Shell alterations in Hexaplex trunculus collected in the vicinity of an impacted zone by industrial marine discharges (Gabès, Southern Mediterranean)

Youssef Lahbib , Tasnime Slama , Sami Abidli , Julius Nouet (1) , Eric Chassefière (1) , Najoua Trigui El Menif

1 GEOPS - Géosciences Paris Saclay

Using the gastropod Hexaplex trunculus, a comparative study of the shell characteristics (morphometrics, microstructure and elemental composition) was carried out in the vicinity of Gabès city (Chatt Essalem, CE) which is known as seriously affected by industrial pollution, and two control zones (Ghanouche, GH and Teboulbou, TB). Gastropods from CE had larger, thicker and heavier shells, associated with bigger apertures and slighter soft bodies. Scanning electron microscope (SEM) revealed the presence of three shell layers having a crossed lamellar structure. The inner layer was thinner, while the median layer was thicker in snails from CE, suggestive of the ability of H. trunculus to remodel the shell microstructure accordingly. Moreover, the median and inner layers were marked by the presence of fibrous interbeds that were numerous and thicker in shells from CE. In this site, shell elemental alteration was also observed with a decrease in Ca, P, S, K and O contents against an increase in C, Cl and Mg compared to control sites. This investigation was in agreement with previous studies and further suggests the deleterious effect of coastal pollution generated by various industrial units implemented around Gabès city on marine organisms.

Mots clés: Gastropod; Shell; Microstructure; Elemental alteration; Tunisia

Domaines: Planète et Univers [physics]

Youssef Lahbib, Tasnime Slama, Sami Abidli, Julius Nouet, Eric Chassefière, et al.. Shell alterations in Hexaplex trunculus collected in the vicinity of an impacted zone by industrial marine discharges (Gabès, Southern Mediterranean). Journal of Sea Research (JSR), 2022, 181, ⟨10.1016/j.seares.2022.102178⟩. ⟨insu-03745287⟩