Interactions Between Temperature Variability and Reproductive Physiology Across Traits in an Intertidal Crab

Area of Science:

• Marine Biology
• Ecology
• Physiology

Background:

• Thermal extremes impact population dynamics through temperature-induced movement.
• Thermal thresholds for animal movement are influenced by physiology and life-history stage.
• Intertidal organisms like the porcelain crab face near-lethal temperatures.

Purpose of the Study:

• To investigate if behavioral thermal limits vary with reproductive state in Petrolisthes cinctipes.
• To understand the influence of reproductive status on thermal thresholds and movement in intertidal crabs.
• To explore the physiological mechanisms underlying temperature-dependent movement in relation to reproduction.

Main Methods:

• Integrated demographic, molecular, behavioral, and physiological measurements.
• Analyzed in situ gene expression (31 genes) and vitellogenin (VG) protein levels.
• Measured voluntary thermal maximum (VTmax) and correlated it with nerve fiber firing rates.

Main Results:

• Gravid females exhibited heat avoidance at lower temperatures (lower VTmax) than non-gravid females.
• Gene expression, including vitellogenin (vg), varied with intertidal elevation and reproductive status.
• VTmax correlated with nerve fiber physiology, suggesting a mechanistic link to movement.

Conclusions:

• Reproductive status significantly influences thermal thresholds and heat avoidance behavior in Petrolisthes cinctipes.
• Interactions between fine-scale temperature variation and reproductive biology are critical for intertidal species' survival.
• Understanding these factors is crucial for predicting population responses to climate change.