The “index of the copulatory apparatus” and its application to the systematics of freshwater pulmonates (Mollusca: Gastropoda: Pulmonata)

M.V. Vinarski

Abstract. The index of the copulatory apparatus (ICA) is calculated as the ratio between lengths of the praeputium and the penis sheath in the copulatory apparatus in freshwater pulmonate mollusks. ICA is often used for species’ delimitation and identification in different taxa of pulmonates, however, its variation (in both intra- and interspecific levels) is still poorly studied that may make troubles for systematicists. The variation of ICA in pond snails (family Lymnaeidae Rafinesque, 1815) has been studied in several aspects (intra- and interpopulation, interspecific). It has been shown that the index varies considerably, and it is almost impossible to identify a single specimen on the base of ICA solely. However, mean ICA values are more useful for taxonomic and identification purposes. Closely related species of lymnaeids demonstrate some extent of overlap between their ranges of ICA variation that hampers their identification but is not a cause for synonymisation. The factors of different origin that potentially may influence the ICA values in freshwater pulmonates have been reviewed. It is revealed that ICA manifests significant ontogenic and (in some lymnaeid species) geographical changes. The use of ICA in pulmonate systematics should be accompanied by data on variation in another characters of conchological or anatomical kind.
Key words: pulmonates, taxonomy, species delineation, species identification, variation, copulatory apparatus, Lymnaeidae

Zoosystematica Rossica, 2011, 20(1): 11-27  ▪  Published in print 28 July 2011

Open full article  


Barker, G.M. 1981. Nembutal for narcotisation of mollusks. Veliger, 24(1): 76.

Beriozkina, G.V. & Starobogatov, Ya.I. 1988. Reproductive ecology and egg clusters of freshwater Pulmonata. Trudy Zoologicheskogo Instituta AN SSSR, 1–306. (In Russian).

Brown, D.C. 1994. Freshwater Snails of Africa and their Medical Importance. Taylor & Francis, London. 673 p.

Colton, H.S. 1915. A provisional key to the subgenera and species of North American lymnaeids. The Nautilus, 28: 119–120.

Davydov, A.F., Kruglov N.D. & Starobogatov, Ya.I. 1981. Experimental crosses of two forms of Lymnaea stagnalis (Gastropoda, Pulmonata) and problems of taxonomy of the subgenus Lymnaea s. str. Zoologicheskiy Zhurnal, 60(9): 1325–1338. (In Russian).

Emberton, K.C. 1989. Retraction/extension and measurement error in a land snail: effects on systematic characters. Malacologia, 31(1): 157–173.

Ginetskinskaya, T.A. 1968. Trematody: ikh zhiznennye tsikly, biologiya i evolyutsiya [Trematodes: their life cycles, biology and evolution]. Nauka, Leningrad. 410 p. (In Russian).

Hubendick, B. 1954. Viewpoints on species discrimination with special attention to medically important snails. Proceedings of the Malacological Society of London, 31: 6–11.

Hubendick, B. 1955. Phylogeny in the Planorbidae. Transactions of the Zoological Society of London, 28: 453–542.

Hubendick, B. 1978. Systematics and comparative morphology of the Basommatophora. In: Fretter V., Peake, J. (Eds.) Pulmonates, 2A: 1–47. Academic Press, London.

Jackiewicz, M. 1996. Concerning Hungarian populations of „Galba palustris“ studied by Kilias (1992) (Gastropoda: Pulmonata: Lymnaeidae). Malakologische Abhandlungen, Museum für Tierkunde Dresden, 18(1): 59–67.

Jackiewicz, M. 1998. European species of the family Lymnaeidae (Gastropoda Pulmonata Basommatophora). Genus, 9(1): 1–93.

Kilias, R. 1992. Vergleichend-anatomische Untersuchungen an “Galba palustris (O.F. Müller)” von ungarischen Fundorten als Beitrag zur palustris-Problematik (Gastropoda, Basommatophora: Lymnaeidae). Malakologische Abhandlungen, Museum für Tierkunde Dresden, 16: 25–29.

de Kock, K.N. & Wolmarans, C.T. 2005. Distribution and habitats of Bulinus depressus and possible role as intermediate host of economically important helminth parasites in South Africa. Water SA, 31(4): 491–496.

Kottelat, M. & Freyhof, J. 2007. Handbook of freshwater fishes of Europe. Kottelat, Cornol, Switzerland & Freyhof, Berlin, Germany. 646 p.

Kruglov, N.D. 1980. The reproductive biology of freshwater pulmonate molluscs (Pulmonata). Zoologicheskiy Zhurnal, 59(7): 986–995. (In Russian).

Kruglov, N.D. 2005. Mollyuski semeistva prudovikov Evropy i Severnoy Azii [Mollusks of the family Lymnaeidae (Gastropoda Pulmonata) in Europe and Northern Asia]. SGPU Publishing, Smolensk. 507 p. (In Russian).

Kruglov, N.D. & Starobogatov, Ya.I. 1985. Methods of experimental hybridization and some results of its application in the taxonomy of Lymnaeidae (Gastropoda: Pulmonata). Malacological Review, 18 : 21–35.

Kunigelis, S.C. & Saleuddin, A.S.M. 1984. Anesthetization of Planorbidae (Mollusca): methodology and pharmacology. Experientia, 40: 584–585.

Lazareva, A.I. 1967. On the systematics of freshwater snails of Kazakhstan from the group Lymnaea palustris Müller (Gastropoda, Pulmonata). Zoologicheskij Zhurnal,46(9): 1340–1349. (In Russian).

Meier-Brook, C. 1964. Gyraulus acronicus und G. rossmaessleri, ein anatomischer Vergleich (Planorbidae). Archiv für Molluskenkunde, 93(5/6): 233–242.

Meier-Brook, C. 1976. The influence of varied relaxing and fixing conditions on anatomical characters in a Planorbis species. Basteria, 40(4/6): 101–106.

Meier-Brook, C. 1983. Taxonomic studies in Gyraulus. Malacologia, 24(1–2): 1–113.

Pointier, J.P., Cazzaniga, N.J., Gonzáles-Sa­las, C., Gutiérrez, A., Arenas, J.A., Bargues, M.D. & Mas-Coma, S. 2006. Anatomical studies of sibling species within Neotropical lymnaeids, snail intermediate hosts of fascioliasis. Memórias do Instituto Oswaldo Cruz, 101(4): 431–435.

Roszkowski, W. 1914. Note sur l’appareil génital de Limnaea auricularia L. & Limnaea ovata Drap. Zoologischer Anzeiger, 44(4): 175–179.

Soldatenko, E.V. & Starobogatov, Ya.I. 2000. Genus Planorbis (Gastropoda: Pulmonata: Planorbidae). Ruthenica, 10(1): 23–35.

Sorensen, R.E& Minchella, D.J. 2001. Snail-trematode life history interactions: past trends and future directions. Parasitology, 123: S1–S18.

Starobogatov, Ya.I., Prozorova, L.A. & Zatravkin, M.N. 1989. Species composition of the family Physidae (Gastropoda Pulmonata Lymnaeiformes) of Siberia and Far East of the USSR (with notes on European physids). Byulleten’ Moskovskogo Obshchestva Ispytatelej Prirody, otdel biologicheskiy, 94(1): 62–78. (In Russian).

Stiglingh, I., van Eeden, J.A. & Ryke P.A.J. 1962. Contributions to the morphology of Bulinus tropicus (Gastropoda: Basommatophora: Planorbidae). Malacologia, 1(1): 73–114.

Stothard, J.R., Loxton, N.J. & Rollinson D. 2002. Freshwater snails on Mafia Island, Tanzania with special emphasis upon the genus Bulinus (Gastropoda: Planorbidae). Journal of Zoology, 257: 353–364.

Suvorov, A.N. 1999. The conflict between operative and conservative subsystems of organisms in the evolution of terrestrial snails (Stylommatophora, Pullmonata). Zoologicheskiy Zhurnal, 78(7): 778–787. (In Russian).

Vinarski, M.V. 2009. Geographical variability in the male genitalia in two stagnicoline species (Gastropoda: Pulmonata: Lymnaeidae). Mollusca (Dresden), 27(2): 157–166.

Vinarski, M.V. & Glöer, P. 2009. Taxonomical notes on Euro-Siberian freshwater molluscs. 4. Re-examination of Limnaea psilia Bourguignat, 1862, with the description of Radix parapsilia n.sp. (Gastropoda: Pulmonata: Lymnaeidae). Archiv für Molluskenkunde, 138(2): 123–136.

Vinarski, M.V., Zuykov, M.A. & Pelletier, E. 2010. A study of the reproductive system of pond snails (family Lymnaeidae) from the impact waterbodies of the Novozybkov District (Bryansk Region) and the River Techa drainage basin. Voprosy radiatsionnoy bezopasnosti, 3: 74–79. (In Russian).

Wilson, R.A. & Denison, J. 1980. The parasitic castration and gigantism of Lymnaea truncatula infected with the larval stages of Fasciola hepatica. Zeitschrift für Parasitenkunde, 61: 109–119.

Yablokov, A.V. 1966. Izmenchivost’ mlekopitayuschchikh [Variability of mammals]. Nauka, Moscow. 364 p. (In Russian).

Zagorodnyuk, I. 2004. Levels of morphological differentiation in closed species of mammals and the concept of hiatus. Visnik L’vivskogo Universitetu, 38: 21–42. (In Ukrainian).

Volume, Year:
Vol. 28. 2019
Vol. 27. 2018
Vol. 26. 2017
Vol. 25. 2016
Vol. 24. 2015
Vol. 23. 2014
Vol. 22. 2013
Vol. 21. 2012
Vol. 20. 2011
Vol. 19. 2010
Vol. 18. 2009
Vol. 17. 2008
Vol. 16. 2007
Vol. 15. 2006
Vol. 14. 2005
Vol. 13. 2004
Vol. 12. 2003
Vol. 11. 2002
Vol. 10. 2001
Vol. 9. 2000
Vol. 8. 1999
Vol. 7. 1998
Vol. 6. 1997
Vol. 5. 1996
Vol. 4. 1995
Vol. 3. 1994
Vol. 2. 1993
Vol. 1. 1992
Suppl. 2. 2018