Family Pristidae – The Sawfish



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Family Pristidae – The Sawfish

Sara McCutcheon

Order: Pristiformes

Family: Pristidae

7 species in 2 Genera



Anoxypristis (1)

Pristis (6)
Diagnostic Characteristics

  • Large toothed rostrum

  • Snout is bladelike with teeth on either side

  • Teeth of equal size and embedded in deep sockets

  • No barbels

  • Body shark-like

  • 2 distinct dorsal fins and a caudal fin

  • Depressed head

  • Maximum length over 6m


Taxonomy

  • Pristis pristis complex (Pristis pristis, P. perotteti, P. microdon)

    • Broad tapering rostrum

    • 15-20 teeth per side (larger teeth)

    • Monocuspidate dermal denticles with keels and furrows

  • Pristis pectinata complex (Pristis pectinata, P. clavata, P. zijsron)

    • Non-tapering rostrum

    • 22-32 teeth per side (smaller teeth)

    • Monocuspidate dermal denticles lacking keels and furrows

  • Anoxypristis cuspidata

    • Very narrow saw

    • 16-29 teeth per side

    • No teeth on the closest quarter of rostrum to head

    • More flattened and triangular teeth

    • Distinct lower caudal lobe

    • Tricuspid dermal denticles


Distribution and Habitat

  • Freshwater, brackish, and marine

  • Nearshore waters

  • Tropical, subtropical and warm-temperate

  • Atlantic, Indian, and Pacific

  • Shallow, estuarine areas are important as nurseries

  • Sandy and muddy substrates

  • Coastal, estuaries, bays, lagoons, rivers, lakes, seagrass, and coral reefs

  • Benthic


Biology

  • Conicospiral intestines and long pyloric stomachs

  • 3 reported instances of intestinal eversion (first non-carcharhinid)

  • Sexual maturity is reached at 10-11 feet for males and 11-12 feet for females

  • Ovoviviparous

  • Gestation of ~ 5 months

  • Litter every other year

  • 6-23 pups

  • Pupping occurs in spring (wet season)

  • Born at 2 feet long

  • Born backwards, saw encased in a sheath of tissue, and teeth do not fully erupt until after birth


Diet

  • The saw is used to catch, kill, and manipulate food 

  • Swipe the saw, stunning or impaling fish

  • Small sawfish – crustaceans and fish

  • Large sawfish – fish (jacks, mullet, ladyfish)


Status

  • All seven species of sawfish are Critically endangered

  • P. pectinata – apparently extinct in the Mediterranean and NE Atlantic

  • P. perotteti – extirpated from most of its range in Atlantic

  • P. pristis – was once common in the Mediterranean and Eastern Atlantic, but has now been extirpated from Europe and the Mediterranean

    • Without timely intervention this sawfish will likely become extinct

  • The major threats to sawfish are fishing, habitat loss and fragmentation

  • Fishing – easily entangled in fishing gear

    • Difficult to remove fish without killing it or removing rostrum

    • Recreational fishermen – regularly caught for their saw

    • Commercial fishermen – bycatch

  • Habitat Loss

    • Extensive coastal development, dredging, mangrove removal, seawall construction, and alteration of freshwater flow


Conservation Efforts – Smalltooth sawfish

  • Listed as Critically Endangered by the World Conservation Union's Shark Specialist Group

  • 1992 – Florida completely protected sawfish within state waters (0 bag limit)

  • 2000 – No evidence that the largetooth sawfish still exists in US waters

  • 2003 – Smalltooth sawfish listed as Endangered under ESA – the first elasmobranch

  • Recovery plan in the works

  • June 2007 – CITES banned the international trade of sawfish and their saws and fins

    • Limited trade of live sawfish from Australia for public aquarium display is still allowed

Bibliography

Adams, W.F., Fowler, S.L., Charvet-Almeida, P., Faria, V., Soto, J. & Furtado, M. 2006. Pristis pectinata. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 05 November 2007.

Carrier, J.C., Musick, J.A., and Heithaus, M.R.. 2004. Biology of Sharks and their Relatives. CRC Press, Boca Raton, FL. pp 142, 416, 427.

Charvet-Almeida, P., Faria, V., Furtado, M., Cook, S.F., Compagno L.J.V. & Oetinger, M.I. 2007. Pristis perotteti. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 05 November 2007.

Compagno, L.J.V., Cook, S.F., Oetinger, M.I. & Fowler, S.L. 2006. Anoxypristis cuspidata. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 05 November 2007.

Cook, S.F., Compagno, L.J.V. & Last, P.R. 2006. Pristis clavata. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. www.iucnredlist.org. Downloaded on 05 November 2007.

Deynat, PP. 2005. New data on the systematics and interrelationships of sawfishes (Elasmobranchii, Batoidea, Pristiformes). Journal of Fish Biology 66 (5):1447-1458.

Florida Museum of Natural History – Icthyology. http://www.flmnh.ufl.edu/fish/Gallery/Descript/DwarfSawfish/DwarfSawfish.html. Viewed on 11/06/07.

Henningsen, AD, Whitaker, BR, and Walker, ID. 2005. Protrusion of the valvular intestine in captive smalltooth sawfish and comments on pristid gastrointestinal anatomy and intestinal valve types. Journal of Aquatic Animal Health 17 (3): 289-295.

Mote Marine Laboratories. www.mote.org. Viewed on 11/06/07.

Nelson, J.S. 2006. Fishes of the World, 4th ed. John Wiley and Sons, Inc, NJ. pp 69, 73.

Peverell, SC. 2005. Distribution of sawfishes (Pristidae) in the Queensland Gulf of Carpentaria, Australia, with notes on sawfish ecology. Environmental Biology of Fishes 73 (4): 391-402.

Robillard M. and Seret, B. 2006. Cultural importance and decline of sawfish (Pristidae) populations in West Africa. Cybium 30 (4): 23-30.

Thorburn, DC, Morgan, DL, Rowland, AJ, and Gill, HS. 2007. Freshwater sawfish Pristis microdon Latham, 1794 (Chondrichthyes : Pristidae) in the Kimberley region of Western Australia. Zootaxa 1471: 27-41.




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