Axolotl Breeding Guide
How to breed Ambystoma mexicanum: sexing, photoperiod and cooling triggers, spermatophore transfer, eggs laid on plants, 2-3 week hatch and live-food larvae.
Overview
Ambystoma mexicanum is a neotenic salamander native to Lake Xochimilco in the Valley of Mexico and is Critically Endangered in the wild, with the wild population estimated at roughly 50 to 1,000 adults. It is widely bred in captivity. Captive animals reach maturity at about one year and show only residual seasonality, spawning year-round, with success dropping slightly from August through October.
Sexing
Males have relatively straight bodies and large glands around the cloaca (vent). Females have round, plump bodies because they are filled with eggs, and they lack the conspicuous cloacal glands; a gravid female is also noticeably wider.
Conditioning
Breeding requires a healthy, well-fed, sexually mature male and female. Photoperiod is the main lever: shortening the daily light period reduces spawning, while gradually lengthening it over weeks increases spawns. A gradual cooling of the water over days or weeks, simulating a seasonal change, can also help trigger breeding behaviour in conditioned animals.
Breeding Setup
- Cold water within the species range (about 14-18°C)
- Surfaces for spermatophore deposition such as rocks, plus plants for egg attachment
- A separate hatching container for the eggs once laid
Spawning Behavior & Trigger
The male initiates courtship by nudging the female with his snout, beginning a mating dance. He deposits spermatophores (sperm packets) on the substrate; the female follows and picks them up with her cloaca, storing the sperm in a structure called the spermatotheca. Females typically lay eggs 12 to 20 hours after mating, shedding them over a period of one to two days. The eggs are laid individually and spread about on rocks and plants rather than in a single mass.
Egg & Fry Care
Because adults will eat the eggs, they should be removed to a separate container; keep no more than about 50-100 eggs or developing embryos per container. At room temperature the eggs hatch in two to three weeks. Feed newly hatched larvae live brine shrimp daily; once larvae reach roughly 4 cm (about 1.5 inches) they can be introduced to soft-moist pellets and gradually weaned off brine shrimp.
Common Challenges
Larvae are strongly cannibalistic: larger individuals try to eat smaller ones, and crowded juveniles often lose toes or feet because they snap at anything that moves during rapid growth. Larvae therefore need ample space, separation by size, and individual feeding.