The cornetfishes are a small family Fistulariidae of extremely elongated fishes in the order Syngnathiformes. The family consists of just a single genus Fistularia with four species, found worldwide in tropical and subtropical marine environments.
Ranging up to 200 cm in length, cornetfishes are as thin and elongate as many eels, but are distinguished by a very long snout, distinct dorsal and anal fins, and a forked caudal fin whose center rays form a lengthy filament. The lateral line is well-developed and extends onto the caudal filament.
They generally live in coastal waters or on coral reefs, where they feed on small fishes, crustaceans and other invertebrates.
Cornetfish are of minor interest for fishing, and can be found in local markets within their range.