Studies on the life cycle of Asymphylodora tincae (Modeer, 1790) (Trematoda: Monorchiidae) in a small lake near Amsterdam

Abstract

Aspects of the life cycle of Asymphylodora tincae have been studied in a small lake near Amsterdam. Bithynia tentaculata, being the only snail species that was very numerous in the lake, was the first as well as the main second intermediate host; adult trematodes were found exclusively in the tench, Tinca tinca. A small part of the cercariae that penetrate into B. tentaculata was able to develop into progenetic specimens. A morphological description is given of the following stages of A. tincae: adult, egg, redia, cercariaeum, metacercaria and progenetic stage. The cercariaeum is identified as Cercariaeum paludinae impurae De Filippi, 1854.It is concluded that A. tincae is a species, capable of large variation regarding both morphological structure (e.g. body spination, size) and life cycle.

Exploring species diversity of lissorchiid trematodes (Digenea: Lissorchiidae) associated with the gravel snail,Lithoglyphus naticoides, in European freshwaters

“…Despite the fact that our current knowledge of life cycles is relatively good for trematodes parasitic in European freshwater fish (Faltýnková et al ., 2016), the vast majority of helminth species are known only from their adult stage (Blasco-Costa & Poulin, 2017). Life cycles are known for some freshwater lissorchiid species, which infect pulmonate (heterobranch) and prosobranch gastropods as first intermediate hosts (Stunkard, 1959; Lambert, 1976; van den Broek & de Jong, 1979; Našincová & Scholz, 1994; Besprozvannykh, 2005; Besprozvannykh et al ., 2012). Numerous other putative but unidentified freshwater lissorchiid cercariae (non-oculate cercariae of cercariaeum type in rediae in snails) are known from different gastropods.…”

Diversity of European lissorchiid trematodes from fish and snail hosts with comments on the validity of the genusParasymphylodoraSzidat, 1943

“…However, Zietse et al (1981) infected tench, T. tinca , with metacercariae designated as A. tincae , but they used larval stages from the snail B. tentaculata . Van den Broek & de Jong (1979) in their study also argue that B. tentaculata acts as first intermediate host of A. tincae and encysted as well as free progenetic metacercariae can be found within one snail. The taxonomic status of the species developing in Bithynia and erroneously designated as A. tincae in these studies is not clear.…”

“…Analysis of the literature showed that a number of larval lissorchiid trematodes are associated with the faucet snail, Bithynia tentaculata (Linnaeus, 1758) in Europe, but most are known only under provisional names, as Cercaria paludinae impurae (Filippi, 1854), Cercariaeum bithyneae Khan, 1962, Cercariaeum helveticum (Dubois, 1929) or Cercariaeum internale Khan, 1962, and are not associated with any adult forms (Khan, 1962; Morley et al, 2004; Cichy et al, 2011). In general, the information available on the life-cycles and specificity of European lissorchiids is very limited, based mainly on comparative morphological analysis and some experimental infections, which sometimes yielded contradictory results (Stunkard, 1959; Van den Broek & Jong, 1979; Našincová & Scholz, 1994). Although molecular approaches provide a reliable elucidation of life-cycles, only one life-cycle of European lissorchiid, namely Palaeorchis incognitus Szidat, 1943, has been confirmed based on DNA sequence comparisons (Petkevičiūtė et al, 2020).…”

The role of Bithynia tentaculata in the transmission of larval digeneans from a gravel pit in the Lower Thames Valley

“…and C. albinea they are likely to be autogenic (permanent species with entire life cycles within the aquatic ecosystem) with the definitive host probably being fish (Williams, 1980). Fish are also definitive hosts of Asymphylodora tincae (Evans, 1978;Van de Broek & de Jong, 1979), whilst on the other hand Notocotylus triserialis, Cercaria parvus and C. tarda are allogenic parasites (life cycle using temporary resident vertebrate host species) of birds (Pike, 1968). The occurrence of the allogenic species Cercaria C (syn.…”