Alligator snapping turtle (Macrochelys temminckii)

Description

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Alligator snapping turtle fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Alligator snapping turtle description

One of the largest freshwater turtles in the world, the alligator snapping turtle (Macrochelys temminckii) is a prehistoric-looking species with a reputation as the ‘dinosaur of the turtle world’ ⁽⁴⁾. It has a camouflaged, ridged upper shell (carapace), a large head and powerful, hooked, beak-like jaws, which, together with its thick, scaly skin and oversized claws, all contribute to its primitive look and set it apart from other freshwater turtles ⁽⁵⁾. The three large, pronounced ridges running down the length of the dark brown to blackish shell somewhat resemble those on the back of an alligator, and earn the species its common name ^{(4) (6)}. The shell also often has algae growing on it, which adds to the snapping turtle’s camouflage ⁽⁶⁾. The tail is almost as long as the shell itself and, together with the chin, throat and neck, is coated with long, pointed tubercles ^{(7) (8)}. The alligator snapping turtle has an unusual way of luring prey; the tongue contains a small, pink, worm-like projection (lure), which is grey at rest but suffused with blood when active, and is wriggled to attract prey into the turtle’s mouth ⁽⁴⁾.

Synonyms

Chelonura temminckii, Macroclemys temminckii.

Size

Length: up to 80 cm ⁽²⁾

Weight

up to 113 kg ⁽²⁾

Alligator snapping turtle biology

The alligator snapping turtle is a solitary species, which mates in the early spring in Florida, or later in spring in the Mississippi Valley, and nests about two months later ^{(8) (9)}. Nests are dug at least 50 metres from the water’s edge, and a clutch containing anything between 8 and 52 eggs may be laid ⁽⁹⁾. Incubation lasts 100 to 140 days and most hatchlings emerge in September or October ^{(8) (9)}. As with a number of reptiles, the sex of the young is determined by incubation temperature; high and low temperatures yield more females and moderate temperatures yield more males. Sexual maturity is attained between 11 and 13 years of age, and alligator snapping turtles have been known to live up to 70 years in captivity, although the lifespan in the wild is unknown ⁽¹⁰⁾.

The alligator snapping turtle actively forages for food at night, but is more of a ‘sit-and-wait’ predator during the day. The turtle lies quietly on the mud bottom with its jaws wide open, its dark colouring and its coating of algae making it almost invisible to fish ⁽⁹⁾. The worm-like lure within the turtle’s mouth is wiggled to entice unwary fish and, when the unlucky prey comes close, the turtle’s jaws are quickly snapped shut ^{(6) (9)}. The alligator snapping turtle not only feeds on a variety of fish, but also on frogs, snakes, snails, worms, clams, crayfish, aquatic plants and even other turtles ⁽⁹⁾.

Alligator snapping turtle range

Endemic to the southeastern region of the United States, occurring in all the river systems that drain into the Gulf of Mexico ^{(1) (4) (9)}.

Alligator snapping turtle habitat

A freshwater species generally found in the deep water of large rivers, canals, lakes and swamps, though hatchlings and juveniles usually live in small streams ⁽⁹⁾. These turtles seldom leave the water, with generally only nesting females venturing onto land, although males have been known to bask ⁽¹⁰⁾.

Alligator snapping turtle status

The alligator snapping turtle is classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾ and listed on Appendix III of CITES ⁽³⁾.

Alligator snapping turtle threats

A major decline in numbers occurred as a result of over-collection by one of the major soup manufacturing companies in the U.S., and alligator snapping turtles are still threatened by over-harvesting for their meat in many areas ^{(8) (11)}. Although some states now prohibit collection of this species, other states allow it with permits ⁽¹²⁾. Other threats to this turtle include habitat destruction and alteration, water pollution and pesticide accumulation ^{(1) (9) (12)}.

Alligator snapping turtle conservation

Collecting wild specimens is prohibited in Arkansas, Florida, Georgia, Indiana, Missouri and Tennessee, but allowed with the necessary permit in Alabama, Illinois, Kansas, Louisiana, Oklahoma and Texas ⁽¹⁾. The alligator snapping turtle has been found in reservoirs throughout its range, and diking of rivers to create winter waterfowl refuges has increased the available habitat in Arkansas and the lower Mississippi Valley, which may help offset some of the habitat degradation and loss seen elsewhere ⁽¹⁾.

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

For more information on the alligator snapping turtle see:

• The Centre for Reptile and Amphibian Conservation and Management:
  http://herpcenter.ipfw.edu/
• Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (1997) Turtles of the World. ETI Information Systems Ltd, Netherlands. Available at:
  http://nlbif.eti.uva.nl/bis/turtles.php

Authentication

Authenticated (01/11/10) by Ryan M. Bolton, Freshwater Turtle Ecologist, University of Guelph, Ontario, Canada.
http://www.artofconservation.ca/

Glossary

Algae

Simple plants that lack roots, stems and leaves but contain the green pigment chlorophyll. Most occur in marine and freshwater habitats.

Carapace

The upper shell in turtles and tortoises.

Endemic

A species or taxonomic group that is only found in one particular country or geographic area.

Incubation

The act of incubating eggs; that is, keeping them warm so that development is possible.

Tubercle

A small wart-like or angular swelling.

References

1. IUCN Red List (November, 2010)
   http://www.iucnredlist.org/
2. Bonin, F., Devaux, B. and Dupré, A. (2006) Turtles of the World. Johns Hopkins University Press, Baltimore.
3. CITES (January, 2007)
   http://www.cites.org/
4. Levine, D. (1994) The alligator snapping turtle, Macroclemys temminckii: giant of the Southeastern States. Tortuga Gazette, 30(9): 1-3. Available at:
   http://www.tortoise.org/archives/macrocl.html
5. National Geographic (January, 2007)
   http://www3.nationalgeographic.com/animals/reptiles/alligator-snapping-turtle.html
6. Brookfield Zoo (January, 2007)
   http://www.brookfieldzoo.org/pagegen/htm/fix/fg/fg_body.asp?sAnimal=Alligator+snapping+turtle
7. Illinois Natural History Survey (INHS) Amphibian and Reptile Collection (January, 2007)
   http://www.inhs.uiuc.edu/cbd/herpdist/species/ma_temminc.html
8. Ernst, C.H., Altenburg, R.G.M. and Barbour, R.W. (1997) Turtles of the World. ETI Information Systems Ltd, Netherlands. Available at:
   http://nlbif.eti.uva.nl/bis/turtles.php
9. Animal Diversity Web (January, 2007)
   http://animaldiversity.ummz.umich.edu/site/accounts/information/Macrochelys_temminckii.html
10. Smithsonian National Zoological Park (January, 2007)
    http://nationalzoo.si.edu/Animals/ReptilesAmphibians/Facts/FactSheets/Alligatorsnappingturtle.cfm
11. The Centre for Reptile and Amphibian Conservation and Management (January, 2007)
    http://herpcenter.ipfw.edu/
12. Saint Louis Zoo (January, 2007)
    http://www.stlzoo.org/animals/abouttheanimals/reptiles/turtlesandtortoises/alligatorsnappingturtle.htm