僧帽牡蛎三倍体和二倍体的生长比较

Growth comparison of triploids and diploids of the oyster Saccostrea cucullata

１９９３ 年采用高温（３７ ℃） 休克处理受精卵１５ ｍｉｎ ，抑制第一极体排放诱导出僧帽牡蛎三倍体，在早期幼虫阶段，处理组幼虫平均壳长显著较对照组大，经过１ 年的养殖，三倍体壳长、壳高、软体部湿重和干重分别比二倍体增加１３ ．２ ％ 、８ ．９ ％ 、１２４ ．６ ％ 和８７ ．１ ％ 。１９９７ 年采用０ ．５ ｍｇ／Ｌ 细胞松弛素Ｂ 在５０ ％ 受精卵出现第一极体时处理受精卵１５ ｍｉｎ 诱导出僧帽牡蛎三倍体，经过１４ 个月养殖，三倍体壳长、壳高、体重和软体部湿重分别比二倍体增加３９ ．２６ ％ 、１７ ．２５ ％ 、７２ ．５０ ％ 和１１８ ．４２ ％ ，除个别月份外，三倍体和二倍体的生长差异显著（ Ｐ＜ ０ ．０５） ，僧帽牡蛎三倍体较二倍体具有明显的生长优势。

In August 1993,fertilized eggs of oyster Saccostrea cucullata were treated with high temperature shock at 37 ℃ for 15 min,which inhibites extrusion of the first polar body to induce the triploidy. After 35 days larval rearing indoor, the juveniles in the treatment groups averaged (2.25±0.45)μm in shell length, but those of the control group only had a shell length of (2.01±0.42)μm on average. The former obviously exceeded the latter in terms of shell length (P<0.05).Over one year's culture ,the triploids increased in shell length, shell height, wet weight and dry weight, which were 13.2%, 8.9%, 124.6% and 87.0% more than those of the diploids, respectively. In April, 1997, cytochalasin B (CB) was used to induce the triploids at a concentration of 0.5 mg/L for 15 min when 50% of the fertilized eggs produced first polar bodies. Monthly observations on their growth from July 1997 to July 1998 indicated that the diploids differs significantly from the triploids in shell length, shell height, body weight and meat weight (P<0.05) except one month or two. After 14 months culture, the triploids gained 39.26%,17.25%,72.50% and 118.42% more than the diploids in shell length, shell height, body weight and meat weight, respectively. All these demonstrate that the triploidy oyster S. cucullata is of significant superiority in growth.