SOME FISHERY BIOLOGICAL ASPECTS OF THE DEEP WATER SHARKIago omanensis INAQABA GULF

SOME FISHERY BIOLOGICAL ASPECTS OF THE DEEP WATER

SHARKIago omanensis INAQABA GULF

By
M. ABDALLAH*
*National Institute ojOceanography and Fisheries, Alexandria, Egypt.
Key words: Fishery, biology, Sharks, lago omanensis, Red Sea.
ABSTRACT
The dwarfsmooth hound Iago omanensis was capturedfrom deep
water 1000 m depth off Ras Abu-Galum (28 0 35′. 5479 N, 034 0 34′.
037 E) in Aqaba Gulf, Red Sea. Length-based estimates ofgrowth
parameters, mortality coefficients and the maximum exploitation
ratio, which generales the maximum sustainable yield, were obtained
using the compieate ELEFAN program. They were found to be;
asymptotic length (L o::J = 64.17 cm, growth constant (K) = 0.410
year1, total mortality (Z) = O. 741 year-1, fishing mortality (F) =
0.035 year-i , natural mortality (M) = 0.706 year-1 and maximum
exploitation ratio (Emax) = 0.6409.
investigation of stomach contents revealed that, this species feeds
on fish, cephalopods, shrimp andpolychaetes. Cephalopods were the
main food ofthe different sized sharks.