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本文是进行幼鲻(鲻鱼幼鱼—Mugil cephalus L.)生物学调查的第二篇报告,阐述了鲻鱼在斯里兰卡沿岸和河口水域中养殖的可能性。作者从1974年11月至1975年10月对沿岸纳贡博(Negombo)湖(北纬7°10′,东经79°50′)捕来的体长为20—55毫米的幼鲻进行了饵料和摄食习性的研究。援食强度,即为计算在每个摄食个体的胃含物中所有饵料生物的数目。幼鲻从4月以后,随着季节的变迁而增加摄食强度,至7—8月份达到高峰。有超过80%的个体全年摄食。饵料(胃含物)由18个属的硅藻、8个属的绿藻、一些鼓藻(desmids—chlor-phyceae)、6个属的蓝绿藻和8种其他饵料所组成。体长小于25毫米的幼鲻胃中没有发现沙粒或有机碎屑。有机碎屑和沙粒出现的百分比是随体长的增长而增加的。就质量而言,硅藻是最好的饵料品种,因为它超过整个饵料的50%。虽然在饵料中只发现黄藻类(Xanthophyceae)的一个属,而它的作用是重要的。我们发现幼鲻每天有定期的摄食活动,其摄食高峰出现在黎明和靠近中午并与潮汐的状况无关。幼鲻各生长期的饵料和摄食行为,就我们调查所得的资料,对24小时内出现的二个摄食高峰和饵料种类的重要性进行了评价,并对鲻鱼和其他植物食性鱼类混养的可能性作了简要的讨论。
This article is the second in a survey of the biology of the juvenile (juvenile mollusk ceillus L.), illustrating the possibility of mandarin fish farming in the Sri Lanka coastal and estuarine waters. From November 1974 to October 1975, the authors carried out feed and treatment of juveniles of 20-55 mm body length captured from Lake Negombo (latitude 7o 10 ’, 79o 50’ E) Research on feeding habits. The intensity of aid is calculated as the number of all food organisms in the stomach of each feeding individual. As young as April, the intensity of food intake increased with the seasons and peaked in July-August. Over 80% of individuals are fed throughout the year. The bait (stomach contents) consists of 18 genera of diatoms, 8 genera of green algae, some desmids-chlor-phyceae, 6 genera of blue-green algae, and 8 other baits. No grit or organic debris was found in the juvenile stomach that was less than 25 mm in length. The percentage of organic debris and grit appearing increases with body length. Diatoms are the best bait varieties by quality because they exceed 50% of the total bait. Although only one genus of Xanthophyceae is found in feed, its role is important. We found that there are regular feeding activities every day in young children. The peak of their feeding occurs at dawn and near noon and has nothing to do with the status of tides. The prevalence of feeding and feeding behaviors in young chickens was evaluated based on the data we collected and the importance of two feeding peaks and food species present within 24 hours was evaluated and polyculture of mackerel and other phytophagous fish The possibility of a brief discussion.