# Caenorhabditis inopinata shows reduced attraction and increased head-swinging compared with C. elegans in plate chemotaxis

## TL;DR

This study compares the chemotactic behaviors of two nematode species, finding differences in odor preference and movement patterns linked to their ecological niches.

## Contribution

The study reveals novel differences in chemotactic behavior and locomotion between C. elegans and C. inopinata.

## Key findings

- C. elegans showed strong attraction to all six odorants tested, while C. inopinata responded to only three.
- C. inopinata exhibited slower movement and more head-swinging compared to C. elegans.
- C. inopinata rarely performed pirouette-like turns, indicating divergent locomotory strategies.

## Abstract

Chemoreception underpins essential animal behaviors.

Caenorhabditis inopinata

, a close relative of

C. elegans

that inhabits fig syconia, provides an opportunity to test how microhabitat shapes odor preference. Using two-point chemotaxis assays, we compared these species across six volatile odorants.

C. elegans

showed strong attraction to all odorants, whereas

C. inopinata

responded only to 2,4,5-trimethylthiazole, 2-butanone, and diacetyl. In addition,

C. inopinata

moved more slowly under both odorant and non-odorant conditions, displayed frequent head-swinging, and rarely executed pirouette-like turns. These findings indicate divergence in odor preference and locomotory behavior, suggesting differences in chemotactic navigation associated with distinct ecological contexts.