COMPARATIVE STUDY ON OCTOPUS VULGARIS (CUVIER, 1797) FROM THE MEDITERRANEAN AND RED SEA COASTS OF EGYPT

COMPARATIVE STUDY ON OCTOPUS VULGARIS
(CUVIER, 1797) FROM THE MEDITERRANEAN AND RED SEA
COASTS OF EGYPT
RAFIK RIAD* AND HOWAIDA R. GABR**
*National Institute of Oceanography and Fisheries, Alexandria, Egypt
**Marine Biology Department, Suez Canal University, Ismailia, Egypt
Rafik_ [email protected]
Keywords: Octopus vulgaris; Red Sea; Mediterranean Sea; Morphometrics; Length-weight
relationship; Coefficient of condition; Natural mortality.
ABSTRACT
Specimens from common octopus, Octopus vulgaris captured from the Red Sea and
Mediterranean Sea showed significant differences in four of seven morphometric
measurements .These differences are sufficient to recognize the populations of this species
in the two habitats. The computed length-Wight relationship and condition factor for
common octopus in both areas showed that representatives of this species from the Red Sea
are heavier than those captured from the Mediterranean Sea for the same length group.
Moreover, the natural mortality coefficient of Mediterranean representatives was
comparatively higher than for the Red Sea octopus. This shows that the environmental
conditions in the Red Sea are more suitable for O. vulgaris than in the Mediterranean Sea.