Overview
The Red-finned Blue-eye (Scaturiginichthys vermeilipinnis) is one of the smallest, rarest, and most vulnerable freshwater fish in the world. Endemic to a single property in central Queensland’s arid interior, this miniature jewel inhabits the shallow, crystal-clear pools of thermal mound springs fed by the Great Artesian Basin, surviving in water depths often scarcely covering its dorsal fin.
Biology and Physical Characteristics
Growing to barely an inch in length, Scaturiginichthys vermeilipinnis features a translucent, shimmering honey-amber body with a silver-white belly. Its crowning hallmark is the piercing, neon-electric blue irises that glow against dark organic sediments. Mature males develop spectacular dorsal, anal, and pelvic fins broadly bordered in brilliant vermilion and crimson, which they flare dramatically during courtship dances.
Behavior and Ecology
Adapted to extreme physiological conditions, the red-finned blue-eye tolerates daily water temperature swings from near freezing up to 38°C (100°F) in water pools only a few centimeters deep. They forage in small schools through submerged sedge roots, picking micro-crustaceans and insect larvae from biofilm mats. Breeding occurs nearly year-round in warm spring vents, with females depositing adhesive eggs individually onto aquatic mosses.
Conservation and Human Impact
Classified as Critically Endangered, the species has been pushed to the edge of extinction by the aggressive introduced Eastern mosquitofish (Gambusia holbrooki), which directly preys on blue-eye fry and outcompetes adults. Bush Heritage Australia, which purchased Edgbaston Reserve in 2008, has engineered innovative solar-powered fish fences, drained infested springs, and established secure quarantine spring complexes to preserve this desert treasure.
Interesting Factoid
The Red-finned Blue-eye lives in natural desert spring puddles so shallow that birds can walk right through them, yet this tiny fish has survived there for hundreds of thousands of years in the middle of the Australian Outback.
Last updated: October 2026