温度、投饵频次对海蜇碟状体生长的影响

实验室条件下,就温度和投饵频次对海蜇碟状体生长过程(伞径生长及活动灵敏度)的影响进行了研究。温度设置为17、21、25℃,投饵频次设置为0.5、1、2、3、4次/d,进行交叉实验。结果表明,温度、投饵频次对碟状体伞径生长的影响均十分显著,且二者的交互作用明显。温度、投饵频次与海蜇碟状体生长之间均存在正相关关系,但各温度下当饵料频次达到一定程度时,投饵频次的增加未对碟状体的平均日生长率产生差异,17℃时每天投饵1次,21℃、25℃时每天投饵2次即能满足碟状体正常生长发育的需求。温度、投饵频次对碟状体的收缩率影响均十分显著,二者的交互作用也很明显。温度与碟状体的收缩率之间成正相关关系,17~21℃时Q10值为2.74,21~25℃时Q10值为1.53,随温度的升高其灵敏度降低。综合本实验条件下的观察结果发现:饵料丰富(即投饵频次相对较高)时,高温(21~25℃)有利于碟状体的生长;饵料不足(即投饵频次相对较低)时,低温(17℃)也有利于碟状体的生长。

Influence of temperature and feeding frequency on the growth of ephyra of jellyfish (Rhopilema esculentum)

The ephyra of Rhopilema esculentum were cultivated under different temperatures (17 ℃, 21 ℃, 25 ℃) and feeding frequency (0.5/d、1/d、2/d、3/d、4/d) levels in laboratory, and the influences of the two environmental factors and their interaction on the ephyrae were observed. The results showed that temperature, feeding frequency and their interaction influenced the growth rate of ephyra of Rhopilema esculentum significantly. Temperature and feeding frequency exhibited a positive correlation with the growth rate of ephyrae of Rhopilema esculentum . Under a specific temperature, the daily growth rate stopped rising when the feeding frequency came to a significant degree. For the 17℃ group, feeding frequency of 1/d could satisfy the growth need for ephyra of Rhopilema esculentum . And for the 21℃ and 25℃ groups, feeding frequency of 2/d could satisfy their growth needs. Temperature, feeding frequency and their interaction influenced the bell pulsation rate of ephyra of Rhopilema esculentum significantly. There is a positive correlation between bell pulsation rate and temperature. The value of Q_(10) under the temperature interval of 17-21℃ and 21-25℃ were 2.74 and 1.53, respectively, which indicated that the sensitivity of bell pulsation rate to the temperature changes decreased with the increase of temperature. The above results suggested that when the food supply is sufficient, high temperature (21-25℃) was beneficial to the growth of ephyrae of Rhopilema esculentum , while when the food supply is inadequate, low temperature was more suitable for their growth.