Eurytrema coelomaticum: influence of the infection on the reproduction and nucleic acids contents in the albumen gland and ovotestis of Bradybaena similaris

Abstract

The number of eggs laid per snail in Bradybaena similaris and the nucleic acids (DNA and RNA) in the albumen gland and ovotestis were quantified in snails infected with sporocysts of the digenetic trematode Eurytrema coelomaticum. The total number of eggs laid per mollusc was reduced by 96.32% at the end of the larval development. The DNA concentration increased by 700%, and the RNA concentration was reduced by 8.38% by the time when the daughter sporocysts of E. coelomaticum were released from B. similaris. The relation between these values and the inhibition of the reproduction observed in infected molluscs is discussed.

Comparison of 18S ribosomal RNA gene sequences of Eurytrema coelmaticum and Eurytrema pancreaticum

“…Previous studies on E. coelmaticum and E. pancreaticum were greatly focused on their morphology, life history, main organs and their functions, and epidemic investigation (Vykhrestyuk and Yarygina 1982;Pinheiro and Amato 1995;Dorny et al 1996. However, no molecular data on E. coelmaticum and E. pancreaticum are available at present, and their relationship is not determined based on molecular data, which have successfully been used in the analysis of phylogeny and in the identification of trematodes (Attwood et al 2002;Park et al 2003;Olson et al 2003).…”

Evaluation of the reproductive profile of Subulina octona (Gastropoda, Subulinidae) experimentally infected by Paratanaisia bragai (Digenea, Eucotylidae)

“…The interference of larval digenetic trematode in the reproduction of the snail first intermediate host is a common phenomenon (Pinheiro and Amato, 1995). The term parasitic castration is used to refer to an interruption or a decrease in the reproductive activity of snails in response to parasitic infections.…”

“…The reproductive behavior of snails during intramolluscan digenetic larval development has been widely studied, especially in aquatic snails belonging to the Family Planorbidae Rafinesque, 1815 (Crews and Yoshino, 1990;Faro et al, 2013). However, there is scarcity of data in the literature on the behavior of terrestrial snails in response to infection by trematodes (Pinheiro and Amato, 1995).…”

“…verified this phenomenon in Biomphalaria glabrata Say, 1818 experimentally infected with doses of 5 and 50 Echinostoma paraensei (Lie and Basch, 1967) miracidia. However, the infection by larval trematodes may lead to reduction of reproductive activity in snails, phenomenon called parasitic castration by Baudoin (1975), as observed by Pinheiro and Amato (1995) in the system Eurytrema coelomaticum (Giard et Billet, 1892) Looss, 1907/Bradybaena similaris (Férussac, 1821). The snail may present a total interruption or partial reduction of reproductive activity resulting from the direct mechanical action of the parasite on the reproductive structures or indirect action, as decrease of the snail's energy reserves or interference in the neuroendocrine system.…”

Eurytrema coelomaticum (Giard & Billet) (Digenea, Dicrocoeliidae) em Bradybaena similaris (Férussac) (Gastropoda, Xanthonychidae): alterações nos depósitos de cálcio e na função reprodutiva do primeiro hospedeiro intermediário

“…Dessa forma, as alterações observadas no ovotéstis de alguns caracóis infectados, no presente estudo, podem ter sido produzidas, devido a um bloqueio da hemolinfa feito pelos esporocistos de segunda geração em desenvolvimento na glândula digestiva e serem relacionadas à castração parasitária indireta. Os resultados obtidos no presente estudo também estão de acordo com os de PINHEIRO & AMA TO (1995). Segundo estes autores B. similaris infectada com E. coelomaticum apresenta uma redução acentuada na oviposição.…”