GC: n
S: SDir (last access: 15 May 2025); Neogen (last access: 15 May 2025).
N: 1. “soft-bodied invertebrate animal, usually with an external shell,” 1783, mollusque (modern spelling from 1839), from French mollusque, from Modern Latin Mollusca (see Mollusca), the phylum name. Related: Molluscuous; molluscan.
2. mollusk. Also known as: Mollusca, mollusc.
- 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. Along with the insects and vertebrates, it is one of the most diverse groups in the animal kingdom, with nearly 100,000 (possibly as many as 150,000) described species. Each group includes an ecologically and structurally immense variety of forms: the shell-less Caudofoveata; the narrow-footed gliders (Solenogastres); the serially valved chitons (Placophora or Polyplacophora); the cap-shaped neopilinids (Monoplacophora); the limpets, snails, and slugs (Gastropoda); the clams, mussels, scallops, oysters, shipworms, and cockles (Bivalvia); the tubiform to barrel-shaped tusk shells (Scaphopoda); and the nautiluses, cuttlefishes, squids, and octopuses (Cephalopoda).
3. Size range and diversity of structure
- Typical molluscan features have been substantially altered, or even lost, in many subgroups. Among the cephalopods the giant squids (Architeuthis), the largest living invertebrates, attain a body length of eight metres (more than 26 feet); with the tentacle arms extended, the total length reaches to 22 metres. Other cephalopods exceed a length of one metre. Many of the remaining molluscan classes show a large variation in size: among bivalves the giant clam (Tridacna) ranges up to 135 centimetres (four feet) and the pen shell (Pinna) from 40 to 80 centimetres; among gastropods the sea hares (Aplysia) grow from 40 to 100 centimetres and the Australian trumpet, or baler (Syrinx), up to 60 centimetres; among placophores the gumshoe, or gumboot chiton (Cryptochiton), achieves a length up to 30 to 43 centimetres; and, among solenogasters, Epimenia reaches a length of 15 to 30 centimetres. Finally, gastropods of the family Entoconchidae, which are parasitic in echinoderm sea cucumbers, may reach a size of almost 1.3 metres. In contrast, there are also minute members, less than one millimetre (0.04 inch) in size, among the solenogasters and gastropods.
4. Mollusks, Echinoderms and Prochordates: mollusc (United States); mollusk (Great Britain).
- An animal belonging to the Mollusca.
- Mollusca: In present use (mainly following the classification proposed by Cuvier in 1788-1800), a phylum or sub-kingdom of animals, comprising the four classes Gastropoda (limpets, snails, etc.), Scaphopoda (tooth-shells), Cephalopoda (cuttlefish, etc.), and Lamellibranchia (oyster, mussel, etc.); the classes Cirrhopoda, Tunicata, and Brachiopoda, included by Cuvier among the Mollusca, are now placed elsewhere, and the Polyzoa have since Cuvier’s time been added to the phylum and again removed.
- shellfish: An aquatic animal having a shell, as the oyster and other mollusks and the lobster and other crustaceans.
5. Cultural Interrelation: We can mention the film The Mollusk Murders (2024) by Joseph E. De Leo.
S: 1. Etymonline (last access: 15 May 2025). 2 & 3. EncBrit (last access: 15 May 2025). 4. TERMIUM PLUS (last access: 15 May 2025). 5. IMDb (last access: 15 May 2025).
OV: mollusc (US)
S: SDir (last access: 15 May 2025); TERMIUM PLUS (last access: 15 May 2025).
SYN:
S:
CR: crustacean, metazoan.
