Naturalist Fact: Diamondback Terrapin

Diamondback Terrapin (Malaclemys terrapin centrata)

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The only turtle that lives entirely in brackish water is the diamondback terrapin (Malaclemys terrapin). This turtle is a habitat specialist, restricted to salt marshes, estuaries, and tidal creeks along the eastern and Gulf coasts of the United States. They are among the most variable of North American turtles, having an array of colors and patterns among the seven subspecies. The species is sexually dimorphic in that the males grow to approximately 13 cm, while the females grow to an average of around 19 cm and have a larger head and jaws than males. They also have a variable diet depending on geographic location, but common foods include periwinkle snails, bivalves, crustaceans, crabs, and scavenged fish. They are primarily diurnal and usually spend the night buried in sediment. Juvenile terrapins are rarely encountered. It is unknown what turtles two years old or younger do, as they are almost never seen.

The diamondback terrapin was once a food staple so cheap that 18th-century tidewater slaves protested the amount of terrapin in their diet. In the 19th-century, though, the diamondback made an unfortunate transition from despised staple to gourmet delicacy. Even though the commercial hunt has largely collapsed, these turtles continue to decline due to coastal development, disturbance on their nesting beaches, road mortality of nesting females, boat injuries, and pollution. They continue to drown in large numbers in pot traps designed for crabs. Maryland, Delaware, and New Jersey laws require terrapin excluders on crab traps, and some states are considering requiring them. In Georgia the terrapin is considered a “species of concern”.

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Naturalist Fact: Cownose Ray

Cownose Ray (Rhinoptera bonasus)

Photo from CheseapeakeBay.net

Photo from CheseapeakeBay.net

First things first: despite their common names of “cownose stingray” and “skate”, cownose rays are technically neither! Cownose rays are unique, so they belong to their very own family of rays. However, these interesting-looking ocean-dwellers can still pack a stinging punch, so avoid the venomous barb at the base of the tail. According to legend, Captain John Smith had an encounter with a cownose ray in Virginia, and the location still bears the name “Stingray Point”.

Despite these cautionary tales, cownose rays are known for their passiveness and will only sting when provoked. They are a common site along their shallow Atlantic coast migration path; found as far north as New England and as far south as Brazil. They often travel in large groups, called “schools”, that are formed based on the sex and age of the rays. Since they use their fins for locomotion, these underwater schools resemble flocks of large birds in underwater flight.

Cownose rays typically reach a wingspan of three feet, which comes in handy when they forage. The rays use their large fins to disturb mollusks in the seafloor sediments, and then they crush their prey using powerful dental plates.

On Little St. Simons, look for cownose rays along the edges of Mosquito Creek during a kayaking adventure—sometimes they even raise a fin to “wave”!

Fun Fact: The stinging barb on a cownose ray grows the same way as your finger nails, so the rays you see in “Touch Tanks” at aquariums are regularly clipped for safety.

 

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