Pathogenesis of hydrocephalus of west-siberian grayling (thymallusarcticusarcticus, pallas) juvenile

Abstract

The article presents data on the development of hydrocephalus in young West-Siberian grayling. The study revealed a diverse impact of hydrocephalus on the vital activity of fish. First of all, it manifests in a significant slowdown in linear and weight growth. At two months of age, the body length and weight of diseased fish are lower than in healthy individuals by 60.9 and 94.0 %, respectively. Ex ternal symptoms of hydrocephalus are expressed in the appearance of well-marked bulges on the head, body deformities and the formation of ruptures of the head tissues. The main stages of hydrocephalus development can be represented in: sluggish behavior, refusal from feed; stationary position on the side at the bottom of aquarium; muscle cramps of increasing frequency; random movements; body deformities and respiratory function disorders. Hydrocephalus, according to our data, can be a completely eliminating factor in the loss of juveniles. Especially, the manifestations of the disease sensitive fish, passing the critical periods of early ontogenesis. The lack of growth and development is directly related to the negative impact of hydrocephalus on the somatic muscles of fish. During the first month there was only compression of fibers due to body deformities, but the second month is characterized by significant damage to the muscles, in particular, the destruction of fibers and the replacement of the formed space with connective tissue. Currently, the hydrocephalus of fish is not studied enough.