Axolotls are paedomorphic or neotenic aquatic salamanders, meaning they retain certain larval characteristics in the adult, reproductive state. They possess feathery external gills and finned tails for swimming. Laboratory animals exist in several color morphs, ranging from wild type (dark, mottled brownish-green) to albino. Axolotls reach lengths on average of 20 cm (9 inches), but can grow to more than 30 cm (12 inches) in length.
The sexes can be easily distinguished in adult axolotls. Males can be identified by their enlarged cloaca (similar to other urodeles), while females have a smaller cloaca and round, plump bodies.
Range mass: 60 to 110 g.
Range length: 30 (high) cm.
Average length: 23 cm.
Sexual Dimorphism: sexes shaped differently
- Brunst, V. 1955. The axolotl (Siredon mexicanum) I. As material for scientific research. Laboratory Investigation, 4: 45-64.