文蛤的底质选择性及潜沙能力研究

Substrate preference and sand burrowing ability assessment of Meretrix meretrix

底质是底栖贝类完成生活史的主要生境,文蛤(Meretrix meretrix)是一种具有较高经济价值的海洋双壳贝类,为了进一步了解文蛤的生态行为学,揭示文蛤对不同类型底质的选择及其潜沙能力,在室内实验条件下,研究了大[(4.90±0.18)cm]、中[(2.72±0.12)cm]、小[(1.13±0.13)cm]3种规格的文蛤对4种底质类型(纯沙质底、3/4沙+1/4泥、1/2沙+1/2泥、1/4沙+3/4泥)的选择性并量化了其潜沙能力。结果表明:实验过程中未出现文蛤死亡,说明3种规格的文蛤在各个底质组合方式实验组中对底质均具有一定的选择性,沙质含量高的底质是各个规格文蛤的优先选择,且其选择能力随着个体规格的增加而增强;文蛤的潜沙率、下潜深度随着文蛤规格的减小而减小,且随着沙质含量的增加而增加,潜沙时间则随着文蛤规格的减小而增加,且随着沙质含量的增加而减小。综合分析认为,文蛤虽然能在不同沙质含量的底质中生存,但沙质含量高的底质是适宜文蛤生存的生境,可为更科学的文蛤增养殖提供数据支撑。

The clam（Meretrix meretrix） is a kind of marine bivalve mollusks with high economic value in aquatic production,and substrate is the major habitat for marine bivalve mollusks. In order to further understand the ecological behavior of clams and investigate the substrate preferences and sand burrowing ability of the clams,clams of three different sizes were studied to assess the substrate preference and sand burrowing ability under laboratory conditions,including large size clams,4. 90 ± 0. 18 cm in body length,medium size clams,2. 72 ± 0. 12 cm in body length,small size clams,1. 13 ± 0. 13 cm in body length,and four different kinds of substrates（pure sand,three quarters of sand mixed with a quarter of mud,one-half of sand mixed with one-half of mud,a quarter of sand mixed with three quarters of mud）. The results showed that there was no death in the course of the experiment,all clams of three sizes can survive in the four kinds of substrates,and had the ability to choose different substrates to a greater or lesser extent,the substrate possessed high content of sand was the optimal choice for all sizes of clams,and the ability to choose substrates enhanced with the increase of the size of clams and the increase of sand content,the depth and percentage of burrowing decreased with the decrease of size of clams and increased with the increase of sand content,the burrowing time decreased with the decrease of size of clams and decreased with the increase of sand content. The results further illustrated that the substrate possessed high content of sand was the optimal choice for all sizes of clams although the clams can survive in different kinds of substrates,and can provide a scientific basis for clam culture.