Lactophrys

Lore & Background

Lactophrys was first proposed in 1839 as a subgenus of Tetrosomus by British zoologist William Swainson. In 1865, Pieter Bleeker designated Ostracion trigonus as the type species of this taxon. Ostracion trigonus was first formally described by Carl Linnaeus in the 10th edition of Systema Naturae published in 1758, with the type locality mistakenly given as India when it is actually the Western Atlantic. The 5th edition of Fishes of the World classifies this genus within the family Ostraciidae in the suborder Ostracioidea within the order Tetraodontiformes. The etymology of Lactophrys is a compound of lactaria, meaning 'milkcow', and ophrys, meaning 'eyebrow', a reference to the spines above the eyes resembling the horns of a cow. Some fishes in this family are known as cowfishes. The genus contains three recognized species. Lactophrys trunkfishes have thick oblong bodies, most of which is encased in a carapace made up of thickened and enlarged hexagonal plate-like scales joined to each other. There are gaps in the carapace for the mouth, eyes, gill slits, fins and tail, although the bases of the dorsal and anal fins are completely encircled by the carapace. This genus does not have spines at the eyes, but sometimes has a spine at each corner of the lower rear carapace and there are no spine-like scales on the caudal peduncle. They have small mouths with fleshy lips and a row of no more than 15 moderately sized conical teeth in each jaw. The largest species is the buffalo trunkfish (L. trigonus) with a maximum published total length of 55 cm (22 in).

Reader's Guide

Lactophrys trunkfishes are significant for their unique defensive adaptations. Their entire body, except for openings for the mouth, eyes, gill slits, fins and tail, is encased in a rigid carapace of hexagonal plate-like scales, providing physical protection. Additionally, they secrete a colorless toxin from glands on their skin when touched, which is only dangerous when ingested, so divers are not immediately harmed. However, predators as large as nurse sharks can die from eating a trunkfish. The genus also has taxonomic significance: its type species was originally mislocalized by Linnaeus as India when it actually occurs in the Western Atlantic. The etymology reflects the cow-like appearance of the spines above the eyes in related species, linking the genus to the common name 'cowfishes'. With only three recognized species, Lactophrys represents a small but distinctive group within the boxfish family Ostraciidae, classified in the order Tetraodontiformes.

Did You Know?

• The type species Ostracion trigonus was described by Carl Linnaeus in 1758 with the type locality mistakenly given as India instead of the Western Atlantic.
• Lactophrys trunkfishes secrete a colorless toxin from skin glands when touched, which can kill predators as large as nurse sharks if ingested.
• The largest species in the genus, the buffalo trunkfish (Lactophrys trigonus), reaches a maximum published total length of 55 cm (22 in).