Common Snapping Turtle

C. serpentina has a rugged, muscular build with a ridged carapace (upper shell) that varies in color from tan to brown and black, although ridges tend to be more pronounced in younger individuals. The straight-line carapace length in adulthood may be nearly 50 cm (20 in), though lengths of 25–47 cm (9.8–18.5 in) are more common. C. serpentina usually weighs 4.5–16 kg (9.9–35.3 lb). Per one study, breeding common snapping turtles were found to average 28.5 cm (11.2 in) in carapace length and 22.5 cm (8.9 in) in plastron length and weigh about 6 kg (13 lb). Males are larger than females, with almost all weighing in excess of 10 kg (22 lb) being male and quite old, as the species continues to grow throughout life. Any specimen above the aforementioned weights is exceptional, but the heaviest wild specimen caught reportedly weighed 34 kg (75 lb). Common snapping turtles kept in captivity can be quite overweight due to overfeeding and have weighed as much as 39 kg (86 lb). In the northern part of its range, the common snapping turtle is often the heaviest native freshwater turtle. Common snapping turtles have well-developed olfactory organs, nerves, and bulbs that suggest that this species has a great sense of smell.

Common habitats for these turtles are shallow ponds or streams. Some may inhabit brackish environments, such as estuaries. These sources of water tend to have an abundance of aquatic vegetation due to the shallow pools. Some describe them as habitat generalists as they can occupy most permanent bodies of water. Common snapping turtles sometimes bask—though rarely observed—by floating on the surface with only their carapaces exposed, though in the northern parts of their range, they also readily bask on fallen logs in early spring. In shallow waters, common snapping turtles may lie beneath a muddy bottom with only their heads exposed, stretching their long necks to the surface for an occasional breath. Their nostrils are positioned on the very tip of the snout, effectively functioning as snorkels.

Diet. Common snapping turtles are omnivorous. Important aquatic scavengers, they are also active hunters that use ambush tactics to prey on anything they can swallow, including many invertebrates, fish, frogs, other amphibians, reptiles (including snakes and smaller turtles), unwary birds, and small mammals. There has been no documented difference between the diets of males and females. …

The common snapping turtle is a traditional ingredient in turtle soup; consumption in large quantities, however, can become a health concern due to potential concentration of toxic environmental pollutants in the turtle's flesh.