瀬戸内海山口湾における絶滅危惧種アオギスSillago parvisquamis(キス科)の標本に基づく生息と繁殖の確認 <論文>

Report on Distribution and Spawning of Small-scale Sillago, Sillago parvisquamis (family Sillaginidae), Based on Specimens from Yamaguchi Bay in Western Seto Inland Sea, Japan. <Article>

Shigeta Toshihiro

Usuki Hironori

Tomiyama Takeshi

Sakai Yoichi

Saito Hidetoshi

Shimizu Norio

広島大学総合博物館研究報告

Bulletin of the Hiroshima University Museum

[PISSN] 1884-4243

[EISSN] 1884-3999

[NCID] AA12459864

瀬戸内海山口湾で2005 ～ 2008 年に,絶滅危惧種アオギスSillago parvisquamis 8 標本(SP-YB1 ～ 8)を採集した。全長226.5 ～ 320.1mm,体長197.7 ～ 281.0mm,いずれも雌で,年齢はSP-YB1 ～ 6 が1才,SP-YB7 が3才,およびSP-YB8 は4才で,全個体が2004年級であった。卵巣の組織学的検討より,SP-YB1 ～ 7 では,最も発達した正常な卵母細胞は第三次卵黄球期か胚胞移動期で,排卵後濾胞細胞を有し,活発な産卵活動が確認された。釣りCPUE(個体数/3時間/ 人)は,2005 ～ 2012年では,5 ～ 7月は0.2(n=24),通年では0.1(n=49)であった。2004年級を主な対象とした2005 ～ 2006年の2年間では,5 ～ 7月は0.3(n=14),通年では0.2(n=23)であった。今回,標本に基づき山口湾を生息地および繁殖地として記載した。

Small-scale sillago, Sillago parvisquamis, were collected from Yamaguchi Bay, western Seto Inland Sea, Japan. This species has been evaluated as an endangered species in Japan. Eight specimens (sample no. SPYB1-8) collected in 2005-2008 were 226.5-320.1 mm TL, 197.7-281.0 mm SL and were all adult females. The ages of SPYB1-6, 7, and 8 were 1, 3, and 4 years, respectively, and all individuals were of the 2004 class. Judging from ovarian histological samples, the most developed stage of normal oocytes in SPYB1-7 was the tertiary yolk globule stage or the migratory nucleus stage. All individuals had a lot of post-ovulatory follicles. Therefore, these two evidences indicate spawning. The catch per unit effort (CPUE) (indiv. / 3 hours / person) by fishing in 2005-2012 was 0.2 for the spawning season (n=24) and 0.1 for the whole year (n=49). For the 2004 class, CPUE in 2005-2006 was 0.3 for the spawning season (n=14) and 0.2 for the whole year (n=23).

This is the detailed report of the distribution and spawning of Sillago parvisquamis based on specimens from Yamaguchi Bay.

アオギス

キス科

絶滅危惧種

山口湾

Sillago parvisquamis

endangered species

Sillaginidae

Sillago parvisquamis

Small-scale sillago

Yamaguchi Bay

Zoology [ 480 ]

jpn

広島大学総合博物館

Copyright (c) 2013 広島大学総合博物館 Hiroshima University Museum

[ISSN] 1884-4243

[NCID] AA12459864