to prefer the highest temperatures of all of the tunas and for this 

 reason they occur at shallow depths in Japanese waters ^ but in the warm 

 seas of the south it appears that they are generally most numerous at 

 about the iOO-meter level and that they occur at even greater depths^ 



These fish attain a length of about 2„000 mm,, and a body weight 

 of about 70 kgo 



5o Weothunnus rarus (Kishinouye) 



In Japanese called koshinaga^ bintsuke^ hashibip shiroshibi p 

 and in Formosa seibanmaguroo 



Figure llo^-^Neothunnus raruso 



First dorsal with 13 spines ;, second dorsal with 14 rays and 

 8-9 finletso Anal with 14 rays and 8 finlets< Nura^ber of scales in 

 one longitudinal row about 220n Gill-rakers 5 - 6 / 15 - 17o 



Body length 3o5 - 4 times the head lengthy about 4 times the 

 body deptho Head length about 6 times the diamet&r of the eye^ and 

 3 - 3o5 times the length of the snouts 



The body is fusiform and deep with a long caudal portion„ The 

 head and the eyes are comparatively small and the snout is short„ The 

 scales are minute,, The pectoi^ls are short, their tips reaching to the 

 vicinity of a point below the posterior edge of the base of the first 

 dorsal fino The second dorsal and the anal are not produced and are 

 only slightly longer than the first dorsalo The ventrals are well 

 developedo 



In general they closely resemble immature yellowfin, but the 

 gill-rakers are fewer and there is no air bladdoro The coloration, too, 

 is in general the same as that of the yellowfin, but a peculiar charac= 

 teristic is that the finlets are yellow with gray edgeso 



The flesh is of an extraordinarily pale pink color and is 

 somewhat softo When eaten raw the flavor is said to be inferior to 

 that of the yellowfin^ but during the summer it is very delicious o 



This is the smallest among the tunas, and individuals 700 mmo 

 in length and about 7-8 kgo in weight are rather rare„ 



The species is distributed in Japanese waters from southern 

 Kyushu to southern Korean it is seen commonly in the south and for the 

 most part it occurs in the coastal waters.. 



Besides this species, Jordan and Evermann have reported 

 Kjshinoella zaccares from Hawaiio In this species the gill-rakers 

 are more numerous than in raruSo In the waters of Formosap too, there 



33 



