''Haliotis dalli'', common name the Galápagos abalone, is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of sea snail, a marine gastropod

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in the

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Haliotidae ''Haliotis'', common name abalone, is the only genus in the family Haliotidae. This genus once contained six subgenera. These subgenera have become alternate representations of ''Haliotis''. The genus consists of small to very large, edible, ...

, the abalones. It has been confused in the past with '' Haliotis pourtalesii'' Dall, 1881, that occurs off Florida. This was due to the destruction of the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

of ''Haliotis pourtalesii'' in the

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of 1871. ;Subspecies: * ''Haliotis dalli dalli'' Henderson, 1915 * ''Haliotis dalli roberti'' McLean, 1970 (synonym: ''Haliotis roberti'' McLean, 1970)

Description

The description given by W.H. Dall in 1889 of ''Haliotis pourtalesii'' matches exactly the description used in 1915 by J.B. Henderson in describing ''Haliotis dalli'', with W.H. Dall agreeing. "The small shell has a pale brick-red color, with white dots on some of the spirals. The shell is rather elevated, with about two and a half whorls. The

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is small and prominent. It contains about 25 holes of which five remain open. The margins of these are rather prominent. Outside the row of holes the usual sulcus is strongly marked. About midway from the suture to the lines of holes is a raised rib, rather obscure, but differing in different individuals and corresponding to an internal sulcus. Between the central ridges and the suture there are no undulations or transverse ridges of consequence. The

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consists of well marked, rather flattish, spiral, close-set threads, sometimes with a single finer intercalary thread, overlaid by smaller rather compressed transverse ridges, in harmony with the incremental lines. On top of the spirals the ridges bulge like the threads of worsted on canvas embroidery. The

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is situated well forward and with subvertical sides. The interior surface is pearly. The coil of the spire is rather close and the margin of the columella is flattened." This species differs from most other ''Haliotis'' species by having a very narrow lateral tooth in the radula and having concentric rings on the cephalic tentacles. It shares these characteristics only with ''Haliotis roberti'' (which has become the subspecies ''Haliotis dalli roberti'', (McLean, 1970)) and '' Haliotis pourtalesii'' and the subspecies ''Haliotis pourtalesii aurantium'' (Simone, 1998)Geiger, D. L. 1998. ''Recent genera and species of the family Haliotidae (Gastropoda: Vetigastropoda).'' The Nautilus 111: 85–116.

Distribution

This species occurs in the Pacific Ocean off the Galapagos Islands and Western Colombia.

References

* Geiger D.L. & Owen B. (2012) ''Abalone: Worldwide Haliotidae''. Hackenheim: Conchbooks. viii + 361 pp.

External links

* {{Taxonbar, from=Q3139440 Gastropods described in 1915 dalli