Fishes of the Western North Atlantic 183 



water shoaler than 15—18 fathoms than in deeper water, while many come so close in 

 shoreward that they are often found stranded on the beach, especially after rough 

 weather. The greatest depths from which positively identified specimens have been 

 recorded are 31-44 fathoms off the coasts of Virginia, Delaware, New Jersey, and Long 

 Island, New York;i-* 71-80 fathoms off southern Massachusetts ;i2^ 30 fathoms on the 

 southwestern part of Georges Bank;^^'' 25 fathoms near Seguin Island, Maine; and 50 

 fathoms off the Bay of Fundy.'^' It tolerates a wide range of temperature, from about 

 20-21° C (68-70° F)"2 in summer to as cold as about 3-4° C (37-39° F) in winter.'^^ 

 Specimens have survived until heated to 29.1-30.2° C (84.4-86.4° F), even though 

 taken from the cool water of Passamaquoddy Bay.^^* 



The maximum salinity recorded on bottom within the zone regularly inhabited 

 by R. erinacca is 33.8 "/oo, the usual upper limit a little less than 33 "/oo- The great 

 majority of the population lives in salinities lower than 32.5 %o the year round, but 

 29-30 "/oo is about the lower limit of its optimum range, except in Long Island Sound, 

 where it is found in water with salinity of only about 27 "/po. It has never been reported 

 from fresh water, and specimens placed in the latter showed signs of great physiological 

 disturbance. "5 



Stomach contents listed for R. erinacea include hermit and other crabs {Cancer^ 

 Ovalipes, Panopaeus, Pagurus), shrimps, amphipods, copepods, annelid worms (chiefly 

 Nereis), ascidians, bivalves including razor shells (Ense//a), and fragments of squids. 

 Crabs are an important item, for 29 "/o of the Skates opened in one series of examin- 

 ations at Woods Hole contained them, 15 "/o contained bottom-living shrimps of one 

 kind or another, and 6 % had eaten squid. In Long Island Sound, amphipods were 

 found to be the chief food, followed by crabs and shrimp (see above). It also preys 

 on small fish, including the sand launce (Jmrnodytes), alewives (Pomolobus), herring 

 (Clupea), cunners (Tautogolabrus), silversides (Menidid), tomcod (Microgadus), flounders 

 {Paralichthys), and silver hake (Merluccius). 



It appears that R. erinacea produces eggs throughout its latitudinal range, except 

 perhaps toward its southern limits, for egg cases have been found as far north as Halifax 

 Harbor, Nova Scotia. "« For an account of fertilization and egg laying, see p. 188. 



R. erinacea probably does not carry out any extensive migrations along the coast 

 with the change of seasons. It has been described repeatedly as coming up into shallower 

 water for the summer and moving out into deeper water in autumn or early winter. 



128. Specimens collected by the U. S. Bureau of Fisheries steamer Albatross II and examined by us. 



129. Specimens trawled on the Albatross III. 



130. Ten specimens trawled on September 5, 1926, during one of the cod tagging cruises of the U. S. Bureau of Fisheries. 

 It was not represented among the Skates taken in 37 trawl hauls at 40 fathoms or deeper on the northern part of 

 the Bank in September 1929. For details of these catches, see Bigelow and Schroeder (Bull. U. S. Bur. Fish., 48, 

 1936: 324). 



131. Huntsman, Contr. Canad. Biol. (1921), 3, 1922: 57. 132. Off New Jersey and southern New England. 



133. Shoal water off the eastern end of Long Island, New York, and off Connecticut; also southern side of Gulf of St. 

 Lawrence. 



134. Huntsman and Sparks, Contr. Canad. Biol., N. S. 2, 1924: 102. 



135. Chaisson (Contr. Canad. Biol., Fisher., N. S. 5, 1930: 479). 



136. Vladykov, Nat. canad., 6j [(3)/], 1936: 213, 215. 



