166 UNDERWATER GUIDE TO MARINE LIFE 



similar habits and some are difficult to identify. Therefore, skates will be 

 considered as one group. 



skates: Raja species 



Skates are ground fishes found over sand, mud, gravel, or shell bottoms. They 

 are rather inactive by day, at which time they lie on the bottom, sometimes half 

 buried. To bury themselves, they stir up the bottom with their pectorals and 

 let the sand or mud fall back on them. They depend a good deal on protective 

 coloration to avoid being detected, their grayish or brownish, often spotted 

 or mottled bodies blending in well with the substrate. When alarmed they tend 

 to press their bodies closely to the bottom and may form a suction between 

 their bodies and the bottom which makes them difficult to dislodge. If further 

 alarmed, they may curl themselves into sort of a ball and lash violently with 

 their spiny tails. Some have electric organs on their tails able to deliver half a 

 volt. The adaptive value of such a small shock is not known. The skates are not 

 exclusively bottom fishes. Frequently, they come to the surface to bask in the sun 

 after the manner of many sharks. Skates, like most rays, have many rows of small, 

 pointed or flat teeth in the jaw which form a crushing or grasping dentition. 

 Their prey is quite varied but usually consists of crustaceans, molluscs, worms, 

 and small to medium-sized fishes. With active prey, such as fish, their method of 

 securing food is by ambush. They lie on the bottom until a victim comes their 

 way, then quickly pounce on it, holding it down with their bodies, and then 

 grasping it in their jaws. This method of capture is made necessary by the 

 position of the jaws on the underside. Locomotion is achieved by undulating 

 waves passing from front to rear in the pectoral fin. Skates can swim surprisingly 

 fast, at which time the pectorals are used in a flapping motion like the wings 

 of a bird. The tail may aid in steering. 



Skates mate with their ventral sides together and are frequently caught in 

 this position. One or both claspers are inserted. The egg capsules or sea purses 

 Cfig. 73) are 3 to 8 inches long and contain one to several eggs. They are laid 

 in the summer and adhere to rocks, shells, algae, etc., hatching in four and 

 one-half to fifteen months. The courtship and mating procedure should be easy 

 to observe by the swimmer. Males are smaller than females by about one-third. 

 Sometimes, several follow a single female and strike each other with the spiny 

 parts of the pectorals. These spiny pectoral patches are also used to grasp the 

 female while mating. Skates make excellent food. Raie au heiirre noire is a 

 French culinary delicacy. Skates reach 6 feet and 60 pounds but are mostly 

 much smaller. A list of some common species follows: 



East Coast: 



1. Common Skate (Litde Skate, Hedgehog Skate): Raja erinacea 



This is a small skate, reaching only 20 inches in length. The spines arc in 

 a distinctive pattern with no spines of large size directly on the midline. 

 This is the most common New England skate, found in shoal water and 

 to 80 fathoms, usually over a sandy bottom. It ranges from Cape Hattcras to 

 Nova Scotia. 



2. Clear-Nosed Skate (Briar Skate, Summer Skate): Raja eglanteria 



There are two translucent areas on the side of the snout and there is a 



