Hematological and biochemical parameters of the Gray seal Halichoerus grypus (Phocidae) in the Kandalaksha State Nature Reserve (Russia)

• Main Authors: Irina A. Erokhina, Nikolay N. Kavtsevich, Tatyana V. Minzyuk
• Format: Article
• Language: English
• Published: Fund for Support and Development of Protected Areas 2020-01-01
• Series: Nature Conservation Research: Zapovednaâ Nauka
• Subjects: biochemistry; hematology; peripheral blood; physiological status assessment; rare species; red data book
• Online Access: http://ncr-journal.bear-land.org/article/248

The paper presents results of the study of cellular composition and biochemical parameters of blood in gray seal (Halichoerus grypus grypus) in the Kandalaksha State Nature Reserve (Bolshoy Ainov Island, Barents Sea). Animals have been studied in an early postnatal period of development, i.e. from birth to weaning. We have determined the following blood parameters: leukocyte blood differential count and indicators of the functional activity of the cells, describing a level of nonspecific bactericidal activity, i.e. content of myeloperoxidase and cationic protein in granulocytes. The set of biochemical parameters includes the basic indicators of metabolism: total protein and its fractions, urea, creatinine, uric acid, glucose, lactic acid, total lipids, triglycerides, cholesterol, calcium, phosphorus, sodium, potassium, magnesium, iron, enzymes (aminotransferases, lactate dehydrogenase, alkaline phosphatase, α-amylase, γ-glutamyltransferase, creatine kinase). The values of hematological and biochemical parameters are within the limits of a norm described for H. grypus of the same ages. This allows us to characterise a status of pups born in 2006 and 2013 as a normal one. We have determined that in the first month of H. grypus' life the bactericidal function of leucocytes is carried out, mainly, by myeloperoxidase. Cationic protein serves only as an addition in the bactericidal system. Changes of metabolic characteristics in H. grypus during an early postnatal period are similar to those in terrestrial mammals. At the same time, the level of some indicators should be served as a feature of pinniped metabolism. So, gamma-glutamyltransferase activity, being a marker of passive immunoglobulins transfer in newborns, is almost 10 times lower than in terrestrial animals. The activity of alkaline phosphatase acted as an animal fatness index and to differentiate the catabolic and anabolic statuses, is higher in young H. grypus than in terrestrial mammals of the same age. Newborn H. grypus individuals also have a high blood oxygenous capacity, which is comparable with the indices of adults. Halichoerus grypus individuals born in 2006 and 2013 had similar hematological and biochemical blood parameters. The obtained values of blood parameters could be accepted as reference indices. They could be used to evaluate animal status and influence of various natural and anthropogenic factors on H. grypus.