Longcomb sawfish
Longcomb sawfish | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Chondrichthyes |
Subclass: | Elasmobranchii |
Superorder: | Batoidea |
Order: | Rhinopristiformes |
Family: | Pristidae |
Genus: | Pristis |
Species: | P. zijsron
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Binomial name | |
Pristis zijsron Bleeker, 1851
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The longcomb sawfish, narrowsnout sawfish or green sawfish (Pristis zijsron) is a species of
Description
The longcomb sawfish is possibly the largest species of sawfish, reaching a total length of up to 7.3 m (24 ft), but rarely more than 6 m (20 ft) today.[1][4] Its upperparts are greenish-brown to olive, while the underparts are whitish.[4][6][7]
A combination of characters are necessary to distinguish it from the other sawfish species: the longcomb sawfish has teeth to near the base of the
Distribution and habitat
The longcomb sawfish is native to tropical and
The longcomb sawfish is mainly found in coastal marine,
Behavior and life cycle
The longcomb sawfish feeds on fish,
Little is known of its
Conservation
The longcomb sawfish has declined drastically and is listed by the
Historically the longcomb sawfish has been recorded in 37 countries, but it has been
Longcomb sawfish have few natural enemies, but can fall prey to large sharks and crocodiles.[6]
Small numbers are kept in
Threats
The longcomb sawfish faces significant threats attributed to intense and poorly managed fishing pressure throughout its range. This pressure arises from both commercial and small-scale fisheries, including artisanal, cultural, and subsistence practices. Various fishing gears such as gillnets, trawls, and lines are utilized, with the distinctive toothed rostra of sawfish making them particularly vulnerable to entanglement, especially in gillnets and trawls. Over recent decades, fishing effort has escalated across the species' range, driven by escalating demand and exploitation in the fin and meat trade.[1]
The longcomb sawfish encounters high fishing pressure, resulting in poorly regulated and unmanaged exploitation. Bycatch in both commercial and small-scale fisheries, driven by escalating demand for fins and meat, poses a considerable threat. The species is frequently retained for these valuable parts, contributing to population decline. In some regions, measures such as the release of sawfishes by fishers may still lead to significant at-vessel and post-capture mortality, further impacting population viability.[1]
Critical habitats of the longcomb sawfish, including inshore freshwater, estuarine, mangrove, and coastal areas, are under threat due to habitat loss and degradation. The reduction of mangrove areas in Southeast Asia, for instance, is estimated to be around 30% since 1980. The most affected habitats are those crucial for nearshore and estuarine nursery activities. Additionally, potential impacts on adult longcomb sawfish associated with offshore oil and gas extraction, including activities like seismic surveys, further compound habitat threats in various regions.[1]
Historically, the northwest region of Australia provided relatively undisturbed coastal habitats for the longcomb sawfish. Presently, various factors pose substantial threats to the species in Western Australia, including coastal developments such as mining, natural resource operations, and oil and gas extraction. These developments introduce structures like lighted jetties, dredged shipping channels, and offloading structures, potentially hindering the movement of juvenile longcomb sawfish along the coastline. The increased prevalence of these structures may lead to population fragmentation or the destruction of vital juvenile habitats for the species.[1]
See also
- Threatened rays
Notes
References
- ^ . Retrieved 20 May 2023.
- ^ "Appendices | CITES". cites.org. Retrieved 2022-01-14.
- ^ Froese, Rainer; Pauly, Daniel (eds.) (2017). "Pristis zijsron" in FishBase. November 2017 version.
- ^ ISBN 9780643109148.
- ^ a b c d e f g h i j k Department of the Environment (2017). "Pristis zijsron — Green Sawfish, Dindagubba, Narrowsnout Sawfish". Department of the Environment and Energy. Retrieved 14 November 2017.
- ^ a b c d e f g h Seitz, J.C. "Green sawfish". Ichthyology. Florida Museum of Natural History. Retrieved 14 November 2017.
- ISBN 0-7309-8363-3.
- JSTOR 1442018.
- S2CID 3352391.
- ^ Whitty, J. & N. Phillips. "Pristis zijsron (Bleeker, 1851)". Sawfish Conservation Society. Retrieved 17 November 2017.
- ^ doi:10.1002/aqc.2525.
- S2CID 83912626.
- ^ )
- ISSN 0043-5481.