【摘要】 研究了方格星虫Sipunculusnudus胚胎与幼体发育。实验用亲虫于1999—2001年每年的5—8月分别采自北海市白虎头、大冠沙及高德海区。用人工授精法获得胚胎,用自然受精法获得幼体并观察其发育状况。研究表明,在25℃水温下,从受精卵到孵化出海球幼体(Pelagosphericlar va),胚胎发育需50—52h;在水温28—29℃下,需38—40h。在水温28—29℃下,从初孵出的海球幼体到附着变态期幼体,需13—15d。附着幼体经过7—10d发育后才完成变态,成为稚虫。更多还原

【Abstract】 Observations were made in this experimental study on embryonic and larval developments of peanut worm Sipunculus nudus. The parent worms used were collected from Baihutou, Daguansha and Gaode in the nearshore waters of Beihai City from May to August over 1999 to 2001. Fertilized eggs were obtained by striped-spawning for purpose of embryonic development observation, and the earliest pelagospheric larvae were gained through natural release and hatching-out for purpose of larval development observation. The results indicated that, at water temperature of 25℃, the duration of embryonic development from fertilized eggs to the hatching-out of the earliest pelagospheric larvae covered 50-52 hours; and at 28-29℃, 38-40 hours. At water temperature of 28-29℃, the earliest pelagospheric larvae took 13-15 days to develop into the settling stage, and another 7-10 days to go through metamorphose and into adult worm.更多还原