''Phanerolepida transenna'' is a rare

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 ...

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 Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

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 ...

Turbinidae, the turban snails.Bouchet, P. (2012). ''Phanerolepida transenna'' (Watson, 1879). Accessed through:

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

at http://www.marinespecies.org/aphia.php?p=taxdetails&id=580239 on 2012-09-01 It is the sole living species in this genus.

Description

The small, high, carinated shell has a sturdy turbinate shape. It is inflated on the base, thin, and sculptured. Its color pattern is yellowish with small ruddy spots. The

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 of spirals with quasi unique net-like, finely incised rhombohedral patterns. A similar (but not identical) surface pattern appears in '' Homalopoma granuliferum'' Nomura & Hatai, 1940 (family Colloniidae). Close to the suture is a row of disconnected beads. Between this and the carina are three rows of appressed beads, of which the highest is the weakest. These four rows are parted from one another by furrows, each of which is a little broader than the thread above it. The carina also consists of a row of appressed beads. It is stronger than the other beads both in breadth and height, and the furrow above it is a little broader and deeper than the rest. On the base are seven rows of appressed beads of nearly equal width and distance from one another; the first joins the outer lip, the central row twines up the pillar. These rows of beads make their appearance on the second

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 ...

, and on all the upper whorls more than 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 ...

. The carina is sharply expressed by a constriction above and below it. Longitudinals—the whole surface is crossed obliquely by not quite contiguous threads, which are almost as strong as the spirals. Between the threads are narrow, deep, long pits. Each alternate thread is crowned by a bead at the suture. Color: the surface is dull and rough, yellowish, sparsely spotted on the spirals with a ruddy brown, which is almost crimson on the infra-sutural beads. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

is high and conical, the whorls being barely rounded. The apex is small but flattened, the embryonic 1 whorls scarcely project. The seven whorls increase in size in a regular manner. they are almost flat, while the body whorl alone is slightly convex, rounded, and carinated at the periphery and tumid on the base, in the center of which is a most minute umbilical chink. The suture is deeply and squarely impressed below the carina. 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 slightly oblique, squarish, and nacreous. The outer lip is very thin, very slightly descending, and drawn in a little horizontally at its junction with the body, and then well rounded in its whole sweep to the point of the columellar lip, near which it is externally crenulated by the ends of the basal threads. The columella is short, straight, slightly tubercled on its inner side, hardly toothed in front, and still less angulated at its junction with the outer lip. The columellar lip is very thin, slightly excavated longitudinally, and reverted on the minute umbilicus, which it almost wholly conceals. Behind it is a very narrow furrow. The thin operculum has a concave-convex shape with no visible external spirals. The callus is extensively developed.Carole S. Hickman, ''Review of the Bathyal Gastropod Genus Phanerolepida (Homalopomatidae) and a Description of a New Species from the Oregon Oligocene''; The Veliger v.15 (1972-1973)
/ref>

Distribution

This deep-water species occurs off the

Philippines The Philippines (; fil, Pilipinas, links=no), officially the Republic of the Philippines ( fil, Republika ng Pilipinas, links=no), * bik, Republika kan Filipinas * ceb, Republika sa Pilipinas * cbk, República de Filipinas * hil, Republ ...

and

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

between 600 m and 800 m.

References

External links

World Register of Marine Species
{{Taxonbar, from=Q7180444 transenna Gastropods described in 1879