Integrated Biomarker Response for Environmental Assessment Using the Gastropod Phorcus turbinatus along the Northern and the Northeastern Coasts of Tunisia.

This work aims to assess the spatial and temporal variations of four biomarkers activities and to integrate their biological responses in a battery using the gastropod Phorcus turbinatus. The monitoring was carried out during the period between April 2014 and January 2015 at six stations along the northern and the northeastern coasts of Tunisia. The Fulton condition factor was estimated and the activities of catalase, acetylcholinesterase and glutathione-S-transferase were evaluated by spectrophotometry. A multi-biomarker battery approach was used to assess ecosystems' condition and to identify environmental impacts on the organisms. The results suggest that the enzymatic activities of CAT and GST depend especially on seasons. As for AChE activity, it was similar between seasons and stations. The values of the integrated biological response were maximal at Jarzouna in summer and at Sidi Daoued in winter, indicating the presence of severe stressors suffered by the organisms. This perturbation may be due to the enrichment of the waters by xenobiotics, namely polycyclic aromatic hydrocarbons, insecticides, phosphate wastes, PCBs and pesticides. Thus, P. turbinatus seems to be a good bioindicator of chemical pollution, constituting an adequate tool for a bio-monitoring program.

Caligus tunisiensis n. sp. (Copepoda: Caligidae) parasitic on the painted comber Serranus scriba (L.) (Perciformes: Serranidae) from the Mediterranean Sea, off the Tunisian coast.

A new species of parasitic copepod, Caligus tunisiensis n. sp. (Caligidae), is described based on two female specimens collected from the gills of the painted comber, Serranus scriba (L.), caught in the Mediterranean Sea, off the Tunisian coasts. The new species belongs to the Caligus productus-species group established by Boxshall & Gurney (1980) as it shares the following set of character states: (i) antenna with well-developed posterior process on proximal segment; (ii) posterior margin of distal exopodal segment of leg 1 lacking typical plumose setae, or retaining single vestigial seta; and (iii) 2-segmented exopod of leg 4 armed with IV spines on compound distal exopodal segment. Detailed morphological comparisons between the new species and the core members of the C. productus-species group revealed that the new species closely resembles with C. productus Dana, 1852 and C. temnodontis Brian, 1924. However, the new species can be distinguished from its congeners in having: (i) a female maxilliped bearing a prominent bi-lobate myxal process, opposing tip of the claw; (ii) leg 4 protopod ornamented with a patch of spinules on the posterolateral surface; and (iii) an abdomen ornamented with two rows of minute spinules at the posterolateral corners.

Biological and biochemical assessment in Phorcus articulatus (Lamarck 1822): contamination and seasonal effect.

This work aims to diagnose the state of the northeastern coasts of Tunisia using P. articulatus species. Biological parameters, protein and metallothionein content, enzymatic activities, and metallic concentration were assessed at four stations during four seasons and analyzed by multiple regressions. The comparison of biological ratios showed minima at Sidi Daoued and maxima at Korbous where metallothioneins were maximal. The catalytic activity was low during summer and higher during cold periods contrary to acetylcholinesterase activity. Concerning glutathione S-transferase, its activity was important at Kelibia in autumn and at La Goulette and Sidi Daoued in warm seasons. The metallic concentrations were low at Korbous and maximal at Kelibia and Sidi Daoued stations. Kelibia seems to be the most polluted site followed by Sidi Daoued and La Goulette (industries, urbanization and fishing ports). The pollution seems to be reduced at Korbous station having more suitable conditions for the proliferation of monodonts.