Mollusc shell - Wikipedia
A mollusc shell is formed, repaired and maintained by a part of the anatomy called the mantle. Any injuries to or abnormal conditions of the mantle are usually reflected in the shape and form and even color of the shell.
List of mollusks | Gastropods, Bivalves, Cephalopods | Britannica
Mollusks are soft-bodied invertebrates of the phylum Mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body. Along with the insects and vertebrates, mollusks are one of the most diverse groups in …
Mollusk | Definition, Characteristics, Shell, Classification, & Facts ...
2024年11月11日 · mollusk, any soft-bodied invertebrate of the phylum Mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body.
Mollusca - Wikipedia
Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat, as numerous groups are freshwater and even terrestrial species.
Mollusk - Definition, List, Examples, Characteristics, and Image
2024年4月30日 · Mollusks have a soft, unsegmented, bilaterally symmetrical body dorsally covered by a hard shell made of chitin and conchiolin, a protein hardened with aragonite (a crystal form of calcium carbonate). Shell.
How are seashells created? Or any other shell, such as a snail's …
2006年10月23日 · Seashells are the exoskeletons of mollusks such as snails, clams, oysters and many others. Such shells have three distinct layers and are composed mostly of calcium carbonate with only a...
15.4: Mollusks and Annelids - Biology LibreTexts
2021年9月23日 · Mollusks show a variety of morphologies. Many mollusks secrete a calcareous shell for protection, but in other species, the shell is reduced or absent. Mollusks are protostomes. The dorsal epidermis in mollusks is modified to form the mantle, which encloses the mantle cavity and visceral organs.
How Seashells Take Shape - Scientific American
2018年4月1日 · Using the tools of differential geometry, a mathematical discipline that studies curves and surfaces, we have determined that the elaborate shapes of shells arise from a few simple rules that the...
14.4: Phylum Mollusca - Biology LibreTexts
2022年7月31日 · Phylum Mollusca is a large, marine group of invertebrates. Mollusks show a variety of morphological variations within the phylum. This phylum is also distinct in that some members exhibit a calcareous shell as an external means of protection. Some mollusks have evolved a reduced shell. Mollusks are protostomes.
Phylum Mollusca | manoa.hawaii.edu/ExploringOurFluidEarth
Molluscs have a mantle or mass of soft flesh that covers the soft body and encloses the internal organs. In many species, the mantle produces a hard shell. Not all molluscs produce a shell. Many molluscs have a radula, which, in most species, is a rasp-like scraping organ