What is unique about the class Polyplacophora?

What is unique about the class Polyplacophora?

What is unique about the class Polyplacophora?

Polyplacophorans are a class of the phylum Mollusca and are commonly known as Chitons. They are easily distinguishable from the superficially similar Limpets (which are part of the Gastropoda) by the fact that their shell is composed of eight separate plates, rather than being just one piece.

What type of animal is in class Polyplacophora?

Chitons are molluscs and are related to slugs and snails (gastropods), mussels and oysters (bivalves), and squids and octopuses (cephalopods). Within the phylum Mollusca, chitons belong to a distinct group known as the Polyplacophora.

What are the characteristics of chiton?

Chitons are flattened, elongately-oval, with eight overlapping dorsal shell plates or valves, bordered by a thick girdle formed from the mantle that may be covered with spines, scales, or hairs.

What does the Radula look like in a Polyplacophora?

Not only chitons’ shells are hard. Chitons, like snails, possess a rasp tongue (radula), which they use to rasp food off the ground, if they are not among the few carnivorous species, such as Placiphorella rubra (see below)….Chitons (Placophora)

Class Species No.
Caudofoveata 120
Molluscs (Mollusca) 55.400

How is the shell of Chitons unique?

After a chiton dies, the individual valves which make up the eight-part shell come apart because the girdle is no longer holding them together, and then the plates sometimes wash up in beach drift. The individual shell plates from a chiton are sometimes known as “butterfly shells” due to their shape.

What is the scientific name for chiton?

Chitons/Scientific names

How many teeth are found in a row of radula?

seven teeth
Taenioglossan radula: seven teeth in each row: one middle tooth, flanked on each side by one lateral and two marginal teeth (characteristic of the majority of the Caenogastropoda). These operate like ‘rakes’, scraping algae and gathering the resultant detritus.

What are the three body parts of a mollusk?

The mollusk body can generally be divided into three regions: the head, the foot, and a cluster of internal organs called the visceral mass.

What does the name Polyplacophora mean?

• POLYPLACOPHORA (noun) Meaning: Small class of marine mollusks comprising the chitons; sometimes considered an order of the subclass Amphineura. Classified under: Nouns denoting animals.

What is a chiton shell?

They are also sometimes known as sea cradles or “coat-of-mail shells”, or more formally as loricates, polyplacophorans, and occasionally as polyplacophores. Chitons have a shell composed of eight separate shell plates or valves.

What are the physical characteristics of a Polyplacophora?

What are the characteristics of Polyplacophora? 1 Possess eight calcareous plates that overlap to form a linear chain. 2 Surrounding mantle developed into thick girdle, often bearing spines, scales or bristles. 3 Poorly developed head. 4 Lack eyes and sensory tentacles. 5 Large radula with many teeth. 6 Open circulatory system. 7 Protostomate.

Is the Polyplacophora of North America important to humans?

Class Polyplacophora is not of significant economic importance to humans in contemporary society, although indigenous people of the Pacific coast of North America are reported to have eaten Cryptochiton stelleri. Kozloff, E. N. 1990. “Class Polyplacophora,” pp. 376-382 in Invertebrates.

How big do Polyplacophora get at high tide?

Nevertheless, most chitons are between 1 and 10 centimetres in length. Polyplacophora are easily seen along the shoreline, as some species inhabit the intertidal zone (the area between high tide and low tide maxima).

What kind of food does a Polyplacophora eat?

Abundant, on rocks or sand; herbivorous on red algae with some brown algae. Many have a commensal scale worm Arctonoe vittata and/or a pea crab Opisthopus living in pallial groove between side of foot & inner edge of girdle; several species of filamentous red algae also grow on dorsal portion of girdle.