南北方地区宽体金线蛭繁殖性能研究

Study on the reproductive performance of Whitmania pigra in northern and southern regions

为了研究北方地区和南方地区宽体金线蛭的繁殖性能,试验采用生态学方法观察亲蛭和初孵仔蛭形态,测定和统计亲蛭成活率、亲蛭体重下降率、卵茧大小、产卵茧量、卵茧孵化率和卵茧孵出率,比较南北方地区宽体金线蛭繁殖性能差异,分析4种规格北方地区宽体金线蛭亲蛭与繁殖性能的关系。结果表明:繁殖期北方地区和南方地区宽体金线亲蛭均出现生殖环带,北方地区宽体金线蛭腹侧呈褐黄色,而南方地区宽体金线蛭腹侧呈棕黄色;北方地区宽体金线蛭体重[(3.89±1.63)g]极显著小于南方地区宽体金线蛭[(8.12±0.43)g](P<0.01)。繁殖期后北方地区和南方地区宽体金线蛭亲蛭成活率分别为(96.34±4.30)%和(93.33±0.00)%(P>0.05);北方地区宽体金线蛭亲蛭体重下降率[(57.96±3.63)%]显著高于南方地区宽体金线蛭[(49.04±0.89)%](P<0.05)。北方地区宽体金线蛭产卵茧量[(2.00±0.47)枚/尾]略低于南方地区宽体金线蛭[(2.47±0.05)枚/尾](P>0.05),而南方地区宽体金线蛭卵茧重量极显著大于北方地区宽体金线蛭卵茧(P<0.01)。北方地区和南方地区宽体金线蛭的卵茧孵化率分别为(73.90±24.24)%和(59.30±1.37)%,卵茧孵出率分别为(6.84±2.29)尾/枚和(13.06±3.92)尾/枚。初孵北方地区宽体金线蛭和南方地区宽体金线蛭的体色不同,体重差异不显著(P>0.05)。北方地区宽体金线蛭亲蛭体重与成活率、体重下降率、产卵茧量、孵化率和仔蛭体重无相关性(P>0.05),与卵茧的大小和孵出率相关(P<0.05)。说明北方地区和南方地区宽体金线蛭亲蛭繁殖期形态和繁殖性能有一定差异。

In order to study the reproductive performance of Whitmania pigra in northern and southern regions,in the experiment,ecological methods were used to observe the morphology of parent leeches and newly hatched leeches.Parent leech survival rate,parent leech body weight loss rate,egg cocoon size,egg cocoon yield,and egg cocoon hatching rate were determined and counted,to analyze the reproductive performance of Whitmania pigra in northeern and southern regions,and the relationship between the parent leeches and the reproductive performance of 4 specifications of Whitmania pigra.The results showed that reproductive rings appeared in both the northern and southern Whitmania pigra during the breeding period.The ventral side of the northern Whitmania pigra was isabellinus,while that of the southern Whitmania pigra was brown.The body weight of the northern Whitmania pigra[(3.89±1.63)g]was significantly smaller than that of the southern Whitmania pigra[(8.12±0.43)g](P<0.01).After the breeding period,the survival rates of the northern and southern Whitmania pigra were(96.34±4.30)%and(93.33±0.00)%,respectively(P>0.05).The weight loss rate of the northern Whitmania pigra[(57.96±3.63)%]was higher than that of the southern Whitmania pigra[(49.04±0.89)%](P<0.05).The egg cocoon yield of the northern Whitmania pigra[(2.00±0.47)pieces/tail]was slightly lower than that of the southern Whitmania pigra[(2.47±0.05)pieces/tail](P>0.05),while the cocoons of leech eggs of the southern Whitmania pigra were significantly larger than those of the northern Whitmania pigra(P<0.01).The hatching rates of egg cocoons of the northern and southern Whitmania pigra were(73.90±24.24)%and(59.30±1.37)%,respectively;and the hatching rates of egg cocoons were(6.84±2.29)tail/piece and(13.06±3.92)tail/piece,respectively.The body color of the newly hatched northern and southern Whitmania pigra was different,but the difference in body weight was not significant(P>0.05).There was no correlation between the body weight of the parent leeches of the northern Whitmania pigra and the survival rate,weight loss rate,cocoon production,hatching rate and offspring body weight(P>0.05),but it was related to the cocoon size and hatching rate(P<0.05).The results suggested that the morphology and reproductive performance of Whitmania pigra during breeding period between the northern and southern regions had some differences.