几种因素对太平洋纺锤水蚤摄食率的影响

Effects of Some Factors on Feeding Rates of Acartia Pacifica

于 １９９３ 年 ３～６ 月对厦门港浮游桡足类优势种太平洋纺锤水蚤（ Ａｃａｒｔｉａ ｐａｃｉｆｉｃａ Ｓｔｅｕｅｒ）的摄食率及其与温度、盐度、食物浓度、食物种类、饥俄、食性等因素的关系进行了研究，为太平洋纺锤水蚤的生态和人工培养研究提供重要理论依据．结果表明：１）太平洋纺锤水蚤对三角褐指藻（ Ｐｈａｅｏｄａｃｔｙｌｕｍ ｔｒｉｃｏｒｎｕｔｕｍ ）的清滤率（ Ｆ， ｍ Ｌ／ｉｎｄ·ｈ）和滤食率（ Ｇ， ｃｅｌｌｓ／ｉｎｄ·ｈ）受温度的影响显著， Ｆ 和 Ｇ 随温度（１０～２５ ℃）升高而增加，但温度达到或超过 ３０℃反而因不适应而降低，最适摄食温度在 ２５ ℃左右（ Ｆ 和 Ｇ 分别为０．０５８ 和 ９．３３×１０４）．２）盐度对 Ｆ 和 Ｇ 也有显著影响， Ｆ 和 Ｇ 随盐度（１３～２６）升高而增加，但盐度达到或超过 ３０～３２，反而降低，最适摄食盐度在 ２６ 左右（ Ｆ 和 Ｇ分别为 ０．０３０ 和 ４．３７×１０４ ）．３）食物浓度从 ６．２２×１０５ 升高至 １．００×１０７ ｃｅｌｌｓ／ｍ Ｌ， Ｆ 有降低趋势，而 Ｇ 则有升高趋势；最大 Ｆ 和 Ｇ 分别为 ０．０３ 和 １１．３７×１０４ ｃｅｌｌｓ／ｉｎｄ·ｈ．４）太平洋纺锤水蚤对 ９

Effects of temperature、salinity、food concentration、food items,and starvation on feeding rates of Acartia pacifica Steuer,a dominant planktonic copepod in Xiamen Harbour,were studied during the period from March to June,1993. It was found that filtering rates ( F ,mL/ind·h) and grazing rates ( G ,cells/ind·h) on Phaeodactylum tricornutum were greatly affected by culture temperature, which increased with temperature (10~25 ℃) and decreased when temperature was up to 30 ℃. The optimal temperature for feeding was around 25 ℃, at which F and G were 0.058 and 9.33×10 4 respectively. F and G were also greatly affected by salinity, which increased with salinity from 12 to 26 and began to decrease when salinity reached to 30~32. The optimal salinity for feeding is around 26,at which F and G were 0.030 and 4.37×10 4 respectively. F tended to decrease and G to increase when food concentration increased from 6.22×10 5 to 1.00×10 7 cells/mL. F on 9 species of common algae was as follow: Spirulina platensis (5.570)  Skeletonema sp.(0.020)> Platymonas subcordiformis (0.017)> Heterogloea sp .(0.016)> Isochrysis galbana (0.014)> Phaeodactylum tricornutum (0.010)> Chlorella sp .(0.006)> Biddulphia sinensis (0.001), Corethron hystrix (0.001). F and G of pre starved Acartia pacifica were higher than those of the pre fed. F and G were highest (0.034 and 11.56×10 4) for those pre starved for 48h,but F and G began to decrease when starvation was longer than 48h because of unusual physiological effect of starvation and crowd. Acartia pacifica predated on animal food (newly hatched Artemia nauplii) when algal food was not available. The ingestion rate ( I ,nauplii/ind·h) was up to 0.223 if food availability was sufficient. The maxium grazing rate on algal food (0.746 μgC/ind·h) was about 5.5 times that of the maxium ingestion rate on animal food (0.137 μgC/ind·h),which implied that Acartia pacifica be a more herbivorousely omnivorous copepod.