Peripheral Blood Parameters of Three Species with Different Ecologies (Scombridae and Berycidae)

— The hematological parameters of the peripheral blood of the Atlantic chub mackerel Scomber colias , bonito Sarda sarda, and splendid alfonsino Beryx splendens are presented based on materials of scientific monitoring on board the fishing vessels in the exclusive economic zones of Morocco and Mauritania in the years 2004–2017. A larger number of immature erythropoietic cells was recorded in the alfonsino, which is probably due to its possible vertical feeding migrations to greater depths with high pressure and low oxygen content. The analysis of erythropoiesis and the leukocyte formula revealed features of physiological and immunological aspects. Bonito has a higher monocyte content than atlantic chub mackerel and alfonsino, which indicates a high level of innate cellular immunity, represented by phagocytosis.