Large-tooth Sawfish

Pristis perotteti

Profile / Morphology 1

All modern sawfishes appear in some respects to be more shark-like than ray-like, with only the trunk and especially the head, ventrally flattened. The presence of an extended rostrum (snout) having laterally protruding teeth is the main feature that separates all sawfishes from sharks and rays. The rostrum has a saw-like appearance, hence the name of sawfish.

Diet 2

Largetooth sawfish feed on benthic invertebrates and small schooling fishes. The saw is used for grubbing prey in the sediment and for attacking prey (usually schooling fishes) as well as for defense.

Average lifespan 2

up to 30 years

Size / Weight 2

Maximum size has been reported to be between 20 and 21.3 feet (6.1-6.5 m) total length with weights between 1100 and 1300 pounds (500 to 600 kg).

Habitat 2

Different populations of largetooth sawfish spend more or less time in freshwater areas, and some populations outside the US were exclusively found in freshwater. Largetooth sawfish are generally more tolerant than most fishes to a range of environmental conditions, but they generally prefer soft-sediment habitats in nearshore areas.

Range 2

Pristis perotteti historically inhabited warm-temperate to tropical marine waters in the Atlantic and eastern Pacific Ocean, and also possibly in the eastern Mediterranean, and freshwater habitats in Central and South America and Africa. Historical occurrences of largetooth sawfish in North America were much more limited than those of the related smalltooth sawfish and were strictly confined to shallow (< 33 feet or 10 m), near-shore, warm-temperate and tropical waters (>64-86 oF; 18-30oC), estuarine localities, partly enclosed lagoons, and similar situations. In the United States, largetooth sawfish were reported mainly along the Texas coast and east into Florida waters, but now it is considered extirpated in the United States. The last confirmed largetooth sawfish reported in US waters was in 1941 in Florida and 1943 in Texas (Burgess and Curtis 2003).

Reproductive / Life span 2

These sawfish are ovoviviparous, which means they have live birth but the young are nourished only with yolk provided to the egg at the beginning of development (i.e., there is no placenta). Litter sizes are one to 13 individuals, with an average of 7.3 individuals. The gestation period for Pristis perotteti is approximately five months, and females likely produce litters every second year. Maturity occurs around 10 years of age.

They are relatively long-lived, reaching 30 years of age.

Relatives 2

The largetooth sawfish and the smalltooth sawfish (Pristis pectinata) are similar in appearance. The two species can usually be differentiated by noting the number of teeth on one side of the rostrum. P. perotteti can have between 14 and 21 rostral teeth on one edge of the saw, whereas P. pectinata usually has 23 to 34. These two species can also be distinguished by observing that in P. perotteti the first dorsal fin originates in front of the pelvic fins, while in P. pectinata the first dorsal fin originates along the same axis as the pelvic fins. The pectoral fins of P. perotteti are proportionally larger than those of P. pectinata. Furthermore, only P. perotteti has a distinct lower lobe on its caudal fin (McEachran and Fechhelm 1998, Compagno and Last 1999).

Found in the following Estuarine Reserves 2

Mission-Aransas (TX), Grand Bay (MS), Weeks Bay (AL)

Water quality factors needed for survival 2

•Water Temperature: 18-30 °C
•Turbidity: low to high
•Water Flow: no data, adults likely tolerant of high flows
•Salinity: varies
•Dissolved Oxygen: unknown

Threats 2

•Bycatch
•Habitat degradation

Largetooth sawfish have low intrinsic rates of increase, which means they experience slow population growth. This makes them particularly vulnerable to excessive mortalities and rapid population declines, because recovery from such events may take decades. Incidental commercial catch, commonly called bycatch, was likely the most significant factor in the decline of sawfish populations in U.S. waters. Commercial and recreational fisheries for largetooth sawfish occurred in other parts of the world. Sawfish are extremely vulnerable to overexploitation due to their exceptional propensity for getting entangled in net gear and because of their restricted preferred habitat. Habitat degradation likely impacts the species given their inshore distribution and human activities in those areas.

Conservation notes 2

Importance to Humans and Estuaries
There were small commercial and recreational fisheries for this species. There is a small curio trade for their unique rostrum (saw) and the rostral teeth are prized for use as spurs in cockfighting.

How to Help Protect This Species
Because this species uses estuaries and freshwater areas they are susceptible to water pollution and damage to and alteration of stream channels and riparian zones. Therefore, efforts to protect the species include:
•Minimize runoff of neighborhood pollutants, fertilizer, and sediment into local streams are helpful to this species, and other estuary dwelling species.

•Join a stream or watershed advocacy group in your area to protect your local estuary ecosystems.
•Support restoration of more natural water flow regimes.

•Support research into the ecology and conservation of the species.

Largetooth sawfish are a prohibited species in Florida, Louisiana, and Alabama, which means they are not allowed to be personally possessed.

Sources and Credits

  1. Adapted by GTMResearchReserve from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Pristis_perotteti
  2. (c) GTMResearchReserve, some rights reserved (CC BY-SA)

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