THE CAPELIN OF THE NORTH PACIFIC — SCHULTZ 



19 



of the standard length. These were all mature fish and in a spawning 

 condition. Young smelt are usually slenderer than the adults, which 

 may explam the "slenderer body." 



Tentatively/ Mallotus elongatus Mori is referred to the synonymy 

 of Mallotus catervarius on the basis that the type locaHty, Korea, is in 

 the North Pacific and the lack of characters separating it from species 

 already described. 



The specimens of Mallotus catervarius that were mature ranged in 

 length from 89 to 109 mm (average 95.8 mm), while the mature speci- 

 mens of Mallotus mllosus from Newfoundland, measured by us, were 

 129 to 166 mm (average 150.7 mm) in standard length. Sleggs 

 (1933, pp. 22-23) gives the lengths from 106 to 202 mm for breeding 

 individuals. This indicates that the capelin of the North Pacific 

 Ocean matures at a much smaller size than the capelin of the North 

 Atlantic Ocean. Besides the smaller size at maturity, table 4 indi- 

 cates that M. catervarius differs statistically from M. villosus in regard 

 to the following characters: Number of pectoral fin rays; number of 

 scales in the lateral hue; number of scales above and below the lateral 

 line; length of head; length of maxillaries; and length from snout to 

 insertion of pectoral fui. 



A single specimen of M. catervarius may be distinguished from a 

 smgle specimen of M. mllosus by means of the character index, which 

 equals the number of fin rays in dorsal + anal + pectoral + the num- 

 ber of scales below the lateral Ime — the total number of gill rakers, for 

 each individual specimen. When the numerical values of the char- 

 acter index are arranged in the form of a frequency table (table 5), 

 no overlapping of the frequencies occurs for catervarius and villosus. 

 The difference between the means of the character index for the two 

 species is 7.84 and the ratio of this difference to the square root of the 

 sum of the squares of the two probable errors is 4, indicating probable 

 significance. 



Table A.— The differences between the means oj certain characters of Mallotus 

 catervarius and M. villosus and the ratio of these differences to their probable error 



Character 



Number of rays in pectoral fin 



Number of scales in lateral line 



Number of scales above lateral line - 



Number of scales below lateral line 



Length of head 



Length of maxillaries 



Length from snout to insertion of pectoral fin 



« During the past four years I have tried repeatedly to obtain capelin from Korea, but without success. 

 When a large series of Mallotus from Korea are studied, M. elongatus may prove to be a valid species. 



