Journal of Parasitic Diseases

, Volume 42, Issue 4, pp 582–588 | Cite as

New species of macrocercous and megalurus cercariae infecting the freshwater snail, Paludomus (Paludomus) tanschauricus (Gmelin, 1771) in Malabar, Kerala

  • N. K. SanilEmail author
  • K. P. Janardanan
Original Article


The present paper describes two new species of cercariae infecting the freshwater snail, Paludomus (Paludomus) tanschauricus from Malabar, Kerala. Paludomus tanschauricus collected from the hill streams at Vattakkundu in the Wayanad district of Kerala harboured a macrocercous cercaria, Cercaria sp. XX Malabar n. sp. characterized by a disproportionately large tail. Developmental stages were recovered from the hepatopancreatic tissues of the snail host. Cercariae encysted on the gills of the fish, Haludaria melanampyx. Snails collected from Papanashini rivulet at Thirunelli, also from Waynad district were infected with a megalurous cercaria, Cercaria sp. XXI Malabar n. sp. possessing an elongated tail with an adhesive cup-like sucker at its tip. Redial stages developed in the hepatopancreas while the cercariae were found to encyst on any available substrate. The morphology and morphometry of these two cercariae along with their developmental stages are studied in detail and compared with related species to establish their systematic positions.


Macrocercous Megalurous Cercaria Sporocyst Paludomus (Paludomus) tanschauricus Malabar Kerala 



The authors are grateful to the Head, Department of Zoology, University of Calicut for providing necessary facilities. One of the authors (NKS) is grateful to the Council of Scientific and Industrial Research (CSIR) for financial support in the form of a Senior Research Fellowship.

Author’s contribution

Dr. KPJ designed and guided the study. Dr. NKS carried out the survey, collected and studied the cercariae in detail. The manuscript was written by both the authors.

Compliance with ethical standards

All the required ethical standards were complied with.

Conflict of interest

The authors declare that that there is no conflict of interest between them.


  1. Ostrowski de Núñez M, Quintana MG (2008) The life cycle of Stephanoprora aylacostoma n.sp. (Digenea: Echinostomatidae), parasite of the threatened snail Aylacostoma chloroticum (Prosobranchia, Thiaridae), in Argentina. Parasitol Res 102(4):647–655CrossRefGoogle Scholar
  2. Ditrich O, Scholz T, Aguirre-Macedo L, Vargas-Vazquez J (1997) Larval stages of trematodes from freshwater mollusks of the Yucatan Peninsula, Mexico. Folia Parasitol 44:109–127Google Scholar
  3. Ismail N, Hafez SA (1984) Two new cercariae from Melanopsis praemorsa (L., 1758) (Thiaridae) snails in Azraq oasis, Jordan. Jpn J Parasitol 33(4):353–359Google Scholar
  4. Køie M (1986) The life-history of Mesorchis denticulatus (Rudolphi, 1802) Dietz, 1909 (Trematoda, Echinostomatidae). Z Parasitenk 72:335–343CrossRefGoogle Scholar
  5. Nasir P, Diaz MT (1973) Freshwater larval trematodes XXXII. Twenty new species of Venezuelan cercariae. Riv Parassit 34(1):1–44Google Scholar
  6. Ostrowski de Núñez M (2007) Life-cycle of Stephanoprora uruguayense (Digenea, Echinostomatidae) in Argentina. J Parasitol 93:1090–1096CrossRefGoogle Scholar
  7. Peter CT, Srivastava HD (1955) Cercaria ratnagiriensis n. sp., a megalurous cercaria from Paludomus obesa (Philippi). In: 42nd Proceedings of the Indian science congress, Part III, pp 284–285Google Scholar
  8. Premvati G (1954) Three new species of cercariae from the snail Melanoides tuberculatus (Müller). J Zool Soc India 6:43–50Google Scholar
  9. Ramakrishna, Dey A (2007) Handbook on Indian freshwater molluscs. Zool. Surv. India, Kolkata, pp 1–399Google Scholar
  10. Sewell RBS (1922) Cercariae indicae. Indian J. Med. Res. 10:1–370Google Scholar
  11. Subba Rao NV (1989) Handbook of freshwater molluscs of India. Zool. Surv. India, Calcutta, pp 1–289Google Scholar
  12. Vasandakumar MV, Janardanan KP (2005) Two new species of cercariae from thiarid snails in Malabar, Kerala. Geobios 32(4):233–236Google Scholar
  13. Vasandakumar MV, Janardanan KP (2006) Two new species of xiphidiocercaria from the thiarid snail, Paludomus tanschauricus in Malabar, Kerala. Zoos’ Print J 21(3):2183–2185Google Scholar
  14. Velasquez CC (1969) Life Cycle of Cloacitrema philippinum sp. n. (Trematoda: digenea: Philophthalmidae). J Parasitol 55(3):540–543CrossRefGoogle Scholar

Copyright information

© Indian Society for Parasitology 2018

Authors and Affiliations

  1. 1.Department of ZoologyUniversity of CalicutThenhipalamIndia
  2. 2.Central Marine Fisheries Research InstituteCochinIndia

Personalised recommendations