What is the difference between annelids and molluscs?
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What is the difference between annelids and molluscs?
Mollusks are invertebrates such as the common snail. Most mollusks have shells. Annelids are worms such as the familiar earthworm. They have segmented bodies.
Are mussels Gastropoda?
The freshwater mollusks include two classes, the Gastropoda (snails and limpets) and the Bivalvia (clams and mussels). The gastropods constitute the most diverse class of the phylum Mollusca, with about 75,000 species of marine and freshwater snails worldwide.
Are mollusks Metameric?
Are molluscs metameric organisms? The body of molluscs is not divided into segments. Considering just this aspect, they appear to be evolutionarily closer to nematodes than to annelids.
Are mussels cephalized?
Notice that mussels are HEADLESS! Remember, their snail-like ancestors DID have heads. That is, they were cephalized. The fossil record shows that these early snails were abundant in the ocean 550 million years ago, at a time when many new predators were arriving on the scene.
What is a mussel phylum?
Mollusca
Blue mussel/Phylum
Are mussels Cephalized?
What are the Similarities Between Mollusks and Arthropods? Mollusks and arthropods belong to two phyla of Kingdom Animalia. Both groups contain invertebrates.
Do mussels have bilateral symmetry?
Bilateral symmetry is a feature of mussel bivalves as well as the mother-of-pearl appearance on the inside of the shell. Taxonomists refer to bivalves as having bilateral symmetry where the shells are mirror opposites of one another. If one opens the shells at the hinge, the bilateral symmetry is apparent.
What do molluscs and annelids have in common?
Both molluscs and annelids probably evolved from free-living flatworms. Both flatworms and molluscs are triploblastic, bilaterally symmetric, and cephalized. But molluscs have developed a true coelom, an internal body cavity enclosed by mesodermal membranes.
Do mollusks have a radula?
The mantle may or may not secrete a shell of calcium carbonate. In addition, many mollusks have a scraping structure at the mouth, called a radula (Figure 1). The muscular foot varies in shape and function, depending on the type of mollusk (described below in the section on mollusk diversity).
What do mussels live in?
Also known as edible mussels, these creatures live in a blue-black bivalve shell. The mussel itself is tan-colored and full of protein, vitamins, and minerals. Mussels mostly stay in one place, eating plankton that they filter from the water.
What phylum do annelids belong to?
The annelids traditionally include the oligochaetes, which include the earthworms and leeches, the polychaetes, which are a marine group, and two other smaller classes. The phyla Mollusca and Annelida belong to a clade called the Lophotrochozoa, which also includes the phylum Nemertea, or ribbon worms ([link]).