Examination of the bioindicator potential of Oncholaimus campylocercoides (Oncholaimidae,Nematoda) from Bizerte bay (Tunisia)

We have tested the use of the free-living nematode Oncholaimus campylocercoides as a bioindicator of petroleum pollution. This was analysed using a polluted-reference sampling strategy for one year in Bizerte bay (Tunisia). We noted a decrease in body dimensions together with many biometric anomalies when organisms are exposed to petroleum compounds. The three first moults and the egg-production phase of specimens of O. campylocercoides from the polluted site TRIC (Tunisian Refining Industries Company) took longer. The egg volume was negatively affected by pollution and the development from egg to juveniles J1 in one side and from juveniles J4 to males from TRIC beach on another side seems to be faster.Our results demonstrated that biometry, life cycle and fecundity are useful indices to biomonitor hydrocarbon pollution in marine ecosystems. Juveniles of the second and third stage and gravid females of O. campylocercoides seem to be the most appropriate bioindicators.