食物对湖北钉螺(Oncomelania hupensis)发育繁殖的影响

用浮游植物(A)、鲫鱼(B)、河蚌(C)、蚯蚓(D)及以浮游植物与3种动物分别混合组成(E、F、G)的7种饲料喂养钉螺,观察其幼螺成活、生长及雌螺产卵量.结果表明,饲料G喂养的钉螺幼螺成活率(43%)明显高于其他饲料(0~33.3%,),B和C喂养钉螺,其幼螺在一个月内全部死亡;在25℃的条件下,饲料A和G喂养的幼螺发育最快,105d其体长分别为6.89mm和6.81mm,且显著长于(P<0.05)饲料D、E、F喂养的钉螺(其体长分别为3.05mm、4.51mm、5.11mm).在25℃的温度条件下饲料A饲养的钉螺产卵时间长、产卵量高(13.9%),与混合型饲料G喂养的钉螺产卵量(14.1%)相当,而明显高于(P<0.05)饲料D、E、F喂养的钉螺(分别为2.9%、10.1%、11.0%);动物型饲料B和C产卵时间短、产卵量最低(不到2%).因此,植物饲料A和混合饲料G适宜于喂养钉螺.

Effects of food on development and reproduction of Oncomelania hupensis

Seven types of fodder were used to feed Oncomelania hupensis, the types of fodder were phytoplankton（A） ,crucian carp（B）,mussels（C）,earthworm（D） and the composition of phytoplankton and the three types of animals above（E,F,G）, the survival and the growth of the young snails, the fecundity of female snails were observed in this experiment. The results showed that the survival rate （43%） of the young O. hupensis snails fed with type-G fodder was significantly higher than the ones fed with other types of fodder（0—33.3%）. The young O. hupensis snails fed with type-B and type-C fodder all died within a month. At 25℃, the growth of young snails fed with type-A and type-G fodders was fastest in all, and they lead to 6. 89 mm and 6. 81 mm length respectively, which are significantly longer than those fed with type-D, type-E and type-F fodders （3.05 mm,4. 51 mm and 5.11 mm, respectively）. At 25 ℃, the snails fed with type-A fodder showed a long spanning time and high fecundity（13. 9%）, which was similar to that of the snails fed with type-G fodder （14. 1%）. They were significantly higher than those fed with type-D, type-E and type-F fodders （2.9%, 10. 1% and 11.0%, respectively）. The ones fed with types B and C showed a short spanning time and low fecundity （less than 2%）. According to the results above, the fodder type-A and fodder type-G were better than other fodders in feeding the snails.