''Pseudodaphnella alternans'' is a
species of
sea snail
Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...
, a marine
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusk in the
family Raphitomidae
Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". '' Malacologia'' 47(1-2). . 3 ...
.
[MolluscaBase (2019). MolluscaBase. Pseudodaphnella alternans (E. A. Smith, 1882). Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=596309 on 2019-11-11]
Description
The length of the shell attains 6 mm, its diameter 2.5 mm.
The ovate shell contains probably 7
whorl
A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs).
Whorls in nature
File:Photograph and axial plane floral ...
s (the
apex is missing). The 5 remaining whorls are slightly convex and contain 12 longitudinal ribs (continuing to the base of the body whorl). The spiral lirae form small nodules when crossing the ribs (4 in the penultimate whorl, 10 in the body whorl) and are very cancellate. The
aperture is very narrow and measures about 3/7 of the total length. The outer
lip is incrassate with about 6 denticules within and is somewhat sinuate at the top. The
siphonal canal
The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...
is narrow, short and truncate.
The colouring of this species is very remarkable. In the upper whorls the ribs are alternately brown and white, and the lowest liration, which is in conjunction with the suture and encircles the middle of the
body whorl
The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk.
In gastropods
In gastropods, the b ...
, is wholly white. The fifth and sixth lirations on the last, reckoning from the suture, are rather far apart, and the longitudinal ribs between them are uniformly brown.
Smith E.A. (1882). Diagnoses of new species of Pleurotomidae in the British Museum. Annals and Magazine of Natural History. ser. 5, 10: 296-306
/ref>
References
External links
*
Kilburn, R. N. (2009). Genus Kermia (Mollusca: Gastropoda: Conoidea: Conidae: Raphitominae) in South African Waters, with Observations on the Identities of Related Extralimital Species. African Invertebrates. 50(2): 217-236
Li B.-Q. [Baoquan
& Li X.-Z. [Xinzheng">aoquan">Li B.-Q. [Baoquan
& Li X.-Z. [Xinzheng(2014) Report on the Raphitomidae Bellardi, 1875 (Mollusca: Gastropoda: Conoidea) from the China Seas. Journal of Natural History 48(17-18): 999-1025]
{{DEFAULTSORT:Pseudodaphnella alternans
Pseudodaphnella, alternans
Gastropods described in 1882