The excessive use of pesticides at different stages of crop production can pose a great danger to the aquatic environment, and particularly to fish. The purpose of the present work was to assess the negative effects of chlorpyrifos (CPF) on the liver histological architecture and the activities of marker enzymes in common carp (Cyprinus carpio Linnaeus, 1758), by applying a multi-biomarker technique. The tested insecticide is categorized as a priority pollutant in surface waters in terms of Directive 2013/39/EU. The carps were exposed to different and environmentally relevant CPF concentrations for 72 h (a short-term acute experiment). The results showed that the tested insecticide alters the liver histological structure, causing degenerative lesions, such as granular and vacuolar degeneration; necrobiotic alterations and necrosis, as well as changes in the circulatory system. In addition, CPF induces changes in the enzymatic activity of lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), alanine aminotransferase (ALAT), cholinesterase (ChE), glutathione peroxidase (GPx) and catalase (CAT). The results from such experimental set ups could be successfully used in the legislation related to the protection of water bodies from contamination, in areas with intensive application of plant protection products used in agricultural practices, and also in implementing the Water Frame Directive by using multi-biomarker approaches.

For the first time, transplants with moss-bags and mussels together were applied to study the water quality in standing water bodies. The tested species: Fontinalis antipyretica Hedw. and Sinanodonta woodiana (Lea, 1834) were collected from unpolluted sites and analyzed to obtain background levels. Then, the moss and mussels were left in cages for a period of 30 days in three reservoirs where both are not present naturally. Two of the reservoirs suffer from old industrial contamination and one is affected by untreated wastes. Twenty-four compounds were studied, among them trace elements Al, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Zn and organic priority substances: six polybrominated diphenyl ethers (PBDEs) congeners and short-chain chlorinated paraffins (SCCPs). The trace element accumulation was significant after the exposition period in all studied stations. PBDEs and SCCPs were also accumulated up to two times more in the moss tissues. PBDEs in the mussels exceeded the environmental quality standard (EQS). The applied combined transplants, and especially the moss-bags, revealed severe contamination with heavy metals not detected by the water samples. The moss and the mussel followed a different model of trace element and PBDEs accumulation. The SCCPs levels were alarmingly high in all plant samples. The study confirmed PBDEs and SCCPs as bioaccumulative compounds and suggested that an EQS for SCCPs in biota needs to be established.

The tissue expression of human histo-blood group antigens (HBGA) in vertebrates, as well as their evolutionary tendencies and relation to histogenesis, especially in the reproductive system, are not entirely understood.The present research comprises a large-scale immunohistochemical study of HBGA A and B expression in ovaries and testicles of 14 species belonging to six classes of free-living vertebrates from Chondrichtyes to Mammalia .We present novel data for ABH antigen reactivity in reproductive organs of vertebrates which have not been studied so far. Our results suggest that HBGA are evolutionary stable structures, most possibly related to vitellogenesis in oocytes with high yolk content. The tendency observed in A and B antigen expression is mostly associated with the processes of gamete differentiation and vitellogenesis, rather than with the evolutionary development of vertebrate species.