折叠萝卜螺卵粒孵化时间及不同饵料对仔螺生长的影响

为了研究折叠萝卜螺（Radix plicatula Benson）卵粒孵化时间和生菜叶、水生生物附着物、微囊料3种饵料及其部分组合对仔螺生长的影响，其中，生长分0～2、3～5周龄2个阶段，在室内条件下，统计10条新产卵袋卵粒孵化时间，分析投喂不同饵料及组合仔螺体质量等生长参数差异。结果显示：水温25.0～32.5 ℃，折叠萝卜螺卵粒孵化时间6.0～7.5天，平均孵化率96.37%；水温22.5～32.5 ℃，不同饵料及组合0～5周龄仔螺成活率差异不显著、生长差异显著；0～2周龄仔螺投喂水生生物附着物+微囊料生长速度最快，投喂水生生物附着物次之；初始体质量0.005 g的3～5周龄仔螺投喂生菜叶+微囊料生长速度显著快于生菜叶和微囊料；初始体质量0.026g的3～5周龄仔螺投喂生菜叶和生菜叶+微囊料生长速度快，之间差异不显著。研究表明：水温25.0～32.5 ℃，折叠萝卜螺卵粒孵化时间6.0～7.5天，平均孵化率96.37%；0～2周龄仔螺投喂水生生物附着物生长速度快，3～5周龄螺投喂生菜叶生长速度快，同时投喂微囊料对0～5周龄螺有促生长作用。本研究可为折叠萝卜螺规模化生产提供依据。

The study of egg hatching time for the snail Radix plicatula and effects of different diets on growth performance to the juvenile snails

In order to study the egg hatching time and the effects of lettuce leaves, aquatic periphyton, artificial pellets, as well as their partial combinations on growth performance to the juvenile snails Radix plicatula, a subset of 10 newly laid egg masses were collected and their hatching time were record under indoor conditions. In addition, the shell length, shell width, body weight and survival rate for the juvenile snails feeding with different diets were analyzed. The results showed that: The egg hatching time was 6.0～7.5 days with a 96.37% hatching rate when the water temperature ranged from 25.0 ℃ to 32.5 ℃. There was no significant difference in the survival rate for the 0～5 week old snails feeding with different diets, however, significant difference in the growth performance was found among the snail in different diet groups. The growth rate for 0～2 weeks old snails feeding with lettuce + aquatic periphyton was the fastest, followed by the snails feeding with aquatic periphyton. The growth rate for 3～5 weeks old snails with an initial body weight of 0.005 g feeding with lettuce + artificial pellets was greater than that feeding with lettuce or artificial pellets. Furthermore, no significant differences were found between the 3～5 weeks old snails with an initial body weight of 0.026 g fed by lettuce or lettuce + artificial pellets for their shell height, shell width and body weight. The results indicated that: The R. plicatula egg hatching time is 6.0～7.5 days with a mean hatching rate of 96.37% with the water temperature ranging from 25.0 ℃ to 32.5 ℃. Aquatic periphyton and the leaves of lettuce are ideal food sources for 0～2 weeks old and 3～5 weeks old R. plicatula, respectively, and artificial pellets have a promoting effect on the growth of juvenile snails. The results of this study will provide a basis for large-scale production of R. plicatula.