Sparktail eggs are found in the rivers and tributaries of Ark. These eggs are known to be extremely light, so they often float with the river currents. Sparktail mothers don't seem to care much; they just lay the egg and leave. Sometimes the river currents in Ark reverse and cause Sparktail eggs to run with an underground river beneath the Egg Cave. Sparktail eggs continue to follow this river, until they reach a small pool of water that surfaces at the Egg Cave.
Sparktail are most commonly found in Ark Bay just outside of Ark City. They are easily recognizable because of their shiny appearance; when a ray of sunlight hits them, they are instantly illuminated. It's weird, yet glorious to watch the moon rise on Ark shores, because Sparktail are bioluminescent and cause Ark Bay to glow.