574 Memoir Sears Foundation for Marine Research 



The difference in appearance between the sexes becomes greatly accentuated with 

 the approach of spawning time, when the skin on maturing males thickens along the 

 bands of modified scales, each of which develops a finger-like extension clothed with 

 epidermis (Fig. 135 g— i), so that the nuptial bands then appear as two furry or plush- 

 like ridges (Figs. 133, 135 f). Templeman has reported {lio: 146) that "while maturing 

 males showed only faint traces of these ridges on May 20th all the males near the 

 beaches have well developed spawning ridges a month later"; this illustrates the 

 rapidity with which this nuptial development may take place. Small roundish so- 

 called nuptial tubercles also develop along the rays of the pectoral, pelvic, dorsal, 

 and anal fins (Fig. 135 c); these are most prominent and the most numerous on 

 the paired fins, less so on the dorsal, and usually sparsest and smallest (or lacking) 

 on the anal. Scattered tubercles also develop on the lower side of the head (jp: 417— 

 420). In maturing males the outer ends of the terminal branches of the rays along the 

 midsection of the anal fin fuse together at their tips to form a plate-like structure 

 (Fig. 135 d; jj^: 200). 



Finally, in Pacific specimens the vertebrae are reported to be more numerous on the 

 average in males (av. 65.65) than in females (av. 65.13) (jp: 419), but in Atlantic 

 specimens as more numerous in females (av. 65.65) than in males (av. 65.52) (jjo: 148), 

 a puzzling situation that we are not in a position to clarify. 



Remarks. Capelin are small, slender, silvery, smelt-like fishes, growing to a max- 

 imum length of about 7.5—8 inches (p. 579). Though marine in habit, they run up 

 into very shallow water to spawn, and occasionally into the mouth ot rivers. They 

 are North Boreal to Arctic in nature and are present in countless multitudes in their 

 centers of abundance. They are distinguishable from Osmerus by the differences given 

 on p. 554. 



Range. North Atlantic and tributary parts of the Arctic; in the eastern Atlantic, 

 from Spitsbergen and Jan Mayen {^48: 90), southeastern Greenland, Iceland, White 

 Sea, and northern Norway southward to Trondheim Fjord in abundance, occasionally 

 to Oslo Fjord and the Faeroes;-^ in the western Atlantic, from southwestern Green- 

 land, Hudson Bay, and northern Labrador, southward to Newfoundland (including 

 the islands of St. Pierre and Miquelon), the Gulf of St. Lawrence, northern Nova 

 Scotia, and occasionally to the eastern part of the Gulf of Maine; Arctic coasts of 

 Alaska and Canada (Bathurst Inlet, Coronation Gulf, and Welcome Gulf) {8y: 

 ']io\ 88: 187, 188; Bean in 5<5: 135); in the North Pacific southward to the Strait 

 of Juan de Fuca in the east and to Korea {66: i) and northern Japan (^j: ^^) in 

 the west. 



Species and Subspecies. The capelins of the North Atlantic and North Pacific were 

 originally described as two separate species, the former as villosus Miiller 1777 {6y : 

 245), the latter first as catervarius Pennant 1784'^ {75'- cxxvii) and later as socia/is 



25. Jensen {48: 90, ftn.) has reported four specimens (in the Museum in Copenhagen) for the Faeroes, taken in 1S70, 

 and A.Vedel Taning informs us that 50 were trawled among the Faeroes in 1938. 



26. This account was evidently taken from Steller {108: 149), as pointed out by Schultz {g8: 15). For the nomenclatural 

 validity of this name, see Hubbs and Chapman {44: 296). 



