Some stylet cercariae and a microphallid type in British freshwater molluscs

Abstract

Cercaria helvetica XXXIII Dubois and the cercaria of Sphaerostoma bramae (Müll.) are redescribed and their metacercariae, which occur in various invertebrates, are described. Additional observations are made on C. parvus Khan and C. tarda Khan and their metacercariae, occurring mainly in arthropods, are described. C. wentloogensis sp.nov. has four pairs of penetration glands, a slender, thickened stylet 0·03 mm long and the flame-cell formula2[(2 + 2 + 2) + (2 + 2 + 2)].C. rumniensis sp.nov. has four pairs of penetration glands lying dorsally to the acetabulum, a slender thickened stylet 0·03 mm long and at least 20 flame cells arranged in pairs. C. octoglandulata sp.nov. is a virgulate species with four pairs of penetration glands, a partially thickened stylet 0·029–0·032 mm long and the flame-cell formula 2[(3 + 3 + 3) + (3 + 3 + 3)]. Each of these new species develops in sporocysts in the digestive gland of the prosobranch mollusc Bithynia tentaculata. A cercaria occurring in the digestive gland of B. tentaculata and assigned to the Microphallidae on the structure of its metacercaria is considered to encyst in the digestive gland without emerging. It bears no stylet or penetration glands and the cysts occur in the snail in exceedingly large numbers.All of these cercariae were found in freshwater molluscs collected at the Wentloog level near Cardiff, South Wales.

A note on the occurrence of the digenetic trematode Sphaerostoma bramae (Müller) in the intestine of the European eel, Anguilla anguilla (L.)

“…Indeed, so far as we are aware, the only previous published records are Thomas' (1957Thomas' ( , 1958 observation of an ' accidental infestation ' of one of 243 eels with the allocreadiids Crepidostomum farionis (Muller, 1784) and C. metoecus (Braun, 1900) in west Wales, and Pike's (1967) mention of the occurrence of Sphaerostoma bramae (Muller, I776), also a member of the Allocreadiidae, in eels in South Wales.…”

High parasite diversity in a neglected host: larval trematodes ofBithynia tentaculatain Central Europe

“…corresponds well to cercariae of S . bramae described by Wikgren (1956), Wesenberg-Lund (1934), Pike (1967) and Bykhovskaya-Pavlovskaya & Kulakova (1971). However, our cercariae differ from cercariae of S .…”

“…bramae , has been reported in B . tentaculata in Europe: in Denmark (as Cercaria micrura ; Wesenberg-Lund, 1934), Finland (Wikgren, 1956), Lithuania (Petkevičiūtė et al ., 1995), the Netherlands (as C. micrura ; Keulen, 1981), Russia (as C. micrura ; Bykhovskaya-Pavlovskaya & Kulakova, 1971), Ukraine (as C. micrura ; Zdun, 1961) and the UK (Pike, 1967). Comparative sequence analysis suggested Sphaerostoma sp.…”

Larval trematodes in bithyniid snails (Gastropoda: Bithyniidae) in the lake-rivers systems from the steppe zone (The West Siberian Plain, Russia)

“…The cercariae of Prosthogonimidae, Lecithodendriidae, and Pleurogenidae were of the «stylet group». These species are widely distributed in bithyniid snails in Palaearctic: Great Britain (Pike, 1967;Morley et al, 2004), Holland (Boddeke, 1960;Borgsteede et al, 1969), Czech Republic (Žďárská, 1963), Ukraine (Chernogorenko, 1983), Germany (Faltýnková & Haas, 2006), Middle Asia (Aristanov, 1986), Kazakhstan (Belyakova-Butenko, 1971), and Russia (Ginetsinskaya, 1959;Kupriyanova-Shachmatova, 1962;Bykhovskaya-Pavlovskaya & Kulakova, 1971;Ataev et al, 2002;Serbina, 2005Serbina, , 2008. They were found as the most frequent in all countries where samples were collected.…”