SOME BIOLOGICAL ASPECTS ON ONE SPECIES OF COCKLES (BIVALVES) IN PORT- SAID COASTS

The present study focused on one cockle species that dominated at Port- Said coasts. It is Anadara uropigimelana. Various biological aspects were studied in details and the results are summarized as follow: Shell length of Anadara uropigimelana ranged forY = 0.8998 X + 0.6585 (for length-height relationships)Y = 0.8161 X -2.1917 (for length- width relationships)Y= 0.6801 X- 5.2267 (for length-ligament relationships)Y= 0.0002 X 3.1165 (for length- total weight relationship)Y= 0.0001 X 3.1006 (length- shell weight relationship)Y = 5E- 05 X 3.113 (length- wet weight relationship)Y = 3E -05 X 2.7977 (length-dry weight relationship).Low growth rates of shell dimensions and body weights took place during the spawning period of this species. A positive relationship was found between the age of the cockle and the absolute growth in term of shell length and total weight. In case of relatHistological description revealed that:1- Anadara uropigimelana is a diocious species. In addition, ripe ova of A. uropigimelana are surrounded by follicular sacs and attached to other gametogenic stages by fine filaments. After spawning, atresis (oocyte degeneration) appeared in A. uropigimel2- This species is characterized by continuous spawning. A simple synchronization was found between both sexes in the partially spawned phases.3- The interfollicular connective tissue of Anadara uropigimelana serves as a nutrient reserve utilized during gametogenesis. Spent gonad of this species contained the largest abundance of the interfollicular connective tissue, which was rich in nutritiveAnadara uropigimelana is characterized by external fertilization as in most bivalves. The different age groups of the species followed the same pattern of gonad development. However, the larger individuals of the species contributed largely to the reprodu