| Tridacninae Temporal range: | |
|---|---|
 | |
| Two "giant clams", from the two current genera : Hippopus hippopus & Tridacna squamosa . | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Mollusca |
| Class: | Bivalvia |
| Subclass: | Heterodonta |
| Order: | Cardiida |
| Family: | Cardiidae |
| Subfamily: | Tridacninae Lamarck, 1819 |
| Genera | |
See text | |
Tridacninae, common name, the giant clams, is a taxonomic subfamily of very large saltwater clams, marine bivalve molluscs in the family Cardiidae, the cockles.
This subfamily contains the largest living bivalve species, including Tridacna gigas , the giant clam. They have heavy shells, fluted with 4–6 folds. The mantle is usually brightly colored. They inhabit coral reefs in warm seas in the Indo-Pacific region. Most of these clams live in symbiosis with photosynthetic dinoflagellates (zooxanthellae).
Sometimes the giant clams are still treated as a separate family Tridacnidae, [1] but modern phylogenetic analyses included them in the family Cardiidae as a subfamily. [2] [3] Two recent genera and eight species are known:
Recent genetic evidence has shown them to be monophyletic sister taxa. [4]
In some areas, such as the Philippines, smaller members of the subfamily are farmed to supply the marine aquarium trade and food trade towards east Asia.
Tridacinae originated in Western Europe during the Eocene, expanding eastwards towards Arabia by the Oligocene, and becoming established in its modern distribution in the Indo-Pacific during the Pliocene-Pleistocene. [5]
Clam is a common name for several kinds of bivalve molluscs. The word is often applied only to those that are edible and live as infauna, spending most of their lives halfway buried in the sand of the seafloor or riverbeds. Clams have two shells of equal size connected by two adductor muscles and have a powerful burrowing foot. They live in both freshwater and marine environments; in salt water they prefer to burrow down into the mud and the turbidity of the water required varies with species and location; the greatest diversity of these is in North America.
Bivalvia, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. Bivalves as a group have no head and they lack some usual molluscan organs like the radula and the odontophore. They include the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances.
A cockle is an edible, marine bivalve mollusc. Although many small edible bivalves are loosely called cockles, true cockles are species in the family Cardiidae. True cockles live in sandy, sheltered beaches throughout the world. The distinctive rounded shells are bilaterally symmetrical, and are heart-shaped when viewed from the end. Numerous radial, evenly spaced ribs are a feature of the shell in most but not all genera.
The giant clams are the members of the clam genus Tridacna that are the largest living bivalve mollusks. There are actually several species of "giant clams" in the genus Tridacna, which are often misidentified for Tridacna gigas, the most commonly intended species referred to as “the giant clam”.
Tridacna is a genus of large saltwater clams, marine bivalve molluscs in the subfamily Tridacninae, the giant clams. They have heavy shells, fluted with 4 to 6 folds. The mantle is brightly coloured. They inhabit shallow waters of coral reefs in warm seas of the Indo-Pacific region. These clams are popular in marine aquaria, and in some areas, such as the Philippines, members of the genus are farmed for the marine aquarium trade. They live in symbiosis with photosynthetic algae (zooxanthellae). Some species are eaten by humans.
The maxima clam, also known as the small giant clam, is a species of bivalve mollusc found throughout the Indo-Pacific region. They are much sought after in the aquarium trade, as their often striking coloration mimics that of the true giant clam; however, the maximas maintain a manageable size, with the shells of large specimens typically not exceeding 20 centimetres (7.9 in) in length.
Hippopus hippopus, also known as the Horse Hoof clam and Strawberry clam, is a species of Giant Clam in the Family Tridacna and the family Hippopus. Hippopus is delicacy in many southeast asian countries due to its high quality meat.
Hippopus is a genus of large tropical saltwater clams, marine bivalve molluscs in the subfamily Tridacninae, the giant clam subfamily, of the family Cardiidae.
Tridacna crocea, the boring clam, crocus clam, crocea clam or saffron-coloured clam, is a species of bivalve in the family Cardiidae. It is native to the Indo-Pacific region. It is occasionally found in the aquarium trade where it is often simply referred to as crocea.
Tridacna derasa, the southern giant clam or smooth giant clam, is a species of extremely large marine clam in the family Cardiidae.
Freshwater bivalves are one kind of freshwater mollusc, along with freshwater snails. They are bivalves which live in freshwater, as opposed to saltwater, the main habitat type for bivalves.
Corculum is a genus of small saltwater clams, marine bivalve molluscs in the family Cardiidae, the cockles. They maintain Symbiodinium dinoflagellates as symbionts.
Corculum cardissa, the heart cockle, is a species of marine bivalve mollusc in the family Cardiidae. It is found in the Indo-Pacific region. It has a symbiotic relationship with dinoflagellates (zooxanthellae), which live within its tissues.
Cardioidea is a taxonomic superfamily of saltwater clams, marine bivalve molluscs consisting of the extant Cardiidae (cockles) and the extinct Pterocardiidae.
Dinocardium is a genus of large saltwater clams or cockles, marine bivalve molluscs in the family Cardiidae, the cockles. There is only one species in the genus, Dinocardium robustum, or the Atlantic giant cockle.
Laevicardium elatum, the giant egg cockle, giant Pacific cockle or the yellow cardinal cockle, is a species of saltwater clam, a cockle, a marine bivalve mollusc in the family Cardiidae, the cockles. This species is found in the tropical Panamic Province, from Southern California south through the Pacific coast of Mexico and the Gulf of California, and as far south as Panama.
Fragum erugatum is a small species of cockle, a marine bivalve mollusc in the family Cardiidae. It is found in the shallow seas off the coast of Western Australia. It is commonly known as the Hamelin cockle, cardiid cockle or heart cockle.
Tridacna noae, also known as Noah’s Giant Clam or the Teardrop clam, is a species of giant saltwater clam. Up until recently, T. noae was mistaken as being part of the giant clam species Tridacna maxima, but is now known to be its own independent species. It has a broad distribution in the Indo-Pacific.
Kuphus polythalamius is a species of shipworm, a marine bivalve mollusc in the family Teredinidae.
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