The distribution of the genus Theodoxus includes Europe and northern Africa and also extends east to southern Iran.[3] No other species within Neritidae have sympatrical distribution with Theodoxus.[4] The distribution of the genus Theodoxus is an exception within Neritidae, because Neritidae live primarily in the southern hemisphere.[4] Species within Theodoxus are the only Neritidae snails, that live in temperate climate.[4]
Bunje & Lindberg (2007) presented the first phylogenetic hypothesis of the clade Theodoxus.[4] The evolution of the genus Theodoxus was affected by separating of Mediterranean Sea and Paratethys sea in Miocene.[4]
Descriptionedit
The shell in this genus is semiovular with a flat apertural plain. There is no umbilicus. The columella and inner whorls are dissolved.[3]
Species in the genus Theodoxus are highly variable in size, in color pattern of the periostracum, in details of the operculum and in the radula, and all these factors can make identification to species level very challenging.[5]
Ecologyedit
These animals live on stones, and often also under stones, in up to 5–6 m depth or deeper, feeding on algal covers.[3]Theodoxus needs rough surfaces in order to be able to digest its food, so a stony substrate is necessary.[3] Green algae [clarification needed] are not consumed; Theodoxus has no cellulases.[3] These snails lay egg capsules containing 30-70 eggs each, usually on the shells of other Theodoxus animals; only one juvenile grows, the other eggs serve as food.[3]
Speciesedit
There were no systematic review of the genus Theodoxus as of 2007.[4] Bunje (2004) noted at least 34 extant taxa at species level in the genus Theodoxus. IUCN Red List (2015) provided conservation status for 23 species of Theodoxus.[6]
Theodoxus fluviatilis (Linnaeus, 1758)[12][16] - type species.[18] synonyms: Theodoxus brauneri (Lindholm, 1908)[18] (but as separate species per[12][16]); Theodoxus brauneri f. lacrymans Lindholm, 1908;[18]Theodoxus brauneri f. alboguttata Lindholm, 1908;[18]Theodoxus brauneri f. pulherrima Lindholm, 1908;[18]Theodoxus lutetianus Montfort, 1810.[3] Bunje (2005)[19] does not consider Theodoxus velox Anistratenko, 1999[20][17] to be a distinct species from Theodoxus fluviatilis.[19][14][17]
This article incorporates public domain text from the reference [3]
^Montfort D. de (1810). Conchyliologie systématique, et classification méthodique des coquilles; offrant leurs figures, leur arrangement générique, leurs descriptions caractéristiques, leurs noms; ainsi que leur synonymie en plusieurs langues. Ouvrage destiné à faciliter l'étude des coquilles, ainsi que leur disposition dans les cabinets d'histoire naturelle. Coquilles univalves, non cloisonnées. Tome second. pp. [1-3], 1-676. Paris. (Schoell). page 350.
^ abBouchet, P. (2014). Theodoxus Montfort, 1810. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=153531 on 2014-11-17.
^ abcdefgh"Genus summary for Theodoxus ". AnimalBase, last modified 24 February 2009, accessed 11 April 2011.
^ abcdefBunje P. M. & Lindberg D. R. (2007). "Lineage divergence of a freshwater snail clade associated with post-Tethys marine basin development". Molecular Phylogenetics and Evolution42(2): 373–387. doi:10.1016/j.ympev.2006.06.026.
^Zettler M. L., Frankowski J., Bochert R. & Röhner M. (2004). "Morphological and ecological features of Theodoxus fluviatilis (Linnaeus, 1758) from Baltic brackish water and German freshwater populations". Journal of Conchology38(3): 305-316. .pdf PDF[permanent dead link].
^The IUCN Red List of Threatened Species. Version 2014.3. <www.iucnredlist.org>. Downloaded on 23 March 2015. (Searching for "Theodoxus".)
^Andrussov (1912). Verh. Russ. min. Ges. St. Pétersburg (2)49: 4
^ abc"Neritaea". Fauna Europaea, last update 27 January 2011, accessed 12 April 2011.
^ abcdefghi(in German) Schütt H. (1965). "Zur Systematik und Ökologie türkischer Süßwasserprosobranchier". Zoologische Mededelingen41(3): 43-72, Plate 1. abstract, PDF.
^Van Damme, D.; Ghamizi, M. (2010). "Theodoxus niloticus". IUCN Red List of Threatened Species. 2010: e.T184690A8314592. doi:10.2305/IUCN.UK.2010-3.RLTS.T184690A8314592.en. Retrieved 17 November 2021.
^ abcdefghijKantor Yu I., Vinarski M. V., Schileyko A. A. & Sysoev A. V. (published online on March 2, 2010). "Catalogue of the continental mollusks of Russia and adjacent territories". Version 2.3.1.
^ abcdeAnistratenko V. V. (2005). "Lectotypes for Tricolia pullus, Gibbula divaricata and Theodoxus fluviatilis (Mollusca, Gastropoda) revisited". Vestnik zoologii39(6): 3-10. PDF .
^ abBunje, P. M. E. (2005). "Pan-European phylogeography of the aquatic snail Theodoxus fluviatilis (Gastropoda: Neritidae)". Molecular Ecology. 14 (14): 4323–4340. doi:10.1111/j.1365-294X.2005.02703.x. PMID 16313596. PDF.
^ abcAnistratenko O. Y., Starobogatov Y. I. & Anistratenko V. V. (1999). "Mollusks of the genus Theodoxus (Gastropoda, Pectinibranchia, Neritidae) from the Black and the Azov seas basin". Vestnik Zoologii33: 11-19.
^Zettler, M.; Van Damme, D. (2010). "Theodoxus meridionalis". IUCN Red List of Threatened Species. 2010: e.T165354A6005925. doi:10.2305/IUCN.UK.2010-4.RLTS.T165354A6005925.en. Retrieved 17 November 2021.
^ abcdZettler M. L. (2007). "A redescription of Theodoxus schultzii (Grimm, 1877), an endemic neritid gastropod of the Caspian Sea". Journal of Conchology39(3): 245-252. abstract. Archived 2011-07-22 at the Wayback Machine
^ abGlöer P. (2002). Die Süßwassergastropoden Nord- und Mitteleuropas. Die Tierwelt Deutschlands, ConchBooks, Hackenheim, 326 pp., ISBN 3-925919-60-0.
^WoRMS (2010). Theodoxus coronatus (Leach, 1815). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=216264 on 2011-04-11
^Van Damme, D.; Ghamizi, M. (2010). "Theodoxus maresi". IUCN Red List of Threatened Species. 2010: e.T21727A9314600. doi:10.2305/IUCN.UK.2010-3.RLTS.T21727A9314600.en. Retrieved 17 November 2021.
^Van Damme, D.; Ghamizi, M. (2010). "Theodoxus marteli". IUCN Red List of Threatened Species. 2010: e.T184623A8302935. doi:10.2305/IUCN.UK.2010-3.RLTS.T184623A8302935.en. Retrieved 17 November 2021.
^Van Damme, D.; Ghamizi, M. (2010). "Theodoxus numidicus". IUCN Red List of Threatened Species. 2010: e.T21728A9314774. doi:10.2305/IUCN.UK.2010-3.RLTS.T21728A9314774.en. Retrieved 17 November 2021.
^ abcGoodwin D. R. (2006). "The Discovery of Neritina (Theodoxus ) cariosa (Wood, 1828) on the Island of Maui, Hawaii (Gastropoda: Neritidae)". Visaya Net 11 pp. PDF.
^Mansoorian A. (2001). "Freshwater Gastropod of Khuzestan Province, South-West Iran". Iranian Int. J. Sci.2(2): 9 pp. PDF.
^Glöer P. & Pešić V. (2012). "The freshwater snails (Gastropoda) of Iran, with descriptions of two new genera and eight new species". ZooKeys219: 11-61, doi:10.3897/zookeys.219.3406.
Eichhorst T.E. (2016). Neritidae of the world. Volume 2. Harxheim: Conchbooks. pp. 696–1366
External linksedit
Wikimedia Commons has media related to Theodoxus.
Bandel K. (2001). "The history of Theodoxus and Neritina connected with description and systematic evaluation of related Neritimorpha (Gastropoda)". Mittelungen aus dem Geologisch-Palaontologischen Institut Universitat Hamburg85: 65–164. abstract.