Escape performance in the cyclopoid copepod Oithona davisae

Abstract

Escaping a predator is one of the keys to success for any living creature. The performance of adults (males, females, and ovigerous females) of the cyclopoid copepod Oithona davisae exposed to an electrical stimulus is analysed as a function of temperature by measuring characteristic parameters associated with the escape movement (distance covered, duration of the appendage movement, mean and maximum escape speeds, Reynolds number). In addition, as a proxy for the efficiency of the motion, the Strouhal number was calculated. The escape performance showed temperature-dependent relationships within each adult state, as well as differences between sexes; additionally, changes owing to the presence of the egg sac were recorded in females. In a broader perspective, the results collected reveal the occurrence of different behavioural adaptations in males and females, adding to the comprehension of the mechanisms by which O. davisae interacts with its environment and shedding new light on the in situ population dynamics of this species.

Contrasting responses of Thermocyclops crassus and T. oithonoides (Crustacea, Copepoda) to thermal stress

“…Species exhibit varying degrees of tolerance to environmental factors, with death occurring if the tolerance limit of a particular species is exceeded 2 , 3 . The ability of a species to resist the new thermal conditions may determine how vulnerable it is to temperature increases brought on by climate change 4 – 7 . Along with long-term increases in temperature, other warming events could affect aquatic animals.…”