Pleuroceridae

Last updated

Pleuroceridae
Io fluvialis.jpg
Io fluvialis
Athearnia anthonyi.jpg
Athearnia anthonyi
Scientific classification OOjs UI icon edit-ltr.svg
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Superfamily: Cerithioidea
Family: Pleuroceridae
Fischer, 1885
Diversity [1] [2]
About 150 extant species
Synonyms
  • Anaplocamidae Dall, 1921 ·
  • Ceriphasiidae Gill, 1863 ·
  • Ceriphasiinae Gill, 1863 · > junior subjective synonym
  • Ellipstomatidae Hannibal, 1912 ·
  • Gyrotominae Hannibal, 1912 ·
  • Strepomatidae Haldeman, 1864

Pleuroceridae, common name pleurocerids, is a family of small to medium-sized freshwater snails, aquatic gilled gastropod mollusks in the superfamily Cerithioidea.

Contents

Description

(Original description) This animal is fluviatile and similar to those found in the family Thiaridae; however, it is oviparous and possesses a mantle that is not fringed. According to William Stimpson, these organisms lack copulatory organs. The central tooth of the radula is short, wide, and arched at the base, featuring a multi-cuspidate edge. The lateral tooth is rhomboidal with a very well-developed primary cusp, while the marginal teeth are narrow and pectinated at their extremities. Additionally, the jaws are polygonal and scaly.

The shell is either melaniform or cerithiform in shape. The aperture may be entire, sinuous, or canaliculated, and the outer lip is sharp. The operculum is thin and paucispiral, with an anterior and submarginal nucleus.

The mollusks belonging to this family have a geographic distribution that is limited to North America. Of the 464 species described by Tryon in his 1875 monograph, approximately half originate from Tennessee and Alabama. These shells are so abundant that they literally cover the surface of the rocky riverbeds, sometimes leaving barely an inch of free space. Their summits are generally eroded.

Stimpson did not find any valid differences between the animals of the genera Io, Ancylotus (synonym of Leptoxis Rafinesque, 1819), and Goniobasis (synonym of Elimia H. Adams & A. Adams, 1854). However, the primary cusp of the lateral tooth in Ancylotus is very wide and obtuse, whereas it is acuminate in the genera Goniobasis, Io, and Gyrotoma. [3]

These snails have an operculum and typically a robust high-spired shell.

Reproduction is iteroparous, and juvenile snails emerge from eggs laid on a firm surface by a gonochoristic female. There is no veliger stage.

Evolution

There is very high level of mitochondrial heterogeneity in apparent species of Pleuroceridae (highest among gastropods, also with Semisulcospiridae), that has not been sufficiently explained yet as of 2015. [4] However, it has been suggested that this may be due to pleurocerids having very poor dispersal abilities, allowing even slightly separated populations to see great genetic divergence. [5]

Populations of the pleurocerid species in the Old Appalachians (Virginia south to Georgia) are present on both sides of the Eastern Continental Divide, but there is no difference in the extent of intrapopulation heterogeneity on either side, and there is no evidence for cryptic speciation on either side either. Given the age of the Appalachians, it has been suggested that these populations may be extremely ancient, dating back to the Paleozoic when the initial Appalachian orogeny separated them, to the extent that any geographic signal in the test gene for the divergence estimates has been lost. Levels of genetic divergence appear to be lower in the modern center for pleurocerid diversity (the Alabama and Coosa river systems) than in the Old Appalachians, indicating that the latter may represent the ancestral origin of pleurocerids. [5]

Distribution

As currently defined, this family is confined entirely to eastern North American fresh waters. Similar snails formerly classified with Pleuroceridae, but now assigned to other families are widespread in temperate and tropical parts of Southern and Eastern Asia,[ citation needed ] and Africa.[ citation needed ] Most require unpolluted rivers and streams, but a few are adapted to living in lakes or reservoirs.

Taxonomy

2005 taxonomy

The following two subfamilies have been recognized in the taxonomy of Bouchet & Rocroi (2005): [6]

2009 taxonomy

Subfamily Semisulcospirinae within Pleuroceridae was elevated to family level Semisulcospiridae by Strong & Köhler (2009). [7]

Genera

Genera within the family Pleuroceridae are organized in the one subfamily only since 2009 and they include:

References

  1. ↑ Strong, E.E.; Gargominy, O.; Ponder, W.F.; Bouchet, P. (2008). "Global diversity of gastropods (Gastropoda; Mollusca) in freshwater". Hydrobiologia . 595 (1): 149–166. Bibcode:2008HyBio.595..149S. doi:10.1007/s10750-007-9012-6. hdl:10088/7390.
  2. ↑ Strong, E.E.; Colgan, D.J.; Healy, J.M.; Lydeard, C.; Ponder, W.F.; Glaubrecht, M. (2011). "Phylogeny of the gastropod superfamily Cerithioidea using morphology and molecules". Zoological Journal of the Linnean Society . 162 (1): 43–89. doi:10.1111/j.1096-3642.2010.00670.x.
  3. ↑ Fischer, P. (1880–1887). Manuel de conchyliologie et de paléontologie conchyliologique, ou histoire naturelle des mollusques vivants et fossiles suivi d'un Appendice sur les Brachiopodes par D. P. Oehlert. Avec 23 planches contenant 600 figures dessinées par S. P. Woodward. Paris: F. Savy. p. 705. Retrieved 23 December 2025.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  4. ↑ Whelan, N.V.; Strong, E.E. (2015). "Morphology, molecules and taxonomy: Extreme incongruence in pleurocerids (Gastropoda, Cerithioidea, Pleuroceridae)". Zoologica Scripta . 45 (1): 62–87. doi:10.1111/zsc.12139.
  5. 1 2 Dillon, Robert T.; Robinson, John D. (2009). "The snails the dinosaurs saw: Are the pleurocerid populations of the Older Appalachians a relict of the Paleozoic Era?" . Journal of the North American Benthological Society. 28 (1): 1–11. Bibcode:2009JNABS..28....1D. doi:10.1899/08-034.1. ISSN   0887-3593. S2CID   85340338.
  6. ↑ Bouchet, Philippe; Rocroi, Jean-Pierre; Frýda, Jiri; Hausdorf, Bernard; Ponder, Winston; Valdés, Ángel & Warén, Anders (2005). "Classification and nomenclator of gastropod families". Malacologia . 47 (1–2). Hackenheim, Germany: ConchBooks: 1–397. ISBN   3-925919-72-4. ISSN   0076-2997.
  7. ↑ Strong, E.; Köhler, F. (2009). "Morphological and molecular analysis of "Melania" jacqueti(Dautzenberg & Fischer, 1906): From anonymous orphan to critical basal offshoot of the Semisulcospiridae (Gastropoda: Cerithioidea)". Zoologica Scripta . 38 (5): 483–502. doi:10.1111/j.1463-6409.2008.00385.x.

Further reading

This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.