# Avoidance Behavior in Chinhai Spiny Newt Larvae: Responses to Visual and Chemical Cues from a Novel Predator

## TL;DR

Chinhai spiny newt larvae avoid predators using visual and chemical cues, with stronger responses to larger predators.

## Contribution

Demonstrates how larvae detect and respond to novel predators using sensory cues and size assessment.

## Key findings

- Larvae show strong avoidance and reduced activity in response to visual cues from bullfrogs.
- Chemical cues reduce activity but do not trigger significant avoidance behavior.
- Larvae preferentially avoid larger bullfrogs when both large and small are present.

## Abstract

This study investigates how the larvae of the Chinhai spiny newt recognize and respond to the novel predator, so we used the bullfrog as a representative predator in the experiment. Experiments showed that when only visual cues were provided, the larvae quickly recognized the bullfrog and actively moved away, with a significant reduction in activity level. When only chemical cues were provided, tadpole activity decreased, but no significant avoidance behavior was observed. When presented with both large and small bullfrogs simultaneously, the larvae showed a stronger tendency to avoid the larger bullfrog. The results indicate that the larvae can detect predation threats via both visual and chemical cues, assess risk according to predator body size, and implement appropriate avoidance strategies.

Effective recognition of potential threats is crucial for survival in aquatic habitats, especially for amphibian larvae. As a critically endangered species, understanding how the Chinhai spiny newt (Echinotriton chinhaiensis) larvae recognize novel predators provides key scientific support for developing targeted conservation strategies. Using the American bullfrog (Lithobates catesbeiana) as a representative predator, we examined larval responses by presenting isolated visual or chemical cues, as well as visual cues from predators of differing body sizes. We measured larval avoidance and activity. Results showed that with only visual cues, larvae quickly avoided the bullfrog and significantly reduced their activity compared to controls. With only chemical cues, activity decreased significantly, but avoidance behavior did not. When both large and small bullfrogs were present, larvae avoided the larger individual significantly more. These findings demonstrate that E. chinhaiensis larvae can use visual or chemical cues to detect novel potential predators and assess risk based on size to guide their avoidance behavior. This study provides key empirical data for understanding anti-predator responses in endangered caudate amphibians and informs conservation strategies against potential threats.