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Hinge Line
A hinge line is an imaginary longitudinal line along the dorsal edge of the shell of a bivalve mollusk where the two valves hinge or articulate. The hinge line can easily be perceived in these images of a mussel shell and an ark shell. The hinge teeth Hinge teeth are part of the anatomical structure of the inner surface of a bivalve shell, i.e. the shell of a bivalve mollusk. Bivalves by definition have two valves, which are joined together by a strong and flexible ligament situated on the hin ..., structures which control the articulation of the valves, are often but not always situated along the hinge line. References Mollusc shells {{bivalve-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mytilidae Hinge
The Mytilidae are a family of small to large marine and brackish-water bivalve molluscs in the order Mytilida. One of the genera, '' Limnoperna'', even inhabits freshwater environments. Mytilidae, which contains some 52 genera, is the only extant family within the order Mytilida. Species in the family Mytilidae are found worldwide, but they are more abundant in colder seas, where they often form uninterrupted beds on rocky shores in the intertidal zone and the shallow subtidal. The subfamily Bathymodiolinae is found in deep-sea habitats. Mytilids include the well-known, edible sea mussels. A common feature of the shells of mussels is an asymmetrical shell, which has a thick, adherent periostracum. The animals attach themselves to a solid substrate using a byssus. A 2020 study of the phylogeny of the Mytilidae recovered two main clades derived from an epifaunal ancestor, with subsequent lineages shifting to other lifestyles, and correlating convergent evolution of siphon trai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve Shell
A bivalve shell is the enveloping exoskeleton or mollusc shell, shell of a bivalve mollusc, composed of two hinged halves or ''valve (mollusc), valves''. The two half-shells, called the "right valve" and "left valve", are joined by a ligament and usually articulate with one another using structures known as "teeth" which are situated along the hinge line. In many bivalve shells, the two valves are symmetrical along the hinge line — when truly symmetrical, such an animal is said to be ''equivalved''; if the valves vary from each other in size or shape, ''inequivalved''. If symmetrical front-to-back, the valves are said to be ''equilateral'', and are otherwise considered ''inequilateral''. The bivalve shell not only serves as protection from predators and physical damage, but also for adductor muscles (bivalve), adductor muscle attachment, which can allow the mollusc to "swim" short distances by flapping the valves. The shell is secreted by a soft part of the molluscan body known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consisting of a hinged pair of half-bivalve shell, shells known as valve (mollusc), valves. As a group, bivalves have no head and lack some typical molluscan organs such as the radula and the odontophore. Their gills have evolved into ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Common bivalves include clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. Majority of the class are benthic filter feeders that bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The number of additional fossil species is estimated between 60,000 and 100,000, and the proportion of undescribed species is very high. Many taxa remain poorly studied. 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. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known extant i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valve (mollusc)
A valve is each articulating part of the shell of a Mollusca, mollusc or another multi-shelled animal such as Brachiopod, brachiopods and some Crustacean, crustaceans. Each part is known as a valve or in the case of Chiton, chitons, a "plate". Members of two Class (biology), classes of molluscs, the Bivalvia (clams) and the Polyplacophora (chitons), have valves. Species within one family of very unusual small sea snails, marine (ocean), marine opisthobranch gastropods in the family Juliidae, also have two articulating shells or valves, which resemble those of a bivalve. This exceptional family is commonly known as the bivalved gastropods. Gastropods in general are sometimes called "univalves", because in those that have a shell, the shell is usually in one part. Chitons The valves of chitons are eight dorsum (biology), dorsal, wiktionary:articulated, articulated shell plates, which are frequently coloured and sculpted. After death the girdle that holds the plates together disin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mytilidae
The Mytilidae are a family (biology), family of small to large Marine life, marine and Brackish water, brackish-water bivalve molluscs in the order (biology), order Mytilida. One of the genera, ''Limnoperna fortunei, Limnoperna'', even inhabits fresh water, freshwater environments. Mytilidae, which contains some 52 genera, is the only extant family within the order Mytilida. Species in the family Mytilidae are found worldwide, but they are more abundant in colder seas, where they often form uninterrupted beds on rocky shores in the intertidal zone and the shallow subtidal. The subfamily Bathymodiolinae is found in deep-sea habitats. Mytilids include the well-known, edible sea mussels. A common feature of the shells of mussels is an asymmetrical shell, which has a thick, adherent periostracum. The animals attach themselves to a solid substrate using a byssus. A 2020 study of the phylogeny of the Mytilidae recovered two main clades derived from an epifaunal ancestor, with subseq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hinge Teeth
Hinge teeth are part of the anatomical structure of the inner surface of a bivalve shell, i.e. the shell of a bivalve mollusk. Bivalves by definition have two valves, which are joined together by a strong and flexible ligament situated on the hinge line at the dorsal edge of the shell. In life, the shell needs to be able to open slightly to allow the foot and siphons to protrude, and then close again, without the valves moving out of alignment with one another. To make this possible, in most cases the two valves are articulated using an arrangement of structures known as hinge teeth (often referred to collectively as the "dentition"). Like the ligament, the hinge teeth are also situated along the hinge line of the shell, in most cases. In most families of bivalves, the two valves of the shell are almost perfectly symmetrical with one another along the hinge line, although the placement and shape of the teeth may differ slightly in the left valve and right valve in order for the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
