中国蛤蜊Mactra chinensis Philippi稚贝运动行为学初步研究

为从行为学角度解释中国蛤蜊(Mactra chinensis Philippi)的跑滩现象,研究了规格、温度对其跳跃行为以及底质、流速和周期性干露对其潜沙行为的影响。结果表明,中国蛤蜊运动能力与其规格和水温有关, 3 mm稚贝不具备跳跃能力, 5 mm以上具备跳跃能力;跳跃频率和高度随水温的升高呈上升趋势。中国蛤蜊稚贝潜沙比例均随时间推移逐渐上升;各时间节点中国蛤蜊稚贝在细沙底质的潜沙比例最高,中沙底质次之,粗沙底质最低。施加微弱水流后,中国蛤蜊稚贝潜沙速度和比例显著增加;流速增大到一定程度后部分稚贝被水流冲走,潜沙比例随之下降。周期性干露会导致中国蛤蜊稚贝从底质中爬出,干露时间越长,爬出比例越高。干露后的稚贝重新放置于海水中,部分稚贝会在水面漂浮一段时间后再下落至水底,漂浮比例随干露时间的增加而增加。本研究从行为学角度初步查明了中国蛤蜊跑滩现象,为解决中国蛤蜊防跑滩问题提供了思路。

Karyotypes of three species of the marine Veneroida molluscs

The karyotypes of three species of marine Veneroida molluscs, Solen grandis Dunker, Saxidomus purpuratus Sowerby and Mactra chinensis Philippi were studied by using the adult gill tissues. The chromosomes were-prepared through injecting phytohemagglutinin (PHA) and colchicine, hypotonic treatment, chopping air-dry, and squashing technology. The results show that the diploid chromosome numbers of the three Veneroida species are the same as 2n = 38. The karyotype of Solen grandis is 26m + 6sm + 2st + 4t, NF = 70, the karyotype of Saxidomus purpuratus is 32m + 2sm + 4st/t, NF = 72, and the karyotype of Mactra chinensis is 20m + 16sm + 2st/t, NF = 74. Satellite and sex chromosome were not found among the chromosomes of three species.