著者
岩崎 敬二 木村 妙子 木下 今日子 山口 寿之 西川 輝昭 西 栄二郎 山西 良平 林 育夫 大越 健嗣 小菅 丈治 鈴木 孝男 逸見 泰久 風呂田 利夫 向井 宏
出版者
JAPANESE ASSOCIATION OF BENTHOLOGY
雑誌
日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)
巻号頁・発行日
vol.59, pp.22-44, 2004-07-28
被引用文献数
24 26

To investigate the invasion history and recent geographic distribution of marine organisms introduced to Japan or transferred domestically to non-native regions, a questionnaire survey on their occurrence in the field, including both published and unpublished records, was conducted in 2002-2003. A total of 105 taxa was reported by 94 respondents. According to three criteria, viz. known or unknown geographic origin, established invasion history, and presumed dispersal mechanisms associated with human activities, 42 taxa were designated as non-indigenous species introduced to Japan through human activities, 26 taxa as indigenous species that are distributed both in Japan and other countries but are introduced from abroad to Japan for fisheries or as fish bait, 20 taxa as cryptogenic species which are not demonstrably native or introduced, two taxa as non-indigenous species that have extended their range to Japan through natural dispersion, and one taxon as an indigenous species. The remaining 14 taxa were considered to have been transferred domestically to new areas. Analysis of the years of first record of 42 non-indigenous species suggests that the rate of invasion has increased over the past century, with seven or eight species being introduced per decade after 1960. Data on temporal change in geographic distribution revealed that many non-indigenous species have become widespread recently, from the Pacific coasts of central Japan to the coasts of the Sea of Japan or northward. However, the species listed in the present study are not exhaustive, and more extensive investigations covering all taxa and all presumed dispersal mechanisms are urgently needed before consideration of legislative management of introduced marine organisms.
著者
風呂田 利夫 木下 今日子
出版者
JAPANESE ASSOCIATION OF BENTHOLOGY
雑誌
日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)
巻号頁・発行日
vol.59, pp.96-104, 2004-07-28
参考文献数
27
被引用文献数
3 2

Two introduced crab species, Pyromaia tuberculata and Carcinus aestuarii, occur abundantly in organically polluted waters in Japan. Population studies of these crabs have been conducted in Tokyo Bay, in which summer hypoxia causes destruction of the benthic animal populations on the bottom of the innerhalf of the bay. In fall, a population of P. tuberculata quickly recolonizes that bottom, which has recovered from the hypoxia, by settlement of larvae. Settled crabs reach maturity by the next spring, then release larvae until the subsequent summer hypoxia. Released larvae disperse to the outerhalf of the bay, resulting in recruitment of juveniles into the local population. These recruits reach maturity before the fall under the normoxic conditions prevailing there, then release larvae for recolonization of the innerhalf of the bay. Carcinus aestuarii grows along the shores of river-mouths and in a lagoon of the inner bay, but migrates out onto the bay bottom during fall to spring, when it releases larvae. Released larvae settle along the shores during the spring. Settled crabs grow on the shores with adult crabs that had returned from the bay bottom. Thus the crabs on the shores avoid encountering the bottom hypoxia. These results suggest that the main factor that has allowed the establishment of the new introduced populations in Tokyo Bay is complementarity between the life cycle of these crabs, including adult migration or larval dispersal, and the seasonal availability of a habitat that is recovering from hypoxia.
著者
土田 真二 藤原 義弘 藤倉 克則
出版者
JAPANESE ASSOCIATION OF BENTHOLOGY
雑誌
日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)
巻号頁・発行日
vol.58, pp.84-88, 2003-06-27
被引用文献数
4 14 1

The spatial distribution around hydrothermal vents, population structure, and relative growth parameters of the galatheid crab Shinkaia crosnieri were examined. Surveys were done by the Shinkai 2000 on the Hatoma and Dai-yon Yonaguni Knolls in the southern Okinawa Trough. On the Hatoma Knoll, S. crosnieri inhabited areas (temp. 4.0-6.2°C) about 0.2-2 m away from the active vent (temp. 301°C). In the outer area of the habitat of S. crosnieri (temp. 3.0-3.7°C), dense beds of Bathymodiolus mussels occurred and aggregations of Alvinocaris shrimp were observed. In this survey, 248 specimens of S. crosnieri were collected. Small, probably just post-metamorphic juveniles and large, mature adults co-occurred. Chelipeds of males were proportionally larger than those of females, while abdomens of females were proportionally larger than those of males. Larger chelipeds in males are thought to have evolved through male-male competition for females, and wider abdomens in females are thought to be related to the attachment of fertilized eggs to the abdominal appendages.
著者
大隅 大 弥益 輝文
出版者
JAPANESE ASSOCIATION OF BENTHOLOGY
雑誌
日本ベントス学会誌 = Japanese journal of benthology (ISSN:1345112X)
巻号頁・発行日
vol.55, pp.9-14, 2000-07-25
被引用文献数
3

Specimens of the nudibranch Gymnodoris nigricolor were found on the fins of three gobiid fish species, Amblyeleotris ogasawarensis, Ctenogobiops pomastictus, and C, feroculus, near Oujima and Sesoko Islands, Okinawa, in February and May, 1994. These gobiids inhabit the burrows of snapping shrimps. The nudibranchs could be found attached to any fin (caudal, dorsal, pectoral, anal, and pelvic fins) of these fish, and they appeared to feed on a portion of the fin membrane together with one or two of the adjacent fin rays. In the laboratory, G. nigricolor also attached to a free-living gobiid fish, Bathygobius cocosensis. Nudibranchs gathered in glass tubes that had been used as refuges by A. ogasawarensis and C. pomastictus. This suggests that the nudibranchs were attracted to substances that had originated from the fish and remained in the tubes. The nudibranchs did not always attach to the fins of test fish, and individuals that did so detached themselves 1-2 days later. Their association with the fish thus appears to be a predator-prey interaction. Spawning of Gymnodoris nigricolor was observed in a rearing tank. About 200-700 eggs of 0.15 mm in diameter were found in each egg mass. Embryos hatched 10-11 days after oviposition at 24°C.