Here we describe a new heterophyid species, Heterophyes yacyretana n. sp., and resolve its life cycle experimentally. We found the prosobranch snail Aylacostoma chloroticum in Candelaria, Province of Misiones, Argentina (a sector of the High Paraná River affected by the Yacyretá Dam), naturally infected with opisthorchioid cercariae. These cercariae lacked pigmented eyespots as well as body pigment and possessed 7 pairs of penetration glands arranged in 2 lateral bands, together with 18 pairs of flame cells and a V-shaped excretory vesicle. We exposed specimens of 21 fish species to emerging cercariae and obtained metacercariae from the muscles of the caudal peduncle of 3 species of siluriform fish, and adults from chicks infected with experimentally obtained metacercariae from the albino variety of the bronce corydoras, Corydoras aeneus. The new species differs from other species in the genus by the number of sclerites on the genital sac, the distribution of the vitelline follicles, and the combination of the size relationship of the suckers and the genital sac with respect to the posterior extent of intestinal ceca. Heterophyes yacyretana is the first species of the genus reported from the Americas.

在这里，我们描述了一个新的杂种物种，杂种yacyretana n。并通过实验解决其生命周期。我们发现了原肠螺Aylacostoma chloroticum在阿根廷米西奥内斯省的坎德拉里亚（受亚齐雷塔大水坝影响的帕拉纳河上游部分）自然感染了阿片类鸦片类尾c。这些尾c既没有色素眼点，也没有人体色素，并具有排列在2个侧向带中的7对穿透腺，18对火焰细胞和V形排泄小泡。我们将21种鱼类的标本暴露于新兴的尾尾and，并从3种of形目鱼的尾柄的肌肉中获得了尾尾and，成年幼虫感染了从实验性获得的obtained中的白尾cer变种Corydoras aeneus的白尾variety。。新物种与其他物种的区别在于生殖囊上的巩膜数量，卵黄卵泡的分布以及吸盘和生殖囊的大小关系相对于盲肠后部程度的组合。杂种yacyretana是美洲报道的第一类。