Fishes of the Western North Atlantic 269 



Anterior rays of pectorals extend forward about 80-85 "/q of distance from level 

 of fronts of orbits toward tip of snout. 



Color. Upper surface pale brown with numerous obscure darker spots, sometimes 

 with irregular pale markings; tail similar to disc in adults, but newly hatched specimens 

 with two transverse pale bars, each outlined by a dark crossbar in front of it and another 

 behind. These bars are lost with growth, so that specimens of 180-200 mm may show 

 either one or two; specimens of 280-300 mm have either one or none. Lower surface 

 of disc and pelvics either plain white or with a few small dusky spots on outer parts of 

 pectorals, or one at tip of snout; the tail either white below, variously dark-blotched, or 

 uniformly dark along the posterior third. 



Size. The three smallest specimens we have seen — apparently hatched not long 

 previously but with the filamentous tip of the caudal already lost — were 83-87 mm long. 

 A male of 515 mm is shown to be mature or nearly so by the size of its claspers. The 

 maximum length reported is 24 inches (610 mm). 



Developmental Stages. Egg cases, probably of this species, are dark brown or almost 

 black, squarish and smooth-shelled, 56-59 mm long (exclusive of horns) by 35-39 mm 

 broad, one side nearly flat but the other strongly convex. The horns are thick and at 

 least as long as the capsule (tips broken off in all specimens seen)."* 



Habits. Nothing is known of the diet of this Skate. It has been taken, apparently 

 with equal regularity, on the soft mud and clay bottoms of the deeper troughs and basins 

 as well as on the sand, sand and shells, gravel, and pebbles of the offshore fishing banks. 

 Egg cases, some empty and others containing embryos, apparently of this species,"" have 

 been trawled in the estuary of the St. Lawrence River at i 50-300 meters (82-164 fath.) 

 in July and August. The fact that an empty egg capsule has been found on the shore 

 near Halifax, Nova Scotia, makes it probable that R. senta breeds throughout its geo- 

 graphic range. 



The shoalest captures of R. senta that have been definitely recorded were at 25 

 and 44 fathoms in the southwestern part of the Gulf of Maine, off Cape Cod, and the 

 great majority of records range from 50-250 fathoms off southern New England "^ and 

 210 fathoms off New Jersey to 478 fathoms (one specimen) oft' South Carolina. It is 

 recorded from 82-178 fathoms in the Gulf of St. Lawrence, and from 50-100 fathoms 

 on LaHave and Emerald banks off outer Nova Scotia. 



The lowest temperature from which R. senta has been definitely recorded, in the 

 estuary of the St. Lawrence River, was about 2-4° C (36-39° F). The local populations 

 may also be exposed to temperatures equally low on the banks off southeastern Nova 

 Scotia into the summer when the ice-cold outdraught from the Gulf of St. Lawrence ex- 

 tends coastwise in that direction ;i*2 similar exposure to cold waters is likely on Georges 



139. For description and photographs, see Vladykov (Nat. canad., 6j, 1936: 220-221). 



140. Separable by their small size from those of K. radiata, the only other Skate that is known to occur in the region 

 where they were collected. 



141. K. senta was taken in eight hauls deeper than 100 fathoms by Albatross III between Long. 67°io' and 72°2o' W, 

 but not in 55 hauls shoaler than that. 



142. The bottom temperature on July 29, 1914 was about 2.8° C (37° F) on La Have Bank at 95 fathoms, but 5.6° C 

 (42° F) at 80 fathoms on Emerald Bank off Halifax a week later. 



