How many species of Aplacophora are there?
320 species
Aplacophora is a relatively small group of molluscs that are characterized by their lack of shells and worm-like appearance. Instead of a shell, their mantle secretes tiny calcareous spicules which give them a beautiful shine. There are only about 320 species of these exclusively marine molluscs.
How many shells does a Aplacophora have?
Apart from molluscs with complete shells, such as snails, clams and cuttlefish, there are also the chitons (Polyplacophora). Those do not have a complete shell, but their back is protected by eight shell plates….Shell-less Molluscs (“Aplacophora”)
| Class | Species No. |
|---|---|
| Molluscs (Mollusca) | 55.400 |
Is radula present in Aplacophora?
Aplacophorans have a mouth at the front of their body which opens into a muscular pharynx lined by a thick cuticle. This pharynx is typically connected to one or two pairs of salivary glands and the radula sac.
How many classes of molluscs are there?
The Phylum Mollusca consist of 8 classes: 1) the Monoplacophora discovered in 1977; 2) the worm-like Aplacophora or solenogasters of the deep sea; 3) the also worm-like Caudofoveata; 4) the Polyplacophora, or chitons; 5) the Pelecypoda or bivalves; 6) the Gastropoda or snails; 7) the Scaphopoda, or tusk shells; and 8) …
What are the 8 classes of Mollusca?
Living mollusks are usually grouped into eight classes: Gastropoda (see gastropod), Bivalvia or Pelecypoda (see bivalve), Cephalopoda (see cephalopod), Scaphopoda (tusk shells), Aplacophora (Solenogasters), Caudofoveata (sometimes included in the Aplacophora order), Polyplacophora (chitons), and Monoplacophora.
What are the 5 Mollusca classes?
Phylum Mollusca is a very diverse (85,000 species ) group of mostly marine species, with a dramatic variety of form. This phylum can be segregated into seven classes: Aplacophora, Monoplacophora, Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, and Scaphopoda.
What is phylum of class Polyplacophora?
MolluscaChitons / Phylum
What type of animal is in class Polyplacophora?
marine molluscs
Chitons (/ˈkaɪtənz/) are marine molluscs of varying size in the class Polyplacophora (/ˌpɒlipləˈkɒfərə/), formerly known as Amphineura. About 940 extant and 430 fossil species are recognized.
What is class Aplacophora?
Class AplacophoraWorm-shaped and without shells; marine, mostly in deep water. Possibly representive of the primitive molluscan condition or a secondary reduction from more advanced, shelled ancestors.
What do we know about Aplacophora’s perception and movement?
Little is known about aplacophoran lifespans. Aplacophorans move via cilia through or on substrate. ( Brusca and Brusca, 2003) Little is known about the perception of the Aplacophora. The animals have a simple nerve ring around the esophogus and poorly developed ganglia.
What is the difference between Mollusca and Aplacophora?
A. Molluscan characters coelomate Bilateria with little or no metamerism, a soft body, a pharynx with a radula, gills, a heart, an open circulatory system. B. Aplacophoran characters no shell (mantle), foot, nephridia.
What is the difference between aplacophorans and caudofoveates?
All aplacophorans are marine and many live in the deep sea (to 6000m or more). Caudofoveates are burrowers that feed on detritus and bottom-dwelling microorganisms, while solenogasters feed on cnidarians. Both groups have a radula and lack true nephridia.