Common Snapping Turtles

Chelydra serpentine belongs to the kingdom Animalia because they are multicellular and eukaryotic heterotrophs. They also belong to the phylum Chordata because they had the following features at some point in their lives: pharyngeal slits, dorsal nerve cord, notochord, post-anal tail. Chelydra serpentine have waterproof skin covered in scales, are ectothermic and have hard shelled eggs that are water proof. These features make them a part of the class Reptilia. They belong to the order Testudines (turtles) which means they have the following features: boney shell which is part of their skeleton, a shell on their underside, sharp beaks that replace teeth and allows them to tear their food. There are over 290 species of Testudines alive today
inhabiting all kinds of habitats such as freshwater, marine and terrestrial environments throughout the world. In general turtles are pretty adaptable to different environments and can adapt to different food sources. The family of Chelydra, to which the Common Snapping Turtle belongs to, has many special adaptions.
They have heads and limbs that cannot be fully retracted within the shell. The upper jaw is hook and the jaws are very strong. They have long tales that are roughly the same length as the shell. They also have special skeletal adaptions. From family we can break it down into species. The scientific name for the Common Snapping Turtle is Chelydra serpentine. The Common Snapping Turtles have some unique traits that separate them from other turtles. They have three pronounced ridges on the shell. These ridges are very noticeable as the turtles are young but become worn down with age. They have black, spotted pattern in their eyes that are shaped like a cross. They also have a uniquely yellow underside that makes them stand out from other types of
turtles.
The Common Snapping Turtles upper shell color varies from green to brown to black and often has moss, algae or mud covering it. The back edge of the shell is strongly toothed. The lower shell is smaller than the upper shell and does not provide much protection it is often colored yellowish to tan. The Common Snapping Turtle has a large head and a sharp beak with a hooked upper jaw. The color of the head is often grey to brown or olive. The jaws of the turtle are brighter and usually yellow or cream. When the Common Snapping Turtle first hatches it has an ‘egg tooth’ which is pointed out from its beak and used to break through the shell. This is shed within the first few weeks of its life. Although turtles are notorious for being slow movers the Common Snapping Turtle has large and powerful limbs. They have clawed toes that are webbed for better movement underwater. It is difficult to tell the male and females apart. Males are generally larger than the females and have a more concave under shell. The Common Snapping Turtle reaches maturity around year 8-10 and can live up to 40 years and many more.
The Common Snapping Turtle spends most of its time on the bottom of lakes, streams or other water bodies, or berried in the mud.
During the daytime it is not uncommon to see this turtle floating just below the waters surface. The Common Snapping Turtle has the ability to swim but most of the time it will move by walking on the bottom of the water body. They are Omnivorous. Their main sources of their diet depends on their location, which could include insects, fish, crawfish, worms, tadpoles, snakes, snails, frogs and aquatic plants. They will also feed on dead animals if given the chance. Hatchlings actively forage for food where adults wait for the food source to find them. The adult will quickly extend its head and neck and can capture the prey and tear the flesh with their strong
jaws.
Snapping Turtles overwinter (hibernate) from around October to April depending on weather and location. They stay in shallow water and either sit on the bottom, shelter themselves by digging into the mud or they stay under debris. During this time many Snapping Turtles congregate in one area. If waterways have dried up the common snapping turtle may go into a similar dormant time during the summer months. Breeding will take place at any point in the year where they are active but occurs mostly in the spring and fall. Around June, the females move to areas suitable for nesting that are open and sunny. The females lay, on average, 25-50 eggs and covers the nest with soil. The eggs will hatch in 50-125 days. The temperature affects the sex of the offspring. More females hatch during warmer temperatures where more males hatch during cooler temperatures. Once hatchlings emerge from the nest they must begin their journey to the water. During this time 60%-100% of the young may be lost to predators (raccoons, skunks, foxes, mink, fish, and water snakes).
The Common Snapping Turtle occurs through much of the United States and into Southern Canada. It most occurs in the eastern two thirds of the United States as well as the southern part of Canada. The species also can be found in portions of Mexico, Central America and South America. Turtle farms are also starting in Japan, China and Taiwan. Snapping Turtles will live in almost any aquatic habitat but they prefer slow-moving, quiet waters with muddy bottoms and dense vegetation. They usually inhabit shallow water ways but are also know to live near the shores of deeper waterways. The Common Snapping Turtle is known to inhabit beaver lodges and muskrat burrows for shelter. Young turtles stay in shallower waters and move to deeper waters as they grow larger.
There are threats to the Common Snapping Turtles although scientists are not concerned about this species becoming threatened at this time. Overall the Common Snapping Turtles are very adaptable which makes them more resistant to threats. Some of the common threats are predication of the eggs by different species. 60%-100% of hatchlings are lost to predators before making it to the water. Another threat are the pesticides that are accumulating within the habitats of these turtles. It is causing issues with the hatchlings and them having abnormalities but is not having a large effect on the adults. Habitat loss is also becoming a concern as it is forcing the natural world and the modern world to interact more. Female turtles are often hit by cars while they are traveling to find suitable nesting locations. Turtles are also commonly caught in fishing nets and may drowned before a fishermen would check there nets. Although they are not considered threated the Common Snapping Turtle population has dropped considerably in the north. Canada as well as some of the US states are putting legislation into place that will help with the conservation of the Common Snapping Turtle. Some states have made the capturing of wild Common Snapping Turtles illegal while other states have no regulation on this.
There is concern by the Minnesota Department of Natural Resources about the population of Common Snapping Turtles within the state. In fact the Common Snapping Turtle is listed as an uncommon species within Minnesota. One of the concerns is that they are being overharvested for human consumption. Minnesota issues licensees to harvest unlimited numbers of adults as long as they hit a certain length requirement. The peak of the harvest also occurs during the time when females are laying their eggs (around June) which could have a great effect on the number of surviving offspring in that area. As they are harvested in the spring time the Common Snapping Turtle may still be in hibernation. During this time large numbers of these turtles often hibernate together on the bottom in the sand or mud. If one large group of adult turtles are taken at one time it can have a huge impact on the amount of turtles that will be located in that area for years to come. Studies of these turtles in Minnesota also found high levels of PCBs (polychlorinated biphenyls) in the Mississippi River. The chemicals effects are not yet known but more studies will be conducted on these issues in order to keep the population of the turtles healthy while monitoring the long term effects of these chemicals.
The Common Snapping Turtles also may be causing issues with other species. They may be causing issues with the populations of game fish and waterfowl across the United States. Studies in Connecticut (according to the Department of Energy and Environmental Protection Connecticut) are inconclusive on if the Common Snapping Turtle are to blame for this issue. I expect more research will be done on this issue within the next few years if the problem persists.
References
Chelydra serpentine. (n.d.). Retrieved April 24, 2016, from http://www.iucnredlist.org/details/summary/163424/0
Chelydridae. (n.d.). Retrieved April 24, 2016, from http://animaldiversity.org/accounts/Chelydridae/
Common Snapping Turtle. (n.d.). Retrieved April 24, 2016, from http://www.ct.gov/deep/cwp/view.asp?a=2723 Darwin's Galapagos. (n.d.). Retrieved April 24, 2016, from http://www.darwinsgalapagos.com/animals/reptilia_reptiles.htm
Introduction to the Chordata. (n.d.). Retrieved April 24, 2016, from http://www.ucmp.berkeley.edu/chordata/chordata.html
Species profile: Minnesota DNR. (n.d.). Retrieved April 24, 2016, from http://www.dnr.state.mn.us/rsg/profile.html?action=elementDetail
Turtles: The Carapace-Clad Reptiles. (n.d.). Retrieved April 24, 2016, from http://animals.about.com/od/tortoisesandturtles/p/turtles.htm