Halystina

Halystina is a genus of sea snails, specifically marine gastropod mollusks in the family Pseudomelatomidae. These snails are characterized by their elongated, spindle-shaped shells, which often exhibit a cancellate sculpture, meaning they have intersecting axial and spiral ridges. The aperture of the shell is typically narrow and elongated, with a distinct siphonal canal at the base. The operculum, a shell-like lid that closes the aperture, is usually ovate or pyriform.

The distribution of Halystina species is primarily found in the Indo-Pacific region. They inhabit a range of marine environments, from shallow subtidal zones to deeper waters, often found on sandy or muddy bottoms. The diet of Halystina species is believed to consist of small invertebrates, with some species potentially being predatory.

The taxonomic classification of Halystina has undergone revisions over time. Historically, some species now placed in Halystina were classified under other genera. Ongoing research into the morphology and genetic makeup of these snails continues to refine our understanding of their evolutionary relationships. While not of significant commercial importance, Halystina contributes to the biodiversity of marine ecosystems in its geographical range.