Misawa et al.: Population structure of Okamejei keno/ei 
29 
3 5 
0 100 200 300 400 500 600 
Figure 3 
Plots of selected proportional morphometric characters (in % of total length) for 6 regional 
populations of Okamejei kenojei. (A, B) eye diameter, males and females, (C, D) distance 
between orbits, males and females, (E, F) prenasal snout length, males and females, 
(G, H) distance between nostrils, males and females. EC=East China Sea; YS=Yellow 
Sea; SJ=Sea of Japan; EK=East coast of Kyushu Is.; OS=Osaka Bay; NP=Pacific coast of 
northern Japan. 
NP that had 5 rows of tail thorns ranged between 450 
and 536 mm TL (average: 495 ±28 mm TL), but simi¬ 
lar individuals from other populations ranged between 
288 and 503 mm TL (400 ±37 mm TL), mostly 350-430 
mm TL. Given that the specimens with 5 rows of tail 
thorns were mature, these estimated maturity sizes 
for females differed significantly between NP and the 
other 4 populations, excluding EK (P<0.05). 
Coloration Typical fresh body coloration of 4 regional 
populations (except YS and EK) observed in the pres¬ 
ent study was as follows: EC—dorsal surface dark 
