220 MARINE FISHERIES OF NORTH CAROLINA 



turtles, used for "snapper soup," or with strictly freshwater terrapin, or 

 "sliders," although the latter are sometimes improperly substituted for 

 diamond-backs (Coker, 1906, and Pope, 1939). 



The diamond-back terrapin is primarily an estuarial species, occurring 

 along the entire Atlantic and Gulf coasts in brackish water and even occa- 

 sionally in the rivers above the reach of salt water. It is our only turtle 

 characteristic of brackish waters. It is not found in the sea. All evidence 

 gained from observation in nature and from breeding experiments indicates 

 some dependence upon fresh water. There is as yet no fully satisfactory 

 explanation of its restriction in distribution to brackish water and to only 

 the lower reaches of the fresh waters of certain rivers. Possibly it is a matter 

 of feeding habit, its accustomed food being such as is dependent upon 

 the presence of salt water and the flow of tidal currents. Hay (1904) re- 

 ported that terrapin have been found in the Potomac as far up as within four 

 miles of Washington. The terrapin themselves are not dependent upon salt 

 water surroundings. I and others have had them live and thrive in captivity, 

 in pens supplied only with water from an artesian well, but in such case 

 they were fed with salt water fish. On the other hand, I have tried to keep 

 them in Mississippi River water in Iowa, where they were fed only fresh- 

 water foods; the terrapin survived only a few months (Coker, 1920). 



At one time large diamond-back terrapin were per pound the most val- 

 uable food product from coastal waters (in the retail market). Measure- 

 ment of size is by the length of the under-shell, called the plastron. It is a 

 large individual, and always a female, that has the undershell 6 inches in 

 length. Such terrapin might sell at $50 or $60 a dozen. Hildebrand and 

 Hatsel (1926) reported the Boston market price as one dollar per inch of 

 bottom shell; this gives a rate of $72 per dozen for 6-inch terrapin. Larger 

 terrapin up to 7 or 8 inches would bring higher prices. The length of 8 inches 

 on the bottom shell is rarely exceeded and the maximum is believed to be 

 about 9 inches. A leading dealer in the Baltimore market told me of selling 

 two terrapin to a regular customer, whom he named, for $25. Value in the con- 

 noisseur market depends not only upon the size but also upon appearance. 



Standards of appearance are not precisely describable, but are based 

 primarily upon recognition of the so-called "Chesapeake" type, with the 

 top shell (carapace) flaring behind (widest behind the middle), the head 

 small and relatively pointed, coloration rich and usually dark, the concentric 

 markings on the plates (scutes) of the carapace evident. A terrapin of equal 

 size to the "Chesapeake" but with more nearly parallel sides, larger head, 

 generally lighter or dull color, and smoother shell, would bring a substan- 

 tially lower price. This would be branded a "Carolina" type, although, as 

 will be seen below, both types occur in North Carolina and probably in the 

 Chesapeake. 



