Ocean warming impairs the predator avoidance behaviour of elasmobranch embryos

Area of Science:

• Marine Biology
• Developmental Biology
• Ecology

Background:

• Embryogenesis in elasmobranchs is susceptible to predation.
• Embryonic elasmobranchs exhibit a freeze response (cessation of respiration, tail coiling) to evade predators.

Purpose of the Study:

• To investigate the hypothesis that oxygen requirements limit the duration of the freeze response in embryonic elasmobranchs.
• To determine the impact of incubation temperature on freeze response duration and metabolic consequences in Scyliorhinus canicula embryos.

Main Methods:

• Scyliorhinus canicula embryos were incubated at 15°C and 20°C.
• The duration of the freeze response and its metabolic consequences were measured at each temperature.

Main Results:

• Freeze response duration was significantly reduced at higher temperatures (20°C) compared to lower temperatures (15°C).
• Embryos at 20°C exhibited a 7-fold shorter freeze duration, indicating a negative impact of routine metabolic rate on response duration.

Conclusions:

• Increased metabolic rates at higher temperatures shorten the freeze response duration in embryonic elasmobranchs.
• Climate change stressors, by altering metabolism, can impact crucial behaviors like predator avoidance.
• Altered predator avoidance behavior should be considered in the conservation of oviparous elasmobranchs.