REPRODUCTION AND GROWTH RATE OF TWO SCLERACTINIAN CORAL SPECIES IN THE NORTHERN RED SEA, EGYPT

REPRODUCTION AND GROWTH RATE OF TWO
SCLERACTINIAN CORAL SPECIES IN THE NORTHERN
RED SEA, EGYPT
TAREK A. A. MOHAMED1
, MOHAMED M. A. KOTB2
, ABDEL-FATTAH A.
GHOBASHY3
AND MOHAMED S. DEEK1
1- National institute of oceanography and fisheries, Red Sea branch.
2- Faculty of science, Marine Sciences Dept. Suez Canal University
3- Faculty of science, Zoology Dept. Suez Canal University.
[email protected]
Keywords: Reproduction – Growth – Acropora humilis – Stylophora pistillata – Red Sea.
ABSTRACT
During the present study three sites were chosen to study reproduction and growth of
two dominant coral species, Acropora humilis and Stylophora pistillata. The gonad
development was followed to determine the breeding season in their localities at Hurghada.
Their growth rate in the same localities was also studied. Both species are hermaphrodite
but the male gonads take shorter time to develop and to release gametes. The polyp number
of ova is about 5 in both species for each sex. Breeding occurs in winter months and
releasing of gametes in April for Acropora humilis and planula releasing is during spring.
Planula larva was detected inside Stylophora but not in Acropora. Growth rate reached the
maximum in summer and the least in winter. Higher annual growth rate for Acropora (7.5
mm) was recorded at Abu Qalawa, while the highest rate for Stylophora (6.68 mm) was
recorded at Gotta El-Erg. On the other hand, water currents affect the thickness of
Stylophora pistillata branches while in case of Acropora humilis not affected.