Coelotrochus chathamensis

Classification (WoRMS)

Full classification as recorded by WoRMS: Kingdom: Animalia · Phylum: Mollusca · Class: Gastropoda · Order: Trochida · Family: Trochidae · Genus: Coelotrochus.

Accepted name: Coelotrochus chathamensis · Authority: (F. W. Hutton, 1873) · Taxonomic status: accepted · AphiaID: 598199.

Synonyms and superseded combinations recorded for this taxon: Calliostoma aucklandicum E. A. Smith, 1902; Polydonta chathamensis F. W. Hutton, 1873; Thoristella chathamensis (F. W. Hutton, 1873); Thoristella chathamensis benthicola H. J. Finlay, 1926; Thoristella chathamensis cookiana A. W. B. Powell, 1934; Trochus (Infundibulum) oppressus var. dunedinensis Suter, 1897; Trochus oppressus var. dunedinensis Suter, 1907.

Source: World Register of Marine Species (WoRMS) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=598199 (CC BY 4.0). Accessed 2026-09-23.

Biology and life history (SeaLifeBase)

Measured values published by SeaLifeBase for Coelotrochus chathamensis. Only fields the database actually holds for this species are shown; these are database values, not aquarium guidance.

Habitat zone: benthic · Aquarium trade: never/rarely.

SeaLifeBase notes: Found under stones at low tide (Ref. 89452).

Source: SeaLifeBase species summary (SpecCode 153042) — https://www.sealifebase.se/summary/Coelotrochus-chathamensis.html (CC BY-NC 3.0 — non-commercial use only). Accessed 2026-09-23.

Distribution and occurrence records (GBIF)

333 georeferenced occurrence records for Coelotrochus chathamensis are published through GBIF from 1 countries or marine areas. The map above plots 38 distinct locations from a sample of 333 records, omitting 13 inland records that carry an institution's coordinates rather than a collection site; it shows where the species has been observed and reported, not a modelled range.

Most records by country or area: New Zealand (333).

Marine regions with a valid WoRMS distribution record: New Zealand Exclusive Economic Zone.

Source: GBIF Occurrence Search (taxonKey 6787780) — https://www.gbif.org/occurrence/search?taxon_key=6787780&has_coordinate=true (records CC0 / CC BY); WoRMS distribution records (MarineRegions) — https://www.marinespecies.org/aphia.php?p=taxdetails&id=598199 (CC BY 4.0); Natural Earth 110m basemap — https://www.naturalearthdata.com/ (public domain). Accessed 2026-09-23.

Description and natural history (Wikipedia)

The length of the shell varies between eight mm and 10 mm. The small shell has a conical shape, the sides are straight or slightly convex. The angle of the spire is 70°. The five, rarely six, whorls are flat with an elevated upper edge, and, together with the base, spirally striated. The pointed protoconch is regularly conical, and consists of about two whorls. These are not marked off from the succeeding whorl. This one is, smooth, with two or three spiral red bands. The last two whorls increase rapidly in size. They are flat to slightly convex above, concave below before reaching the strong and prominent cingulum. The body whorl has a distinct peripheric keel.

The sculpture consists of five to six low spiral threads, the lower and upper margins much elevated, especially the former. They are crossed by broad nodulous radiate ribs, which, however, do not extend over the lower half of the whorl. These ribs are often obsolete. The suture is superficial, with a nodulous border below. The false umbilicus is narrow and not very deep. The oblique aperture is rhomboidal. The outer and basal lip are a little convex, forming a sharp angle where they meet.

The oblique columella is slightly concave. It has an almost imperceptible posterior fold, but the anterior portion is nearly smooth. The axial cavity is small and smooth. The color of the shell is white, buff with pink or oblique brownish purple stripes or spots. The flat base of the shell is white with interrupted pink, subequal spiral lines.

Coelotrochus chathamensis is endemic to New Zealand and occurs the Chatham Islands, Southern North Island, Stewart Islands and the Auckland Islands.

Source: Wikipedia: Coelotrochus chathamensis — https://en.wikipedia.org/wiki/Coelotrochus_chathamensis (CC BY-SA 4.0). Accessed 2026-09-23.