Total protein in hemolymph of crawfish Pontastacus leptodactylus as a parameter of the functional state of animals and a biomarker of quality of habitat

Abstract

Analysis of total protein in hemolymph was performed by Lowry method on sexually mature crawfish Pontastacus leptodactylus. The total protein content in the crawfish hemolymph was studied for one year. The protein concentration varied widely, amounted to from 12 to 95 mg/ml, and depended on season and the molting cycle phase. There are presented histograms for distribution of animals for the protein level during different seasons and their character is analyzed. In summer the amount of protein is maximal prior to molt and decreases by 40% at once after it. There is studied the diapason of total protein concentrations in hemolymph, in which survival of crawfish at unfavorable changes in habitat is maximal. The adaptive possibilities of crawfish with the low protein content are attenuated. The crawfish with the protein concentration in hemolymph lower than the «critical» one were submitted for different time by action of hydroquinone (1 g/l) used as a model toxicant. A brief action did not affect the protein content in hemolymph. At a long toxic action the protein level in hemolymph fell, on average, by 40%, which preceded death of the animals. Possible mechanisms of positive correlation of the protein concentration in the crawfish hemolymph and of their survival at deterioration of quality of the water medium are discussed.