Morphological and Molecular Characterization of two trematode worms in the gastropod Asolene pulchella (Anton, 1859)

DELLAGNOLA FEDERICO; MONTES M; SANDRI, MELISA; MARTORELLI S; VEGA ISRAEL A.

Merlo, San Luis

Congreso; XXXV Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2017

Sociedad de Biología de Cuyo

Asolene pulchella (Caenogastropoda, Ampullariidae) is a native gastropod from La Plata River basin. In a previous study we reported the presence of parasite forms Trematoda (Plathyhelminthes) in the digestive gland of adult snails from Regatas Lake (Buenos Aires). In this work identified two parasites with a morphological and molecular approach. The digestive gland of Asolene pulchella showed a large amount of larval forms (sporocystes and redia) with internal cercariae in diverse degree of development. These parasites are placed in the connective tissue and the hemocoelic spaces of the digestive gland. MOrphologicla features of sporocysts and redia (obtained from digestive gland homogenates), and cercaiae (obtained by isolation under constant light) showed two morphotyes of parasites. The first morphotype shared similar characters with species of the Plagiorchiida order (xiphidiocercariae armatae opisthioglyphe-type) while the second morphotype showed similar characters of the Echinostomatidae family (belonging Echinostomida order). A sequence corresponding to the ITS1 (an internal transcribed spacer located between RNA 18S and RNA 5.8S ribosomal genes) was amplified (PCR) using DNA extracted from digestive gland as template. Sequencing and phylogenetic reconstruction by maximum likelihood were made. Two sequences were found: one of them (900 bp) was akin to the Xiphidiata order, while the other (700 pb) was related to Equinostomatidae family. The latter taxon has parasitic, symbiotic relationship with prosobranch snails. Although the morphological and molecular findings were congruent, other molecular studies are being conducted for the identification of these parasites at species level.