Replication Data for: Terrestrial emergence reflects lower thermal preferences in the mangrove rivulus (Kryptolebias marmoratus)

In other ectothermic species, hypoxia is known to decrease thermal preference. Before physiological acclimation restores respiratory function, it is therefore plausible that fish that have emerged onto land will seek cooler temperatures beyond what is achieved by simple evaporative cooling. To test this idea, two strains of laboratory-raised mangrove rivulus were placed in a thermal gradient that provided the option of land and water to determine how their preferred temperature was informed by choice of the surrounding environment.

We hypothesized that selecting land would be associated with anapyrexia, or a purposeful selection of lower temperatures. In trials where thermal gradients were provided in aquatic, terrestrial, or combined settings, mangrove rivulus selected cooler temperatures only when on land. These findings support the premise that terrestrial emergence serves an active thermoregulatory strategy.