A molecular and morphological study of a trematod worm founded in the digestive gland of Asolene pulchella (Caenogastropoda, Ampullariidae)

MELISA SANDRI; ISRAEL VEGA; FEDERICO DELL AGNOLA

Mendoza

Congreso; XXXIV Reunión Anual de la Sociedad de Biología de Cuyo; 2016

Sociedad de Biología de Cuyo

Asolene pulchella (Anton 1839) is a freshwater snail that inhabit La Plata River basin. The population of Regatas Lake (Buenos Aires, Argentina) shows a high prevalence of unidentified cercaria (Digenea, Platyhelminthes). This larval stage lives in hemocoelic spaces and connective tissues from digestive gland of this ampullariid snail, which is an intermediate host of trematodes. An internal transcribed region (ITS 1) of 900 base pair, codified between two ribosomal genes (that codified for both 18S and 5.8S subunits) was amplified by polymerase chain reaction (PCR) using a set of specific primers for digenean worms (S20T2, 5´-GGTAAGTGCAAGTCATAAGC-3´, 5.8S1, 5´-GCTGCGCTCTTCATCGACA-3´). The phylogenetic analysis (BLAST analysis, Maximum Likelihood phylogenetic analysis) showed that this organism belongs to the order Plagiorchiida and it is associated with other species of the Xiphidiata suborder, which display a stylet associated to oral sucker. In addition, we identified the main morphological characters of cercariae from digestive gland. They have a spined body (98 µm long and 57 µm wide), a well-developed spined tail (81 µm long and 12 µm wide) and penetration glands. Ducts of these glands converge in the oral sucker, which hold a conspicuous stylet. A ventral sucker and a reniform excretory vesicle in the base of tail are also observed. These morphological, morphometric and molecular observations suggest that A. pulchella host a digenean worm belongs to Xiphidiata suborder.