Behaviors that come out of a copepod's mind

Abstract

Many aquatic environments are changing much faster than the gene pools of animals inhabiting them. To better predict how a copepod will behave, it is helpful to try to fathom the world from its sensory and cognitive system. Studies of genes, hormones, neuropeptides, and neural circuits can reveal underlying mechanisms while behavioral studies may capture their integrated outcomes. From the literature, which is richest for the calanoids Acartia and Calanus and the harpacticoid Tigriopus , we find that copepod decision‐making is centralized in the central nervous system. Copepod decision‐making and behavior can be described and modeled as (i) a dialogue between competing survival circuits that link sensing and behavior via (ii) subjective internal models and (iii) an ontogeny‐ and state‐dependent value system, the latter modulated by clock genes and hormones. Thereafter, (iv) competing neurobiological states can lead to (v) a global organismic state with (vi) narrowed attention. Then, (vii) the copepod's predictive models of near‐future expectations, based on (viii) its memory and (ix) learning from (x) previous prediction errors, will find the expectedly most attractive decision. From this follows our definition of the copepod mind as the integrated cognitive mechanisms underlying decision‐making: (i) awareness of itself, of some past experiences, and of its surroundings; (ii) capacity for competing emotions; and (iii) expectations to the effects of its actions. Copepod behavior and development can be understood and modeled from the decisions that come out of such minds.