Ultrasound description of the coelomic cavity of the axolotl (Ambystoma mexicanum) in a healthy population: a pilot study

Abstract

Axolotls (Ambystoma mexicanum) are widely studied for human medical research. While critically endangered in wildlife, they have also become popular as household pets. Although they have been kept in captivity for over a century, coelomic organs description of their anatomy remains limited, and this species presents significant variations compared to other amphibians. Ultrasound is a non-invasive, painless medical imaging technique, well-suited for investigating internal organs or other structures. This study describes ultrasound appearance of the axolotl coelomic cavity. Identification, localization and parenchyma description of major organs are reported on 28 neotenic axolotls by using frequencies between 7 to 15 MHz. Results were confirmed by comparing ultrasound and necropsy on one male and one female. The heart, lung surface, liver and reproductive tracts were observed. Measurements with confidence intervals were calculated for spleen, kidneys, testicles, gastric wall, gallbladder, and pylorus. Hyperechoic millimetric particles in gallbladder or ascites were occasionally detected. Pancreas and bladder could not be observed. The outcomes of this research include the production of images combined in an atlas. The experiment showed a repeatable and easily accessible protocol for anatomy-morphological assessment in axolotl medicine and is the necessary step before identification of lesions.