【作者】 廖志洪；

【导师】 林小涛；

【作者基本信息】 暨南大学 ， 水生生物学， 2005， 硕士

【摘要】 本研究在进行云斑尖塘鳢人工繁殖的工作基础上,通过实验生态的方法,对饵料大小与密度、光照强度和饥饿等因素影响下云斑尖塘鳢仔鱼的摄食特性进行了研究,探讨了适合云斑尖塘鳢仔鱼生长和提高其存活率的最适条件。 研究结果表明,在30±1℃条件下,从孵化出膜至2日龄,云斑尖塘鳢仔鱼处于内源营养期,以卵黄囊和油球作为仔鱼继续发育的营养物质来源。仔鱼的开口时间为孵出后第3天,至第5天卵黄囊消耗完毕,其内源性营养期为2天,混合营养期也仅有2天。 云斑尖塘鳢仔鱼对食饵没有明显的选择性,决定其摄食发生率的主要因素是饵料的大小。大小范围在0.04～0.12mm的饵料比较适合云斑尖塘鳢仔鱼的开口摄食。全长和口宽对仔鱼的摄食发生率和摄食强度都存在显著影响,随着仔鱼全长的增长和口宽的增大,其摄食发生率显著增加,摄食强度也明显增大。开口期仔鱼在饵料密度为10ind/mL以上的摄食情况较佳。 云斑尖塘鳢仔鱼摄食有一定的时间规律,各日龄仔鱼多集中在16:00～00:00光照较弱的时候进行摄食,在清晨04:00～08:00的时候也有个摄食小高峰出现。夜间在不同光照强度下仔鱼均在16:00～00:00这一时段出现比较高的摄食发生率,5日龄仔鱼在100～500Lx的光照强度下摄食发生率有所提高,而8日龄和12日龄仔鱼则在10～100Lx有较高的摄食发生率。 在30±1℃条件下,云斑尖塘鳢仔鱼的不可逆点(PNR)出现在仔鱼孵化出膜后的第6～7天。PNR点后的1～2天,是饥饿仔鱼大量死亡的时期。延迟投饵2天以上使云斑尖塘鳢仔鱼的存活率显著下降。 饥饿使云斑尖塘鳢仔鱼各项形态学指标增长停滞。不论是饥饿组还是投喂组,云斑尖塘鳢仔鱼在孵化出膜后的第5天均出现“胸角”这一形态学特征,因此不宜以“胸角”作为云斑尖塘鳢饥饿仔鱼的唯一判断指标。更多还原

【Abstract】 The effects of diet size, light intensity, and starvation on early development and feeding behaviors of Oxyeleotris marmoratus larvae were studied, with the aim to find an optimal way for larvae breeding.The results showed that from hatching to 2 days after hatching (DAF) at the temperature of 30±1℃, the larvae were at the endogenous stage, consuming the yolk-sac for further development. They began feeding in 3 DAP, and the yolk-sac was exhausted in 5 DAF. Therefore, the mixotrophic stage of larvae only lasted for 2 days.The larvae showed obvious selectivity for the size and density of diet. The suitable size of diet for larvae preying ranged from 0.04mm to 0.12mm. The larvae fed effectively under a diet density of 10ind/mL. Moreover, total length(TL) and mouth width(MW) of the larvae had significant effects on the feeding intensity, and the fish fed more intensively with larger TL or MW.The larvae had feeding rhythm. The highest feeding frequency occurred at 16:00~00:00 and a higher one at 04:00~08:00. The feeding frequencies of the fish under the light intensity of 100~500Lx for the larvae of 5 DAH and 10~100Lx for larvae of 8 and 12 DAH increased, compared to those under the light intensity of OLx, 10Lx, and 1000Lx.At the temperature of 30±1℃, the point-of-no-return(PNR) of the larvae occurred at 6~7 DAH. High mortality of the animals appeared in 1~2 days after PNR. The larvae livability obviously decreased due to delayed feeding for more than 2 days.Some morphological indexes of the larvae stagnated when they were starving. However, pectoral angle appeared in 5 DAH in either starved larvae or fed larvae. Accordingly, pectoral angle wasn’t the morphological index affected by starvation.更多还原