Taxonomy
- Kingdom: Animalia
- Phylum: Mollusca
- Class: Gastropoda
- Subclass: Vetigastropoda
- Order: Lepetellida
- Family: Anatomidae
- Genus: Anatoma
- Species: Anatoma sagamiana (Okutani, 1970)
Description
Anatoma sagamiana is a minute marine gastropod, commonly referred to as a micromollusk. Adult shells typically reach a maximum height of approximately 1.5 mm. The shell is trochiform (top-shaped) with a low spire and a pronounced peripheral keel. Like other members of the family Anatomidae, it possesses a characteristic slit or foramen situated near the outer lip, which functions in exhalant water flow. The shell surface is generally smooth with fine growth lines; coloration is usually translucent to whitish. Detailed anatomical information beyond shell morphology is sparse in the published literature.
Distribution and Habitat
The species was first described from specimens collected in Sagami Bay, central Honshū, Japan. Reported occurrences are therefore confined to Japanese coastal waters, particularly the northwestern Pacific region. A. sagamiana inhabits subtidal zones, typically found on soft sediment or among fine detritus at depths ranging from 50 m to 200 m, although precise depth limits are not comprehensively documented.
Ecology
As a member of the Anatomidae, A. sagamiana is presumed to be a grazer of microalgae and bacterial films on substrate surfaces. Its small size suggests a role in the meiofaunal community, contributing to nutrient cycling within benthic ecosystems. Specific dietary studies for this species have not been published.
Reproductive Biology
Information on the reproductive strategy of A. sagamiana is not available in the scientific record. Anatomid gastropods generally exhibit separate sexes (dioecy) and release planktonic larvae, but confirmation for this species is lacking.
Conservation Status
No assessment of Anatoma sagamiana has been made by the International Union for Conservation of Nature (IUCN). The species is not known to be of commercial importance and has not been reported as threatened.
References
- Okutani, T. (1970). New and little‑known marine gastropods from Sagami Bay, Japan. Publications of the Seto Marine Biological Laboratory, 17, 113–124.
- Geiger, D. L. (2012). Monograph of the Little Slit Shells (Gastropoda: Scissurellidae, Anatomidae, Larocheidae, Depressizonidae, Sutilizonidae, Temnocinclidae). Volume 1: Anatomidae. Santa Barbara Museum of Natural History Monographs, 7, 1–100.
- WoRMS (World Register of Marine Species). Anatoma sagamiana (Okutani, 1970). Accessed April 2026.
Note: While the general characteristics of the genus Anatoma and family Anatomidae are well documented, specific data on A. sagamiana (e.g., detailed anatomy, exact depth range, and life history) remain limited.