What is "ridgehead"

n. Any of the family ''(taxlink Melamphaidae family noshow=1)'' of small, deep-sea stephanoberyciform fish.

Ridgeheads, also known as bigscales, are a family (Melamphaidae, from the Greek melanos [black] and amphi [by both sides]) of small, deep-sea stephanoberyciform fish. The family contains approximately 37 species in five genera; their distribution is worldwide, but ridgeheads are absent from the Arctic Ocean and Mediterranean Sea. Although the family is one of the most widespread and plentiful of deep-sea families, none of its members are of interest to commercial fishery.

These fish are named for their large scales and pronounced cranial ridges, as well as for their typically dark brown to black coloration. Ridgeheads are the largest and most diverse family of their order.