snail-cardiac-activity (2026)

This repository contains all data and code used in the study:

"Cardiovascular adjustments during experimentally induced retraction and locomotion in the invasive terrestrial snail Cornu aspersum (Müller, 1774)"

---

Overview

This repository provides a reproducible workflow to quantify cardiac activity and locomotion speed in the land snail Cornu aspersum.

The approach combines optocardiography based on pixel intensity changes, automated stripe tracking on a snail treadmill using TrackMate, and deep learning-based segmentation with StarDist 2D.

Signal processing and heart rate variability (HRV) analyses are implemented in R to investigate the relationship between physiological adjustments and experimentally induced behavioral states, such as retraction and locomotion.

---

Contents

• data/: Raw and processed datasets
• scripts/: R scripts for data extraction and analysis
• imagej/: ImageJ macros for pixel intensity extraction and stripe detection
• Figures/: Optocardiograms and Experimental setup images for Optocardiography

---

Reproducibility

All scripts conducted in ImageJ and R are provided in sequential order:

1. 01_heart_pixel_data_obtention.imj
2. 01_Optocardiography.R
3. 02_Extracting_HRV_metrics.R
4. 03_HR_HRV_vs_behavioral_states_analyses.R
5. 02_Macro_Trackmate_stripe_tracking.ijm
6. 04_speed_curation_and_speed_vs_heartrate_analyses.R
7. 05_Body_size_vs_HR_analyses.R

---

Requirements

R

• R (version 4.4.2)
• Required packages:
  • tidyverse
  • pracma
  • gridExtra
  • readxl
  • signal
  • writexl
  • RHRV
  • lme4
  • MuMIn
  • scales
  • lmodel2

Fiji / ImageJ

• Fiji-ImageJ
• Required plugins:
  • Java
  • CSBDeep
  • TensorFlow
  • TrackMate
  • StarDist 2D
  • TrackMate-StarDist 2D

---

Data Availability

All data and code required to reproduce the analyses are included in this repository.

---

Author

E. Alejandro Pardo-Sarmiento

---

License

• The source code in this repository is licensed under the MIT License.
• All data and figures are licensed under the Creative Commons Attribution 4.0 International License (CC BY 4.0).