短蛸的早期生长特征

Early Growth Characteristics of Post-Hatching Octopus ocellatus (Mollusca: Cephalopoda)

中文关键词: 短蛸  腕长  胴长  浮游期  底栖期

英文关键词: Octopus ocellatus  Arm length  Mantle length  Planktonic stage  Benthic stage

中文摘要:

      对孵化后1~50日龄短蛸(Octopus ocellatus)幼体的体重、全长、腕长及胴长进行测量，观察并分析其早期生长变化特征。在水温为22℃~24℃的养殖条件下，初孵短蛸平均全长为10.03 mm。11日龄幼体开始营底栖生活，以此为分界线划分为浮游期和底栖期。 结果显示，1~11日龄浮游短蛸体重增长为立方函数增长类型，y = 0.0001x3 – 0.0019x2 + 0.0098x + 0.0409；11~50日龄的底栖短蛸体重增长为指数函数增长类型，y = 0.0284e0.092x。在1~50日龄短蛸幼体的生长过程中，体重(g)与全长(mm)呈立方函数关系，y = –8e–07x3 + 0.001x2 – 0.011x + 0.099；全长(mm)与腕长(mm)呈线性关系，y = 1.314x + 4.952；体重、全长及腕长分别与日龄呈立方函数关系，y = 6e–05x3 – 0.003x2 + 0.036x – 0.03、y = 0.0004x3 + 0.002x2 + 0.307x + 10.604、y = 0.0004x3 – 0.007x2 + 0.364x + 4.205。通过研究短蛸幼体的生长发育特征，从而加深了对幼体生长的了解，并为短蛸人工繁育的研究提供参考依据。

英文摘要:

      The early growth characteristics of Octopus ocellatus larvae raised under culture conditions were analyzed. Ten larvae were sampled at different periods from post-hatching to when larvae were 50-days-old, and their body weight, total length, arm length, and mantle length were measured. We described the growth characteristics of O. ocellatus, to define the different phases characterizing this species’ post-hatching development. The larval stages of O. ocellatus were divided into a planktonic stage and a benthic stage, with benthic life beginning at the age of 11 d. At water temperatures of 22℃~24℃, the cultured larvae could grow from an average total length of 10.03 mm on the first day post-hatching to a benthic octopus with an average length of 16.21 mm by the 11th day post-hatching. The results showed that the body weight of planktonic O. ocellatus increased with time according to a cubic function, the equation of which was: y = 0.0001x3 – 0.0019x2 + 0.0098x + 0.0409. On the other hand, benthic O. ocellatus body weight increased according to an exponential function, the equation of which was: y = 0.0284e0.092x. The total length of O. ocellatus larvae exhibited a cubic relationship with body weight, the equation of which was: y = –8e–07x3 + 0.001x2 – 0.011x + 0.099. Total length was linearly related with arm length, as represented by the equation: y = 1.314x + 4.952. Body weight, total length, and arm length exhibited cubic growth functions over time, as represented by the equations: y = 6e–05x3 – 0.003x2 + 0.036x – 0.03, y = 0.0004x3 + 0.002x2 + 0.307x + 10.604, and y = 0.0004x3 – 0.007x2 + 0.364x + 4.205, respectively. The larval body is transparent, and the visceral mass of the larva is a golden color during the first day post-hatching. As the individual grows, the color deepens to a yellowish brown. Newly hatched O. ocellatus usually have 14 to 16 suckers, and with the constant growth of the larval wrist the number of wrist suckers gradually increases. The new suckers appear at the end of the wrist, each beginning as a small, raised bulge that then increases in size until a new sucker is formed.