Changes in morphological indexes of young atlantic salmon misiniu: eksperimentinis tyrimas

Morphological indexes are indicative of toxicant effects in fish. Unfortunately, morphological parameters [gill-, liver-, kidney-, viscero-, etc., somatic indexes and the integrated condition factor (CF)], are usually determined in field studies to assess the general fish condition under effect of multicomponent pollution and did not reflect the effects of specific polluting substances (e.g. heavy metals). The purpose of this study was to experimentally evaluate the effect of priority heavy metal model mixture formed based on Maximum-Allowable-Concentration accepted for Lithuanian receiving water bodies (Zn - 0.1, Cu - 0.01, Ni 0.01, Cr - 0.01, Pb - 0.005 and Cd - 0.005 mg/L, respectively) on condition parameters of one-year-old Atlantic salmon after seven-, fourteen- and twenty eight- day exposure. Significant changes in liver-, kidney- and viscero-somatic indexes were determined, while CF and branchio-somatic-index were found to be not indicative for such kind of the exposure. Correlation analysis between the parameters studied revealed a number of meaningful patterns. The obtained data were compared with the results of the field study in salmonid rivers. Keywords: Atlantic salmon, heavy metals, morphological indexes, organo-somatic index, bioindicator. Santrauka. Morfologiniai rodikliai--tai toksinio poveikio zuvims indikatoriai. Sie rodikliai (imitimo koeficientas, visceralinis, ziaunu, kepenu, inkstu ir kt. somatiniai indeksai) paprastai yra taikomi gamtiniuose tyrimuose, norint ivertinti bendra zuvu fiziologine bukle, veikiant daugiakomponentei tarsai, neisskiriant konkreciu tersalu (pvz., sunkiuju metalu) poveikio. Sio tyrimo tikslas--eksperimentiskai nustatyti ir ivertinti morfologiniu rodikliu pokycius po 7-iu, 14-os ir 28-iu paru ekspozicijos, veikiant atlantines lasisos jauniklius prioritetiniu sunkiuju metalu misiniu esant didziausioms leistinoms koncentracijoms (DLK), nustatytoms Lietuvos vidaus vandenims: Zn--0,1; Cu--0,01; Ni--0,01; Cr--0,01; Pb--0,005 ir Cd--0,005 mg/l, atitinkamai. Nustatyti visceralinio, kepenu ir inkstu somatiniu indeksu zymus pokyciai, taciau imitimo koeficiento ir ziaunu somatinio indekso pokyciai buvo nereiksmingi visa ekspozicijos laikotarpi. Istirtu rodikliu koreliacine analize atskleide keleta svarbiu desningumu. Gauti duomenys palyginti su gamtinio tyrimo lasisinese upese rezultatais. Reiksminiai zodziai: atlantine lasisa, sunkieji metalai, morfologiniai rodikliai, organo somatinis indeksas, bioindikatorius.