Hydrofoneilla

Hydrofoneilla is a rare and fascinating genus of deep-sea snails belonging to the family Raphitomidae, part of the larger clade of marine gastropods. These small, elongated mollusks are primarily found in the abyssal and hadal zones of the Pacific Ocean, often inhabiting depths exceeding 2,000 meters. Their name derives from the Greek words *hydro-* (meaning water) and *phoinos* (purple or reddish), though the exact etymology of *Hydrofoneilla* itself is less clear, possibly referencing their translucent or faintly colored shells.

Hydrofoneilla species are characterized by their slender, conical shells, typically measuring between 1 and 3 centimeters in length. The shells are often semi-transparent, allowing the soft body to be partially visible, and may exhibit subtle coloration ranging from pale yellow to reddish-brown. Their operculum—a hard structure used to seal the shell opening—is well-developed, aiding in protection against predators and environmental pressures at extreme depths.

These snails are believed to be scavengers or detritivores, feeding on organic matter that settles to the ocean floor. Their ecological role remains poorly understood due to the challenges of studying deep-sea environments. Hydrofoneilla species are not well-studied compared to more common marine gastropods, and only a few species have been formally described, including *Hydrofoneilla pacifica* and *Hydrofoneilla profundicola*.

Like many deep-sea organisms, Hydrofoneilla is highly sensitive to changes in its habitat, such as pollution, deep-sea mining, or climate-induced shifts in ocean chemistry. Their limited distribution and specialized adaptations make them indicators of deep-sea health, though their conservation status is not yet assessed due to insufficient data. Research on this genus continues to rely on deep-sea expeditions and advances in remote imaging technology.