Overview
Anderson’s Salamander (Ambystoma andersoni), locally known in Mexico as the achoque de Zacapu, is an extraordinary, permanently paedomorphic amphibian endemic strictly to Lake Zacapu and adjacent spring channels in Michoacán, Mexico. Close relative of the famous axolotl, this aquatic salamander never undergoes complete metamorphosis into a terrestrial form under natural conditions, retaining its larval branchial gills and dorsal fin throughout its adult reproductive life.
Biology and Physical Characteristics
Ambystoma andersoni is instantly recognized by its robust, stocky body adorned with a distinctive leopard-like camouflage of dense black or dark chocolate blotches over a vibrant rusty-orange to golden background. Its broad, flattened head is framed by three pairs of luxuriant, deep crimson external gill rami featuring dense filaments that extract dissolved oxygen from cool volcanic spring waters. The species possesses small, webbed feet, a muscular keel-shaped tail with an expansive caudal fin, and small dark eyes without mobile eyelids.
Behavior and Ecology
This entirely aquatic salamander spends its lifecycle gliding among dense stands of submerged vegetation (such as Potamogeton and Ceratophyllum) along the lakebed. It feeds through explosive buccal suction: opening its broad mouth rapidly creates negative pressure that draws water along with crayfish, snails, and aquatic bugs directly into its pharynx. Breeding occurs throughout spring and early summer, with females affixing fertilized gelatinous clutches to the stems of submerged water plants.
Conservation and Human Impact
Ambystoma andersoni is categorized as Critically Endangered on the IUCN Red List due to its extremely restricted single-lake distribution. Threats include municipal water extraction lowering lake levels, agricultural runoff carrying agricultural fertilizers, and the introduction of predatory exotic fish species such as carp (Cyprinus carpio) and black bass (Micropterus salmoides) that consume salamander eggs and larvae. Local indigenous communities and university conservation projects now monitor water quality and run captive breeding reserves.
Interesting Factoid
Like the axolotl, Anderson’s Salamander retains its juvenile gills and never grows up to walk on land, while possessing the remarkable ability to regrow entire limbs, parts of its heart, and spinal cord tissue following injury.
Last updated: October 2026