Spergo Glandiniformis
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''Spergo glandiniformis'' is a
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...
, a marine
gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000  extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
in the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Raphitomidae Raphitomidae is a Family (biology), family of small to medium-sized sea snails, marine (ocean), marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families" ...
.


Description

The length of the shell reaches 40 mm. (Original description) The large, slender shell is glandiniform, with a typical brown sinusigera
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 " ...
of 3½
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). In nature File:Photograph and axial plane floral diagra ...
s, followed by 8 normal whorls. The color is pale madder brown, more or less zoned in harmony with lines of growth, and with a peripheral and basal spiral paler band feebly indicated. The
columella Lucius Junius Moderatus Columella (, Arabic: ) was a prominent Roman writer on agriculture in the Roman Empire. His in twelve volumes has been completely preserved and forms an important source on Roman agriculture and ancient Roman cuisin ...
in the young is stained with a darker brown, or pinkish white in the full-grown shell. 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. Spire ...
is rather pointed. The apical whorls are sculptured with incised spiral grooves below the shoulder and with numerous small oblique riblets over which the grooves run. The space between the shoulder and the suture behind it is slightly impressed, smooth, or crossed by distant low sharp wrinkles, very narrow and not corresponding to the ribs. All this
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 ...
becomes rapidly obsolete, and on the greater part of the shell the sculpture is confined to silky lines of growth, faint traces of obscure spiral lines, and a few feeble narrow threads on the base and 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 i ...
under a pale thin epidermis. The
body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...
is compressed at the periphery, as in ''Glandina parallela'' (synonym of
Euglandina rosea ''Euglandina rosea'', the rosy wolfsnail or cannibal snail, is a species of medium-sized to large predatory air-breathing land snail, a carnivorous terrestrial pulmonate gastropod mollusk in the family Spiraxidae.MolluscaBase eds. (2020). Mollus ...
(Férussac, 1821) ) giving the body whorl a subcylindric aspect. The suture is appressed. The
aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...
is long, rather narrow, internally smooth, and with very little callus on the columella or body. The outer
lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...
is sharp, emarginate before and behind and arched forward in the middle. The columella is obscurely thickened behind, attenuated anteriorly, as long as the siphonal canal, straight, but slightly twisted. The siphonal canal and anal emargination are wide and shallow. The animal is of a yellowish color. The columellar muscle is attached very deeply within the shell. The foot is strong. In the alcoholic specimen it is transversely wrinkled below, wrinkled and more or less granose at the sides above, the posterior end obtusely pointed. Anteriorly it is wider, with the lateral angles produced and the anterior margin double. The rostrum is quite peculiar, dilate, and squarely cut off at the end, which exhibits a flat, circular face concentrically wrinkled, with a very large rounded mouth, the edge of which is deeply radially wrinkled, giving it a papillose aspect externally. The horizontal line joining the bases of the tentacles will pass below the central axis of the rostrum, which is also distinctly constricted behind the tentacles. The surface of the rostrum is smooth, its dorsal line arched. The tentacles are short, stout, transversely wrinkled, and distinctly larger distally. There is a slight enlargement near their bases, where a small, black pigmented eyespot is clearly visible on both. There is no trace of an operculum or opercular lobe, nor any epipodial processes. Raising the mantle, which has a slightly thickened, smooth edge, we find, rather far back, the verge, which consists of a rather stout, recurved basal portion, above which it is constricted, the remainder being more slender, subcylindrical, slightly enlarged distally, but beyond this tapering to a point. The organ is smaller in proportion to the size of the animal than in most Pleurotomidae. Above, on the dome of the mantle, is attached the rectum, with an evenly tapered adherent termination and a longitudinally wrinkled subcylindrical lumen. To the left of this the muciparous gland and kidney cover a broad strip of the mantle. Farther to the left we find a ctenidium composed of a single series of leaflets of the ordinary type, succeeded on the left by a well-developed Sprengel's organ, as usual, of a dark-olive color. The siphon, which is closely adjacent, is of very substantial tissue, with an external tinge of olive brown. It presents nothing unusual. Internally the anatomy offers several points of interest. Within the oral orifice is an immense " crop " or pharynx (22 mm. long in the specimen examined), which, from the deep longitudinal wrinkles of its surface, is evidently capable of being greatly distended. It has a smooth, rather tough, lining without any horny appendages, and is lubricated by the discharge of several muciparous glands of rather small size. Its inner end is abrupt, and at the left of the middle line is the opening of the oesophagus, very much smaller than the pharynx in diameter. The proboscis proper is very short (in spirits), only about one-sixth as long as the pharynx, and therefore, unless capable of great extension in the living state, probably can not be extruded from the oral opening. The pharynx of the specimen examined was partly filled with a dark-greenish matter, apparently of a mucous character, which showed no traces of organization, leading to the supposition that the pharynx was adapted to the engorgement of large masses of protoplasmic matter rather than the pursuit of living animals of a higher order, as in most Toxoglossa. The modification is analogous to that by which '' Turcicula'', a derivative from a phytophagous stock, has become adapted to gorging itself with large quantities of foraminifera, algae being absent from its habitat. The tooth sac opens near the end of the proboscis, but being filled with coagulated mucus, and extremely reduced in size by degeneration, could not be discovered until the mass was boiled in caustic potash in the hope of finding some traces of teeth. The teeth are set regularly in a single row on each side of an epithelial strip of rather horny (not chitinous) consistency, the points of the teeth inclined obliquely inward and overlapping a little. The width of the
radula The radula (; : radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters ...
from base to base of the opposite teeth is 1/125 of an inch. The length of the developed radula is about 1/20 of an inch. There are forty or more developed teeth in each row, besides ten or twelve undeveloped germs of teeth. The fully developed teeth are 1/200 of an inch in length and about one-fourth as wide as long. This, for a creature over 4 inches long when extended, seems very minute. The form of the teeth is much like that of
Bela Bela may refer to: Places Asia *Bela Pratapgarh, a town in Pratapgarh District, Uttar Pradesh, India *Bela, a small village near Bhandara, Maharashtra, India *Bela, another name for the biblical city Zoara * Bela, Dang, in Nepal *Bela, Janakpur, ...
; they are sharply pointed, translucent, and composed of a plate like the die for a steel pen folded closely upon itself with a U-shaped section. The shaft is set in a chitinous yellow socket, which is extended on the back of the tooth so as to form a little hooked knob. Opposite this many of the teeth show a small sharp basal denticle. The anterior arm of the U is shorter than the other and obliquely trimmed off toward the apex of the fang. There is a well-marked oval poison gland, about 2.5 mm. long, with a slender duct folded twice upon itself, very tortuous, and about 15 mm. long. Behind the proboscis the alimentary canal continues with moderate size for nearly a whorl, when there is an inconspicuous enlargement corresponding to a stomach, with its inner walls longitudinally wrinkled and no marked pyloric curve. It contained merely mucus, and resembled a slight enlargement of the esophagus rather than a well-differentiated stomach. The upper portion of the animal could not be extracted from the spire in spite of all efforts, and so great an advantage in this respect is given by the deep insertion of the columellar muscle, I was unable to withdraw any part of the animal in good condition until after cutting into the penultimate whorl with a file and severing the muscle with a fine scalpel. This is a very interesting form, evidently related to some of Verrill's Fleurotomellae, but differing in important respects as may be seen by the generic diagnosis. It should be remembered that Verrill's type is P. pacMrdi, which differs considerably from most of the species afterwards referred to the group. An examination of specimens of ''Pleurotomella agassizii'', Verrill, showed that the oral opening in that species did not markedly differ from other species of Pleurotomidae and the tentacles were eyeless and cylindrical. The specimen being a female, the forms of the verge, which often offer good characters, could not be compared, but Verrill describes it in ''P. packardi'' as "very large and long, round, nearly cylindrical, except near the tip, where it tapers; in alcoholic specimens it is nearly as thick as the neck, from which it arises." It will be observed that this description does not accord closely with the characters in ''Spergo''. W.H. Dall, Report on the Mollusca and Brachiopoda dredged in deep water, chiefly near the Hawaiian Islands, with illustrations of hitherto unfigured species from Northwest America; Proceedings of the United States National Museum. vol. 17 (1895)


Distribution

This marine species occurs off Oahu Island,,
Hawaii Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only sta ...
at a depth of 616 m.


References


W.H. Dall, Report on the Mollusca and Brachiopoda dredged in deep water, chiefly near the Hawaiian Islands, with illustrations of hitherto unfigured species from Northwest America; Proceedings of the United States National Museum. vol. 17 (1895)


External links


Gastropods.com: ''Spergo glandiniformis''
* glandiniformis Gastropods described in 1895 {{Raphitomidae-stub