What makes Scaphopoda unique?

What makes Scaphopoda unique?

Yet again the scaphopoda are unique in that they have no flow through of water (usually across the ctenidia). The deoxygenated water is expelled through the upper most end of the shell by a muscular contraction of the foot. Water enters the mantle cavity by means of another unique scaphopodan development; the pavilion.

What are examples of Scaphopoda?

Dentaliidae
DentaliidaGadilida
Tusk shell/Lower classifications

Where do tusk shells come from?

Tusk shells are found in cool and warm water oceans worldwide, from seashores to depths down to about 23,000 feet (7,000 meters).

Does Scaphopoda have foot?

SCAPHOPODA, the third of the five classes into which the Phylum Mollusca is divided. ‘ The Scaphopoda are marine Molluscs with the body, especially the foot, adapted to a burrowing life in sand. The foot is cylindrical. …

Does Scaphopoda have mantle?

Mantle. The mantle of a scaphopod is entirely within the shell. The foot extends from the larger end of the shell, and is used to burrow through the substrate.

What does a Scaphopoda lack?

Scaphopods also lack gills. Unlike the previously discussed groups, scaphopods have a U-shaped gut rather than an anterior–posterior configuration of the mouth and anus.

What is the common name for Scaphopoda?

The tusk shells or tooth shells, technically the Scaphopoda /skæˈfɒpədə/ (the scaphopods /ˈskæfəpɒdz/, from Ancient Greek σκᾰ́φης skáphē “boat” and πούς poús “foot”), are members of a class of shelled marine mollusc with worldwide distribution, and are the only class of exclusively infaunal marine molluscs.

Do Scaphopoda have gills?

External morphology of the Scaphopoda. Foot morphology is variable and has been used as a taxonomic character. The pattern of water circulation through the scaphopod mantle cavity is also unique among the molluscs, because water both enters and exits through the small dorsal aperture. Scaphopods also lack gills.

Does Scaphopoda have gills?

How many species of Scaphopoda are there?

350 species
Scaphopods are infaunal organisms and feed on foraminiferans and other interstitial prey. Approximately 350 species occur from the intertidal zone to depths in excess of 7000 m and are present in all the major oceans. Figure 9. External morphology of the Scaphopoda.

What is a Scaphopoda shell?

The Scaphopoda are small but interesting class of molluscs. Their common name is Tusk Shells because the curved, hollow and cylindrical shells resemble small tusks. One of the most distinctive aspect of the Scaphopodan shell is that it is a cylinder and open at both ends. The larger aperture is where the foot and ‘head’ area are located.

What is the morphology of scaphopod mollusc?

The scaphopod mollusc (Figure 9) combines gastropod-like shell morphology with bivalve-like development with cephalopod-like anatomy. Members of the class first appear in the early Paleozoic and the taxon has maintained a slow and steady rate of increase in morphological diversification since then.

What is the difference between Gadilida and scaphopods?

In contrast the shells of the Gadilida are generally smaller and smooth surfaced and widest shortly before the anterior end. Scaphopods are relatively small molluscs ranging in size from around 5 mm in shell length to 19 cm in shell length. The tusk shells appear to be the most recently evolved of the molluscan classes.

How are Scaphopoda bilaterally symmetrical?

The scaphopoda are bilaterally symmetrical, and live with their body completely surrounded by the shell, which encloses the mantle cavity. The body is connected to the dorsal part of the shell by the mantle and is surrounded laterally and ventrally by the mantle cavity.