Regeneration of the Caudal Fin of Atractosteus tropicus The Tropical Gar

Abstract

Abstract Bacground: The tropical gar (Atractosteus tropicus) belongs to the lepisosteidae family, with habitats from southeast Mexico to the south of Costa Rica. Due to its phylogenetic position, slow evolution speed (base substitution), dense genetic map, gene similarity with human beings, and ease of cultivation in laboratories, this organism provides a unique link between tetrapods and the biomedical models of teleosts. This fish is a taxonomic sister group to teleosts such as the zebrafish (Danio reiro), which possesses a high regenerative ability; however, it is not known if the tropical gar shows this same regeneration ability and whether it is similar or identical. Results This study aims to demonstrate the regeneration process of the caudal fin through skeletal and histological staining. For this reason, several juvenile organisms were studied for about two months, fed with artemia (Artemiidae), and anesthetized by immersion with 1% eugenol to carry out the amputation of the caudal fin and obtain the daily samples at different time points or dpa (days post-amputation) dpa. The skeleton was stained with alcian blue and alizarin red to observe the regeneration of the fin by the growth of new cartilage. Histological staining with hematoxylin and eosin was also carried out. Histological sections were made from each sample and stained, observing the regeneration on the uppermost part of the amputation. Conclusions The findings show are remarkable ability for caudal fin regeneration in juvenile individuals from the tropical Gar. Since Garfish are the phylogenetically sister group of teleost fish it offers an opportunity for future research in tissue regeneration.