Anachis facula

Anachis facula is a species of sea snail in the family Columbellidae, the dove snails.^[1]

Anachis facula
Shell of Anachis facula (holotype at MNHN, Paris)
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Family:	Columbellidae
Genus:	Anachis
Species:	A. facula
Binomial name
Anachis facula K. Monsecour & D. Monsecour, 2016

Taxonomy & Discovery

Anachis facula was first described in 2016 by K. Monsecour & D. Monsecour in the volume Tropical Deep‑Sea Benthos 29, stemming from specimens collected during the IRD–MNHN deep-water expeditions around New Caledonia.^[2] It falls within the genus Anachis, which phylogenetic analyses show to be polyphyletic; although Columbellidae as a whole is confirmed as a monophyletic group.^[3]

Morphological Description

Shell size: Grows up to 3.6 mm in length

Shape & Sculpture: While specific details for A. facula are found in the original description (not readily accessible online), related Anachis species are small, elongate-ovate, with finely sculptured surfaces, denticulate outer apertures, and a short siphonal canal typical of columbellid snails.^[4]

Radula & Soft Anatomy: Though not described for A. facula, columbellids typically possess radulae suited for carnivory, including lateral teeth with basal and distal cusps^[5]

Habitat & Distribution

Geographic location: Confined to the waters off New Caledonia in the Southwest Pacific .

• Bathymetric range: Recorded from 520–570 m depth—placing it in the bathyal zone alongside other recently described Anachis species such as:
  • A. incisa (4.5 mm; 516–613 m)
  • A. proclivis (4.4 mm; 435 m)
  • A. pinguis (2.6 mm; 285–600 m)
  • A. constrictocanalis (4.1 mm; 310–601 m) These all derive from the same benthic sampling programs .^[6]

Ecology & Behavior

Feeding ecology: Like other columbellids, likely functions as an epibenthic carnivore or scavenger, feeding on small invertebrates or organic detritus on the seafloor^[7]

Habitat: Inhabits continental slope or bathyal habitats (520–570 m), typically characterized by soft sediments and pressure-adapted fauna collected during IRD/MNHN expeditions^[8]

Phylogenetics & Systematics

Anachis is shown to be polyphyletic, meaning species attributed to this genus do not all share a recent common ancestor; this was determined via analysis of multi-gene datasets involving Colombian species, including Anachis representatives^[9]

Widespread anatomical variation within Columbellidae—such as radula and reproductive organ differences—suggests potential for taxonomic revision as new genetic data emerges

Significance & Conservation

• Represents part of the bathyal gastropod biodiversity discovered via deep-sea survey efforts, of which over 1,000 mollusc species were recorded in New Caledonia and more than 600 were new to science .
• While the conservation status is unassessed, documenting such species improves baseline biodiversity knowledge essential for deep‑sea ecosystem protection and climate impact studies.

Distribution

This species occurs off New Caledonia at depths between 520 m and 570 m.