Seabream (Sparus aurata) hierarchy among alfa and beta subordinates and dominant interplay affects stress responses and phagocytic activity by peritoneal cavity cells

Seabream (Sparus aurata) long-term dominant-subordinate interplay affects phagocytosis by peritoneal cavity cells.

Fish are sensitive to stressful conditions that affect their innate immune systems and increase their susceptibility to diseases. We examined the social stress of paired gilthead seabream (Sparus aurata). Social hierarchies (dominant/subordinate) were characterised by behavioural changes, such as “aggressiveness” and “feeding order”; hierarchical positions were established within an hour of exposure to social stress and remained unchanged for approximately 1 year. To characterise physiological stress, we measured blood plasma levels of cortisol, glucose, and lactate as well as osmolarity and observed that the levels of these stress markers were higher in subordinate individuals than in domi…