Anoplogastridae

Anoplogastridae is a small family of deep-sea fish comprising only two species, Anoplogaster cornuta and Anoplogaster brachycerca. These fish, commonly known as ogrefish or violet deep-sea fish, inhabit the mesopelagic and bathypelagic zones of the world's oceans, typically found at depths between 500 and 5,000 meters. They are characterized by their disproportionately large heads, cavernous mouths filled with long, needle-like teeth, and small, often degenerate eyes. Their bodies are generally elongated and dark in coloration, aiding in camouflage in the perpetual darkness of their environment.

The morphology of Anoplogastridae is highly specialized for their predatory lifestyle. The prominent teeth are believed to be an adaptation for capturing and holding onto prey, which likely consists of smaller fish and invertebrates. Despite their fearsome appearance, they are relatively small fish, with adults typically reaching lengths of no more than 15 centimeters. Information regarding their reproductive biology and life cycle is limited due to the challenges of studying them in their natural habitat. They are considered rare, and their distribution is widespread but patchy.