Study of the localization of pigment cells in the skin of scaly carp of various ages (Cyprinus carpio L.)

Morphological methods of fish research provide an opportunity to study their biological systems – cells, tissues, and organs in normal and pathological conditions – in depth at all levels of structural organization. The work aimed to investigate the morphological features of localization of skin pigment cells in scaly carp (Cyprinus carpio L.) of different ages. The study was conducted in the laboratory of complex ichthyopathological studies at the Department of Ichthyology and Zoology of the Belotserkiv National Agrarian University. One-, two-, and three-year-old scaly carp from the feeding ponds of PJSC “Chernigivrybhosp” were used. From which the scales were removed, skin samples of scaly carp (Cyprinus carpio L.) were used as material for research. Tissue samples were taken from freshly caught fish for the research. Our study established that pigment cells in carp of different ages were localized in the upper and lower layers of the dermis and hypodermis and in the lateral connective tissue septum at the level of the lateral line that divides the lateral muscles. In addition, in the carp of the same age, in contrast to the older age groups, isolated clusters of pigment cells were observed in the loose connective tissue between the muscle fibers of the superficial lateral muscle. During the histological examination, we also discovered the presence of pigment cells in the skin, particularly melanophores. Thus, the skin of peers of scaly carp was located in single clusters and had a rounded shape and a concentrated distribution of melanin pigment. Many melanophores were observed in the lower layer of the dermis at the border with the hypodermis. In the area of the lateral line, in the connective tissue septum, at the level of the deep lateral muscle, large strands of melanophores were detected.