Some
species bioindicator of the state of "good health" of the sea- part two
Bulla
striata -
Kerkena -This
species, very sensitive to pollution, prefers the Posidonia
fields in shallow waters.
Tricolia
speciosa
This tiny herbivorous
gastropod (14 mm in length ) lives on the leaves of Posidonia to
eat small algae which are growing on. This beautiful shell from Jerba
island is very sensitive to pollution.
Gibbula
ardens
This gastropod
(16 mm in diameter ) lives in shallow waters among
Zostera fields. This beautiful shell from the southern
Bibans lagoon is very sensitive to pollution.
Photos: J. Zaouali