DIAMONDBACK TERRAPIN

By:CRISPIN DRIVER-SCHRODER

Malaclemys terrapin

 

TAXONOMY

Kingdom: Animalia

Phylum: Chordata

Class: Reptilia

Order: Chelonia

Family: Emididae

Genus: Malaclemys

Species: terrapin

 

Diet and Feeding Habits

  • Diet: This species of turtle eats snails, soft shelled mollusks, insects, small fish, and crustaceans.
  • Predators: Along with raccoons, Bald eagles, gulls, and crows, other curious animals will eat the Diamondback terrapin, and or young.
  • Place in food web: The diamondback is a predator of small fish, snails, and crustaceans, so it is carnivorous, but they “can” also eat plants so it’s hard to tell exactly if it’s carnivorous or an omnivore.
  • Competitors: Other turtles that eat the same food.

 

PHYSICAL DESCRIPTION

 

Diamondback Terrapins are a species of turtles that get their name from a raised diamond pattern on their shell. The males and females differ in that the shell size of a female is an average of 9” while the males are on an average of 6” from head to tail. The top of the shell on both males and females are usually olive colored or light brown, which is important in helping it blend in its environment. The plastron is usually light yellow to orange, with a few rare green to grey ones appearing as well. At the bridge the shell is at its thickest, also since this species is a vertebrate, the vertebrae are underneath and the bridge protects it from damage. Hatchlings have special plastron markings that are kind of like yolk sacs on the underbelly to distinguish them from juveniles, and adults are much bigger than juveniles as a way to distinguish them.

One adaptation that this species has is a very powerful jaw that is used to break or crush-open it’s the shells of (mollusks, crabs, snails, and other prey). This species also has a very unique salt gland behind its eyes, called a lacrimal gland that prevents the turtle from dehydrating by desalinating water for drinking. Like all reptiles, this species is cold blooded. This means it can take on the temperature of its surroundings, which is why you can sometimes see turtles basking in sunlight to get warm.

 

HABITAT

It is dawn and the creatures of the brackish marsh are waking. This is the habitat of the Diamondback Terrapin. Crawling out from under the tall reeds and grass, an adult male Diamondback terrapin wakes to a warm windy morning on a beach of Long Island Sound in southeastern New York. After waking he goes to find breakfast in a nearby tidal pool. The tidal pool is buzzing with good selections for its meal; snails, small Fiddler crabs, small fish, etc. The terrapin chooses an easy crab to crush open with its powerful jaw and so he eats a delectable breakfast. After breakfast he goes up to the top of a sand dune to bask in the warm sunlight. The marsh is busy with life as crows, gulls, and the occasional Bald eagle swoop down to pick up their breakfast. The ground is almost black with tiny crabs and snails. On the other side of the marsh a baby Diamondback terrapin is crawling out onto the dangerous beach, out in the open where a Bald Eagle swoops down and feasts on the little parcel of food. As dusk approaches the adult terrapin will have to defend itself against raccoons, bigger birds, and other curious animals.

 The Diamondback terrapin is Diurnal (which means it’s active in the daytime); it also has a hibernation period, which is from November to mid April. This particular terrapin has a range from Cape Cod to the Gulf Coast in brackish (salt/fresh water) marshes. These terrapins have a particular schedule for the year, which is in spring they emerge from hibernation and breed, in summer they wander and disperse among the land from the Cape Cod to Texas coastline. In fall they retreat to their homeland to get ready for winter, and at last in winter they go into a stage of hibernation under the reeds and tall grass of the marsh, hidden from predators desperate for food. The climate is mild, but can get very windy and rainy cold. The oceans rarely rise above 60° F, but in summer in the shallows it can reach 80°F.

 

NATURAL HISTORY

Desperately trying to get out of the hot sand dune, a tiny hatchling Diamondback terrapin emerges. Hatchlings are only 1 inch long when they hatch, after being incubated by constant temperature sand for 60-120 days. Crawling as fast as he can, the terrapin races to the nearest body of water, may it be a swamp, tidal pool, or even the open ocean for shelter. It may seem unusual to us, being so helpless when we are born, but the hatchlings survive on their own once they are born.

For the rest of its juvenile life, it will be growing furiously to reach sexual maturity. After reaching this point they only grow 5% more each year. Sexual maturity in the terrapin is more related to size than age. When a male reaches sexual maturity, after roughly 5-8 years, it would be between 8 or 9 centimeters long. For females they would be 14 centimeters long, which could take up to 10 years! What is really amazing is that in order to grow to sexual maturity, it takes most of the Diamondback’s lifespan. Males typically live for 9-10 years, while females live between 10 and 12 years. So once they reach sexual maturity they are ready to sexually reproduce through internal fertilization.

The Diamondback terrapin is believed to have a relative from 200 million years ago in the Triassic period. That was the 2 foot long monster turtle called Proganochelys. They were found as fossils in Greenland , Thailand , and Germany . Through time, the turtle has shrunken to about one foot long; losing much of its intimidation factor, so it has more predators.

BIBLIOGRAPHY

Brennessal, Barbara. Diamonds In the Marsh. University Press of New England, Lebanon, NY 2006

“Diamondback terrapin”, University of Delaware Graduate College of Marine Studies. http://www.ocean.udel.edu/kiosk/terrapin.html

“Diamondback terrapin” Graduate college of Marine Studies, Delaware US http://www.ocean.udel.edu/kiosk/terrapin.html

“Malaclemys terrapin” Natureserve Explorer http://www.natureserve.org/explorer/servlet/NatureServe?sourceTemplate=tabular_report.wmt&loadTemplate=species_RptComprehensive.wmt&selectedReport=RptComprehensive.wmt&summaryView=tabular_report.wmt&elKey=103845&paging=home&save=true&startIndex=1&nextStartIndex=1&reset=false&offPageSelectedElKey=103342&offPageSelectedElType=species&offPageYesNo=true&post_processes=&radiobutton=radiobutton&selectedIndexes=103342&selectedIndexes=104664&selectedIndexes=105998&selectedIndexes=105877&selectedIndexes=104233&selectedIndexes=102474&selectedIndexes=103845 2/10/07

Park, I. 2000. "Malaclemys terrapin" (On-line), Animal Diversity Web. Accessed March 30, 2007 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Malaclemys_terrapin.html.

Raven, Peter H. and Johnson, George B. Biology, Sixth Edition, New York, NY: McGraw-Hill companies inc. 2002

“terrapin, Encyclopedia Brittannica, 2007. Encyclopedia Brittannica Online. 12 Mar, 2007

 

 

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