Heavy metals influence on the ctenophores Mnemiopsis leidyi and Beroe ovata bioluminescence

Abstract

Investigations were conducted in the Department of biophysical ecology of Kovalevsky IMBR of RAS in September - October of 2013 and 2015. The body length of the gathered for experiments ctenophores was 35 - 40 mm. Characteristics of the ctenophores light emission were studied under the mechanical and chemical stimulations, with the usage of laboratory complex "Svet". The following HM salts: Cu2S04, ZnCl2, PbCl2 and HgCl2 in different concentrations were used in our experiments. The just-caught samples, contained in the clean marine water were used as a control. The exposition time was 1, 3 and 24 hours under the temperature of 21 ± 2°C. The investigations results have shown considerable variability of the ctenophore luminosity characteristics in dependence of metal concentration and exposition duration. It was stated that minimal concentrations of cooper, zinc and mercury stimulates ctenophores bioluminescence and the high ones inhibit. The alien ctenophore luminescence inhibition was registered under the lead activity under all investigated concentrations. We can place investigated metals as following: Zn < Cu < Hg < Pb, according to the force of the toxic influence on the ctenophore bioluminescence. Thus, alien ctenophore bioluminescence parameters can serve as a sensitive express-indicator of the resistance degree to the heavy metals impact and be the expressive index of the marine environment regional pollution.