Ophiotaenia karipuna n. sp. (Eucestoda: Proteocephalidae), a parasite of Erythrolamprus miliaris (Linnaeus, 1758), with redescription of Ophiotaenia arandasi (Santos and Rolas, 1973) from the Brazilian Amazon

Ophiotaenia is the most diverse genus among proteocephalids, composed of species commonly found parasitizing snakes worldwide. However, the diversity of Ophiotaenia in the Neotropical region is still underestimated. This study describes Ophiotaenia karipuna n. sp. found parasitizing Erythrolamprus miliaris in the State of Amapá, Brazil. Additionally, we redescribe Ophiotaenia arandasi based on a re-examination of type series and newly collected material from Erythrolamprus taeniogaster in the State of Pará, Brazil. The new species differs from its congeners in the following characteristics: scolex width, number of testes, relative length of the cirrus–sac, absence of a vaginal sphincter, presence of a vestigial apical organ resembling a sucker, and relative size of the ovary in relation to the surface of the proglottid. Furthermore, we provide taxonomic information for Ophiotaenia arandasi not reported in the original description, including morphology of embryophore, uterine development, and the absence of the vaginal sphincter in the species. Ophiotaenia karipuna n. sp. represents the 21st- species described in snakes -from the Neotropical region and the first formally described in the Brazilian Amazon. Additionally, we provide the first ultrastructural analysis, a new host, and locality records for O. arandasi.