{{Short description|Species of cartilaginous fish}} {{Speciesbox | image = Pristis clavata (Dwarf sawfish) in Aqua park.png | image2 = Pristis clavata 2.jpg | image2_caption = ''Pristis clavata'' in the [[Maxell Aqua Park Shinagawa]] | status = CR | status_system = IUCN3.1 | status_ref = <ref name="iucn">{{cite iucn |author1=Grant, M.I.|author2=Charles, R.|author3=Fordham, S.|author4=Harry, A.V.|author5=Lear, K.O.|author6=Morgan, D.L.|author7=Phillips, N.M.|author8=Simeon, B.|author9=Wakhida, Y.|author10=Wueringer, B.E. |year=2022 |title=''Pristis clavata'' |volume=2022 |article-number=e.T39390A68641215 |doi=10.2305/IUCN.UK.2022-2.RLTS.T39390A68641215.en |access-date=9 December 2022}}</ref> |status2=CITES_A1 |status2_system=CITES |status2_ref=<ref>{{cite web|url=https://cites.org/sites/default/files/eng/app/2023/E-Appendices-2023-05-04.pdf|title=CITES Appendices I, II and III|date=4 May 2023|access-date=20 May 2023|publisher=Convention on International Trade in Endangered Species of Wild Fauna and Flora|page=54}}</ref> | taxon = Pristis clavata | authority = [[Samuel Garman|Garman]], 1906 }}
The '''dwarf sawfish''' or '''Queensland sawfish''' ('''''Pristis clavata''''') is a [[sawfish]] of the [[Family (taxonomy)|family]] [[Pristidae]], found in tropical [[Australia]]. This [[endangered species]] is the smallest species in its family.
==Description== [[File:Rostrum of Pristis clavata.png|left|thumb|Rostrum]] [[File:Pristis clavata (Dwarf sawfish) in Aqua park shinagawa.png |thumb|Ventral side of dwarf sawfish]]
The dwarf sawfish has a torpedo-shaped body that resembles that of a shark, and grows to a length of about {{convert|3.2|m|ft|round=0.5|abbr=on}}. It has broad, triangular pectoral fins and large, upright dorsal fins. The first dorsal fin is located directly above, or slightly behind, the origins of the pelvic fins, and the caudal fin has a very small lower lobe. The snout is broad and flat and is elongated into a [[Rostrum (anatomy)|rostrum]] with around twenty pairs of rostral teeth. The rostral teeth are rounded and lack the grooves seen in [[Largetooth sawfish]], and if present, they are very small and limited.<ref>{{Cite web|url= https://www.researchgate.net/figure/Comparison-of-the-rostral-tooth-shape-of-Pristis-microdon-and-Pristis-clavata-from-the_fig9_279542495 |title= Freshwater Sawfish Pristis microdon Latham, 1794 (Chondrichthyes: Pristidae) in the Kimberley region of Western Australia |website= researchgate}}</ref> This fish is usually greenish-brown, or occasionally yellowish-brown, on its dorsal surface, and whitish underneath.<ref name=Curtis>{{cite book|author1=Curtis, Lee K. |author2=Dennis, Andrew J. |author3=McDonald, Keith R. |title=Queensland's Threatened Animals |url=https://books.google.com/books?id=gsaXOp6qKawC&pg=PA82 |year=2012 |publisher=Csiro Publishing |isbn=978-0-643-09614-1 |pages=82–}}</ref>
==Distribution and habitat== The dwarf sawfish is native to the western and central [[Indo-Pacific]] region and historically had a much wider range than it does now. Its present confirmed range is from southern [[New Guinea]] to the tropical region of northern [[Australia]].<ref name=iucn/> A recorded sighting from the [[Canary Islands]] was probably of a different species. It typically inhabits inshore waters, estuaries, tidal mudflats and sometimes the lowest reaches of rivers.<ref>{{cite web |url=http://www.fishbase.org/summary/Pristis-clavata.html |title=''Pristis clavata'' |author=Garilao, Cristina V. |publisher=FishBase |access-date=2015-08-19}}</ref>
==Ecology== [[File:Pristis clavata shinagawa aqua stadium.jpg|thumb|Dwarf sawfish head]] This sawfish feeds mainly on fish, but also eats molluscs and crustaceans.<ref>{{cite web |url=http://www.nmfs.noaa.gov/pr/species/fish/dwarfsawfish.htm |title=Dwarf Sawfish (''Pristis clavata'') |date=2014-12-16 |publisher=NOAA Fisheries |access-date=2015-08-19}}</ref> The rostrum has large numbers of pores adapted for [[electroreception]] and is probably also used to manipulate prey. Its sensory input helps the fish move about in the muddy waters in which it often lives.<ref>{{cite journal |author1=Wueringer B.E. |author2=Peverell S.C. |author3=Seymour J. |author4=Squire Jr. L. |author5=Kajiura S.M. |author6=Collin S.P. |year=2011 |title=Sensory Systems in Sawfishes. 1. The Ampullae of Lorenzini |journal=Brain, Behavior and Evolution |volume=78 |issue=2 |pages=130–149 |doi=10.1159/000329515 |pmid=21829004 |s2cid=16357946 }}</ref> Although they are sometimes found in deep water, most movements take place while the tide is either rising or falling, and movements during each tidal cycle may be up to {{convert|10|km|mi|1|abbr=on}}. At high tide the fish tend to forage and rest among the [[mangrove]]s.<ref name=Curtis/>
Little is known of the breeding habits of the dwarf sawfish. The fish are [[Ovoviviparity|ovoviviparous]] with the developing embryos feeding on the yolks of their eggs. It is not known how many young can be carried at one time nor how frequently the fish can breed, but the young are about {{convert|65|cm|in|0|abbr=on}} long when they are born. Maximum longevity in this species is estimated to be forty-eight years.<ref name=Curtis/>
==Status== The dwarf sawfish is protected in Australian waters, but elsewhere in the world, sawfishes are harvested for their meat, fins, rostrums and oil. The main threat facing the dwarf sawfish is being caught as [[bycatch]] in gillnets and trawl nets. That this is the cause of declining numbers is demonstrated by the fact that populations are declining fastest in heavily fished areas. The [[International Union for Conservation of Nature]] has assessed the conservation status of this fish as "[[critically endangered]]". There is a need for education of fishermen about safe release practices and how to manage their fisheries. However, the threats are continuing, and there is no reason to believe that the population of dwarf sawfish is recovering from previous declines.<ref name=iucn />
Due to the decrease in the number of individuals, this species is rarely stored in aquariums, and as of 2021, 2 individuals (1 male and 1 female) are in kept in the Japanese public aquarium [[Aqua Park Shinagawa]].<ref>{{Cite web|url= https://kids.rurubu.jp/article/35213/ |title= "裏の顔"が人気！ノコギリエイの展示は3水族館のみ。性格・特徴、世界唯一展示も|website=るるぶkids|language=Japanese|date=13 September 2020|access-date=20 May 2023}}</ref><ref>{{Cite web|url=http://www.aqua-park.jp/en/aqua/facility/upperfloor.html|archive-url=https://web.archive.org/web/20201005083227/http://www.aqua-park.jp/en/aqua/facility/upperfloor.html|archive-date=5 October 2020|title=Guide to the facility UPPER FLOOR (2F) | Maxell Aqua Park Shinagawa |website=Maxell Aqua Park Shinagawa}}</ref>
==See also== {{Portal|Sharks}} *[[List of threatened rays]]
==References== {{Reflist|colwidth=30em}}
==External links== *{{Commons category-inline|Pristis clavata|''Pristis clavata''}} *{{Wikispecies-inline|Pristis clavata|''Pristis clavata''}} *[http://shark-references.com/species/view/Pristis-clavata Species Description of Pristis clavata at www.shark-references.com]
{{Taxonbar|from=Q244406}}
[[Category:Pristis|Pristis]] [[Category:Fish described in 1906|dwarf sawfish]] [[Category:ESA endangered species]]