Didacna profundicola

Didacna profundicola
Illustrations of a specimen initially identified as Cardium catillus and now attributed to D. profundicola (1887)
Scientific classification
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Cardiida
Family: Cardiidae
Genus: Didacna
Species:
D. profundicola
Binomial name
Didacna profundicola
Logvinenko & Starobogatov, 1966

Didacna profundicola is a brackish-water bivalve mollusc of the family Cardiidae, the cockles. It has a trapezoidal, thin, white or pink-white shell, up to 10–15 mm (0.39–0.59 in) in length, with flattened ribs. The species is the deepest-dwelling bivalve of the Caspian Sea. It lives in the middle and southern parts of the sea at depths between 75 and 475 m (246–1,558 ft).

Description

Didacna profundicola has a trapezoidal, thin, moderately convex shell, with a narrower anterior margin, 25–38 flattened radial ribs and a distinct rounded posterior ridge. The shell length is up to 10–15 mm (0.39–0.59 in), the height is up to 7–9 mm (0.28–0.35 in), and the convexity is up to 7 mm (0.28 in). The coloration is white or pink-white, with thin yellow-grey periostracum. The hinge consists of one cardinal tooth in both valves. The cardinal tooth of the left valve is distinctly curved towards the anterior margin.[1][2][3]

Distribution and ecology

Didacna profundicola is the deepest-dwelling bivalve of the Caspian Sea. It lives in the middle and southern parts of the sea at depths between 75 and 475 m (246–1,558 ft). The species may presumably reach a depth of around 500 m (1,600 ft) or even 700 m (2,300 ft).[2][4][5]

The species is only known from the modern (Holocene) fauna.[3][6]

Taxonomy

Didacna profundicola was described by Boris Mikhailovich Logvinenko and Yaroslav Igorevich Starobogatov in 1966. Together with Didacna protracta the species has been placed in the new section Protodidacna[7] which is now considered to be a possible synonym of the genus Didacna.[8] The type locality of D. profundicola is in the central part of the Caspian Sea off Turkmenistan (39°38'N, 52°02'E) at a depth of 94 m (308 ft). The holotype is kept in the Zoological Institute of the Russian Academy of Sciences.[9][10]

The specimens described by Oscar Andreevich Grimm in 1877 under the name Cardium catillus[11] are now attributed to D. protracta and D. profundicola.[2][5]

References

  1. ^ Logvinenko, B. M.; Starobogatov, Y. I. (1969). "Tip Mollyuski. Mollusca" [Phylum Molluscs. Mollusca]. In Birshteyn, Y. A.; Vinogradov, L. G.; Kondakov, N. N.; Kuhn, M. S.; Astakhova, T. V.; Romanova, N. N. (eds.). Atlas bespozvonochnykh Kaspiyskogo morya [Atlas of the Invertebrates of the Caspian Sea] (in Russian). Moscow: Pishchevaya Promyshlennost. p. 328.
  2. ^ a b c Kijashko, P. V. (2013). "Mollyuski Kaspiyskogo morya" [Molluscs of the Caspian sea]. In Bogutskaya, N. G.; Kijashko, P. V.; Naseka, A. M.; Orlova, M. I. (eds.). Identification keys for fish and invertebrates of the Caspian Sea (in Russian). Vol. 1. Fish and molluscs. St. Petersburg; Moscow: KMK Scientific Press Ltd. p. 356. ISBN 978-5-87317-932-9.
  3. ^ a b ter Poorten 2024, p. 160.
  4. ^ Tarasov, A. G. (1997). "Rakoviny mollyuskov iz psevdoabissali Kaspiya" [Shells of molluscs from the Caspian pseudabyssal]. Doklady Rossiyskoy Akademii nauk (in Russian). 358 (1): 91–92.
  5. ^ a b Vinarski, M. V.; Kijashko, P. V.; Andreeva, S. I.; Sitnikova, T. Y.; Yanina, T. A. (2024). "Atlas and catalogue of the living mollusks of the Aral and Caspian Seas". Vita Malacologica. 23: 1–124. ISBN 978-3-948603-50-2.
  6. ^ Nevesskaja, L. A. (2007). "History of the genus Didacna (Bivalvia: Cardiidae)". Paleontological Journal. 41 (9): 861–949. Bibcode:2007PalJ...41..861N. doi:10.1134/s0031030107090018.
  7. ^ Logvinenko, B. M.; Starobogatov, Y. I. (1966). "Novyye dvustvorchatyye mollyuski iz kaspiyskoy profundali" [New bivalve molluscs from the Caspian profundal]. Biologicheskie Nauki (in Russian). 2: 13–16.
  8. ^ ter Poorten 2024, p. 156.
  9. ^ Vinarski, M. V.; Kantor, Y. I. (2016). Analytical catalogue of fresh and brackish water molluscs of Russia and adjacent countries. Moscow: A. N. Severtsov Institute of Ecology and Evolution of Russian Academy of Sciences. p. 72. ISBN 978-5-9908840-7-6.
  10. ^ Wesselingh, F. P.; Neubauer, T. A.; Anistratenko, V. V.; Vinarski, M.; Yanina, T.; ter Poorten, J. J.; Kijashko, P.; Albrecht, C.; Anistratenko, O. Y.; D'Hont, A.; Frolov, P.; Gándara, A. M.; Gittenberger, A.; Gogaladze, A.; Karpinsky, M.; Lattuada, M.; Popa, L.; Sands, A. F.; van de Velde, S.; Vandendorpe, J.; Wilke, T. (2019). "Mollusc species from the Pontocaspian region – an expert opinion list". ZooKeys (827): 31–124. Bibcode:2019ZooK..827...31W. doi:10.3897/zookeys.827.31365. PMC 6472301. PMID 31114425.
  11. ^ Grimm, O. A. (1877). Kaspijskoe more i ego fauna [The Caspian Sea and its Fauna]. Trudy Aralo-Kaspiiskoi Ekspeditsii (in Russian). Vol. 2 (2). St. Petersburg: St. Petersburg Society of Naturalists. pp. 58–62.

Cited texts

  • ter Poorten, J. J. (2024). A taxonomic iconography of living Cardiidae. Harxheim: ConchBooks. ISBN 978-3-948603-48-9.