Thermal games in crayfish depend on establishment of social hierarchies

Abstract

SUMMARYAn unequal resource distribution is commonly seen in dominance hierarchies, in which the individual with the higher status is more successful in obtaining the resource. One possible resource is preferred temperature. When situations allow, ectotherms regulate their body temperature by behaviourally selecting different environmental conditions, achieving, when possible, a preferred temperature. Using a shuttlebox, the preferred temperature for Procambarus clarkii was determined to be 23.9°C with upper and lower voluntary escape temperatures of 25.9 and 21.8°C, respectively. If this preferred temperature zone (21.8-25.9°C) was valued as a resource, given the choice between a preferred temperature and a non-preferred temperature, crayfish should compete over the preferred temperature, with the dominant individual of dyadic pairs achieving the preferred temperature more often than the subordinate. Using a dual-choice experimental tank, competition over a binary temperature choice between rankestablished paired crayfish was determined under both warm and cold challenge conditions (warm vs preferred temperature and cold vs preferred temperature, respectively). In naive pairings, similar levels of competition over the preferred temperature occurred in both warm and cold challenge trials, as predicted by game theory. In established pairings, however, dominant crayfish gained significantly greater access to preferred temperature in both warm and cold challenge conditions. These results demonstrate that crayfish engage in a cost-benefit assessment during their initial agonistic contests over temperature, but as hierarchies mature, these thermal games are decided by the dominant animal gaining primary access to the temperature resource.

Gaseous Mediators in Temperature Regulation

“…Although virtually all endothermic species, including humans, are capable of developing fever and anapyrexia, it is important to point out that the origin of these responses precedes the origin of endothermy (48,172,318,360). These evolutionarily conserved thermoregulatory responses have been shown to have biological values (170,229,332,393), and are likely to be relevant to clinical practice, as spontaneous increases and decreases in T b frequently occur during serious medical conditions, which include sepsis (281), hemorrhage (51), hypoglycemia (368), and intoxication (125).…”

Predator-Prey Interactions Shape Thermal Patch Use in a Newt Larvae-Dragonfly Nymph Model

“…A main difference between both set-ups was that newt larvae were kept in groups in the outdoor tanks, so the lower occupancy of warm patches in these tanks could be attributed to intra-specific competition among newts (cf. [42]–[44]). However, this explanation does not hold for the dragonfly nymphs.…”

A global review of freshwater crayfish temperature tolerance, preference, and optimal growth

“…Performing both acute and gravitational methods allowed researchers to compare results and account for temporal responses to in situ acclimation. Electronic shuttlebox experiments can eliminate the potential that a crayfish is simply exploring its surroundings and forces active selection based on temperature by increasing or decreasing temperature, eliciting active avoidance of unfavorable temperatures (Tattersall et al 2012).…”