Cytochemical responses of Hediste diversicolor (Nereidae, Polychaete) sampled from polluted sites along the Tunisian coast

Abstract

Polychaetes are usually the most abundant taxon in benthic communities and have been most often utilized as indicator species of environmental conditions. This review finds that, while the use of indicator species for a particular pollutant is not simple, polychaetes can provide a useful means of assessing the effects of poor environmental conditions. Polychaetes may be used as sensitive monitors of water quality especially in terms of the effects of pollutants on life history characteristics. They may also be utilized as general indicators of community diversity but those species indicative of lower diversity may differ geographically and temporally. While sewage is often a mixture of high organic material and other pollutants such as heavy metals and pesticides, high organic situations associated with aquaculture facilities indicates that members of the Capitella capitata species complex and the dorvilleid genus Ophryotrocha are often dominant. Some species of polychaetes are able to live in sediments very high in trace metal content and body burden of these metals often does not reflect sediment concentrations due to regulation by these species. Many species seem relatively resistant to organic contaminants and pesticides and the effects of these pollutants on life history characteristics of these species may provide a more sensitive assay method. Recent studies using biomarkers in polychaetes to indicate general heavy metal or pesticide contamination has shown some success. Polychaete species known to occur in appreciable densities in the Gulf of Nicoya, Costa Rica, and which have been most often used as indicator species of pollution, are listed as potential taxa for environmental monitoring in this tropical estuary. Rev. Biol. Trop. 56 (Suppl. 4): 11-38. Epub 2009 June 30.Key words: polychaete, indicator species, marine pollution, community diversity, heavy metals, pesticides, organics, biomarkers, tropical, Costa Rica.The polychaetes have long been an obvious choice to act as representative species in the analysis of the health of benthic communities as they are usually the most abundant taxon taken in benthic samples, both in terms of the number of species and numerical abundance. Additionally, unlike nektonic or reptant organism, the polychaetes usually live within the sediments or attached to hard surfaces and, while their larvae may be capable of long distance transport, the adults are relatively inert. This relative immobility ensures chronic exposure to any toxic materials in the environment rather than the episodic exposures of a more vagile organism. Any long-term changes in the wellbeing of the benthos should be reflected in the polychaete community .The life history characteristics of polychaetes also make them good candidates to act as indicator species. The epibenthic filter feeders maximize their exposure to any harmful materials within the water column as they process relatively large amounts of water during feeding. Deposit feeding and interstitial species, which are in intimate c...

Biomarkers responses in different body regions of the polychaeta Hediste diversicolor (Nereidae, Polychaete) exposed to copper

“…In fact, when, CAT activity was induced in P region of worms exposed to 1µM of Cu, the MDA accumulation followed a decreasing trend. A clear evidence of oxidative perturbations reported in previous studies in whole body of H. diversicolor treated with sublethal Cd, Cu and B[a]P proved a reduced capability to prevent lipid peroxidation generated by pollutants as metals, hydrocarbons and nanomaterials (Catalano et al, 2012;Bouraoui et al, 2014;Moschino et al, 2014).…”

“…Specimens of the polychaete H. diversicolor, with mass between 0.4 and 0.6g were collected from Teboulba (Tunisia), which was reported to be a clean site (Banni et al, 2005(Banni et al, , 2007Jebali et al, 2007;Bouraoui et al, 2009Bouraoui et al, , 2014. The animals together with the surrounding sediments were put in polyethylene bottles.…”

“…Polychaetes are the dominant macrofauna within fine sediments and the presence or absence of specific polychaetes is considered as an excellent indication of the condition of the benthic environment (Marcano et al 1996;Lucan-Bouché et al 1999;Carvalho et al, 2013). In the group of the polychaeta, many species seem to exhibit an extraordinary tolerance to various environmental contaminants, being also the most common invertebrates found in polluted areas (Eriksen et al, 1988;Bouraoui et al, 2014). Hediste diversicolor is a marine annelid which lives in estuary sediments rich in microorganisms and toxic agents resulting from pollution.…”