Let's Talk Seashells! -> Nassarius fossatus (Gould, 1850)
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الإنجليزية
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المقدمة من EOL authors
Image based description with several photo samples.
Comprehensive Description
(
الإنجليزية
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المقدمة من Invertebrates of the Salish Sea
Biology/Natural History: Feeds as a predator or primarily a scavenger. Can crawl well on rock, or on top of or just below the surface of sand or mud. They crawl with both sides of the large foot, leaving a distinctive track in the sand. Attracted from long distances by rotting meat, which it can smell with its long proboscis. It can crawl rapidly. When feeding, it wraps its foot completely around the food until it is consumed. May also drill in clams or snails. Predators include the seastar Pisaster brevispinus. When contacted by P. brevispinus, N. fossatus may writhe so violently with its foot that it twists into somersaults and even vaults into the water column. At other times it may simply turn and crawl swiftly away, rocking its shell back and forth. Sometimes the colonial hydroid Clytia bakeri, which is one of few hydroids that grow on exposed sandy shores, is found growing on shells of this species. Deposits its egg capsules on eelgrass or other firm objects in mud flats in late winter and spring. A typical string of eggs may be 6 cm long and contain 45 eggs. The individual capsules are about 3 mm long. They are laid overlapping one another to produce a "shingled" appearance. The wicker-basketlike appearance of the intersecting radial ribs and spiral ridges is the reason this species is called a basket whelk.
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- حقوق النشر
- Rosario Beach Marine Laboratory
Habitat
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الإنجليزية
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المقدمة من Invertebrates of the Salish Sea
Intertidal and more commonly subtidal on sandy areas and mud flats.
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- حقوق النشر
- Rosario Beach Marine Laboratory
Distribution
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الإنجليزية
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المقدمة من Invertebrates of the Salish Sea
Geographical Range: Vancouver Island, B.C. to Laguna San Ignacio, Baja California. This is the most common carnivorous snail on mud flats along the US west coast. It is most common in the northern parts of its range.
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- حقوق النشر
- Rosario Beach Marine Laboratory
Habitat
(
الإنجليزية
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المقدمة من Invertebrates of the Salish Sea
Depth Range: Low intertidal to 18 m
- ترخيص
- cc-by-nc-sa
- حقوق النشر
- Rosario Beach Marine Laboratory
Comprehensive Description
(
الإنجليزية
)
المقدمة من Invertebrates of the Salish Sea
As with all members of family Nassariidae, the coiled shell has a well-developed spire and a siphonal notch or canal but no anal notch. The outer shell is not highly polished and is usually sculptured. The widest part of the aperture is less than half the diameter of the shell. Has a horny operculum. The lowermost portion of the body whorl, including the siphonal canal, is set off from the rest of the shell by a deep groove for most species in the family. Nassarius fossatus has the deep groove and has both axial ribs and spiral ridges, though the axial ribs do not extend as far anteriorly as the anterior groove on the body whorl. The spire is acute. The outer lip of the aperture is finely toothed at the margin and ridged inside. The inner lip of the aperture has a broad callus on the columella, usually orange, that spreads out over the body whorl and extends well posterior to the anterior end of the outer lip. The siphonal canal is short and wide. Besides the anterior siphonal canal, the aperture also has a narrow notch at the posterior end. Usually gray-brown to ash colored shell, with the callus on the columella often orange. Height to 4.5 cm, with about 7 whorls.
- ترخيص
- cc-by-nc-sa
- حقوق النشر
- Rosario Beach Marine Laboratory
Look Alikes
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الإنجليزية
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المقدمة من Invertebrates of the Salish Sea
How to Distinguish from Similar Species: Ilyanassa obsoleta and Searlesia dira do not have the deep anterior groove. Nassarius fraterculus has spiral ridges only on the body whorl. Several other species have axial ribs which reach to the angerior groove. Of these, N. mendicus has much more pronounced axial ribs than spiral ridges, while N. rhinites and N. perpinguis have small axial ribs and spiral ridges which intersect to form distinct beads.
- ترخيص
- cc-by-nc-sa
- حقوق النشر
- Rosario Beach Marine Laboratory
Nassarius fossatus
(
الإنجليزية
)
المقدمة من wikipedia EN
Nassarius fossatus, the channeled basket snail, is a species of sea snail, a marine gastropod mollusc in the family Nassariidae, the nassa mud snails or dog whelks. It is native to the west coast of North America where it is found on mudflats on the foreshore and on sand and mud in shallow water.
Description
This is one of the largest mud snails in the genus and has a robust shell that can reach nearly 5 cm (2 in) long. The width of the body whorl of the spirally coiled shell is about half the total length of the shell and there are about six further whorls of diminishing size. There is a distinctive transverse groove on the lowermost portion of the body whorl. The surface of the shell is sculpted with fine axial ribs and spiral ridges, giving it a basket-like texture. The aperture is less than half the diameter of the shell and can be closed by a horny operculum. There is a siphonal notch at the edge of the aperture through which a breathing siphon can be extended. The lip of the aperture is finely toothed at the margin and slightly ridged inside. The columella (the central supporting structure around which the shell is coiled) is thickened at the aperture and is usually orange. The rest of the shell surface is grayish-brown or ashy gray and is matte in appearance.[2]
Distribution and habitat
This species is native to the coasts adjoining the northeastern Pacific Ocean. Its range extends from Vancouver Island to Baja California. It is found intertidally on mudflats and also subtidally on sandy and muddy substrates to a depth of about 18 m (59 ft).[2][3]
Behavior
Nassarius fossatus is a predator and scavenger. When the tide is out it crawls across the surface of the mud leaving a distinctive trail. It is able to detect odors with its long proboscis and when it finds something edible, it winds its foot round it and rasps at the surface with its radula. A dead fish in a creek has been found to attract snails from as far away as 30 m (98 ft) downstream.[3] N. fossatus can similarly detect the approach of a predator such as the starfish Pisaster brevispinus. Its reaction is either to crawl away rapidly, rocking its shell from side to side, or do a spectacular flip or series of flips, catapulting itself with its muscular foot.[3]
Nassarius fossatus lays its eggs on eelgrass or some other solid object on the surface of the mudflats. First it cleans a portion of leaf blade with its radula, then it forms a fold in its foot connecting its genital pore with its mucous pedal gland. The egg mass passes along this fold and the pedal gland is used to cement the egg capsule to the leaf blade. This process takes about ten minutes, during which time the snail's body and shell oscillate from side to side. After this, the snail moves forward slightly and repeats the process, eventually producing a series of flattened capsules that overlap each other giving a shingled effect.[3] A typical egg string may contain 45 eggs and be 6 cm (2.4 in) long.[2]
References
Nassarius fossatus: Brief Summary
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الإنجليزية
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المقدمة من wikipedia EN
Nassarius fossatus, the channeled basket snail, is a species of sea snail, a marine gastropod mollusc in the family Nassariidae, the nassa mud snails or dog whelks. It is native to the west coast of North America where it is found on mudflats on the foreshore and on sand and mud in shallow water.
Nassarius fossatus
(
البلجيكية الهولندية
)
المقدمة من wikipedia NL
Nassarius fossatus is een slakkensoort uit de familie van de Nassariidae.[1] De wetenschappelijke naam van de soort is voor het eerst geldig gepubliceerd in 1850 door Gould.
Bronnen, noten en/of referenties Geplaatst op:
09-03-2013
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