Ranavirus infection does not reduce heat tolerance in a larval amphibian

Area of Science:

• Ecology
• Pathology
• Herpetology

Background:

• Extreme heat and infectious diseases pose significant threats to wildlife.
• Pathogen infections often reduce host heat tolerance, increasing vulnerability to heat stress.
• The combined impacts of heat events and emerging diseases on wildlife are understudied.

Purpose of the Study:

• To investigate the effects of ranavirus infection on the heat tolerance of larval wood frogs (Lithobates sylvaticus).
• To determine if ranavirus infection alters critical thermal maximum (CTmax) in wood frog larvae.

Main Methods:

• Larval wood frogs were experimentally infected with ranavirus.
• Critical thermal maximum (CTmax) was measured in both infected and uninfected larvae.
• Viral loads were quantified in infected individuals.

Main Results:

• Ranavirus infection did not significantly reduce the CTmax of wood frog larvae.
• A positive correlation was observed between CTmax and ranavirus viral load.
• Infected larvae maintained heat tolerance despite high viral loads.

Conclusions:

• Ranavirus infection does not impair heat tolerance in larval wood frogs, contrary to expectations based on other pathogens.
• Wood frog larvae may prioritize maintaining CTmax, potentially to facilitate behavioral fever for pathogen clearance.
• Infected wood frogs are unlikely to face increased risk from heat stress due to ranavirus infection.