摘要
2002年6月至2003年5月,对洞庭湖周边水域不同季节1 183尾野生黄鳝进行体重、体长测量及性腺观察鉴定.统计分析结果:黄鳝体长29 cm左右为Ⅰ龄组,42 cm左右为Ⅱ龄组,49 cm左右为Ⅲ龄组,56 cm左右为Ⅳ龄组;雄性频率最高出现在5月(20.0%),其次为8月(16.7%),再次为4月(15.4%)和3月15.3%);雌性平均体长为(28.4±5.9)cm,间性平均体长为(35.6±6.3)cm,雄性平均体长为(39.8±8.1)cm;体长25～30 cm的雌性与间性比为1︰0.034,初步认为体长30 cm左右为性逆转的起点;体长30～50 cm是雌雄间体出现的高峰,50～60 cm是雄鳝出现的高峰;体长40 cm以下雌性占多数,50 cm以上雄性占多数,体重15 g以下几乎全为雌性(占99.2%),但有极个别的雌雄间体和雄性出现,体重15～25 g的雌性与间性比为1︰0.067,初步认为体重25 g左右为性逆转的起点;体重25～55 g是雌雄间体出现的高峰,体重150 g以上仍有部分雌性个体;黄鳝人工繁殖选择野生黄鳝体重65 g以下,体长40 cm以下,可基本保证雌鳝占大部分;黄鳝体重65 g以上,体长50 cm以上,可基本保证雄鳝占大部分.
From June 2002 to May 2003, a total of 1 183 wild rice-field eels, Monopterus allbus （Zuiew） were measured on body length, weight and observed on gonad for testing sex in Dongting Lake basin. The result shows that the eels with body length of 29, 42, 49 and 56 cm or so fell into the categorg of the first, the second, the third and the forth age groups, respectively. The frequency of male was 16.7%, 15.4% and 15.3% in August, April and March in proper order, while it reached the highest, 20.0%, in May. The mean length of females, intersexes and males are（28.4±5.9） cm, （35.6±6.3） cm and（39.8±8.1） cm, respectively. It is tentatively thought that the body length 30 cm or so are starting point for the sex reversal, because the ratio of females and intersexes was 1 ： 0.034 in groups with body length 25-30cm. The peak frequency of inter-sexes was present in groups 30-50 cm, while that of males was present in groups 50-60cm. The ratio of females is higher in groups below 40 cm, and the ratio of males is higher in groups over 50 cm. The ratio of females is 99.2% in groups below 15 g, but only a few intersexes and males present. It is tentatively thought that body weight 25g or so are starting point of the sex reversal, because the ratio of females and intersexes was 1 ： 0.067 in groups 15-25 g. The peak frequency of inter-sexes was present in groups 25-55 g, the females over 150 g are in the minority. It is fundamentally assured that the females below 40 cm in body length and below 65 g in weight are preponderating and the males over 50 cm and over 65 g are preponderating, when the parents of wild rice-field eel were selected during artificial reproduction.
出处
《湖南农业大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第4期469-473,共5页
Journal of Hunan Agricultural University(Natural Sciences)
基金
国家自然科学基金项目(30270229)
湖南省教育厅重点项目(04A038)
湖南省"十一五"重点建设学科资助
关键词
黄鳝
性比
体长
体重
洞庭湖区
Monopterus allbus
sex ratio
body length
body weight
Dongting Lake basin
