Britannica Sources used in this answer

How do lobsters display dominance and submission after fighting?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

red deer stags (Cervus elaphus) — Aggressive behaviour A pair of red deer stags (*Cervus elaphus*) competing for possession of a female in the rutting season.

In the context of aggressive behaviour, lobsters establish a clear hierarchical relationship following a series of fights. Once a victor is determined, the animals display distinct postures to signal their social status:1

Dominant posture: The victor consistently adopts a stance characterized by raised legs and forward-directed antennae.1
Submissive posture: The loser adopts a submissive posture and actively avoids future conflicts with the dominant individual.1

These behaviors are regulated by neuroendocrine mechanisms, specifically involving the neurohormones serotonin and octopamine. Serotonin is associated with the control of dominance; experimental increases in serotonin levels can induce a dominant posture and increase an animal's willingness to fight. Conversely, octopamine—an invertebrate analog of norepinephrine—promotes submissive behavior. Within the central nervous system, specific nerve cells connect to motor neurons that generate these postures, with the activation of these systems being facilitated or suppressed based on the lobster's established social status.1