Triacanthodinae is a subfamily of marine ray-finned fishes belonging to the family Triacanthodidae, the spikefishes. This subfamily comprises nine genera and a total of nineteen species and all, except one species, are found in the tropical and subtropical waters of the Indo-Pacific. The exception is found in the western Atlantic Ocean.
Triacanthodinae is the nominate subfamily of the family Triacanthodidae, a taxon name first proposed by the American biologist Theodore Gill in 1862.[1] In 1968 the American ichthyologist James C. Tyler proposed that the family Triacanthodidae be split into two subfamilies, establishing the subfamily Hollardiinae for the genera Hollardia and Parahollardia.[2] The 5th edition of Fishes of the World classifies the family Triacanthodidae in the suborder Triacanthoidei along with the family Triacanthidae, the triplefins.[3]
Triacanthodinae is a name based on its type genus Triacanthodes. which appends -odes, meaning "is similar to", onto Triacanthus, a genus these fishes were thought to be clsoley related to.[4]
Triacanthodinae contains the following genera and species:[2]
Triacanthodinae spikefishes are distinguished from the taxa in the subfamily Hollardiinae by the possession of a low, thin crest on the front of the supraoccipital and in having a flat, horizontal basin-like projection to the plevic bone.[2] The largest species in the subfamily is Halimochirurgus alcocki with a maximum published standard length of while the smallest is Atrophacanthus japonicus which has a maximum published standard length of .
Triacanthodinae spikefishes are mainly found in the Indo-Pacific region, with one species Johnsonina eriomma in the Western Atlantic Ocean. These benthic fishes are found in deeper water.[3]