[3] Its embryos have been found to have symbiotic algae living in and around them,[4] the only known example of vertebrate cells hosting an endosymbiont microbe (unless mitochondria are considered).

Two uneven rows of yellowish-orange spots run from the top of the head (near the eyes) to the tip of the tail (dorso-lateral ranging).

[12] Vernal pools are suitable breeding sites for these amphibians as they dry often enough to exclude fish that eat the salamander eggs and larvae, while retaining water long enough to allow amphibian larvae to complete development and metamorphose into terrestrial adults.

[14] Outside of the breeding season, these salamanders spend their time in forests with well-drained soils that contain many burrows dug by small mammals.

They cross Henry Street to get to their breeding grounds, vernal pools which form on the other side of the road, an event common among amphibians and known as the Big Night.

[19] Ambystoma maculatum has several methods of defense, including hiding in burrows or leaf litter, autotomy of the tail, and a toxic milky liquid it excretes when perturbed.

Thus spotted salamanders may learn landmarks in their habitat that are reliable indicators of resource locations or provide orientation clues for migration to and from breeding ponds.

[10] Spotted salamanders feed on earthworms, slugs, snails, spiders, millipedes, centipedes, insects, algae and other invertebrates.

[28] During the majority of the year, spotted salamanders live in the shelter of leaves or burrows in deciduous forests.

However, when the temperature rises and the moisture level is high, the salamanders make their abrupt migration towards their annual breeding ponds.

[30][31] This polymorphism is thought to confer advantages in vernal pools with varying dissolved nutrient levels, while also reducing mortality from feeding by wood frog larvae.

[35] C. amblystomatis provides increased oxygen and supplemental nutrition from fixed carbon products via photosynthesis[36] and removes the embryo's nitrogenous waste (ammonia) in the egg capsule, aiding in the salamander's embryonic development and growth.

[37] The developing salamander thus metabolizes the oxygen, producing carbon dioxide (which then the alga consumes).

Photosynthetic algae are present within the egg capsule of the developing salamander embryo, enhancing growth.

However, the widely used herbicide, atrazine, has been found to significantly lower hatching success rate by eliminating the symbiotic algae associated with the egg masses.