Effect of Low and Ultra-Low Concentrations of N-Methyl-Nꞌ-Nitro-N-Nitrosoguanidine on Meristic Traits, Vertebral Phenotypes, and Anomalies of the Roach Rutilus rutilus Spine
摘要
The common roach Rutilus rutilus eggs developed for 48 h (from fertilization until onset of organogenesis) in N-methyl-N'-nitro-N-nitrosoguanidine solutions at concentrations 3 × 10−1, 3 × 10−2, 3 × 10−3, 3 × 10−4, 3 × 10−5, 3 × 10−6, and 3 × 10−7 mg/L. Exposure to the solution induced an increase in growth rate and in proportion of fish with vertebral anomalies, as well as occurrence frequency of vertebral phenotypes in 4 months old experimental summerlings (one summer old fingerlings) in relation to control. Response of roach organism to particular concentrations was likewise revealed through change in the number of soft rays in the pectoral and ventral fins and vertebra, as well as the number of vertebra with anomalies. Minimum effect was observed after exposure to concentration 3 × 10−4 mg/L; the greatest changes in the number of meristic traits and vertebral phenotypes were triggered by concentration 3 × 10−6 mg/L; the most serious vertebral abnormalities were observed after exposure to concentration 3 × 10−1 mg/L. Dependence of the considered indicators on solution concentration is of a complicated nonlinear character.