著者

駒田 格知

出版者

The Ichthyological Society of Japan

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.28, no.4, pp.437-444, 1982

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In order to establish a basis for distinguishing normal and abnormal structures, this paper reports on the growth of vertebral centra in the cyprinid fish, <I>Zacco platypus</I> Temminck et Schlegel.Specimens, 10.0-110.0 mm in standard length (SL), were collected from the Yahagi River, Aichi Prefecture, in August, 1978.Juvenile fish were collected from the Ibi River, Gifu Prefecture in October 1978 and in April 1979.Length and diameter of centra of the 263 specimens were measured for different growth stages, seasons and sexes.<BR>Ossification of vertebrae begins in the postlarval stage, at about 8.0 mm SL.In fish smaller than 16.0 mm SL, all centra are almost equal in length.At 24.0-26.0 mm SL, lengths of centra located at the anterior part of the caudal region are longer than those in the other regions.As the fish grow, growth rate becomes greater in the middle part of the column than the other regions.The diameters of centra in fish of 10.0-16.0 mm SL show no difference associated with the portion of centra through the vertebral column.In fish larger than 24.0 mm SL the diameter of centra located at the anterior part of the column and around the transitional area between the abdominal and caudal region is larger than those in the other regions.In the adult stage, there are no sexual differences in the length and the diameter of centra.<BR>The proportions of vertebral column length to standard length in specimens of 10.0-16.0 mm SL are significantly smaller than those in specimens above 24.0 mm SL.And, there are significant differences on the ratios of total length of centra to column length between the three size-groups, 10.0-11.0 mm SL, 15.0-26.0 mm SL and above 60.0 mm SL (t-test, P<0.001).<BR>The lengths of centra in juvenile fish (15.0-16.0 mm SL, 19.0-20.0 mm SL) collected in April are larger than those in October and August, but the diameters of centra in the former are smaller than those in the latter two months.There is no difference in the length and the diameter of centra between juvenile fish in August and those in October.The ratios of spinal column length to standard length of juvenile fish in April are significantly larger than those in August and in October (t-test, P<0.001).

著者

駒田 格知

出版者

The Japanese Society of Fish Pathology

雑誌

魚病研究 (ISSN:0388788X)

巻号頁・発行日

vol.8, no.2, pp.127-135, 1974-03-30 (Released:2010-02-10)

参考文献数

14

被引用文献数

1 1

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天然および養殖の変形アユについて,その外部形態およびSOFTEX撮影による骨組の調査を行なった。 1. 変形アユは,その外部形態から,頭部から吻部にかけて絶壁状カーブを画く,下顎骨ゆがみ,鰓蓋彎曲,背鰭欠損,腹鰭欠損,尾柄部上下・左右曲がり,脊椎骨彎曲,脊椎骨短縮の8つの特徴が認められた。 2. 体長/頭長,体長/吻端~斑紋の距離の各相対比は短縮変形において他より小さく,頭長/眼径の値は,上・下顎骨ゆがみおよび骨曲がり変形アユで他より小さいが,頭長/頭高は正常アユが他より大きく,頭高/頭幅は逆であった。 3. 変形アユにおいて,上顎骨・歯骨・鰓蓋・腹鰭で同一個体で,同時的に異常が起こる場合が多い。 4. 背鰭および腹鰭欠損の場合,同時に神経間棘および腰帯も欠如している。 5. 脊椎骨数は,上顎骨ゆがみ,歯骨変形および腹鰭欠損アユにおいて,他よりも2~3本少くなっている,さらに短縮変形アユでは,正常な場合のそれとの差はないが,尾椎における椎骨の長さが著るしく短縮している。 6. 背鰭・腹鰭および鰓蓋の欠損変形は,養殖アユにのみ見られ,口器近辺骨格および脊椎骨異常は,天然・養殖アユともに認められた。

著者

駒田 格知

出版者

Japanese Association for Oral Biology

雑誌

歯科基礎医学会雑誌 (ISSN:03850137)

巻号頁・発行日

vol.28, no.5, pp.541-550, 1986-10-20 (Released:2010-10-28)

参考文献数

16

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サケ科魚類の口腔および咽頭には多数の歯が植立し, その分布状況は骨の形態や配置と共に属や種の重要な分類形質として認められている。一方, サケ科魚類数種においては成熟期に達すると口部の骨格系および歯系に著るしい性差が生ずると報告されている。しかし, その詳細については不明なことが多い。そこでサケ科サケ属サケ, Oncorhynchus keta, の産卵期成魚の口部骨格系および歯系に関してその大きさや歯胚率等について測定し雌雄間で比較した。サケ雄成魚の口部を構成する骨は同年齢・同体長の雌成魚に比べて大きく, それら骨上に植立する歯の長さも大きい。この傾向は口部両顎を構成する骨や歯においてより顕著であった。さらに, 雄成魚の顎骨上の歯の数は雌成魚より少ないが, 機能歯の割合は高く, 脱落歯の数も多い。このような性差は産卵・受精期における雄成魚の攻撃的行動等の生活習性と深く関連していると推測された。

著者

駒田 格知

出版者

日本魚類学会

雑誌

魚類学雑誌 (ISSN:00215090)

巻号頁・発行日

vol.28, no.4, pp.437-444, 1982-02-27 (Released:2011-07-04)

参考文献数

23

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In order to establish a basis for distinguishing normal and abnormal structures, this paper reports on the growth of vertebral centra in the cyprinid fish, Zacco platypus Temminck et Schlegel.Specimens, 10.0-110.0 mm in standard length (SL), were collected from the Yahagi River, Aichi Prefecture, in August, 1978.Juvenile fish were collected from the Ibi River, Gifu Prefecture in October 1978 and in April 1979.Length and diameter of centra of the 263 specimens were measured for different growth stages, seasons and sexes.Ossification of vertebrae begins in the postlarval stage, at about 8.0 mm SL.In fish smaller than 16.0 mm SL, all centra are almost equal in length.At 24.0-26.0 mm SL, lengths of centra located at the anterior part of the caudal region are longer than those in the other regions.As the fish grow, growth rate becomes greater in the middle part of the column than the other regions.The diameters of centra in fish of 10.0-16.0 mm SL show no difference associated with the portion of centra through the vertebral column.In fish larger than 24.0 mm SL the diameter of centra located at the anterior part of the column and around the transitional area between the abdominal and caudal region is larger than those in the other regions.In the adult stage, there are no sexual differences in the length and the diameter of centra.The proportions of vertebral column length to standard length in specimens of 10.0-16.0 mm SL are significantly smaller than those in specimens above 24.0 mm SL.And, there are significant differences on the ratios of total length of centra to column length between the three size-groups, 10.0-11.0 mm SL, 15.0-26.0 mm SL and above 60.0 mm SL (t-test, P<0.001).The lengths of centra in juvenile fish (15.0-16.0 mm SL, 19.0-20.0 mm SL) collected in April are larger than those in October and August, but the diameters of centra in the former are smaller than those in the latter two months.There is no difference in the length and the diameter of centra between juvenile fish in August and those in October.The ratios of spinal column length to standard length of juvenile fish in April are significantly larger than those in August and in October (t-test, P<0.001).