8 research outputs found

    First record of the Starry Weever Trachinus radiatus (Cuvier, 1829) from the Madeira archipelago

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    The Starry Weever (Trachinus radiatus, Cuvier 1829) is one of nine extant species of the Trachinidae family, which typically inhabit sandy-bottomed environments. This species is widespread throughout the Mediterranean Sea and in the Eastern Atlantic from continental Portugal to Angola, including the Canary Islands (Seret & Opic 2011; Smith, 2016). It has, however, not yet been recorded from the Azores, Madeira, and the Cabo Verde Islands. Carneiro et al. (2019) mentioned a museum specimen allegedly from Madeira Island in the Paris Natural History Museum (MNHN-IC-2005-2436,1925) but this specimen is not from Madeira, it is from Casablanca fish market (Iglesias pers. comm. To the second author). We herein provide the first true record of T. radiatus from the Madeira archipelago, in the Northeast Atlantic Ocean.info:eu-repo/semantics/publishedVersio

    Mark-recapture validates the use of photo-identification for the widely distributed blue-spotted ribbontail ray, Taeniura lymma

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    The ability to identify individual animals can provide valuable insights into the behaviour, life history, survivorship, and demographics of wild populations. Photo-identification (photo-ID) uses unique natural markings to identify individuals and can be effective for scalable and non-invasive research on marine fauna. The successful application of photo-ID requires that chosen distinguishing markings are unique to individuals and persist over time. In this study, we validate the use of dorsal spot patterns for identifying individual blue-spotted ribbontail rays (Taeniura lymma) in conjunction with traditional tagging methods. Spot patterns were unique among T. lymma with 90.3% of individuals correctly identified using I3S photo-matching software from images taken up to 496 days apart. In comparison, traditional physical tagging methods showed a tag loss rate of 27% and a maximum tag retention period of only 356 days. Our findings demonstrate the effectiveness of photo-ID as a tool to monitor populations and better understand the ecology of the blue-spotted ribbontail ray without the need for physical tagging. The validation of photo-ID for this widespread species is important as it enables behavioural and demographic changes to be easily tracked in relation to coastal threats such as human development and habitat degradation.</p

    Neotype designation and re-description of Forsskål’s reticulate whipray Himantura uarnak

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    International audienceA continuing impediment to the taxonomy of the reticulate whipray Himantura spp. species complex is the absence of a type specimen for H. uarnak (Gmelin [ex Forsskål], 1789). Here, reticulate whipray specimens were sampled from the Jeddah region in the Red Sea, the assumed type locality of H. uarnak, and characterized genetically at the cytochrome-oxidase subunit 1 (CO1) locus. One of these specimens now in the fish collection of the California Academy of Sciences was designated as neotype. The maximum-likelihood phylogeny of all available CO1 gene sequences from the genus Himantura had the following topology: ((H. leoparda, H. uarnak), (H. undulata, (Himantura sp. 2, (H. australis + Himantura sp. 1))), H. tutul), where H. uarnak haplotypes formed a distinct lineage sister to H. leoparda. Based on these CO1 gene sequences, the geographic distribution of H. uarnak includes the eastern Mediterranean, the Red Sea, the East African coast, and the Arabian Sea. At least one lineage in the reticulate whipray species complex remains to be named

    Neotype designation and re-description of Forsskål’s reticulate whipray Himantura uarnak

    No full text
    International audienceA continuing impediment to the taxonomy of the reticulate whipray Himantura spp. species complex is the absence of a type specimen for H. uarnak (Gmelin [ex Forsskål], 1789). Here, reticulate whipray specimens were sampled from the Jeddah region in the Red Sea, the assumed type locality of H. uarnak, and characterized genetically at the cytochrome-oxidase subunit 1 (CO1) locus. One of these specimens now in the fish collection of the California Academy of Sciences was designated as neotype. The maximum-likelihood phylogeny of all available CO1 gene sequences from the genus Himantura had the following topology: ((H. leoparda, H. uarnak), (H. undulata, (Himantura sp. 2, (H. australis + Himantura sp. 1))), H. tutul), where H. uarnak haplotypes formed a distinct lineage sister to H. leoparda. Based on these CO1 gene sequences, the geographic distribution of H. uarnak includes the eastern Mediterranean, the Red Sea, the East African coast, and the Arabian Sea. At least one lineage in the reticulate whipray species complex remains to be named

    Neotype designation and re-description of Forsskal's reticulate whipray Himantura uarnak

    No full text
    A continuing impediment to the taxonomy of the reticulate whipray Himantura spp. species complex is the absence of a type specimen for H. uarnak (Gmelin [ex Forsskal], 1789). Here, reticulate whipray specimens were sampled from the Jeddah region in the Red Sea, the assumed type locality of H. uarnak, and characterized genetically at the cytochrome-oxidase subunit 1 (CO1) locus. One of these specimens now in the fish collection of the California Academy of Sciences was designated as neotype. The maximum-likelihood phylogeny of all available CO1 gene sequences from the genus Himantura had the following topology: ((H. leoparda, H. uarnak), (H. undulata, (Himantura sp. 2, (H. australis + Himantura sp. 1))), H. tutul), where H. uarnak haplotypes formed a distinct lineage sister to H. leoparda. Based on these CO1 gene sequences, the geographic distribution of H. uarnak includes the eastern Mediterranean, the Red Sea, the East African coast, and the Arabian Sea. At least one lineage in the reticulate whipray species complex remains to be named

    Low diversity and abundance of predatory fishes in a peripheral coral reef ecosystem

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    Abstract Semi‐enclosed seas are often associated with elevated local threats and distinct biogeographic patterns among marine fishes, but our understanding of how fish assemblage dynamics vary in relation to relatively small semi‐enclosed seas (e.g., the Gulf of Aqaba) remains limited. Baited remote underwater video surveys (n = 111) were conducted across ~300 km of coral reef habitats in the Gulf of Aqaba and the northern Red Sea. A total of 55 predatory fish species were detected, with less than half of all species (n = 23) observed in both basins. Relative abundance patterns between the Gulf of Aqaba and the northern Red Sea were variable among taxa, but nearly twice as many predatory fish were observed per unit of effort in the northern Red Sea. In general, assemblages in both basins were dominated by three taxa (Epinephelinae, Carangidae, and Lethrinidae). Large‐bodied and threatened species were recorded at very low abundances. Multivariate analysis revealed distinct assemblage structuring of coral reef predators between the Gulf of Aqaba and the northern Red Sea. Most of the species driving these differences were recorded in both basins, but occurred at varying levels of abundance. Environmental factors were largely unsuccessful in explaining variation in assemblage structuring. These findings indicate that biological assemblages in the Gulf of Aqaba are more distinct than previously reported and that reef fish assemblage structuring can occur even within a relatively small semi‐enclosed sea. Despite inter‐basin assemblage structuring, the overall low abundance of vulnerable fish species is suggestive of overexploitation in both the Gulf of Aqaba and the northern Red Sea of Saudi Arabia. As the region surveyed is currently undergoing large‐scale coastal development, the results presented herein aim to guide spatial management and recovery plans for these coral reef systems in relation to this development

    Widespread diversity deficits of coral reef sharks and rays

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    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
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