Categories
vol-31REPRODUCTIVE BIOLOGY OF THE TROPICAL SEA
CUCUMBER HOLOTHURIA ATRA (ECHINODERMATA:
HOLOTHUROIDEA) IN THE RED SEA COAST OF EGYPT
ABDEL-RAZEK, F.A.
*
, ABDEL-RAHMAN, S.H.
*
, EL-SHIMY, N.A.
**
and OMAR, H.A
*
* National Institute of Oceanography and Fisheries
** Faculty of Science, Assuit University
Keywords: Holothuria atra, Red Sea, Maturation, G.S.I, spawning season and fecundity.
ABSTRACT
Although the echinoderms have been the subject of various investigations by many
authors, those of the Red Sea species till now; have received little attention. Sea cucumbers
(Holothuroidea) are marine animals that present in the group of echinoderms. They are
distributed from the shore to the greatest depths. The importance of detailed reproductive
biological studies on Holothuria atra are necessary due to its important role in the
conservation of the marine environment. Samples of the present study was collected from
three sites at north Hurghada City, Red Sea during the period from January to December
2003. Four maturity stages were assigned for each sex as immature, maturing, ripe and
spent stages. From the monthly and size distribution of these maturity stages of both sexes,
it was found that the ripe stage was observed most time of the year for Holothuria atra with
high abundance in June and November for males and from June to December for females.
The observed size at first sexual maturity was found at 16.5 cm and 15.5 cm total length for
males and females, whereas the calculated size was 16.5 cm for females and 17.5 cm for
males respectively. The maximum observed oocyte diameter was observed during the
intensive period of spawning season for Holothuria atra being in the range from 175 to 200
(µm). Fecundity of Holothuria atra was found to be in the range from 12110 to 1342278
oocytes for individuals of size range from 21.0 to 25.0 cm total length. The relation
between absolute fecundity and gonad weight is best fitted by a linear regression.
