Eatoniella fuscosubucula

Eatoniella fuscosubucula
Holotype of Eatoniella fuscosubucula from Auckland War Memorial Museum
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Littorinimorpha
Superfamily:	Cingulopsoidea
Family:	Eatoniellidae
Genus:	Eatoniella
Species:	E. fuscosubucula
Binomial name
Eatoniella fuscosubucula Ponder, 1965
Synonyms [1]
Eatoniella (Dardanula) fuscosubuculaPonder, 1965 Eatoniella (Eatoniella) fuscosubuculaPonder, 1965

Eatoniella fuscosubucula is a species of marine gastropod mollusc in the family Eatoniellidae. ^[1] First described by Winston Ponder in 1965, it is endemic to New Zealand, found low tide and moderately deep water around the southern South Island, Stewart Island, the Auckland Islands, and around Hicks Bay in the eastern North Island.

Description

Type specimen from Curio Bay, Southland

In the original description, Ponder described the species as follows:

Shell small, broadly conical, with a large D-shaped aperture, white, but with a brown, inner chitinous layer showing through. Spire short, whorls 4, rapidly increasing, convex, sutures indistinctly false margined; body whorl large, swollen, periphery and base rounded. Aperture large, D-shaped; peristome thickened, continuous; inner lip concave, wide, expanded, columella nearly vertical, produced below. Outer lip thickened posteriorly and internally, sharp edged and strongly excavated. Colour of spire dark yellowish-brown due to chitinous layer showing through, the otherwise transparent-white. Aperture and lower part of base white.

Animal: (Portobello). Unpigmented, and typical of the genus. (Preserved material).
Operculum: D-shaped, convex, marginal areas wide, transparent, yellowish, peg curved, solid, grooved. Muscle insertion area extensive, yellow. Very weak growth lines and spirals present.

Radula: Central rather small, 2 + 1 + 2; lateral 2 + 1 + 2, with dorsal and ventral thickenings. Inner marginal with one broad cusp and a long basal process. Outer marginal finely serrate, with a broad base. The structure of the inner marginal tooth is unique in the family. ^[2]

The species measures 1.4 mm (0.055 in) by 0.95 mm (0.037 in). ^[3] It can be distinguished from E. dilatata due to its colour and larger size, and from E. verecunda due to its smaller size, larger aperture, thinner shell and brown inner layer. ^[2]

Taxonomy

The species was first described by Winston Ponder in 1965, who used the name Eatoniella (Dardanula) fuscosubucula. ^[2] The modern convention of formatting of the name without a subgenus (as Eatoniella fuscosubucula) was established by Hamish Spencer and Richard C. Willan in 1995. ^{[4] [5]} The holotype was collected by Elsie C. Smith in January 1950 from Paterson Inlet, Stewart Island. It is held by the Auckland War Memorial Museum. ^{[6] [7]}

Distribution and habitat

The species is endemic to New Zealand, found in southern South Island, Stewart Island, the Auckland Islands, and around Hicks Bay in the eastern North Island. The species is found in low tide to moderately deep water, ranging in depths between 0–55 m (0–180 ft) below sea level. ^{[2] [8]}

References

1. Eatoniella fuscosubucula Ponder, 1965 . Retrieved through: World Register of Marine Species  on 9 December 2025.
2. Ponder, W. F. (1965). "The Family Eatoniellidae in New Zealand". Records of the Auckland Institute and Museum . 6: 47–99. ISSN   0067-0464. JSTOR   42906115. Wikidata   Q58676802.
3. "Eatoniella fuscosubucula". New Zealand Mollusca. Retrieved 9 December 2025.
4. Spencer, H. G.; Willan, R. C. (1995). "The marine fauna of New Zealand: Index to the fauna. 3. Mollusca" (PDF). New Zealand Oceanographic Institute Memoir. 105: 1–125. ISSN   0083-7903. Wikidata   Q66411987.
5. Morley, Margaret S. (April 1997). "New Zealand Mollusc Name Changes from Powell (1979) to Spencer & Willan (1996)". Poirieria. 20: 13–22.
6. Blom, Wilma M. (2025). "Annotated Catalogue of Fossil and Extant Molluscan Types in the Auckland War Memorial Museum". Bulletin of the Auckland Museum . 22. doi:10.32912/BULLETIN/22. ISSN   1176-3213. OCLC   1550165130. Wikidata   Q135397912.
7. "Eatoniella fuscosubucula". Collections Online. Auckland War Memorial Museum . Retrieved 9 December 2025.
8. Powell, A.W.B. (1979). New Zealand Mollusca: Marine, Land and Freshwater Shells. Auckland: Collins. p. 92. ISBN   0002169061.