Cowries,  who were specially abondant in Gabès gulf,  are, to day, in constant regression on the impact of pollution  and eutrophication due to the discharges of industrial  phophate wastes in the gulf.
Zonaria pyrum- 45mm  in length
 

 
Luria lurida - 52 mm in length
Luria lurida and Zonaria pyrum are Atlantic subtropical sea-shells extremely variable in shape as well in coloration  (click on shape and coloration to know more about these cowries).
Ranella olearia - Oil- vessel triton-
This carnivorous gastropod  can reach  25 cm in length. It lives on mud coarse (gravel) bottoms between 50 et 200 m depth. In Tunisia it is only present in the north and specially in  Tabarka area where it is oversfished  to sell to the tourists.

Photos by J. Zaouali