A new species of Serpinema Yeh (1960) (Nematoda: Camallanidae) in a captive false map turtle, Graptemys pseudogeographica pseudogeographica (Gray, 1831) (Testudines: Emydidae), in Portugal

A new species of Serpinema Yeh, 1960 (Nematoda: Camallanidae) is described from a captive false map turtle, Graptemys pseudogeographica pseudogeographica (Gray, 1831), admitted to a veterinary clinic in Lisbon, Portugal. Serpinema pseudogeographicum n. sp. is characterised by seven pairs of precloacal papillae, two pairs of adcloacal papillae and five pairs of postcloacal papillae, a combination unique among all currently valid species of the genus, together with two unequal spicules bearing a distally bifurcated right spicule, and a conspicuous lobed cuticular process on the anterior vulvar lip. Partial 18S rDNA and COI sequences provide complementary molecular support: the 18S rDNA phylogeny places S. pseudogeographicum n. sp. as sister to S. cayennensis in a well-supported lineage within Serpinema , whereas the COI data strongly support its recognition as a distinct species. The new species is the first nominal representative of Serpinema described from material recovered in Europe since S. microcephalus Dujardin, 1845, and its recovery from an exotic turtle host highlights both the role of the exotic pet trade as a pathway for parasite introduction and the value of opportunistic sampling during veterinary procedures for advancing knowledge of helminth diversity.