Phenotypic and Transcriptomic Analysis Revealed a Lack of Risk Perception by Native Tadpoles Toward Novel Non-Native...

Area of Science:

• Ecology
• Conservation Biology
• Molecular Biology

Background:

• Introduction of alien species threatens native biodiversity, especially in vulnerable mountain lake ecosystems.
• Non-native fish pose a significant risk to endemic amphibians in southwest China's mountain lakes.
• The prey naivety hypothesis suggests native species may not recognize novel predators, increasing vulnerability.

Purpose of the Study:

• To assess the impacts of non-native fish on endemic amphibians in China.
• To compare phenotypic and genetic responses of tadpoles to native versus translocated fish.
• To provide evidence for the prey naivety hypothesis in amphibian-fish interactions.

Main Methods:

• Conducted an ex-situ experiment exposing Chaochiao Brown Frog tadpoles to fish kairomones.
• Compared phenotypic plasticity (total length, tail length, tail muscle width) in tadpoles.
• Analyzed gene expression patterns (differentially expressed genes) in liver and tail muscle tissues.

Main Results:

• Tadpoles exhibited significant phenotypic plasticity in response to native fish kairomones but weaker responses to translocated fish.
• Transcriptional analysis revealed substantially more differentially expressed genes in native fish treatments compared to translocated fish treatments.
• Unique differentially expressed genes in the native fish treatment were enriched in stress response, energy metabolism, and muscle development pathways.

Conclusions:

• Native tadpoles demonstrate a lack of risk perception towards novel non-native fish, supporting the prey naivety hypothesis.
• Findings provide phenotypic and molecular evidence of impaired predator recognition in native amphibians.
• Urgent conservation actions, including non-native fish management, are crucial for protecting endemic amphibians.