温度、盐度和规格对毛蚶滤水率的影响

Effects of Temperature, Salinity and Size on Filtration Rate of Ark Shell Scapharca subcrenata

采用室内实验生态学方法,在5L的聚乙烯水箱充气静水系统中研究不同温度(20℃、24℃、28℃、32℃)和盐度(16、20、24、28、32)下,壳长26.24～33.99mm(小)、39.67～43.63mm(中)和49.55～50.94mm(大)毛蚶Scapharca subcrenata的滤水率。结果表明,毛蚶滤水率随体质量的增大而增加,单位体质量的滤水率随规格的增大而减小,可表示为FR=aW^b,不同时间段内,b值平均为0.6692;在温度20～32℃范围内,小、中、大3种规格毛蚶滤水率先升后降,在24℃时滤水率最大,分别为(1.5740±0.2852)L·g^(-1)·h^(-1)、(1.2963±0.2200)L·g^(-1)·h^(-1)、(0.6972±0.0764)L·g^(-1)·h^(-1),24℃和28℃时差异不显著(P>0.05),但显著高于其他温度组(P<0.05)。不同规格毛蚶滤水率对温度的敏感性表现为:小规格>中规格>大规格;在盐度16～32范围内,毛蚶滤水率随盐度的升高先升后降,盐度24和28时,毛蚶滤水率达最大值,显著高于其他盐度组(P<0.05);盐度(x)与毛蚶滤水率(y)的关系可拟合为:y=-0.0016x^2+0.0769x-0.5872(R2=0.7571)。本研究结果可为毛蚶摄食生态研究提供参考。

The filtration rates were determined in ark shell Scapharca subcrenata with shell length of 26.24 ~33.99 mm(small),39.67~43.63 mm(middle)and 49.55~50.94 mm(large)in a aerated hydrostatic water system with 5 L polyethylene tanks at water temperature of 20 ℃, 24 ℃, 28 ℃, and 32 ℃ and a salinity of 16, 20, 24, 28, and 32 by a laboratory experimental ecology method.The results showed that the filtration rate of the clam was increased with increase in body weight, with decrease in filtration rates per body weight with an increase in the body sizes, and their relationship was corresponded to the exponent function regression, FR=aWb,with average b value of 0.6692 in different periods. The filtration rates of the clam with three sizes were found to be increased along with the temperature rising from 20 to 24, and then decreased at water temperature of 24 to 32, with the maximal filtration rate at 24 ℃,(1.5740 ±0.2852)L·g-1·h-1 in small clam,(1.2963 ±0.2200)L·g-1·h-1 in mid-sized clam and(0.6972±0.0764)L·g-1·h-1, in large clam, without significant difference between 24 ℃ and 28 ℃(P > 0.05), and significantly higher than at water temperature of 20 and 32(P < 0.05). The descending order of sensitivity to temperature was expressed in the clam with various length as small size>medium size>large size. The filtration rate was increased initially and then decreased as salinity increased at salinity from 16 to 32, with the maximal filtration rate at a salinity of 24 and 28, and significantly higher than at a salinity of 16, 20, and 32(P < 0.05). The relationship between filtration rate(y)and salinity(x)was expressed as y=-0.0016 x2+0.0769 x-0.5872(R2=0.7571). The findings provide theoretical evidence for feeding ecology of the clam.