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

Abstract

(Férussac, 1821) was experimentally studied in infected and uninfected snail s maintained in laboratOlY under controlled conditions ofnutrition, humidity and temperature. The ca\cium ofthe shell s of infected and uninfected snail s was quantitled by using a technique of volumetric complexation. The amount of calciull1 present in the tissue was evaluated by using the histochemistry techniques of Dahl and von Kossa. The alteration in the reproductive I'unction was evaluated through the egg production, and by histological follow up 01' the snai ls gametogenesis, in the infec ted and uninfected snails. The Student's test "t" showed that there was no sign ificant difference in rel ation to size, weight and calcium concentration in the shells ofinfected and uninfected snails, The analysi s of nonlinear regression, polynomial of 4 1h order, showed an highly positive relation to weight and size of shell to infccted and uninfected snails, and an weakly signitlcant relation to calcium concentration in the shells and shells size of infected snail s. The histochell1istlY techniques dell10nstrated a large calcium deposition in the cells of the digestive glands of the infected snail s when cOll1pared to the uninl'ected ones. The histological study ofthe ovotestis ofthe infected snails dell1ons-trated that the gametogenesis ofthese snails was abnormaJ. The ovulogenesis was the most alterated and at 45 days post-infection the histological sections showed no ovocytes preselll in the ovotestis. KEY WORDS. EW)'lre1l7a coe/Ol11aliclIlII, Bradybaena sil11ilaris, ca\cium deposits, parasitic castration Gastrópodes terrestres estocam grandes quantidades de sais de cálcio, que são depositados principalmente, na concha e na glândula digestiva (WILBUR & TOMPA J 979). A infecção por estágios larvais de digenéticos, pode provocar uma maior deposição de cálcio nas células dagl ândula digestiva dos moluscos infectados (MALEK & CHENG J 974). Estes moluscos podem apresentar alterações em seu

The urban ponds as a potential risk in the transmission of parasites

“…It has been demonstrated that in male H. parchappii, the infestation of certain digenea may produce a decrease in the size of the penis (Merlo et al 2017). These alterations in H. parchappii had also been observed in Biomphalaria glabrata (Say, 1818), Bradybaena similaris (Férussac, 1821), Chilina dombeyana (Bruguière, 1789), and Hydrobia ventrosa (Montagu, 1803;Théron & Gérard, 1994;Paschoal & Amato, 1996;Olmos & George-Nascimento, 1997;Kube et al 2006;Valdovinos & Balboa 2008, Horak & Kolarova, 2011.…”

Revaluation of the taxonomic characters and distribution of Omalonyx geayi (Gastropoda, Succineidae)

“…This pathology is well documented for many Gastropoda species (e.g. Wilson & Denilson 1980;Paschoal & Amato, 1996;Jordaens et al, 2007;Voutilainen et al, 2009;Averbuj & Cremonte, 2010).…”

“…Travassos (1928) subsequently used specimens of Omalonyx from Mato Grosso, Brazil as experimental host for this trematode which develops in the slug's visceral cavity, but does not infest host organs. Montresor et al (2008) (Robinson, 1953;Rowan, 1955;Paschoal & Amato, 1995, 1996, 2001. Unfortunately, our Omalonyx material was preserved in alcohol and not suitable for determination of the family or specific identity of the parasites infecting the gonad and hermaphrodite duct.…”

An improvement of calcium determination technique in the shell of molluscs

“…When the results were expressed in ppm of CaCO 3 /mg of shell, wet weight, according Pinheiro and Amato (1995), the presence of organic matter may give us an erroneous interpretation because they not reflects directly the calcium alterations in the shell. Paschoal and Amato (1996) observed that in B. similaris infected with Eurytrema coelomaticum (Giard et Billet, 1892) the weight of the shell increases, but the calcium amount is reduced. So, Pinheiro and Amato (1995) technique must be masked and the results may not express the alterations in the calcium content in the shell, but they may be masked by the increase in the organic matter in the shell.…”

“…Many physiological alterations may affect the calcium reserves in the shell and in the hemolymph of mollusks (Souza et al, 2000;Lira et al, 2000;Pinheiro, 1996). Calcium determination in the shell of the snails is an important parameter that is widely used as an indirect evaluation of metabolic alterations, influence of the environment and conditions of stress on the physiology of molluscs (Paschoal and Amato, 1996;Brandolini and Amato, 2001;Moreira et al, 2003). The calcium present in the shell is predominantly found as calcium carbonate incorporated in the shell structure as calcite and aragonite crystals associated to the organic matrix, composed basically by conchiolin.…”