''Phymorhynchus cingulatus'', common name the ringed turrid, 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
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
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...
in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
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). . 39 ...
.
Description
The length of the shell attains 73 mm, its diameter 30 mm.
The large, fusiform shell is of a rich reddish-brown. It is deepest on the
columella, with a closely adherent, very thin, polished epidermis. The shell contains seven
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, without the
protoconch
A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...
, which is lost in the specimen, while the outer coat of the apical whorls is much eroded. The whorls are full and rounded. The suture is distinct, not appressed or channeled. The transverse
sculpture
Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...
consists only of fine inconspicuous lines of growth. The spiral sculpture consists of two sorts: first, a fine, sharp, slightly irregular striation, which covers the whole surface; secondly, of revolving elevated cinguli, of which three on the periphery are more widely and deeply separated and more elevated than the others. These three have interspaces equal to or wider than themselves. On 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 ...
in front of the periphery the cinguli are flat-topped little elevated wide bands with narrower interspaces, this sculpture becoming obscure toward 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 ...
. Above the periphery is one well-marked cingulum slightly turretting the whorl which inclines from it to the suture in a flattened manner. The
aperture
In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane.
An opt ...
is pointed in front, wider behind. The columella is simple, perfectly straight, anteriorly attenuated. The body and columella show a thin dark brown glaze. The outer
lip is very thin, sharp, crenulated by the outside sculpture, which also grooves the interior. The notch is shallow, wide; fasciole hardly visible; canal short, wide, hardly differentiated and straight.
Dall, W.H. (1890) Scientific results of explorations by the U.S. Fish Commission Steamer Albatross. No. VII – Preliminary report on the collection of Mollusca and Brachiopoda obtained in 1887–88. Proceedings of the United States National Museum, 12, 219–362, pls. 5–14
Distribution
This marine species occurs off Ecuador
Ecuador ( ; ; Quechua: ''Ikwayur''; Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechua: ''Ikwadur Ripuwlika''; Shuar: ''Eku ...
and the Galapagos Islands.
References
* Finet, Y. (1991) The Marine Mollusks of the Galapagos Islands. In: Galápagos Marine Invertebrate. Taxonomy, Biogeography, and Evolution in Darwin's Islands. Plenum Press. New York and London, p. 253-280.
* Keen, A.M. (1958) Sea Shells of Tropical West America. Stanford University Press, Palo Alto, 1st edition, 624 pp.
* Powell A. W. B. (1966). The molluscan families Speightiidae and Turridae. An evaluation of the valid taxa both Recent and fossil, with lists of characteristic species. Bulletin of the Auckland Institute and Museum 5: 1-184
* Finet, Y. (2001) The marine mollusks of the Galapagos Islands: a documented faunal list. Editions du Muséum d' Histoire naturelle, Genève, 237 pp
External links
*
Gastropods.com: ''Phymorhynchus cingulatus''
Matthew J. James (2013), Galápagos Marine Invertebrates
{{DEFAULTSORT:Phymorhynchus Cingulatus
cingulatus
Gastropods described in 1890