The incidence and distribution in Britain of the trematodes of Talpa europaea

Abstract

1. Moles were collected from four main areas, Suffolk, Cheshire-Staffordshire, Westmorland-Yorkshire, and south-west Scotland, and examined for the presence of flukes. Three species were found: Itygonimus lorum from all the areas (and in one mole from Oxford); I ocreatus from Suffolk; Omphalometra flexuosa from Suffolk and Cheshire-Staffordshire.2. The sex of the host has no effect on the incidence of parasitism with flukes.3. I. lorum is almost exclusively a parasite of the lower half of the intestine, whereas I.ocreatus and O. flexuosa are predominantly parasites of the upper half of the intestine.4. The commonest number of flukes of any of the three species to find in a mole is one, though two individuals is almost as common a number in the case of I. lorum. Nevertheless, large populations of I. ocreatus or O. flexuosa and moderate numbers of I. lorum are on occasion found in one mole.5. Premunition does not occur with infestations of I. lorum and probably not with I. ocreatus and O. flexuosa.6. The distribution of each species even within an area where it occurs is very patchy and local. This is probably bound up with restricted movement of the hosts, whether final or intermediate, and may also be associated with the influence of soil conditions on the intermediate hosts.7. There appears to be no seasonal variation in the presence of flukes in moles.8. Simultaneous infestation with more than one species of fluke is rare. It is possible for O. flexuosa to live in company with I. lorum or I. Ocreatus, but the two Itygonimus species were never found together in the same mole.9. The presence of flukes in a mole has no effect on the rest of the intestinal helminth population of the host.

The helminth community of Talpa romana (Thomas, 1902) (Insectivora, Talpidae) in southern Italy

“…Considering the prevalence of I. ocretaus in the specimens studied, the absence of I. lorum is also difficult to explain. Frankland (1959), in T. europaea from British islands, and Casanova (1993), in T. occidentalis from the Iberian Peninsula, found an apparent interaction between I. lorum and I. ocreatus at the level of the individual host. In both host species, specimens parasitized by Ityogonimus always harboured only one of the two species, with apparent exclusion of the other.…”

Parasite Communities: Patterns and Processes

“…This might seem like a significant difference, but if there are 30 species, unless we had hypothesized in advance that this particular pair would be exclusive, we could not construe the observation as strong evidence for interaction, since there are 435 pairs. Frankland (1959) (1968) present an example of two trematode species in snails in which double infections are less frequent than expected, and argue that one species prevents infection by the other. However, one can construct a binary (presence-absence) species X island matrix and randomize it, subject to the constraint that each island maintains the number of species observed in nature and each species occupies the number of islands observed in nature.…”

First finding of Ityogonimus lorum and I. ocreatus co-infection in the Iberian mole, Talpa occidentalis

“…occidentalis is well known and includes digeneans, cestodes, nematodes and acanthocephalans (Casanova et al, 1996;Ribas and Casanova, 2006 Davies, 1932;Frankland, 1959;Chiriac and Popescu, 1973;Casanova, 2005, 2006). Moreover, I. ocreatus has also been cited parasitizing the Italian mole, Talpa romana (Thomas, 1902), in Calabria (Southern Italy) (Milazzo et al 2002).…”

“…were 11.0% for I. lorum and 1.9% for I. ocreatus, and a co-infection of both brachylaimids was never found by these authors. In this sense, Frankland (1959) and Casanova (1993) hypothesised about an apparent negative interaction between I. lorum and I. ocreatus at the level of the individual host, since both European moles and Iberian moles parasitized by Ityogonimus harboured exclusively one of the species.…”