High-elevation hypoxia impacts perinatal physiology and performance in a potential montane colonizer

Area of Science:

• Ecology and evolutionary biology
• Physiological ecology
• Climate change biology

Background:

• Climate change drives species range shifts, particularly along elevational gradients.
• Increased elevation leads to reduced oxygen availability (hypoxia), potentially impacting reproduction and development in oviparous (egg-laying) organisms.

Purpose of the Study:

• To investigate the effects of high-elevation hypoxia on the embryonic development and early-life performance of the viperine snake (Natrix maura).
• To assess the long-term consequences of high-elevation incubation on offspring performance after returning to lower elevations.

Main Methods:

• Artificially incubated viperine snake embryos under simulated high-elevation (hypoxia) and low-elevation (normoxia) conditions using a split-clutch design.
• Monitored hatching success, embryonic heart rates, and hatching timing.
• Assessed post-hatching performance (body size, swimming speed) and conducted reciprocal transplant experiments of juveniles.

Main Results:

• Hatching success was unaffected by incubation elevation.
• Embryos at high elevation exhibited higher heart rates and earlier hatching.
• Hatchlings from high-elevation incubation were smaller and slower swimmers, with impaired performance upon transfer to low elevation.

Conclusions:

• While high-elevation incubation does not prevent viable offspring production in oviparous ectotherms, it imposes physiological challenges.
• Early-life performance limitations due to high-elevation development may negatively impact adult phenotypes and fitness-related traits.
• Understanding these impacts is crucial for predicting species' responses to climate change-induced range shifts.