環境特性の異なる青蓮寺湖(ダム湖)と西の湖(低地沼沢)のオオクチバスについて生殖腺の組織学的観察を行った。両湖ともに晩秋から初夏にかけて発達した卵母細胞を持つ雌が出現し,精子形成の盛期は春秋に認められた。産卵期は青蓮寺湖で4月下旬～6月下旬,西の湖で4月中旬～5月中旬と推定された。本種は秋季から成熟を開始するため春～初夏の産卵期を最大限に利用でき,本邦の多様な環境に容易に定着した一要因となっていると考えられた。
Gonadal maturations of the largemouth bass collected from Lakes Shorenji (typical reservoir) and Nishinoko (typical swamp) were histologically analyzed. The age and the minimum size at first maturation in both lakes and both sexes were estimated as 2-year-old and about 230 mm SL, respectively. Although their spawning periods were estimated as being from late April to late June in Lake Shorenji and from mid-April to mid-May in Lake Nishinoko, well-developed yolked oocytes were found in the ovaries of the fish from both lakes from late fall to early summer. The peaks of spermatogenesis occurred in spring and fall, male gonadosomatic indices indicating high values in winter. These reproductive cycles of largemouth bass, which started to develop from fall, extended their spawning period and May have been an important factor of naturalization of the species into various environments in Japanese inland waters.
雑誌名
日本水産學會誌
巻
68
号
2
ページ
151 - 156
発行年
2002-03-15
ISSN
0021-5392
書誌レコードID
AN00193422
権利
社団法人日本水産学会
本文データは学協会の許諾に基づきCiNiiから複製したものである
フォーマット
application/pdf
著者版フラグ
publisher
日本十進分類法
460
その他のタイトル
Gonadal maturation of largemouth Bass Micropterus salmoides in Lakes Shorenji and Nishinoko, Central Japan
三重県青蓮寺湖と滋賀県西の湖におけるオオクチバスの生殖腺成熟
50A6727.pdf
(819.18KB)
