曼氏无针乌贼Sepiella maindroni de Rochebrune繁殖习性的初步观察

曼氏无针鸟贼在我国沿海分布很广,是我国产量最高的一种头足类,在浙江舟山一带,形成了一种重要渔业,关于它的生物学习性,特别是关于它的繁殖习性,过去国内还报道不多,了解这种习性,在制定繁殖保护措施时,甚为必要,因此我们在参加浙江省水产资源调查工作期间,曾在鸟贼的主要产卵渔场,舟山中街山列岛的青滨,迸行了这种鸟贼的饲养及繁殖习性的观察,1963年和1964年复赴青滨,对于这种鸟贼的交配产卵及受精等方面作了进一步的试验观察,现将初步观察结果,作此报道,可以在生产上提供一些参考资料,同时在生物学理论上也似乎有一定意义。

PRELIMINARY OBSERVATIONS ON THE BREEDING HABITS OF THE SQUID,SEPIELLA MAINDRONI DE ROCHEBRUNE

The mating activities of the squid, Sepiella maindroni, were observed in the aq-uariums on Tsing-pan Island, Chou shan, Chekiang, under experimental conditions fromMay to June 1960 and May to July 1963 and 1964. Eyery year from April to June,the squids migrate to inshore areas for spawning. The mantle lengths of the male andfemale specimens under observation range from 7. 1 to 11.5 Cm. Copulation activities occur frequently. Postures of squids in copulation are shownin Fig. 1. From the observations we found that the male passes spermatophores tothe female's oral region. The sperm-mass is discharged and attached to the buccalmembrane and at the base of the left lateral arms of the female. The outer tuniclesof spermtophores are often formed in the female's stomach. The egg membrane is formed in the arms of the female. At first, the arms curvedown and the base of which rounds up to form a cavity into which her funnel extends,then nidamental glands and oviductal gland secrete gelatin into it to form the egg mem-brane, and finally, the egg passes through the funnel into the membrane. The black pig-ment of the egg membrane comes from its own ink sac when the egg membrane is beingformed. It seems that the fertilization of the squid's eggs takes place near the buccalmembrane.