Metazoan endoparasites of snakes from Argentina: Review and checklist with distributional notes and remarks

This article presents a checklist of metazoan parasites of snakes from Argentina, along with a comprehensive review of the relevant literature published between 1922 and June 2023, covering various aspects of interest. We compiled 34 species of metazoan endoparasites from 28 studies. The subclass Digenea showed the highest number of species (n = 22 species), followed by the phylum Nematoda (n = 8 species), and the subclass Pentastomida (n = 3 species and 1 taxa inquirenda). Dipsadidae was the family of snakes with the most species examined for metazoan endoparasites (n = 20 species). In contrast, Viperidae had the largest number of specimens surveyed (n = 343). Of 23 provinces, 15 (65.2%) presented at least one report of metazoan endoparasites in snakes. The northeastern provinces showed the highest richness of metazoan endoparasites and host diversity. Many articles focused on taxonomy, but studies on parasite ecology were not found. Although taxonomic accuracy was high in most reports, some records were correctly deposited in zoological collections or geo-referenced. This is the first attempt to include all groups of metazoan endoparasites of snakes from Argentina in a single checklist in the last century.

Detection of a Larva of Armillifer armillatus in a Potto (Perodicticus potto) from the Republic of the Congo

We determined the complete sequence of the mitochondrial DNA (mtDNA) of a parasite discovered between the subcutaneous tissue and the peritoneum of an African nocturnal non-human primate (NHP). The parasite and host sequences were obtained by a combination of Sanger sequencing and nanopore MinION techniques. Analyses of mtDNA gene arrangements and sequences unambiguously showed that the parasite investigated was the pentastomid Armillifer armillatus, also commonly named the tongue worm. The full-length mitochondrial genome of A. armillatus, measuring 16,706 bp in length, contains 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes, an arrangement identical to that of previously described pentastomid mitochondrial genomes. We describe here the second full mitochondrial genome of A. armillatus to date. To identify the NHP host, maximum likelihood phylogenetic analyses of a 441-bp fragment on the 12S rDNA gene and of a 1,140-bp fragment of the mitochondrial cytochrome b strongly support clustering with the African lorisid Perodicticus potto, a species that has rarely been reported as an intermediate host of this parasite.

History of Discovery of Parasitic Crustacea

Parasitic Crustacea have been present in scientific literature since Linnaeus introduced the first classification system (binomial nomenclature). Crustaceans are considered to be the most morphologically diverse arthropods, with currently 19 parasitic orders known to science. This chapter reviews the history of discovery for each of the major parasitic Crustacea groups, highlighting some of the key developments that have influenced our current understanding of these parasites. Each taxonomic group is briefly introduced, followed by a synopsis on some of the outstanding contributions within that group. Knowledge development is followed, from the first parasites discovered to other historical highlights that influenced the groups up to this point. Other important discoveries (both taxonomic and ecological) are also noted, serving as a preview to the host-parasite interactions covered in the subsequent chapters. Additionally, several researchers who have added significant contributions to our knowledge of the parasitic Crustacea (specifically in taxonomy and discovery) are introduced, along with photographs of a select few. This historical review of the crustacean parasites provides a background to these diverse and abundant organisms and will contribute to a better understanding of their unique niche in the aquatic environment.

The complete mitochondrial genome of the pentastomid Armillifer grandis (Pentastomida) from the Democratic Republic of Congo

We present the first complete mitochondrial genome of the pentastomid Armillifer grandis (Arthropoda: Pentastomida) collected from the lungs of a rhinoceros viper (Bitis nasicornis) in the Democratic Republic of Congo. The full length mitochondrial genome of Armillifer grandis, which measures 16,073 bp in length, contains 13 protein-coding genes, 2 ribosomal RNA genes, and 22 transfer RNA genes. A clear A + T bias is observed in the mitogenome of Armillifer grandis with an overall base composition of 34.6% A, 29.4% T, 29% C, and 6.9% G, and a GC content of 35.9%. The gene arrangement is identical to that of previously described pentastomid mitogenomes.

The nomenclature of the recent Pentastomida (Crustacea), with a list of species and available names

The taxonomy of the Recent members of the crustacean subclass Pentastomida is based on nine accepted family names derived from 12 available names, 24 generic names derived from 37 available names (plus two incorrect subsequent spellings and one nomen nudum) and 124 accepted species names derived from 183 available names of which six remain incertae sedis as to their generic assignment. Compilation of this list has revealed that existing catalogues have included misspellings, wrong attributions and dates of the authors of taxa, and incorrectly nominated type-species. These are corrected here with reference to the original descriptions and diagnoses. Notably, all families except one were erected much earlier and by authors other than Fain (1961), who was credited by Martin & Davis (2001) and other authors before and afterwards with seven of the nine families they recognised. Other significant taxonomic anomalies are revealed. Raillietiellidae Sambon, 1922 is a senior synonym of Cephalobaenidae Heymons, 1922, the name in popular usage for the family including Cephalobaena Heymons, 1922 and Raillietiella Sambon, in Vaney & Sambon, 1910; here the two genera are placed in separate families following Almeida & Christoffersen (1999). Heymonsia Hett, 1934, considered a junior synonym of Raillietiella, is a nomen nudum. Raillietiella geckonis (Diesing, 1850) is a potential senior synonym of several SE Asian species of this genus. Raillietiella frenata Ali, Riley & Self, 1981 is a widely used species name but is a subjective junior synonym of R. hebitihamata Self & Kuntz, 1960 according to its own authors. Morphological and molecular evidence suggest that R. indica Gedoelst, 1921 is a subjective senior synonym of both species. The priority of Linguatulidae Haldeman, 1851 over Linguatulida Vogt, 1851, erected as a family in the same year, is established by applying the First Reviser rule. Linguatula serrata Frölich, 1789 is herein selected as the type-species of Prionoderma, making it an objective synonym of Linguatula Frölich, 1789. The priority of L. serrata over Taenia rhinaris Meyer, 1789 and T.capraea Abildgaard, 1789, all published in the same year, is established by applying the First Reviser rule. The purported synonymy of Netrorhynchus Zenker, 1827, also misspelled Nettorhynchus, with Armillifer Sambon, 1922 would seem to be ill-founded and without popular support. Armillifer australis Heymons, 1935, published as a subspecies of A. moniliformis (Diesing, 1836), is both a senior synonym and a homonym of A. australis Riley & Self, 1981. Humboldt (1812) is confirmed as the author of Porocephalus Humboldt, 1812 and P. crotali Humboldt, 1812. Pentastomidae Shipley, 1909 is an older family name than its subjective synonym Porocephalinae Sambon, 1922, but prevailing usage allows the latter to be retained as a family name. Cayerina mirabilis Kishida, 1927 is a genus and species from a Japanese frog that has not appeared in the more recent pentastome literature. Sebekia minor (Wedl, 1861) is an objective senior synonym of the more widely used S. wedli Gigioli, in Sambon, 1922. The importance of the many junior synonyms will become evident should refined morphological and molecular evidence reveal cryptic species or greater host-specificity than presently recognised.

Parasite assemblages in the Western whip snake Hierophis viridiflavus carbonarius (Colubridae) from southern Italy

Parasite assemblages of the Western whip snake Hierophis viridiflavus carbonarius were investigated from the Calabria region in southern Italy. A total of 14 parasite taxa including 6 nematodes, 3 acanthocephalans, 2 cestodes, 2 digeneans and a single pentastomid was identified. Within the study area, H. v. carbonarius serves as the final host for seven species of helminths, of which only four (Hexametra quadricornis, Kalicephalus viperae, Paracapillaria sonsinoi and Renifer aniarum) can be considered as snake specialists, while one (Oswaldocruzia filiformis) is shared with other reptiles and amphibians, and two (Paradistomum mutabile and Rhabdias fuscovenosa) with lizards. A large proportion of larval forms of six helminth taxa (about 95% of all helminths collected) was found, for which H. v. carbonarius serves as an intermediate and/or paratenic host; however, adult stages of helminths were prevalent in snakes with snout-to-vent length greater than 70 cm. Our results suggest that ontogenetic and ecological factors should exert a strong influence upon the helminth assemblage of Western whip snakes. We concluded that H. v. carbonarius plays an important role in southern Italy as an intermediate/paratenic host for species of helminths infecting vertebrate groups which may include this snake species within their feeding chain. Eleven taxa, including three potential agents of zoonosis, were added to the poorly known parasite fauna of this host.