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An undetermined species of flagellate, Ichthyobodo sp. (Kinetoplastea: Tetramitidae), is reported for the first time on the gills of the federally threatened leopard darter, Percina pantherina (Moore and Reeves) (Perciformes: Percidae), from the Cossatot River (Little River drainage of the Red River system) of the Ouachita Mountains of Arkansas, U.S.A. Ichthyobodo necator (Henneguy, 1883), once considered a single cosmopolitan species, has been shown to be a complex of sibling species in fresh and marine waters. Gene sequences would be required to determine the species of Ichthyobodo parasitizing P. pantherina.
Parabronema skrjabini is a spirurid nematode occurring in the abomasum of ruminants. The parasite's developmental cycle involves insects such as Lyperosia titillans as the intermediate host; the adult worms may cause gastric congestion, ulceration of the mucosa, and reduced weight. The present study uses scanning electron microscopy to describe the morphological features of adult P. skrjabini obtained from the abomasum of sheep. Male and female worm length measured 15 and 36–38 mm, respectively. In both sexes, the mouth was widest dorsoventrally and had 2 lateral pseudolabia each with 2 cephalic papillae and an amphid. The anterior end had dorsal and ventral cuticular shields and 6 horseshoe-shaped cordons. At the anterior end, an excretory pore was located on the ventral side. In addition, 2 lateral ciliated cervical papillae and a single lateral ala were observed. In the female, the vulva was near the anterior end of the body, and the tail end was curved dorsally with a bluntly conical tip and 2 phasmids near its extremity. The male posterior end was coiled spirally, had small caudal alae, interrupted longitudinal ridges, 4 pairs of precloacal papillae, a double papilla near the cloaca, 2 pairs of postcloacal papillae, and 2 phasmids. The shape, size, and arrangement of precloacal and postcloacal papillae were different. Furthermore, 4 pairs of sessile papillae were seen near the phasmids, which were also different in shape and size, but similar in arrangement. The spicules were very unequal and dissimilar.
Turtle acanthocephalans, within the genus Neoechinorhynchus, are a relatively understudied group of organisms, and most of these reports are scattered throughout the literature. This has resulted in a relatively poor understanding of host–parasite associations for turtle Neoechinorhynchus species. Therefore, the goal of this review was to assess the literature for acanthocephalan reports in turtle hosts to better understand host–parasite trends relating to turtle acanthocephalans. Additionally, a meta-analysis of prevalence and intensity was derived from the available data. A thorough assessment was conducted from peer-reviewed publications, theses, online museum databases, and novel data from turtle surveys throughout Oklahoma and acquired worms from collaborators across the United States. A total of 73 unique reports (peer-reviewed publications, theses, and nonpublished museum voucher records) were identified in this review. Results from this review indicate that turtle acanthocephalans have been reported from 26 states in the United States and 4 states in Mexico. Acanthocephalan species diversity appeared highest in the southeastern and southwestern regions of the United States, with few species reported in Mexico and no reports from Canada. Among all reports of turtle acanthocephalans, the overall meta-prevalence was 58%, and the meta-intensity was 110 worms per turtle. A total of 21 species of turtles have been identified as potential hosts for acanthocephalans, making up 27% of all North American turtle species. The most common turtle family reported was Emydidae, with Trachemys scripta containing the most acanthocephalan species (9 of the 10 currently described species). Lastly, 4 acanthocephalan species, Neoechinorhynchus chrysemydis, Neoechinorhynchus emydis, Neoechinorhynchus emyditoides, and Neoechinorhynchus pseudemydis, appeared the most successful in terms of distribution and turtle host range. Overall, these results suggest that turtle acanthocephalans are common freshwater turtle parasites in the United States and contain a relatively low degree of host specificity. There are likely additional turtle species for which acanthocephalans have yet to be reported and new species to be described. This review provides a novel database of turtle acanthocephalan reports and helps fill in several knowledge gaps regarding turtle–acanthocephalan biogeography, ecology, and host specificity. Finally, suggestions are provided to guide future researchers in testing novel hypotheses that will likely promote turtle acanthocephalan research.
We report the observation of egg-string deposition by females of Gordionus violaceus on the underside of stones in small forest streams in Germany. Egg strings are attached in winding lines to stones, a pattern otherwise known from the genus Chordodes and related genera, but not from the genus Gordionus. The spatial distinction between males (in water) and females (under rocks) may explain observations, in which males dominate in number in collections.
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