Common Snapping Turtle (Chelydra serpentina)

Linnaeus, 1758
8-14 inches (**-** cm).  This is a fairly large turtle with some specimens weighing in excess of 35 pounds (16 kg).  However, there are records of captive specimens weighing in excess of 70 pounds (32 kg).   The carapace is rounded in dorsal view with three longitudinally oriented keels.  The keels are typically found on young specimens and tend to lose definition and become worn smooth as specimens grow older.  The posterior marginal scutes are serrated and the plastron is cruciform and reduced.  the neck is long and the head is large with two barbels present on the chin.  The legs are well developed and powerful.  The feet are webbed and bear well developed claws.  The tail is long and has a single row of serrated  scales that are dorsally oriented.

    The carapace is tan to dark olive brown with radiating dark lines present on each scute.  The lines extend anteriorly to anterio-laterally from each side of the medial keels found in the center of each scute.  The dorsal surfaces of the head, neck, limbs and tail are grayish to buff brown.  The ventral surfaces are almost a uniform wash of beige to creamy yellow.

The common snapping turtle (Chelydra serpentina) has a geographic distribution that extends from southern Canada into the United States, east of the Rocky Mountains, and southward into Mexico, Central America, and Ecuador. Of the two species, alligator snapping turtles occupy a smaller range and are restricted to river systems in the southeastern United States.

Although primarily aquatic, snapping turtles occasionally leave the water to bask or venture about on land. This activity most commonly occurs after heavy rains, during drought when individuals are searching for water, or when females are looking for nesting sites. Ponds, slow-moving creeks and rivers, lakes, and brackish marshes are suitable habitats for snapping turtles. A body of water with a soft, muddy bottom is preferred. In such environs, one can sometimes encounter snapping turtles covered in mud with only the eyes and nostrils exposed. In this position, the snapping turtle is well poised to ambush unsuspecting prey. Not only does its long neck allow the turtle to ambush prey, it also allows a concealed snapper to raise its nostrils to the surface without disturbing its hiding place.   Snapping turtles are opportunistic predators and scavengers that consume a wide range of food items including: algae, duck weed, water hyacinth, water lettuce, crayfish, insects, fish amphibians, reptiles birds and mammals.

    Although this species is known to eat an occasional fish it is considerably slower than most healthy fish thereby consuming mostly those fish that are not as healthy as others.  By culling unhealthy fish the snapping turle esentially improves the quality of fish within healthy aquatic ecosystems.

    Males and females are easy to distinguish.  Mature male specimens are larger than females and the opening of their cloaca extends beyond the marginal scutes of the carapace.  While the opening of the female's cloaca is often well within the perimeter of the posterior marginal scutes.  Females can produce as many as 50 spherical eggs laid each spring.  Typical incubation requires 75-95 days .  Variation in incubation time can be due to the latitude at which the eggs were laid.  depending upon climatic conditions outside the nest, hatchlings may remain inside their nest until the following spring.
from: www.texasturtles.org