抄録
トラフグ親魚の産卵場への回帰性を明らかにするため, 1996〜1998年の産卵期に伊勢湾口部産卵場で漁獲された親魚を用いた標識放流試験を行った。標識魚の再捕場所は全て伊勢湾・熊野灘・遠州灘海域内であった。'96年および'98年放流群は翌年の産卵期に同じ産卵場でそれぞれ4尾と1尾が再捕された。また, '97年放流群も1年後の産卵期に産卵場に近接する海域で1尾再捕され, トラフグの伊勢湾口部産卵場への回帰が強く支持された。さらに, アーカイバルタグ装着トラフグは, その推定位置からおおよそ熊野灘・遠州灘海域内に分布したと考えられた。
In order to clarify the homing behavior of ocellate puffer Takifugu rubripes to the natal spawning ground, adult ocellate puffers of total length 37-60cm caught by purse seine net at the spawning ground off Anori, Mie Prefecture, were released at a location 3 miles south of the spawning ground with disk tags attached in 1996, 1997 and archival tags attached in 1998. The numbers of individuals released in 1996, 1997 and 1998 were 217, 69 and 5, and respectively 58, 14 and 3 fish were recaptured within the area of Ise Bay, Kumano Nada and Enshu Nada. Four individuals released in 1996 and one in 1998 apparently returned to the same spawning ground in the next spawning season after being released. One individual released in 1997 was recaptured very close to the spawning ground off Anori in April 1998. These results imply that adult ocellate puffer return to the same spawning ground and strongly support that this species shows homing behavior to the natal spawning ground. The fish with archival tags implanted were distributed almost within a ±2° longitudinal area around the release and recapture location. It is concluded that adult ocellate puffer seldom migrate in and out between the Kumano and Enshu Nada area and other areas.
