Family Pristidae The Sawfish
description
Transcript of Family Pristidae The Sawfish
Family PristidaeThe SawfishGreek pristis = saw Sara McCutcheon
General Characteristics
• Large toothed rostrum
• Body shark-like
• 2 distinct dorsal fins and caudal fin
• Pectoral fins distinct
• Depressed head
Sawfish vs SawsharkEye
Sawfish vs SawsharkRostrum teeth
Sawfish vs SawsharkGill Position
Sawfish Taxonomy 7 species in 2 Genera
• Pristis pristis – Common sawfish
• Pristis perotteti – Largetooth sawfish
• Pristis microdon – Freshwater sawfish
• Pristis pectinata – Smalltooth sawfish*
• Pristis clavata – Dwarf sawfish
• Pristis zijsron – Green sawfish
• Anoxypristis cuspidata – Knifetooth sawfish
Taxonomy7 species in 2 Genera
Anoxypristis cuspidata (1 sp.)
Pristis pristis complex (3 spp.) Pristis pectinata complex (3 spp.)
3 Types of SawfishPristis pectinata complex• Non-tapering rostrum• Smaller teeth• 22-32 teeth per side
Pristis pristis complex • Broad tapering rostrum • Larger teeth • 15-20 teeth per side
Anoxypristis cuspidata• Very narrow saw • No teeth on the closest quarter of
rostrum to head• 16-29 teeth per side• More flattened and triangular teeth
Habitat
• Benthic• Freshwater,
brackish, and marine
• Nearshore waters
• Bays, lagoons, rivers, lakes, estuaries, seagrass, and reefs
• Sandy and muddy substrate
Distribution
• Nearshore waters
• Tropical, subtropical and warm temperate
• Atlantic, Indian, and Pacific
Biology
• Conicospiral intestines and long pyloric stomachs
• 3 reported instances of intestinal eversion (first non-carcharhinid)
• Juveniles prefer a depth of 10m or less; adults deeper water
• Some species use freshwater nurseries for ~4-5 years
• Immature up to 280cm• Max size 760 cm TL – P. pectinata (350kg)• Max recorded weight 600kg – P. microdon • Max age 30 years
Reproductive Biology
• 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)
ThreatsFishing and Habitat Loss and degradation
Fisheries
• In the late 1800s a fisherman on the Indian River in Florida reported that he caught more than 300 sawfish in one season
Fisheries
• Recreational fisheries for saw trophy
• Commercial fisheries bycatch, saw entanglement
Fisheries
• Chinese medicine – eggs, liver, oil, bile
• Food• Shark fin soup• Decoration• Leather• Curio trade• Saw for spiritual
offerings
Habitat Loss and Degradation
• Extensive coastal development
• Dredging
• Mangrove removal
• Seawall construction
• Alteration of freshwater flow
• Habitat fragmentation
Status
• All 7 sawfish species 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– Likely to become extinct
Conservation Efforts
• Federally (ESA) and internationally (IUCN) protected
• Research • Public education and
outreach • Public sightings
database• Captain’s logbooks
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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