Anatomical insights into fish terrestrial locomotion: a study of barred mudskipper (Periophthalmus argentilineatus) fins based on μCT 3D reconstructions

Mudskippers are a group of extant ray-finned fishes with an amphibious lifestyle and serve as exemplars for understanding the evolution of amphibious capabilities in teleosts. A comprehensive anatomical profile of both the soft and hard tissues within their propulsive fins is essential for advancing our understanding of terrestrial locomotor adaptations in fish. Despite the ecological significance of mudskippers, detailed data on their musculoskeletal anatomy remains limited. In the present research, we utilized contrast-enhanced high-resolution micro-computed tomography (μCT) imaging to investigate the barred mudskipper, Periophthalmus argentilineatus. This technique enabled detailed reconstruction and quantification of the morphological details of the pectoral, pelvic, and caudal fins of this terrestrial mudskipper, facilitating comparison with its aquatic relatives. Our findings reveal that P. argentilineatus has undergone complex musculoskeletal adaptations for terrestrial movement,..., Specimens were collected from Okinawa Island, Japan, complemented by a zebrafish acquired from a local pet shop. Following humane euthanization with 2-phenoxyethanol, they were preserved first in 10% formalin and then stored in ethanol to maintain their integrity for scanning. Before micro-CT scanning, each specimen was stained with an iodine-based solution to enhance soft tissue contrast, thereby improving scan visibility. High-resolution micro-CT scans were then performed using a Zeiss Xradia Versa 510 at the Okinawa Institute of Science and Technology, ensuring detailed visualization of each specimen's anatomical structure.
To visualize the fins' skeletal and muscular structures and their locomotion functions, we developed an animated video. This entailed exporting segmented bone and muscle models in *.stl format from segmentation software into Blender for 3D animation. We programmed the animation sequence with Python in Blender's API, showcasing the muscle groups, movements, and tra..., , # Anatomical insights into fish terrestrial locomotion: a study of barred mudskipper (*Periophthalmus argentilineatus*) fins based on μCT 3D reconstructions

This dataset comprises high-resolution micro-CT image series from five unique raw datasets representing distinct fish species: three aquatic gobies, a zebrafish, and one mudskipper, *Periophthalmus argentilineatus*. Designed to showcase the complete anatomical structures of these species, the dataset focuses on external and internal morphologies. Manual segmentation was applied to the fins (pectoral, pelvic, and caudal). The resulting visualizations can be found in the manuscript.

### Description of data and file structure

Data were obtained via microCT (Zeiss Xradia Versa 510) and are stored in DICOM format. Each species' dataset has been compressed into an RAR archive, labeled with the species name and its size (total length in millimeters). Open-source DICOM viewers can be used to access this data.

Additionally, the dataset i...