温度和密度对日本医蛭繁殖的影响

在实验室网箱中,研究温度(24±1)℃和(20±1℃)与密度(200尾/箱和100尾/箱)对平均体质量1g左右的日本医蛭Hirudo nipponia亲蛭交配率、减重率、产茧数量和体质量的影响,比较卵茧质量(0.05g、0.05~0.1g和0.1g)对孵出仔蛭数量的影响。结果表明:温度(24±1)℃、密度100尾/箱时亲蛭交配率(86±0.06)%和平均产茧量(0.87±0.14)枚/尾最高;亲蛭产茧后平均体质量下降(32.1±0.059)%;繁殖期间共收集卵茧870枚,孵化率87.47%;平均卵茧质量为(0.11±0.009)g(变化范围0.03g~0.25g);密度和温度对产茧量的影响极显著(P0.01),对卵茧平均质量和长短径的影响不显著(P0.05);(24±1)℃组亲蛭的产茧时间比(20±1)℃组缩短10~15d,单日卵茧最高收集量为43枚,(20±1)℃时单日最高收集量24枚;卵茧共孵出仔蛭5 648尾,随着卵茧质量增加产出的仔蛭数量和质量也增加。

Effects of Temperature and Density on Breeding of Leech Hirudo nipponia Whitman

The effects oftem perature(24±1)℃ and(20±1)℃and density(200 individuals and 100 individuals percage)on m at-ing rate of broodstock,num ber of cocoon and body w eightw ere studied in leech (Hirudo nipponia)and effects of cocoon w eight (<0.05 g,0.05~0.1 g and >0.1 g)on num ber ofnew ly hatched larvae w ere also investigated.The results show ed thatthe m axim um m ating rate(86±0.06)% and num berofcocoon(0.87/leech)w ere observed at(24±1)℃ and stocking density of100 leeches/cage, w ith w eightloss of (32.1±0.059)% in the leeches thatreleased cocoons.A totalof 870 cocoons w ith m ean w eightof (0.11 ± 0.009)g each,varying from 0.03 g to 0.25 g,w ere collected during breeding,w ith hatching rate of87.47% .There w as very significant effectoftem perature and density on cocoon num berreleased by leeches(P<0.01),w ithoutsignificanteffectoftem perature and densi-ty on long and shortdiam eters ofthe cocoon and cocoon w eight (P>0.05).The intervaltim e ofcocoon released by leeches w as re-duced by 10~15 d w hen the tem perature rose from (20±1)℃ to(24±1)℃,and the m axim aldaily am ountofcollected cocoon w as 43 at(24±1)℃ and 24 at(20±1)℃,w ith 5648 individualsofnew ly hatched larvae during the experim ent.The quantity and quali-ty ofnew ly hatched larvae w asfound to be im proved w ith increase in w eightofcocoon.