繁殖期におけるホクリクサンショウウオ雄の体の大きさと縄張り形成

抄録

Hynobius takedai was observed in the breeding season at Joyama in the city of Toyama in 1983. Measurements of five dimensions i. e., head width, head length, snout-vent length, tail length, and maximum tail height, were taken and the males were also individually marked. Twenty males and eighteen females appeared at the breeding site, and five of the males succeeded in protecting their territories. The males with territories (MTs) appeared earlier in the water than the males without territories (non-MTs). The males with larger bodies succeeded in protecting their territories and inseminating, since they were dominant in the struggle among fellow males. The snout-vent length of the MTs was more than 50mm, and their heads were wider than those of the non-MTs. The longer the snout-vent length of the MTs was, the larger their head and tail were, compared with those of the non-MTs and the females. The heads of the MTs grew larger and their tails grew longer only during the breeding season.