger sharks support the characterization of the world's largest seagrass ecosystem
    Gallagher AJ, Brownscombe JW, Alsudairy NA, Casagrande AB, Fu C, Harding L, et al.
    Nat Commun, 2022 Nov 01;13(1):6328.
    PMID: 36319621 DOI: 10.1038/s41467-022-33926-1
    Seagrass conservation is critical for mitigating climate change due to the large stocks of carbon they sequester in the seafloor. However, effective conservation and its potential to provide nature-based solutions to climate change is hindered by major uncertainties regarding seagrass extent and distribution. Here, we describe the characterization of the world's largest seagrass ecosystem, located in The Bahamas. We integrate existing spatial estimates with an updated empirical remote sensing product and perform extensive ground-truthing of seafloor with 2,542 diver surveys across remote sensing tiles. We also leverage seafloor assessments and movement data obtained from instrument-equipped tiger sharks, which have strong fidelity to seagrass ecosystems, to augment and further validate predictions. We report a consensus area of at least 66,000 km2 and up to 92,000 km2 of seagrass habitat across The Bahamas Banks. Sediment core analysis of stored organic carbon further confirmed the global relevance of the blue carbon stock in this ecosystem. Data from tiger sharks proved important in supporting mapping and ground-truthing remote sensing estimates. This work provides evidence of major knowledge gaps in the ocean ecosystem, the benefits in partnering with marine animals to address these gaps, and underscores support for rapid protection of oceanic carbon sinks.
    Matched MeSH terms: Sharks*
  6. Fulltext Brown banded bamboo shark (Chiloscyllium punctatum) shows high genetic diversity and differentiation in Malaysian waters
    Lim KC, Then AY, Wee AKS, Sade A, Rumpet R, Loh KH
    Sci Rep, 2021 Jul 21;11(1):14874.
    PMID: 34290296 DOI: 10.1038/s41598-021-94257-7
    The demersal brown banded bamboo shark Chiloscyllium punctatum is a major component of sharks landed in Malaysia. However, little is known about their population structure and the effect of high fishing pressure on these weak swimming sharks. Both mitochondrial DNA control region (1072 bp) and NADH dehydrogenase subunit 2 (1044 bp) were used to elucidate the genetic structure and connectivity of C. punctatum among five major areas within the Sundaland region. Our findings revealed (i) strong genetic structure with little present day mixing between the major areas, (ii) high intra-population genetic diversity with unique haplotypes, (iii) significant correlation between genetic differentiation and geographical distance coupled with detectable presence of fine scale geographical barriers (i.e. the South China Sea), (iv) historical directional gene flow from the east coast of Peninsular Malaysia towards the west coast and Borneo, and (v) no detectable genetic differentiation along the coastline of east Peninsular Malaysia. Genetic patterns inferred from the mitochondrial DNA loci were consistent with the strong coastal shelf association in this species, the presence of contemporary barriers shaped by benthic features, and limited current-driven egg dispersal. Fine scale population structure of C. punctatum highlights the need to improve genetic understanding for fishery management and conservation of other small-sized sharks.
    Matched MeSH terms: Sharks/genetics*
  7. Fulltext Checklist of the coral fish fauna of Xisha Islands, China
    Qiu S, Chen B, Du J, Loh KH, Liao J, Liu X, et al.
    Biodivers Data J, 2021;9:e63945.
    PMID: 33732033 DOI: 10.3897/BDJ.9.e63945
    Background: The Xisha Islands are composed of the Yongle Islands and the Xuande Islands in Hainan Province, China. It has one of the highest species diversity in the world and is also a typical oceanic distribution area of coral reefs globally. The ichthyofauna of the Xisha Islands were recorded by underwater visual census in May 2019 and July 2020. The survey data were combined with previous records of species into the checklist of the Xisha Islands presented herein. A total of 691 species, belonging to 24 orders and 97 families, was recorded. The major families were Labridae, Pomacentridae, Serranidae, Chaetodontidae, Hexanchidae, Lutjanidae, Scaridae, Gobiidae, Scorpaenidae and Carangidae. In this study, the Coral Fish iversity Index (CFDI) of six families (Chaetodontidae, Pomacanthidae, Pomacentridae, Labridae, Scaridae and Acanthuridae) was 229, indicating 756 coral fishes. In terms of the IUCN Red List, one species is Critically Endangered (Glyphis gangeticus), six species are Endangered (Stegostoma fasciatum, Aetomylaeus maculatus, Aetomylaeus vespertilio, Epinephelus akaara, Cheilinusundulatus sp. and Xiphias gladius), 16 species are Vulnerable, and 13 species are Near Threatened in the Xisha Archipelago, so conservation should be strengthened in this area in the future.

    New information: One species is a new record for China (Dischistodus pseudochrysopoecilus) and 23 species are newly found in the Xisha Islands.

    Matched MeSH terms: Sharks
  8. Exclusive predation of sea turtle hatchlings by juvenile blacktip reef sharks Carcharhinus melanopterus at a turtle nesting site in Malaysia
    Bashir Z, Abdullah MM, Ghaffar MA, Rusli MU
    J Fish Biol, 2020 Dec;97(6):1876-1879.
    PMID: 32951197 DOI: 10.1111/jfb.14550
    This study reports the discovery of the exclusive predation of sea turtle hatchlings by several juvenile blacktip reef sharks (Carcharhinus melanopterus) in Chagar Hutang bay on Redang Island, Malaysia, in the South China Sea. Three dead specimens of C. melanopterus were retrieved from ghost nets, and the entire digestive tracts of these sharks solely contained the partially digested bodies of sea turtle hatchlings, with no evidence of the remains of any other prey. Thus, juvenile C. melanopterus may opportunistically feed primarily on turtle hatchlings during times when hatchling abundance is high.
    Matched MeSH terms: Sharks
  9. Fulltext Discovery of a new mode of oviparous reproduction in sharks and its evolutionary implications
    Nakaya K, White WT, Ho HC
    Sci Rep, 2020 07 23;10(1):12280.
    PMID: 32703969 DOI: 10.1038/s41598-020-68923-1
    Two modes of oviparity are known in cartilaginous fishes, (1) single oviparity where one egg case is retained in an oviduct for a short period and then deposited, quickly followed by another egg case, and (2) multiple oviparity where multiple egg cases are retained in an oviduct for a substantial period and deposited later when the embryo has developed to a large size in each case. Sarawak swellshark Cephaloscyllium sarawakensis of the family Scyliorhinidae from the South China Sea performs a new mode of oviparity, which is named "sustained single oviparity", characterized by a lengthy retention of a single egg case in an oviduct until the embryo attains a sizable length. The resulting fecundity of the Sarawak swellshark within a season is quite low, but this disadvantage is balanced by smaller body, larger neonates and quicker maturation. The Sarawak swellshark is further uniquely characterized by having glassy transparent egg cases, and this is correlated with a vivid polka-dot pattern of the embryos. Five modes of lecithotrophic (yolk-dependent) reproduction, i.e. short single oviparity, sustained single oviparity, multiple oviparity, yolk-sac viviparity of single pregnancy and yolk-sac viviparity of multiple pregnancy were discussed from an evolutionary point of view.
    Matched MeSH terms: Sharks/anatomy & histology; Sharks/classification; Sharks/physiology*
  10. Global status and conservation potential of reef sharks
    MacNeil MA, Chapman DD, Heupel M, Simpfendorfer CA, Heithaus M, Meekan M, et al.
    Nature, 2020 07;583(7818):801-806.
    PMID: 32699418 DOI: 10.1038/s41586-020-2519-y
    Decades of overexploitation have devastated shark populations, leaving considerable doubt as to their ecological status1,2. Yet much of what is known about sharks has been inferred from catch records in industrial fisheries, whereas far less information is available about sharks that live in coastal habitats3. Here we address this knowledge gap using data from more than 15,000 standardized baited remote underwater video stations that were deployed on 371 reefs in 58 nations to estimate the conservation status of reef sharks globally. Our results reveal the profound impact that fishing has had on reef shark populations: we observed no sharks on almost 20% of the surveyed reefs. Reef sharks were almost completely absent from reefs in several nations, and shark depletion was strongly related to socio-economic conditions such as the size and proximity of the nearest market, poor governance and the density of the human population. However, opportunities for the conservation of reef sharks remain: shark sanctuaries, closed areas, catch limits and an absence of gillnets and longlines were associated with a substantially higher relative abundance of reef sharks. These results reveal several policy pathways for the restoration and management of reef shark populations, from direct top-down management of fishing to indirect improvement of governance conditions. Reef shark populations will only have a high chance of recovery by engaging key socio-economic aspects of tropical fisheries.
    Matched MeSH terms: Sharks/physiology*
  11. Ocean warming and hypoxia affect embryonic growth, fitness and survival of small-spotted catsharks, Scyliorhinus canicula
    Musa SM, Ripley DM, Moritz T, Shiels HA
    J Fish Biol, 2020 Jul;97(1):257-264.
    PMID: 32383486 DOI: 10.1111/jfb.14370
    Elasmobranchs are key to a healthy marine ecosystem but are under threat from human activities, such as destructive fisheries and shark finning. Embryos of oviparous elasmobranchs may be further challenged during development by rising temperatures and falling dissolved oxygen concentrations in their intertidal environment. However, the impact of climate change on survival and growth of oviparous elasmobranchs is still poorly understood. Here, we investigate the effects of temperature and hypoxia on the growth and survival of small-spotted catshark (Scyliorhinus canicula) embryos by incubating eggs in normoxia 15°C, normoxia 20°C, hypoxia 15°C, or hypoxia 20°C. Incubation under the elevated temperature increased the embryonic growth rate, yolk consumption rate and Fulton's condition factor at hatching, whilst decreasing the total length and body mass of newly hatched sharks. Under low oxygen conditions (50% air saturation) the survival rate of S. canicula embryos dropped significantly and the temperature-induced increase in Fulton's condition factor was reversed. Together, these data demonstrate both the individual and compound effects of elevated temperature and hypoxia on the survival and growth during early ontogeny of a ubiquitous, coastal elasmobranch, S. canicula.
    Matched MeSH terms: Sharks/embryology*; Sharks/physiology*
  12. A new genus and two new species of trypanorhynch cestodes (Tentaculariidae) from the sharksCarcharhinus sorrah(Müller & Henle) andSphyrna lewini(Griffith & Smith) from off the coasts of Malaysia and Mexico
    Palm HW, Morales-Ávila JR, Galván-Magaña F, Haseli M
    Syst Parasitol, 2020 04;97(2):133-142.
    PMID: 32065375 DOI: 10.1007/s11230-020-09904-w
    Two new tentaculariid species were found infecting carcharhiniform sharks from off the coasts of Malaysian Borneo and the southwestern coast of the Baja California Sur, Mexico. Both new species exhibit a homeoacanthous heteromorphous basal and a homeoacanthous homeomorphous metabasal armature. Since this hook arrangement is unique within the tentaculariids and the taxonomy in this group deeply depends on the tentacular armature, Reimeriella n. g. is erected to accommodate R. varioacantha n. sp. ex Carcharhinus sorrah (Müller & Henle) and R. mexicoensis n. sp. ex Sphyrna lewini (Griffith & Smith). Unlike R. mexicoensis n. sp., R. varioacantha n. sp. has a pars bothrialis not overlapping the pars bulbosa and the number of testes is higher. Reimeriella mexicoensis n. sp. possesses very large uncinate to falcate hooks in the basal armature, while in R. varioacantha n. sp. these hooks are almost the same in size as the remaining hooks in both the basal and metabasal armature. The latter species is the first tentaculariid species where the metabasal armature very closely resembles an eutetrarhynchid with a heteroacanthous typical homeomorphous metabasal armature and a high number of spiniform hooks per half spiral row (10-11 vs 6-7 in R. mexicoensis n. sp.) in the metabasal and apical armature. This pattern provides further morphological evidence for the close relationship of the Eutetrarhynchoidea and the Tentacularioidea. Reimeriella varioacantha n. sp. enriches the trypanorhynch fauna from off the coast of Malaysian Borneo while R. mexicoensis n. sp. is a novel record of a tentaculariid trypanorhynch from the Mexican Pacific.
    Matched MeSH terms: Sharks/parasitology*
  13. Fulltext Diagnostic and therapeutic potential of shark variable new antigen receptor (VNAR) single domain antibody
    Cheong WS, Leow CY, Abdul Majeed AB, Leow CH
    Int J Biol Macromol, 2020 Mar 15;147:369-375.
    PMID: 31926922 DOI: 10.1016/j.ijbiomac.2020.01.039
    Conventional monoclonal antibodies (mAbs) have been widely used in research and diagnostic applications due to their high affinity and specificity. However, multiple limitations, such as large size, complex structure and sensitivity to extreme ambient temperature potentially weaken the performance of mAbs in certain applications. To address this problem, the exploration of new antigen binders is extensively required in relation to improve the quality of current diagnostic platforms. In recent years, a new immunoglobulin-based protein, namely variable domain of new antigen receptor (VNAR) was discovered in sharks. Unlike conventional mAbs, several advantages of VNARs, include small size, better thermostability and peculiar paratope structure have attracted interest of researchers to further explore on it. This article aims to first present an overview of the shark VNARs and outline the characteristics as an outstanding new reagent for diagnostic and therapeutic applications.
    Matched MeSH terms: Sharks/immunology*
  14. Fulltext Photo-ID and telemetry highlight a global whale shark hotspot in Palawan, Philippines
    Araujo G, Agustines A, Tracey B, Snow S, Labaja J, Ponzo A
    Sci Rep, 2019 11 20;9(1):17209.
    PMID: 31748588 DOI: 10.1038/s41598-019-53718-w
    The Philippines is home to the second largest known population of whale sharks in the world. The species is listed as endangered due to continued population declines in the Indo-Pacific. Knowledge about the connectivity within Southeast Asia remains poor, and thus international management is difficult. Here, we employed pop-up archival tags, data mining and dedicated effort to understand an aggregation of whale sharks at Honda Bay, Palawan, Philippines, and its role in the species' conservation. Between Apr and Oct 2018, we conducted 159 surveys identifying 117 individual whale sharks through their unique spot patterns (96.5% male, mean 4.5 m). A further 66 individual whale sharks were identified from local operators, and data mined on social media platforms. The satellite telemetry data showed that the whale sharks moved broadly, with one individual moving to Sabah, Malaysia, before returning to the site <1 year later. Similarly, another tagged whale shark returned to the site at a similar periodicity after reaching the Malay-Filipino border. One individual whale shark first identified in East Kalimantan, Indonesia by a citizen scientist was resighted in Honda Bay ~3.5 years later. Honda Bay is a globally important site for the endangered whale shark with connectivity to two neighbouring countries, highlighting the need for international cooperation to manage the species.
    Matched MeSH terms: Sharks/physiology*
  15. Comparison of DNA profiling between fishes and pork meat using polymerase chain reaction-restriction fragment length polymorphisms (PCR-RFLP) analysis
    Safiyyah Shahimi, Wan Sakeenah Wan Nazri, Aminah Abdullah, Norrakiah Abdullah Sani, Sahilah Abd. Mutalib
    Sains Malaysiana, 2018;47:1535-1540.
    Genomic DNA of 13 fish (n=13) species consist of four freshwater which were catfish (Clarias gariepinus), shark catfish (Pangasius larnaudii), tilapia (Oreochromis mossambicus), perch (Lates calcarifer) and nine marine species which were black pomfret (Parastromateus niger), anchovy (Stolephorus commersonii), mabong (Rastrelliger kanagurta), red snapper (Lutjanus erythropterus), herring (Chirocentrus dorab), ray fish (Himantura gerrardii), sardine (Decapterus macrosoma), mackerel (Euthynnus affinis) and tuna (Thunnus tuna) were differentiated using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Seven endonucleases of AluI, BsaJI, HaeIII, HindIII, HinfI, MboI and MboII were examined for the ability to digest cyt b amplicon from each species. Genomic DNA of pork (Sus scrofa domestica) were differentiated from fishes by comparing the digestion patterns produced by similar amplified region and enzymes used. In the present study, it was demonstrated that fishes and pork DNA genome were successfully differentiated using all endonucleases except for HindIII. Thus, PCR-RFLP analysis was found useful for future pork DNA detection in fish products.
    Matched MeSH terms: Sharks
  16. Fulltext The Study of Drag Reduction on Ships Inspired by Simplified Shark Skin Imitation
    Ibrahim MD, Amran SNA, Yunos YS, Rahman MRA, Mohtar MZ, Wong LK, et al.
    Appl Bionics Biomech, 2018;2018:7854321.
    PMID: 29853998 DOI: 10.1155/2018/7854321
    The skin of a fast swimming shark reveals riblet structures that help reduce the shark's skin friction drag, enhancing its efficiency and speed while moving in the water. Inspired by the structure of the shark skin denticles, our team has carried out a study as an effort in improving the hydrodynamic design of marine vessels through hull design modification which was inspired by this riblet structure of shark skin denticle. Our study covers on macroscaled design modification. This is an attempt to propose an alternative for a better economical and practical modification to obtain a more optimum cruising characteristics for marine vessels. The models used for this study are constructed using computer-aided design (CAD) software, and computational fluid dynamic (CFD) simulations are then carried out to predict the effectiveness of the hydrodynamic effects of the biomimetic shark skins on those models. Interestingly, the numerical calculated results obtained show that the presence of biomimetic shark skin implemented on the vessels give about 3.75% reduction of drag coefficient as well as reducing up to 3.89% in drag force experienced by the vessels. Theoretically, as force drag can be reduced, it can lead to a more efficient vessel with a better cruising speed. This will give better impact to shipping or marine industries around the world. However, it can be suggested that an experimental procedure is best to be conducted to verify the numerical result that has been obtained for further improvement on this research.
    Matched MeSH terms: Sharks
  17. Fulltext Cross-Cultural Validation of Mood Profile Clusters in a Sport and Exercise Context
    Quartiroli A, Parsons-Smith RL, Fogarty GJ, Kuan G, Terry PC
    Front Psychol, 2018;9:1949.
    PMID: 30356841 DOI: 10.3389/fpsyg.2018.01949
    Mood profiling has a long history in the field of sport and exercise. Several novel mood profile clusters were identified and described in the literature recently (Parsons-Smith et al., 2017). In the present study, we investigated whether the same clusters were evident in an Italian-language, sport and exercise context. The Italian Mood Scale (ITAMS; Quartiroli et al., 2017) was administered to 950 Italian-speaking sport participants (659 females, 284 males, 7 unspecified; age range = 16-63 year, M = 25.03, SD = 7.62) and seeded k-means clustering methodology applied to the responses. Six distinct mood profiles were identified, termed the iceberg, inverse iceberg, inverse Everest, shark fin, surface, and submerged profiles, which closely resembled those reported among English-speaking participants (Parsons-Smith et al., 2017). Significant differences were found in the distribution of specific mood profiles across gender and age groups. Findings supported the cross-cultural generalizability of the six mood profiles and offer new research avenues into their antecedents, correlates and behavioral consequences in Italian-language contexts.
    Matched MeSH terms: Sharks
  18. Fulltext Oviparous elasmobranch development inside the egg case in 7 key stages
    Musa SM, Czachur MV, Shiels HA
    PLoS One, 2018;13(11):e0206984.
    PMID: 30399186 DOI: 10.1371/journal.pone.0206984
    Embryological stages of oviparous elasmobranch during development can be difficult to identify, requiring magnification and/or fixation of an anaesthetized embryo. These restrictions are poorly suited for monitoring the development of living elasmobranchs inside their egg cases. There are two major aims of this study. The first was to observe elasmobranch embryonic development non-invasively and produce a non-invasive developmental key for identifying the life stages for an elasmobranch inside the egg case. To this end, 7 key developmental stages were identified for the greater spotted catshark, Scyliorhinus stellaris, and are provided here with diagrams from multiple perspectives to demonstrate the key features of each stage. The physiological and ecological relevance of each stage are discussed in terms of structure and function for embryonic survival in the harsh intertidal zone. Also discussed is the importance of the egg case membrane and the protective embryonic jelly. The second aim of the study was to understand the applicability of the 7 developmental stages from S. stellaris to other oviparous elasmobranchs. Thus, changes in embryonic body size and egg yolk volume at each stage were measured and compared with those of the closely related, lesser spotted catshark, Scyliorhinus canicula. We find nearly identical growth patterns and yolk consumption patterns in both species across the 7 developmental stages. Thus, although the 7 developmental stages have been constructed in reference to the greater spotted catshark, we suggest that it can be applied to other oviparous elasmobranch species with only minor modification.
    Matched MeSH terms: Sharks/embryology*
  19. Assessment of metallic trace elements in the muscles and fins of four landed elasmobranchs from Kuala Terengganu Waters, Malaysia
    Ong MC, Gan SL
    Mar Pollut Bull, 2017 Nov 30;124(2):1001-1005.
    PMID: 28807418 DOI: 10.1016/j.marpolbul.2017.08.019
    A study had been carried out to determine Cu, Zn, Cd, Hg and Pb concentrations in the muscle and fins of four elasmobranchs species namely spot-tail sharks, milk sharks, whitespotted bamboo sharks and whitespotted guitarfish from Pulau Kambing LKIM Fishery Complex, Kuala Terengganu, Malaysia. Zinc level was found to have the highest concentration whereas Cd had the lowest concentration in both organs. By comparing both organs, metals concentrations in fins of all elasmobranchs species were higher than muscle. Result obtained was compared with the guidelines set by Malaysian Food Regulation and the provisional tolerable weekly intake was also determined. Current study recommends that the muscle of whitespotted bamboo shark from Kuala Terengganu Waters is likely not to be consumed due to it exceeded the allowable consumption guideline. Finding of this paper is very useful as it provides the baseline data on the pollution status of elasmobranchs in Kuala Terengganu Waters.
    Matched MeSH terms: Sharks
  20. First report of echthrogaleus denticulatus (smith 1874) on the pelagic thresher shark (alopias pelagicus nakamura 1935) from indian EEZ of andaman sea
    Arun Kumar M, Swapnil S, Pradeep H
    Sains Malaysiana, 2017;46:1675-1678.
    The present study reports the occurrence of the pandarid parasite, Echthrogaleus denticulatus as an ectoparasite on the pelagic thresher shark (Alopias pelagicus) from the Indian EEZ of Andaman Sea. A total of 36 parasite specimens were found aggregated near the cloacal aperture of eight pelagic thresher sharks caught as bycatch by multifilament tuna longliner MFV Blue Marlin during July 2015 and February 2016 voyages in Andaman and Nicobar waters. This is the first report of ectoparasite from the Indian EEZ of the Andaman Sea.
    Matched MeSH terms: Sharks
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