Classification :  The American Crocodile belongs to the family Crocodylidae which includes 12 other species of crocodilians.  Crocodylus acutus is the only species of Crocodilian that lives in the United States, and it lives solely in southern Florida.

Appearance : The American Crocodile is one of the larger crocodilian species, males are generally capable of growing to
5 or 6 m, with some rare reports of 7 m individuals. Crocodiles are brownish green, have a long, narrow skull, and pointed snout, and a streamlined body.  Both the upper and lower teeth visible and the most important thing, the fourth tooth in the lower jaw being visible.  In crocodilians the fourth tooth of the lower jaw is always the largest, they are the equivalent of the fangs in a tiger.  Dorsal armor is irregular and much reduced in comparison with other species. There is a distinctive swelling in front of each eye, visible in all except the hatchlings.

Range :  The range of the American Crocodile is extensive throughout Central America and the
north western part of South America, but it is limited in the States to the extreme south of Florida.

Habitat :  This species can be found in both freshwater (including river, lakes and reservoirs) and brackish coastal habitats (including tidal estuaries, coastal lagoons and mangrove swamps).  Crocodiles in these conditions osmoregulate primarily by drinking available freshwater. Possibly the most unusual location is a population which occupies the brackish water cooling canals at the Turkey Point nuclear power plant in Florida. This species also constructs long burrows for aestivation and as a retreat from adverse conditions. Considerable overland distances can also be traveled in search of new habitats.

Prey :   Feeds primarily at night on fish, and other aquatic species including turtles and crabs. Juveniles take small fish and invertebrates. Crocodilians are opportunistic hunters; they eat whatever they can catch if they are hungry. Flying prey can be caught by the crocodilians leaping into the air with thrusts of their powerful tail. Often blamed for the disappearance of domestic animals in more populated areas. Occasional reports of attacks on humans, but authenticated records are very rare. The American crocodile has an interesting way of attracting fish to them. They throw-up a very small bit of food which
attracts fish making them much easier to catch.

Reproduction :  This species is mainly a hole nester, but populations without access to suitable nest sites
which can be excavated (relatively well drained) will build mound nests using whatever nesting materials are available. Flooding creates high mortality. Nesting occurs during the dry season to minimize flooding. The minimum number of eggs laid in the nest can be around 20 in some populations, but is usually between 30 and 60, the mean being around 38.  Hatching, after around 90 days, coincides with the beginning of the annual rains. At hatching, juveniles are around 25 cm in length.

Behavior : American Crocodiles are cold-blooded and have to live in warm climates. They excavate burrows along the water's edge. They emerge from the water, or their burrows, to raise their body temperature by lying in the sun.  During the dry season, they may become sluggish, refuse to eat, and bury themselves in the mud.  If startled on land they will run for
the water and disappear.  Chances of actually seeing one are rare because they are a very elusive reptile.

Jaws : Crocodilians' teeth are mostly identical, thick-walled cones embedded in the outside of the jaw. Rear teeth are more cylindrical and blunter than front teeth. The teeth are not cemented into the jaw but simply attached to the outside, and can be broken off.  Crocodilians can replace their teeth an indefinite number of times.  Crocodilians do not have lips and their mouths leak when closed.  All crocodilians have strong jaw muscles for biting and holding prey. The muscles that close the jaw are extremely strong.  This is in contrast to the very weak muscles that it has to open its mouth.  Prey is not chewed or ground in the mouth: once it is impaled on the sharp teeth, it is swallowed whole.

Three Species in Florida :   You can identify the American Crocodile a lot easier than you might have thought.  Although in Florida there are 2 other species of crocodilian that might look similar at first glance, there are features in the head that set them apart.  The American Alligator has a broader snout and does not have it’s bottom teeth protruding out.
The Caiman also has a broader snout, but it has a shorter head than both the American Alligator and the American Crocodile.  The Caiman also has a bony ridge on the snout just below the eyes.  The American Crocodile is the only Crocodilian in Florida with a narrow snout and protruding teeth.
 

Related Links
 Check out the Crocodile Hunter
 Feeding in Crocodilians
 Croc Myth's and fun Facts

Bibliography

1.  Cogger, H. and R. Zweifel. 1998. Encyclopedia of Reptiles and Amphibians. Academic Press, San Diego, CA.

2.  Harvey, Douglas.  1988.  Living Dinosaurs ?.  Macmillan/McGraw-Hill, New York, NY.

3.  Crocodilian Species List
     http://www.flmnh.ufl.edu/natsci/herpetology/brittoncrocs/csp_cacu.htm#imag

4.  Everglades-American Crocodile
     http://www.miamisci.org/ecolinks/everglades/crocinfo.html

5.  Order Crocodilia
     http://animaldiversity.ummz.umich.edu/chordata/reptilia/crocodilia.html

6.  Jurassosaur's Reptipage: A page devoted to the study of reptiles
     http://freehosting1.at.webjump.com/13361845c/re/reptilis-webjump/