1 44 Memoir Sears Foundation for Marine Research 



bivalve mollusks, small fish of various kinds, and cephalopods of the less active sorts. ^^ 

 Occasionally pieces of eel grass {Zosterd) or algae, even pebbles, are found in the stomach 

 of a Skate, no doubt taken accidentally with its living prey. 



A Skate cannot capture active animals by direct attack because of the ventral 

 position of its mouth, so it swims over its victim by a sudden dart forward and settles 

 down upon it, thus preventing its escape. In fact, in the English Channel, Skates some- 

 times feed almost exclusively on fishes, especially herring. ^^ 



In the case of at least some of the European species (e. g., Raja clavata\ the 

 young are hatched in shallow water, after which they gradually disperse to greater depths 

 as they grow. Some of them also carry out feeding migrations on a considerable scale,** 

 but no precise information is available in this respect for any of the western Atlantic 

 Skates. 



Numerical Abundance. Skates may be extremely numerous locally on suitable bot- 

 toms in temperate and boreal latitudes. In northern Europe, where they are valued for 

 human food, their abundance is reflected in the considerable landings in various coun- 

 tries," for example, about 92,100,000 pounds in 1937, and 92,400,000 pounds in 

 1936, which is equivalent to about 18-46 million individuals, assuming the average 

 weight per Skate to be about 2—5 pounds. 



Statistics of the commercial catch in North America do not afford comparable 

 information for the western Atlantic, for most of the Skates are thrown back. In 1 940 

 the total landings reported for the entire Atlantic seaboard of the United States amounted 

 to only 373,000 pounds, in 1944 to 501,300 pounds. But Skates are far more plentiful 

 than the foregoing might suggest. Average catches of about one Skate to 33 fish of 

 all kinds on long lines have been reported at various localities in the Gulf of Maine.*^ 

 And an average of perhaps 120—150 Skates per square mile in 37 hauls of an otter 

 trawl on Georges Bank (equivalent to about one Skate per four acres of bottom fished) 

 probably far understates the actual numbers present, for the trawl, equipped with large 

 wooden rollers, doubtless passed over many Skates that were lying on the bottom, while 

 others probably escaped the nets as the latter approached them. 



Skates are also abundant from southern New England to New Jersey on sandy 

 bottoms. Old records for a pound net on the shore of Nantucket Sound,** operated 

 during the season of 1871 chiefly for clupeoids and therefore not particularly well 

 placed for ground fish, show that more Skates (2,923) than flatfishes of all kinds com- 

 bined (2,714) were taken. A more recent report states that not less than 10,000 pounds 

 of Skates, weighing 1-5 pounds, were discarded from one lift of a pound net at Bradleys 



41. On the northeastern coast of the United States, as at Woods Hole, Massachusetts, pieces of squid have often been 

 found in Skates' stomachs, although these were probably captured by the latter while in the pound nets or in fish 

 traps in which the Skates were taken. According to information furnished by the Bingham Oceanographic Laboratory, 

 whole squid have been found in Skates caught in otter trawls. 



42. Steven, J. Mar. biol. Ass. U.K., i8, 1932: 23-24. 43. Steven, J. Mar. bid. Ass. U.K., 18, 1932: 18. 



44. England, Scotland, Eire, France, Germany, Holland, Norway, Sweden, Poland, Iceland. 



45. Bigelow and Welsh, Bull. U. S. Bur. Fish., 40 (i), 1925: 57; Bigelow and Schroeder, Bull. U. S. Bur. Fish., .#<?, 

 1936: 324. 



46. At Waquoit, Mass. (Lyman, 6th Rep. Mass. Comm. inl. Fish., 1872: table i). 



