Kuphus is a genus of shipworms, marine bivalve molluscs in the familyTeredinidae. There are four extinctspecies in the genus, Kuphus arenarius, Kuphus incrassatus, Kuphus fistula and Kuphus melitensis. The only extant species is Kuphus polythalamius, the longest bivalve mollusc in the world where the only known permanent natural habitat is Kalamansig, Sultan Kudarat in the Philippines. Members of this genus secrete calcareous tubes. Based only on the calcareous tube, this species was originally thought by Linnaeus to be a tube worm, so he placed it in the genus Serpula. Despite the fact that Kuphus polythalamius is now known to be a mollusc, its common name is the giant tube worm. Since 1981 however, the name "giant tube worm" has also been applied to the hydrothermal vent species Riftia pachyptila, which is indeed a worm, an annelid.
Taxonomy
Large, tusk-shaped, calcareous tubes were occasionally washed up on beaches. There was disagreement among zoologists in the 18th century as to whether the creature which made one of these was a polychaete tube-worm or came from a mollusc. Linnaeus described the species in 1758. He considered that it was a serpulid worm and named it Serpula arenaria, a name which in 1767 he changed to Serpula polythalamia. There was some confusion as to precisely which taxon he was describing, but S. polythalamius became the type species of the genus Serpula, a genus of polychaete worms. In 1770, Guettard introduced the name Kuphus for the genus, realising that the animal was not a worm but a mollusc. This meant that, according to the ICZN rules, the specific name became Kuphus polythalamius.
Fossil species
s of Kuphus polythalamius have been found dating back to the Oligocene. They came from rocks in various tropical and sub-tropical areas including Indonesia, Pakistan, Jamaica, Grenada, South Africa and Somalia. Fossils of the extinct species, Kuphus melitensis, are found in Late Oligocene-aged coralline limestone of Malta Fossils of the extinct species, Kuphus incrassatus, have been found in rocks in Jamaica, Mexico, Panama, Puerto Rico, Trinidad and Tobago, Florida and Mississippi. Another species is Kuphus arenarius that have been recorded in Oligocene to Miocene-aged limestone layers of Asmari Formation in Iran. They are common in sedimentary Tertiary rocks in the Caribbean region. They date back to the Oligocene and Miocene and have been used for absolute dating of the rocks, using the relative proportions of two strontium isotopes in the fossils. Fossils of the extinct species, Kuphus fistula, dating from the Miocene and Pliocene, have been found in various locations in Virginia in the United States.
Fossils found near Warsaw by paleontologist, Friedrich von Huene in 1941 were misidentified as being the teeth and parts of the jaw of a new species of dinosaur, which he named Succinodon putzeri. It was later determined that these were in fact the fossil remains of a marine boring bivalve, a previously undescribed species of Kuphus.
''Kuphus polythalamius''
The tube of Kuphus polythalamius is known as a crypt and is a calcareous secretion designed to enable the animal to live in its preferred habitat, the mud of mangrove swamps. A typical specimen measures in length and is shaped like a truncated elephant's tusk. The wider, anterior end is closed, has a rounded tip, and is about in diameter. From there the tube tapers to an open, posterior end about in diameter, with a central septum. Siphons project through this end for feeding and respiration. They can be withdrawn inside the tube and the end can be sealed with a set of specialised plates or "pallets". The two small valves of the mollusc are inside the tube along with the mantle, gut and other soft organs. In the intact but otherwise empty tube found on the strandline, they can be seen by X-ray photography. Marine biologistRuth Turner studied shipworms and considered that their common ancestor would have been very like Kuphus polythalamius, the most primitive of the teredinids. She believed that the anatomy of the tube was such that the animal would not have been able to burrow in wood as other modern teredinids do, but would instead have lived buried in soft sediments. In April 2017, the species became the focus of international attention when the announcement of a scientific study conducted in the Philippines was misinterpreted by foreign news reporters as the discovery of a rare live specimen. The sample was gunmetal black, and very muscular. While other shipworms feed on submerged wood, K. polythalamius was found to use bacteria in its gills to use hydrogen sulphide in the water as an energy source used to convert carbon dioxide into nutrients. In this respect it resembles the unrelated giant tube worm, which actually is a worm. Videos uploaded to the YouTube video sharing site, however, already show Philippine scientists dissecting specimens as far back as 2010, after a news feature on a giant tamilok, the local name for the common shipworm, was broadcast on a local TV network. The report by local media celebrity Jessica Soho suggests that local residents in the province of Sultan Kudarat, Mindanao island, were familiar enough with the creature to the point of treating it as a delicacy. After the discovery of the species in Sultan Kudarat, various environmental groups launched a campaign to protect the species and its habitat from further destruction and human consumption. Currently, the municipal waters where the species thrive in is protected by the local government.
Distribution
Today, Kuphus polythalamius is found in the western Pacific Ocean, the western and eastern Indian Ocean and the Indo-Malaysian area. The range includes the Philippines, Indonesia and Mozambique. However, the only thoroughly studied natural habitat of the species is in Kalamansig, Sultan Kudarat in the Philippines.
Longest bivalve
The giant clam is generally considered to be the largest bivalve mollusc. It is indeed the heaviest species, growing to over and measuring up to in length, but Kuphus polythalamius holds the record for the largest bivalve by length. A specimen owned by Victor Dan in the United States has a length of, which is considerably longer than the largest giant clam.
