Is the deep-sea crab Chaceon affinis able to induce a thermal stress response?

Fluctuations in the stress level of an organism are expressed in behavioural and molecular changes that can affect its ecology and survival. Our knowledge of thermal adaptations in deep-sea organisms is very limited, and this study investigates the critical thermal maximum (CTmax) and the heat-shock response (HSR) in the deep-sea crab Chaceon affinis commonly found in waters of the North East Atlantic. A mild but significant HSR in C.

The control of food-caching behavior by Western scrub-jays (Aphelocoma californica).

Western scrub-jays (Aphelocoma californica) did not show extinction when caching behavior was never rewarded and they had no choice of where to cache the food. However, when the jays had the choice of caching items in 2 different locations or during 2 successive episodes, and only 1 of each was always rewarded at recovery, they rapidly learned to cache in the rewarded location or episode. When the jays had learned during training trials that their caches were always moved to 1 of 2 locations they did not cache in, then on the test trial they cached in the location that had been previously rewarded.

Western scrub-jays anticipate future needs independently of their current motivational state.

Planning for the future has been considered to be a uniquely human trait [1-3]. However, recent studies challenge this hypothesis by showing that food-caching Western scrub-jays (Aphelocoma californica) can relate their previous experience as thieves to the possibility of future cache theft by another bird [4], are sensitive to the state of their caches at recovery ([5] and S. De Kort, S.