RESEARCH ARTICLE Biomarkers assessment in the peacock blenny Salaria pavo exposed to cadmium Azza Naïja 1 & Justine Marchand 2 & Patrick Kestemont 3 & Zohra Haouas 4 & Ronny Blust 5 & Benoit Chénais 2 & Ahmed Noureddine Helal 1 Received: 4 December 2015 /Accepted: 25 April 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Cadmium (Cd) is one of the most toxic metals and is widely distributed in freshwater and marine environments. It has received much attention from a toxicological perspec- tive. The aim of this study was to assess the effect of Cd in the peacock blenny Salaria pavo, a species of the family of blennies that was used as bioindicator of water pollution. We performed a sublethal contamination of fish to 2 mg CdCl 2 L -1 during 1, 4, 10, and 15 days. Cd accumulation was mea- sured in gills and liver and displayed a significant increase of its concentration throughout the experiment, with slightly higher levels in the liver, except after 4 days. Partial-length cDNA of mt1, mt2, mnsod, cuznsod, cat, and gpx were char- acterized. Results from mRNA expression levels displayed an up-regulation of mt2 and mnsod. Biomarker activities were determined in gills and liver. In gills, data displayed an inhi- bition of EROD and GST activities. Cd exposure significantly increased GPx activities but did not affect CAT levels throughout the experiment. No LPO induction was observed in gills of exposed fish. Regarding the liver, the activity of all enzymes and MDA levels increased significantly from the beginning of the experiment except EROD that increased after 15 days of contamination only. At the histological level, fish exhibited pathological symptoms in gills and liver with a pre- dominance of circulatory disturbances in gills and regressive changes in the liver. Our results displayed that peacock blennies are able to survive Cd toxicity due to various physi- ological adaptation mechanisms. Keywords CdCl 2 . Peacock blenny . Salaria pavo . Cd accumulation . Biomarkers . Transcript levels . Enzyme activity . Histopathology Introduction In the earth’ s crust, Cd is naturally found at 0.1 to 5 ppm. According to the World Health Organization, production of Cd is estimated to be around 18,000 T year -1 which means 90 % of Cd-total emissions in the environment. Cd is a cumu- lative poison: humans absorb 5 % of the total ingested metal, and one third of its total concentration is accumulated in kid- neys. In 1912, Cd had been responsible for the Itaï-Itaï disease characterized by extremely painful fractures of bones (Kjellstrom 1986). The release of Cd in the environment via various industrial production processes has resulted in a strong accumulation of Cd in the aquatic environment over the last century. In the marine environment, the most prevalent chem- ical form found is the chlorocomplex CdCl 2 (Miramand et al. Responsible editor: Cinta Porte Electronic supplementary material The online version of this article (doi:10.1007/s11356-016-6754-6) contains supplementary material, which is available to authorized users. * Justine Marchand justine.marchand@univ-lemans.fr 1 Bioressources: Integrative Biology and Valuation (BIOLIVAL), Higher Institute of Biotechnology of Monastir, Avenue Tahar Hadded, BP 74, 5000 Monastir, Tunisia 2 EA2160 Mer Molécules Santé, LUNAM, IUML-FR 3473 CNRS, University of Le Mans, Le Mans, France 3 Research Unit in Environmental and Evolutionary Biology (URBE), University of Namur (FUNDP), Rue de Bruxelles 61, B-5000 Namur, Belgium 4 Research Unit of Genetic, Laboratory of Histology and Cytogenetic, Faculty of Medicine, Avenue Avicenne, 5019 Monastir, Tunisia 5 Systemic Physiological and Ecotoxicological Research (SPHERE), Department of Biology, University of Antwerp, Groenenborgerlaan 171, 2020, Antwerpen, Belgium Environ Sci Pollut Res DOI 10.1007/s11356-016-6754-6