Please use this identifier to cite or link to this item:
|Title:||Development of the Seastar, Astropecten gisselbrechti Doderlein|
|Publisher:||University of Hawai'i Press|
|Citation:||Komatsu M, Nojima S. 1985. Development of the seastar, Astropeten gisselbrechti Doderlein. Pac Sci 39(3): 274-282.|
|Abstract:||The entire process of development from eggs to juveniles in the
seastar Astropecten gisselbrechti was observed, with special attention to the
external morphology and formation of the skeletal system . The breeding season
of this seastar along the coast of Tsuyazaki (33°47' N, 130°28' E), Fukuoka
Prefecture, Japan, is in June. The eggs are 353 /lm average diameter, semitranslucent,
and pale brown in color. Development proceeded as follows at 25°C:
Embryos develop through a wrinkled blastula stage that lasts about 5 hr (from
5 hr after insemination) by total and equal cleavage. Gastrulae bearing an
expanded distal portion of the archenteron hatch from the fertilization membrane
15hr after insemination. Gastrulae develop into barrel-shaped larvae 11
days after insemination. The larva is free-swimming, and is neither bipinnaria
nor brachiolaria because it lacks an open larval mouth, arms , and ciliary bands.
Rudiments of the adult skeletal plates appear at this time. Metamorphosis is
completed 4 days after insemination, mostly by absorption of the stalk, a larval
organ, or rarely by rupture of the stalk. The newly metamorphosed juvenile is
650 /lm in diameter and bears two pairs of tube-feet on each arm . This is the third
reported observation of a barrel-shaped larva in asteroids.
|Appears in Collections:||Pacific Science Volume 39, Number 3, 1985|
Items in ScholarSpace are protected by copyright, with all rights reserved, unless otherwise indicated.