eLasmobranc Dataset: An Image Dataset for Elasmobranch Species Recognition and Biodiversity Monitoring

This repository contains version 1.0 of the eLasmobranc Dataset, an image dataset designed to support computer vision tasks and scientific analysis focused on the identification and study of elasmobranch species (sharks and rays).

The dataset was developed within the framework of the e-Lasmobranc project at the University of Alicante and is conceived as an open, continuously evolving resource. It results from the integration of external sources (public datasets and web platforms) with original material collected by the research group through collaborations and fieldwork.

Version 1.0 of the dataset includes a total of 1,117 images, corresponding to 807 distinct individuals, belonging to seven target elasmobranch species: Galeorhinus galeus, Galeus melastomus, Leucoraja naevus, Mustelus mustelus, Oxynotus centrina, Scyliorhinus canicula and Torpedo marmorata.

The images originate from both external Creative Commons-licensed sources and original acquisitions. All images are distributed under licenses that permit their use; however, the specific terms and attribution requirements of each license must be respected. The dataset curation process was structured in two phases:

1. Application of basic criteria (minimum visual quality, inclusion of target species, sufficient specimen visibility, and removal of duplicates).
2. Expert validation, discarding images with identification errors or insufficient morphological features.

Most images were captured out of water in order to minimize visual distortions, except for a small number of duly justified cases.

For each image, the following metadata fields were standardized:

• Observation date (DD-MM-YYYY format)
• Country and area of origin
• Original source and license

The repository is organized around a main directory containing the visual data and a set of accompanying files that provide taxonomic, attribution and citation information:

data/
This directory contains independent subfolders for each species. Each subfolder includes images identified by a unique ID encoding the species, individual, and image number (e.g., GG_001_01), together with a species-specific CSV file storing the associated metadata.

In addition, the repository includes:

• Elasmobranch taxonomic keys.xlsx, a descriptive document summarizing the considered species and their characteristic morphological traits.
• attributions.csv, which provides detailed information about the origin, license and attribution of each image.
• citations.txt, containing the citation references for all data sources used.

Scope and intended use

The eLasmobranc Dataset is conceived as a continuously evolving resource. Future versions, expected within an approximate one-year timeframe, will incorporate new images, species, and capture contexts, progressively increasing its representativeness and scientific utility.

Acknowledgements

This research was funded by the eLasmobranc project, which is developed with the collaboration of the Biodiversity Foundation of the Ministry for Ecological Transition and the Demographic Challenge, through the Pleamar Programme, and is co-financed by the European Union through the European Maritime, Fisheries and Aquaculture Fund.

How to cite

If you use the eLasmobranc Dataset in your research, please cite it as follows:

Beviá-Ballesteros, I., Jerez-Tallón, M., Aranda-Garrido, N., Abel-Abellán, I., Antón-Linares, I., Azorín-López, J., Saval-Calvo, M., Fuster-Guilló, A., and Giménez-Casalduero, F. (2026). eLasmobranc Dataset: An Image Dataset for Elasmobranch Species Recognition and Biodiversity Monitoring. arXiv preprint arXiv:2603.10724