Kuphus polythalamia

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Kuphus polythalamia
Kuphus polythalamia (Paletten, from Gray, 1857: plate 39 Fig. 3 [1])

Kuphus polythalamia (Paletten, from Gray, 1857: plate 39 Fig. 3)

Systematics
Order : Myoida
Superfamily : Pholadoidea
Family : Marine clams (Teredinidae)
Subfamily : Kuphinae
Genre : Kuphus
Type : Kuphus polythalamia
Scientific name
Kuphus polythalamia
( Linnaeus , 1767)
Housing tube by Kuphus polythalamia (from Gray, 1857: plate 39 Fig. 1)

Kuphus polythalamia is a shell - type from the family of Schiffsbohrmuscheln (Teredinidae). The species lives in symbiosis with chemoautotrophic, sulfur-oxidizing (or thioautotrophic) bacteria in the mangrove swamps of East Asia.

features

The equally-hinged, strongly gaping housing is greatly reduced and only encloses a very small part of the worm-shaped soft body, which lives upside down in a long, chalky tube stuck vertically in the sediment. The valves are also surrounded by a strong muscle ring at the base, ie some of them are even inner shells. The two flaps are up to 2.6 cm long. The front part is missing the sharp ribs. Overall, the outside of the two flaps is almost smooth. The housing is therefore almost inoperative, because the lower end of the chalky living tube is also closed with a layer of lime, which, however, has to be periodically reabsorbed as the animal grows and enlarges the living tube. The anterior and posterior sphincters are very small. This also indicates that the (original) drilling function of the two flaps is only rarely, if ever, used.

The fully grown soft body up to 1.55 m (1.90 m long; up to 2 m long) and about 6 cm thick is upside down in the chalky living tube. The soft body is dark in color and has a strong muscular wall. The visceral sac is comparatively short and takes up only a tenth of the length of the body, and it lies at the front end of the mantle cavity. The animals do not have a caecum, as is the case with other types of marine bivalve molluscs, which feed primarily on wood. The caecum is always very large in these wood-boring species, because the wood particles are collected in the caecum for digestion. In Kuphus polythalamia , the gills with only one leaf each extend over almost the entire length of the body.

The chalky living tube is slightly twisted and slightly increases in diameter towards the (lower) front end. The siphons at the rear end of the animal (= upper end of the living tube) are long and separated from each other. At the upper end, the chalky living tube occasionally divides into two tubes, which then enclose the siphons. At the lower end, the living tube has a diameter of up to 11.4 cm (4½ inches), at the upper end the diameter decreases to just under 4 cm ( one and a half inches ). The base or the lower end of the living tube is rounded with two overlapping septa and completely closed.

The siphons are half surrounded in the distal part by two additional limestone plates, the so-called pallets. The pallets consist of a stem and a semi-tubular or semi-conical leaf with the stem pointing down. The pallets of Kuphus polythalamia measure up to 5 cm in length, the stem gradually widens to a triangular leaf. The leaf has two horn-like protrusions. If the siphons are pulled back, the two pallets close the opening of the living tube or the two exits of the living tube.

Geographical distribution, habitat and way of life

The distribution area of Kuphus polythalamia stretches from the Philippines , southern China , Taiwan , Indonesia , New Guinea , northern Australia to the Solomon Islands . The species is probably also found in Madagascar and East Africa . The evidence is mostly based only on the lime pipes.

The animal lives in a chalk tube that is stuck vertically in the sediment of mangrove forests . It lives in symbiosis with chemoautotrophic (thiotrophic) bacteria that use hydrogen sulfide to generate energy. The bacteria are held in the gills.

Taxonomy and Phylogeny

The taxon was established by Carl von Linné in 1767 as Serpula polythalamia . At that time he still believed that the species belonged to the worms . It is the type species of the genus Kuphus Guettard, 1770. Synonyms are: Septaria arenarius Lamarck, 1818, Siliquaria bipartita Martin, 1880 (?), Teredo dubia Sivickis, 1928 and Teredo gigantea Home, 1806.

Only a recent species is currently recognized. But there are still three fossil species of the genus, the position of which is uncertain, as the taxonomy z. T. only based on residential tubes. So Kuphus polythalamia is not the only species in the genus, as is sometimes claimed in the zoological literature. The genus Kuphus is (currently) the only genus of the subfamily Kuphinae Tryon, 1862.

According to the molecular biological studies by Distel et al. (2017) Kuphus polythalamia is the sister species of Teredora malleolus .

1941 described the German paleontologist Friedrich von Huene a new dinosaur taxon Succinodon putzeri , a sauropod from the Late Cretaceous of Poland. The taxon was based on a (supposed) lower jaw with teeth. A follow-up investigation showed, however, that it is not the remains of a dinosaur skull from the late Mesozoic , but fossil calcareous tubes from the early Cenozoic , which the revising authors Krystyna Pozaryska and Halina Pugaczewska in 1981 interpreted as living tubes of Teredinids. However , they did not determine them down to the species, but left the fossil remains in the open nomenclature as Kuphus sp. The assignment to Kuphus must be doubted, as the tubes come from fully marine sedimentary rocks. They are much too small (only about 10 cm long, max. Diameter 1.5 cm), and the two authors also found a septation in the upper part near the opening of the living tube, which, taken together, does not speak for a Kuphus living tube.

literature

Individual evidence

  1. ^ A b John Edward Gray: Observations on the genus Furcella, Oken, a conchifer without concho or normal valves, and on the genera Teredo and Chaena. Proceedings of the Zoological Society of London, 25: 243-248, London 1857 Online at www.biodiversitylibrary.org and Plate 39
  2. ^ A b Harry G. Lee: Xray Conchology. Shell-o-Gram: The Official Publication of the Jacksonville Shell Club, Jacksonville Shell Club, Inc., Jacksonville, FL, 1991 [1]
  3. ↑ G. Felix Roch: About a juvenile specimen of Teredo arenaria (Linné) and the systematic position of this species. Beaufortia, 5 (44): 15–21, 1955 PDF (referred to as Teredo arenaria ; here also a picture of the two shell flaps! )
  4. ↑ Rudolf Kilias: Lexicon marine mussels and snails. 2nd edition, 340 p., Verlag Eugen Ulmer, Stuttgart 1997 ISBN 3-8001-7332-8 (p. 163)
  5. ↑ a b c Daniel L. Distel, Marvin A. Altamia, Zhenjian Lin, J. Reuben Shipway, Andrew Han, Imelda Forteza, Rowena Antemano, Ma. Gwen J. Peñaflor Limbaco, Alison G. Tebo, Rande Dechavez, Julie Albano, Gary Rosenberg, Gisela P. Concepcion, Eric W. Schmidt, Margo G. Haygood: Discovery of chemoautotrophic symbiosis in the giant shipworm Kuphus polythalamia (Bivalvia: Teredinidae) extends wooden-steps theory. Proceedings of the National Academy of Sciences , 114 (18): E3652-E3658, doi : 10.1073 / pnas.1620470114
  6. ^ Perceval Wright: Contributions to a Natural History of the Teredidae. Transactions of the Linnean Society of London, 25: London 1866 Online at www.biodiversitylibrary.org
  7. ↑ Creepy primal creature - Researchers find the first living giant wood worm. Retrieved April 19, 2017 .
  8. ↑ Carl von Linné: Systema naturae, Tom. I. Pars II. Editio duodecima reformata. P. 533–1327, Stockholm / Holmia, Salvius, 1767 Online at www.biodiversitylibrary.org (P. 1266)
  9. ↑ a b MolluscaBase: Kuphus polythalamia (Linnaeus, 1758)
  10. ↑ George Zammit Maempel: Kuphus melitensis, a new teredinid bivalve from the Late Oligocene Lower Coralline Limestone of Malta. Mededelingen van de Werkgroep voor Tertiaire en Kwartaire Geologie, 30 (3/4): 155-175, 1993 abstract
  11. ↑ Krystyna Pozaryska, Halina Pugaczewska: Bivalve nature of Huene's dinosaur Succinodon . Acta Palaeontologica Polonica, 26 (1): 27-34, 1981 PDF .