What characteristic is a distinguishing feature of species under class Monoplacophora?

The monoplacophoran animal has a poorly defined head with an elaborate mouth structure on the ventral surface. The mouth is typically surround by a V-shaped, thickened anterior lip and post-oral tentacles; post-oral tentacles come in a variety of morphologies and configurations.

What are 3 characteristics of Polyplacophora?

The main characteristics of Polyplacophora include (1) elongate or oval, dorsoventrally flattened, bilaterally symmetrical, marine; (2) with dorsal shell of eight plates embedded in a tough mantle; (3) mantle-edge stiffened (called the girdle); (4) large, muscular, ventral foot (girdle and foot can act as suction cup); …

What is Monoplacophora?

“bearing one plate
Monoplacophora, which means “bearing one plate,” is a polyphyletic superclass of molluscs that formerly lived at the bottom of the deep sea. Its shell resembles a cap. Members of the Monoplacophora class have an undivided arching shell, a broad flat foot, serially repeated pairs of gills and foot-retractor muscles.

Does Monoplacophora have radula?

The main characteristics of Monoplacophora include (1) small, deep sea, almost bilaterally symmetrical; (2) have undivided arch shell; (3) body with distinct head and radula, without eyes or sensory tentacles (except around the mouth); (4) foot-retractor muscle; (5) anus median, posterior; (6) mantle cavity large, …

What are examples of Polyplacophora?

Chitons/Lower classifications

Which of the following is a characteristic of Scaphopods?

The most distinctive feature of scaphopods is that the tubular shell is open at both ends, not just one end as in most molluscs. Scaphopods live their adult lives buried in sand or mud, with their head end pointed downwards.

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.

Does Polyplacophora have radula?

Each row of the polyplacophoran radula has two mineralized teeth used to abrade the substrate, and two longer teeth that sweep up any debris. The other 13 teeth on each row do not appear to be involved in feeding.

What are 3 characteristics of mollusks?

The three most universal features defining modern molluscs are a mantle with a significant cavity used for breathing and excretion, the presence of a radula (except for bivalves), and the structure of the nervous system.

What are the 5 main classes of Mollusca?

Mollusks can be segregated into seven classes: Aplacophora, Monoplacophora, Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, and Scaphopoda. These classes are distinguished by, among other criteria, the presence and types of shells they possess.

What is a unique characteristic of a Mollusca?

Despite their amazing diversity, all molluscs share some unique characteristics that define their body plan. The body has a head, a foot and a visceral mass. This is all covered with a mantle (also known as a pallium) that typically secretes the shell.

What are the 4 major molluscs?

The major classes include gastropods, bivalves, and cephalopods. Use the resources below to answer the questions that follow. The world’s largest mollusk is a colossal squid, which measures 14 feet in length. The smallest mollUSks are snails that are microscopic in size.

What are the three most common characters of molluscs?

The most universal characteristics defining modern molluscs are a mantle with a significant cavity used for breathing and excretion, the presence of a radula, and the organization of the nervous system.

What are the 8 classes of Mollusca?

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 3 types of mollusk?

The three major groups of mollusks are gastropods, bivalves, and cephalopods (SEF ul o pods). The largest group is the gastropods. These are mollusks like snails and slugs that have just one shell or no shell at all. Gastropods creep along on their broad foot.

What are the 3 layers of a mollusc shell?

The shell is made of three layers: the nacreous layer, an inner iridescent layer of nacre (mother-of-pearl) composed of calcium carbonate that is continuously secreted by the mantle, the prismatic layer, a middle layer of chalky white crystals of calcium carbonate in a protein matrix and the periostracum, an outer …