沿岸

The ecological studies on the migration, spawning and growth of puffers are not enough to promote their propagation. The authors examined the appearing and the maturing habits of puffers by the data of the catch and the specimens caught with the Shikanoshima Set-net, which was located at the coastal water of the Chikuzen-kai in the Sea of Japan, from January to December, 1982. The results obtained are’as follows: 1) Puffers were much in volume in December-July and some species of them appeared almost through the year. Takifugu vermicularis, T.pardalis, T. poecilonotus and T. niphobles appeared much in volume in May-June. January-April, December-February and May-June, respectively. Other species of puffers were little in every month. 2) The period when these species appeared most in volume corresponded to the period of the high gonadosomatic index (GSI) in each species, and this relation suggested that the puffers approached to and inhabited the coastal area during the high GSI period. 3) On the basis of changes of GSI, the spawing areas at the near Shikanoshima on the Chikuzen-kai were presumed, that is, Takifugu vermicularis and T. poecilonotus would not span-n at the shallow part of the coastal water in the Chikuzen-kai, but at the relatively offshore area enclosed by Tsuyazaki, Shingu and the Island of Ainoshima. The spawning area of T. pardalis and T. niphobles would be the area near the Shikanoshima Set-net. Especially, T. niphobles was confirmed to spawn at the shore of the Shikanoshima.