Buccinum oblitum
Encyclopedia
Buccinum oblitum is a species
of sea snail
, a marine gastropod mollusk in the family
Buccinidae
, the true whelks.
is up to 20 mm high, solid, with 5-6 moderately convex whorls
and a conical spire
. The last whorl is about 70% of total height. Protoconch
of one smooth, mucronate whorl. Teleoconch is with a variably developed sculpture
consisting of spiral cords and threads, and slightly flexuous or straight axial folds. There are usually three cords on the early spire whorls, rather flat and as broad as the interspaces, later the second-order spiral threads are intercalated. The main spiral cords tend to form small knobs at their intersections with the axial folds, which are narrower than the interspace and may be wanting on part or whole of the spire. Body whorl
is somewhat constricted around the canal, which is not delimited by a ridge. Aperture
is oval, merging into a broad and short siphonal canal
. Outer lip is slightly thickened, smooth inside. Parietal and columellar edge are appressed, forming a thin callus which hardly extends over the previous whorl. Colour is whitish with diffuse, pale brown flames and blotches.
This apparently disjunct distribution
is puzzling, but no appreciable morphological difference can be detected.
The type locality stated by Sykes (1911) is "Porcupine" 1869 sta. 65, which is North of the Hebrides, 61º10'N, 02º21'W, 345 fathoms. The lectotype
in USNM is reported (Bouchet & Warén, 1985, and current USNM calalogue) to be from sta. 55 which is 60º04'N, 06º19'W, 605 fathoms.
.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of sea snail
Sea snail
Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....
, a marine gastropod mollusk in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Buccinidae
Buccinidae
Buccinidae is a very large and diverse taxonomic family of large sea snails, often known as whelks or true whelks.True whelks are mostly marine gastropod mollusks in the clade Neogastropoda...
, the true whelks.
Description
The shellGastropod shell
The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
is up to 20 mm high, solid, with 5-6 moderately convex whorls
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...
and a conical spire
Spire (mollusc)
A spire is a descriptive term for part of the coiled shell of mollusks. The word is a convenient aid in describing shells, but it does not refer to a very precise part of shell anatomy: the spire consists of all of the whorls except for the body whorl...
. The last whorl is about 70% of total height. Protoconch
Protoconch
A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...
of one smooth, mucronate whorl. Teleoconch is with a variably developed sculpture
Sculpture (mollusc)
The sculpture of a mollusc shell is the three-dimensional ornamentation on the outer surface, as distinct from the basic shape of the shell itself or colouration. Sculpture may be concave as well as convex. Sometimes it has microscopic detail. Sculpture refers to the calcareous outer layer, not the...
consisting of spiral cords and threads, and slightly flexuous or straight axial folds. There are usually three cords on the early spire whorls, rather flat and as broad as the interspaces, later the second-order spiral threads are intercalated. The main spiral cords tend to form small knobs at their intersections with the axial folds, which are narrower than the interspace and may be wanting on part or whole of the spire. Body whorl
Body whorl
Body whorl is part of the morphology of a coiled gastropod mollusk.- In gastropods :In gastropods, the body whorl, or last whorl, is the most recently-formed and largest whorl of a spiral or helical shell, terminating in the aperture...
is somewhat constricted around the canal, which is not delimited by a ridge. Aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
is oval, merging into a broad and short siphonal canal
Siphonal canal
Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is drawn into the mantle cavity and over the gill and which serves as a chemoreceptor to locate food. In many carnivorous snails, where the siphon is particularly long, the structure...
. Outer lip is slightly thickened, smooth inside. Parietal and columellar edge are appressed, forming a thin callus which hardly extends over the previous whorl. Colour is whitish with diffuse, pale brown flames and blotches.
Distribution
Distribution of Buccinum oblitum include:- Eastern Atlantic, from the Faroes to southwestern Ireland in 300-1000 m.
- Strait of GibraltarStrait of GibraltarThe Strait of Gibraltar is a narrow strait that connects the Atlantic Ocean to the Mediterranean Sea and separates Spain in Europe from Morocco in Africa. The name comes from Gibraltar, which in turn originates from the Arabic Jebel Tariq , albeit the Arab name for the Strait is Bab el-Zakat or...
in 362-526 m. - Gorringe RidgeGorringe RidgeThe Gorringe Ridge is a seamount in the Atlantic Ocean. It is located about 130 miles west of Portugal, between the Azores and the Strait of Gibraltar along the Azores-Gibraltar fault zone...
seamount, moderately common in 155-1040 m. - Ampère and Seine seamounts, rare in 235-325 m.
This apparently disjunct distribution
Disjunct distribution
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but widely separated from each other geographically...
is puzzling, but no appreciable morphological difference can be detected.
The type locality stated by Sykes (1911) is "Porcupine" 1869 sta. 65, which is North of the Hebrides, 61º10'N, 02º21'W, 345 fathoms. The lectotype
Lectotype
In botanical nomenclature and zoological nomenclature, a lectotype is a kind of name-bearing type. When a species was originally described on the basis of a name-bearing type consisting of multiple specimens, one of those may be designated as the lectotype...
in USNM is reported (Bouchet & Warén, 1985, and current USNM calalogue) to be from sta. 55 which is 60º04'N, 06º19'W, 605 fathoms.
Ecology
The type of larval development is direct (non-planktotrophic) inferred from paucispiral protoconchProtoconch
A protoconch is an embryonic or larval shell of some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod...
.