Erythropoiesis in Teleost Fishes: The Fantastic Biological Process

ABSTRACT Global fish production exceeds 170 million tons in 2023, and provides a high‐quality protein source for humans. However, various factors may contribute to hypoxic stress and anemia, which contribute to yield loss in fish production. Elevated red blood cell counts or activation of erythropoiesis are well‐known responses to anemia and hypoxia stress in fish. Erythropoiesis is the process of formation of new erythrocytes, from hemopoietic stem cells, through the differentiation of erythroblasts, to the maturation of red blood cells. This step‐wise process is governed by complex transcriptional, post‐translational, and epigenetic programs in response to extracellular signals. This review summarizes developing knowledge regarding erythropoiesis in teleosts, including the wave and site of erythropoiesis, specification of the erythroid lineage, and molecular regulation mechanisms. A summary of research gaps is presented, to be addressed by future research on teleosts. Understanding erythropoiesis facilitates improved fish husbandry and selective breeding of hypoxia‐tolerance fish, to ultimately contribute to increased production.