Red blood cells (RBCs)—erythrocytes—of Osteichthyes are primarily known for their involvement in the process of gas exchange and respiration. Currently, physiological properties of RCBs in fish should also include their ability to participate in defense processes as part of the innate and adaptive immune mechanisms. In response to viruses, bacteria, and fungi or recombinant nanoparticles, they can modulate expression of genes responsible for immune reactions, influence activity of leukocytes, and produce cytokines, antimicrobial peptides, and paracrine intercellular signaling molecules. Via the complement system (CR1 receptor) and owing to their phagocytic properties (erythrophagocytosis), RBCs of Osteichthyes can eliminate pathogens. In addition, they are probably involved in the immune response as antigen-presenting cells via major histocompatibility complex class II antigens.

Osteichthyes的红细胞（RBC）-红细胞主要因参与气体交换和呼吸过程而闻名。目前，RCBs在鱼类中的生理特性还应包括它们参与防御过程的能力，这是先天和适应性免疫机制的一部分。响应病毒，细菌和真菌或重组纳米颗粒，它们可以调节负责免疫反应的基因的表达，影响白细胞的活性，并产生细胞因子，抗菌肽和旁分泌细胞间信号分子。通过补体系统（CR1受体）并由于其吞噬特性（红细胞吞噬作用），鱼胸金龟的RBC可以消除病原体。此外，