Evaluation of architectural and histopathological biomarkers in the intestine of brown trout (Salmo trutta Linnaeus, 1758) challenged with environmental pollution

Barišić, Josip; Filipović Marijić, Vlatka; Mijošek, Tatjana; Čož-Rakovac, Rozelinda; Dragun, Zrinka; Krasnići, Nesrete; Ivanković, Dušica; Kružlicová, Dáša; Erk, Marijana (2018) Evaluation of architectural and histopathological biomarkers in the intestine of brown trout (Salmo trutta Linnaeus, 1758) challenged with environmental pollution. Science of the Total Environment, 642 . pp. 656-664. ISSN 0048-9697

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Official URL: https://doi.org/10.1016/j.scitotenv.2018.06.045

Abstract

In the present study novel histopathological approach, using fish intestine as a sensitive bioindicator organ of pollution impact in the freshwater ecosystem, was proposed. Histopathological alterations were compared between native brown trout (Salmo trutta Linnaeus, 1758) from the reference (Krka River spring) and pollution impacted location (influence of technological/municipal wastewaters and agricultural runoff near the Town of Knin) of the karst Krka River in Croatia. In brown trout from both locations, severe parasitic infestation with acanthocephalan species Dentitruncus trutae was found, enabling evaluation of acanthocephalan infestation histopathology, which indicated parasite tissue reaction in a form of inflammatory, necrotic and hyperplastic response that extended throughout lamina epithelialis mucosae, lamina propria, and lamina muscularis mucosae. New semi-quantitative histological approach was proposed in order to foresee alterations classified in three reaction patterns: control tissue appearance, moderate (progressive) tissue impairment and severe (regressive and inflammatory) tissue damage. The most frequent progressive alteration was hyperplasia of epithelium on the reference site, whereas the most frequent regressive alterations were atrophy and necrosis seen on the polluted site. Furthermore, histopathological approach was combined with micromorphological and macromorphological assessment as an additional indicator of pollution impact. Among 15 observed intestinal measures, two biomarkers of intestinal tissue damage were indicated as significant, height of supranuclear space (hSN) and number of mucous cells over 100 µm fold distance of intestinal mucosa (nM), which measures were significantly lower in fish from polluted area compared to the reference site. Obtained results indicated that combined histological and morphological approach on fish intestinal tissue might be used as a valuable biological tool for assessing pollution impact on aquatic organisms. Therefore, semi quantitative scoring and multiparametric morphological assessment of intestinal tissue lesion magnitude should become a common approach to handle environmental pollution impact.

Item Type:

Article

Additional Information:

The financial support of the Croatian Science Foundation for the project no. IP-2014-09-4255 Accumulation, Subcellular Mapping and Effects of Trace Metals in Aquatic Organisms (AQUAMAPMET) is gratefully acknowledged. Special thanks to Dr. Damir Valic and Dr. Damir Kapetanovic for collaboration on the common fish sampling.

Uncontrolled Keywords:

fish ; karst Krka River ; wastewater discharge ; alterations scoring ; intestinal mucosa lesion index ; morphometry

Subjects:

NATURAL SCIENCES > Chemistry

Divisions:

Division for Marine and Enviromental Research

Projects: