Emmelichthyidae

 Emmelichthyidae is a small family of small to medium-sized marine ray-finned fishes known commonly as rovers, bonnetmouths or rubyfishes.

Taxonomy
Emmelichthyidae was first proposed as a taxonomic grouping in 1867 by the Cuban naturalist Felipe Poey. The 5th edition of Fishes of the World classifies the family in the suborder Sciaenoidei, alongside the drum family Sciaenidae, in the order Acanthuriformes. Other authorities classify the Emmelichthyidae and the Sciaenidae as incertae sedis within the series Eupercaria. The Catalog of Fishes retains this family within the Acanthuriformes but does not recognise the suborder Sciaenoidei. The family was formerly regarded as being much larger, including a wide range of plankton-eating fish, but most of the genera previously included were discovered to be unrelated examples of parallel evolution, and were moved to other families.

Genera
The family Emmelichthyidae contains the following three genera:

Characteristics
Emmelichthyidae are streamlined fishes with much of their heads and bodies covered in small ctenoid scales which also extend on the base of both the dorsal and anal fin. They have distensible jaws and large mouths with the maxillae widely expanded and clearly scaled. The lower jaw protrudes slightly and the teeth highly reduced or there are none at all. The rear margin of the operculum has a pair of flat spines. The dorsal fin is long and may be divided into 2 fins with the anal fin being similar and opposite the soft-rayed portion of the dorsal fin. The caudal fin has a deep fork. Typically these fish do not exceed 50 cm in length.

Distribution
Emmelichthyidae is distributed in tropical and warmer temperate waters in the Indo-Pacific, southern Pacific, eastern Atlantic, and Caribbean Sea.