Changes in morphological and biochemical parameters of Littorina sitkana (Philippi R.A., 1846) during Podocotyle sp. (Dujardin, 1845) and Himasthla littorinae (Stunkard H.W., 1966) metacercariae infaction

The purpose of our study was to establish indicators of infection of Littorina, as well as to study the influence of invasion on their morphological and biochemical parameters. As a result, the relationship between the intensity of metacercariae infection and the morphological parameters of the mollusk shell has not been established. The tissue and cellular response of mollusks to the invasion of Podocotyle spp. and Himasthla littorinae was revealed including increased mucopolysaccharide production. The amino acid composition shifted towards an increase in some indicators, and the content of crude protein in infested mollusks increased by 1.5 times. Due to the influence of trematodes on the mollusk and the activation of the host mollusk’s defense mechanisms against invasion, with its high intensity and duration of the pathological process, a complete or partial loss of the beneficial qualities of the meat is likely.