MORPHOFUNCTIONAL CHARACTERISTICS OF PARENCHYMATOUS ORGANS OF THE CASPIAN SEAL (PUSA CASPICA) IN CONDITIONS OF ANTHROPOGENIC IMPACT

摘要

Since the end of the twentieth century, there has been a steady reduction in the number of the Caspian seal population. The dominant factors affecting the population and reproduction of marine mammals are toxicant pollution. To determine the physiological state of seals in the present-day conditions, a histological examination of their parenchymatous organs was carried out. In all the studied organs, a tendency of active replacement of cells by connective tissues was noted. The same was also observed in the digestive system (stomach, intestine, pancreas, liver), the excretory system (kidney) and organs of hemopoiesis and immunological protection of spleen. It was found that in the investigated specimens of seals, the highest pathological disorders were in their spleen and kidneys. The data obtained have revealed significant pathological changes in the internal organs of Caspian seals testifying to an increasing anthropogenic impact, which is the leading factor responsible for the depression of the Pusa caspica (Gmelin 1788) population in the Caspian Sea.