Plankton and Benthos Research
Online ISSN : 1882-627X
Print ISSN : 1880-8247
ISSN-L : 1880-8247
Original Papers
Development and polyp formation of the giant box jellyfish Morbakka virulenta (Kishinouye, 1910) (Cnidaria: Cubozoa) collected from the Seto Inland Sea, western Japan
Sho ToshinoHiroshi MiyakeSusumu OhtsukaKazuya OkuizumiAya AdachiYoshimi HamatsuMakoto UrataKazumitsu NakaguchiSyuhei Yamaguchi
ジャーナル フリー

2013 年 8 巻 1 号 p. 1-8


The giant cubozoan Morbakka virulenta was collected from the central part of the Seto Inland Sea, western Japan in October 2009, in order to observe its development and polyp formation. Fertilization occurred externally. Demersal fertilized eggs were obtained during the incubation of mature females and males kept at a temperature of ca. 17 to 21°C. From the two-cell stage onwards, fertilized eggs developed into blastulae within 4 h. The development of the blastulae stopped for 21 days after forming blastocysts. This formation of blastocysts is up to now unique within the Cnidaria. The planulae, which developed inside the cysts and lacked larval ocelli, this being characteristic for the Cubozoa, finally metamorphosed into polyps bearing only a single tentacle. The 16-tentacled-stage in polyps was reached about three months after this metamorphosis. Budding occurred in eight-tentacled polyps and swimming polyps were released nine days after the commencement of budding. These unique developmental features of M. virulenta may shed additional light on the evolution of life history strategies in the Cnidaria.

© 2013 The Plankton Society of Japan, The Japanese Association of Benthology