Psiloteredo megotara

Psiloteredo megotara
Psiloteredo megotara (from Forbes and Hanley, 1848–53, Vol. 4, Plate 1, Fig. 6)
Systematics
Order : Myida Superfamily : Pholadoidea Family : Marine clams (Teredinidae) Subfamily : Teredininae Genre : Psiloteredo Type : Psiloteredo megotara
Scientific name
Psiloteredo megotara
( Hanley in Forbes & Hanley, 1848)

Psiloteredo megotara, interior view of the left flap, palette, from Forbes and Hanley, 1848–53, vol. 4, plate 18, fig. 1–2.

Psiloteredo megotara is a shell - type from the family of Schiffsbohrmuscheln (Teredinidae). Due to the low salinity tolerance (27 to 37 PSU), the species is generally not a threat to wooden structures in the water or to wooden ships.

features

The housing , which has the same flaps , is up to 1.3 cm long. It is slightly taller (1.4 cm) than it is long and very bloated; this results in a largely spherical overall shape. It sits in front of the worm-shaped body and only covers a very small part of it. The soft body is about one centimeter thick and up to one meter long. The case (about 1 × 1 cm) is comparatively short with a small, triangular front part that is covered with longitudinal grooves. The dorsal margin is concave. The central main part of the housing is oblique-triangular; the front smaller part starts at the top, set off by a sloping edge. The surface of the middle part mainly shows only growth strips and a few radial elements in the center. The front part, the hemispherical auriculum, sits on the middle part diagonally upwards in a dome shape. The surface is almost smooth. The shell is thin and fragile and is made of aragonite . There are two sphincters.

The siphons are fused together over a third of their length. On the outside of the siphons, there are two accessory lime plates, the so-called pallets. The pallets are elongated, paddle-shaped, but quite wide in relation to their length (L / W ratio: 1.3). The outer line often shows several kinks, the stem is pointed and very short in relation to the total length (only about ¼ of the total length). They are up to 1.3 cm long and 0.7 cm wide. They are almost completely calcified and the organic content is low. The outer side is convex, the surface roughened. The inside is concave and smooth. At the front end there is a semicircular depression on the inside. The front of the leaf has a border made of organic, transparent periostracum . The aragonitic lining of the drill pipe is grooved and flaky at the exit of the pipe.

The gills are greatly reduced. This suggests that the species mainly feeds on wood.

Geographical distribution, habitat and way of life

The range of the species is the temperate part of the North Atlantic and its tributaries. The species penetrates into the North Sea , the western Baltic Sea as well as the Mediterranean and the Black Sea . It is also found on the North American east coast. The species may be restricted to floating wood.

Psiloteredo megotara is only slightly salinity tolerant (27 to 37 PSU), but can withstand large temperature fluctuations (1–25 ° C).

The species is already known from the Miocene of Twistringen .

development

In one spawning season, females produce more than 100 million relatively small eggs, less than 45 µm in diameter. The eggs are released into the open water and fertilized there. From the fertilized eggs, trochophora larvae develop quickly, often in less than 12 hours, and the Veliger larvae in a further 12 hours, which then float in open water for three to four weeks and feed on microplankton before they settle on one piece Fix wood.

Taxonomy

The species was first described by Sylvanus Hanley in 1848 under the original binomial Teredo megotara . Today the taxon is placed in accordance with the genus Psiloteredo Bartsch, 1929.

literature

• Ruth D. Turner: A survey and illustrated catalog of the Teredinidae (Mollusca: Bivalvia). 265 pp., Museum of Comparative Zoology, Harvard University, Cambridge 1966 Online at biodiversitylibrary.org.

Individual evidence

1. ^ ^{A b c} Edward Forbes, Sylvanus Charles Hanley: A history of British Mollusca and their shells. 3 volumes, London, Van Voorst, 1848–1853. Vol. 1: i-lxxx [1853], 1-486 [1848], pl. A – W, ​​AA – ZZ, AAA – ZZZ [dates uncertain]; Vol. 2: 1-480 [1 dec. 1849], 481-557 [1850]; Vol. 3: 1-320 [1850], 321-616 [1851]; Vol. 4: 1-300 [1852], pl. 1–114F (publication dates uncertain). Online at www.biodiversitylibrary.org (p. 77).
2. ↑ ^{a b c} Luísa MS Borges, Lucas M. Merckelbach, Íris Sampaio, Simon M. Cragg: Diversity, environmental requirements, and biogeography of bivalve wood-borers (Teredinidae) in European coastal waters. Frontiers in Zoology, 11, 13, 13 pp., 2014
3. ↑ Paul Chambers: Channel Island Marine Molluscs: An Illustrated Guide to the Seashells of Jersey, Guernsey, Alderney, Sark and Herm. 321 pp., Charonia Media, 2008, ISBN 978-0-9560655-0-6 , p. 280.
4. ↑ Luísa MS Borges: The internal structure of the pallets of Nototeredo norvagica and Psiloteredo megotara (Bivalvia: Teredinidae): implications for subfamilial allocations. Zoomorphology, 135 (1): 33-41, 2016 doi : 10.1007 / s00435-015-0277-4
5. ^ Arie W. Janssen: The mollusc fauna of the Twistringer layers (Miocän) of Northern Germany. Scripta Geologica, 10: 1-96, Leiden 1972 PDF (p. 20).
6. ↑ MolluscaBase: Psiloteredo megotara (Hanley in Forbes & Hanley, 1848)