Pachysentis gethi (Machado-Filho, 1950:526)
Geth's spiny-headed worm
Taxonomy & Nomenclature
Synonym/s: Prosthenorchis gethi Machado-Filho, 1950:526
Etymology:
The species name gethi is dedicated to Dr. Geth Jansen (Machado-Filho, 1950:528).
Taxonomic history:
Originally described as Prosthenorchis gethi, the species was transferred to the genus Pachysentis by (Schmidt, 1972).
Conservation Status
Last record: 1950 or before (Machado-Filho, 1950:526)
Reported as globally rediscovered by (Corrêa da Silva, 2015 [Master's thesis]; Muniz-Pereira et al., 2016), but see below.
After the original description of the species by Machado-Filho (1950:526), there was no Brazilian record of the species until it was reportedly globally rediscovered there in 2014-2015 (Corrêa da Silva, 2015 [Master's thesis]; Muniz-Pereira et al., 2016). However, decades before this, an initial report of Pachysentis rugosus from the host Spilogale pygmaea in Guerrero, Mexico (López-Forment & Urbano, 1979) was re-identified as P. gethi by (Salgado-Maldonado, 1979 fide García-Prieto et al., 2010, 2012). While two years later in 1979, P. gethi was recorded from the host Didelphis virginiana in La Esperanza, Colima, Mexico by (Lamothe-Argumedo et al., 1981 fide Monet-Mendoza et al., 2005 + fide García-Prieto et al., 2010, 2012). It is not clear to me whether these Mexican records are valid or represent a misidentification of a congener such as P. rugosus (or some other possibility).
Distribution & Habitat
Brazil (& Mexico?)
Type locality: Aurá municipality, Pará, Brazil (Machado-Filho, 1950:528; Muniz-Pereira et al., 2016)
Other localities reported:
Rio de Janeiro, Brazil (Machado-Filho, 1950:528)
Puerto Marqués, Guerrero, Mexico (Salgado-Maldonado, 1979 fide García-Prieto et al., 2010, 2012)
La Esperanza, Colima, Mexico (Lamothe-Argumedo et al., 1981 fide Monet-Mendoza et al., 2005 + fide García-Prieto et al., 2010, 2012)
Anatomy & Morphology
Biology & Ecology
A parasitic species that has been reported in the intestines (both small and large) of three mustelid species in Brazil: Eira barbara, Galictis cuja and Galictis vittata (Vieria et al., 2008). Mexican host records of Spilogale pygmaea and Didelphis virginiana also exist (Salgado-Maldonado, 1979; Lamothe et al., 1981; but see García-Prieto et al., 2010), but are of uncertain veracity to the present author.
Hypodigm
Type material fide Vieria et al., 2008 (other citations):
CHIOC 17836 a (holotype and allotype) (Gomes et al., 2019:589 [accession number only])
CHIOC 9203 (paratype)
CHIOC 15680 (paratype) (Gomes et al., 2019:589 [accession number only])
CHIOC 17837 b-d (paratype) (Gomes et al., 2019:589 [accession number only])
CHIOC 17838 a-b (paratype) (Gomes et al., 2019:589 [accession number only])
CHIOC 17841 (paratype)
CHIOC 17846 (paratype) (Gomes et al., 2019:589 [accession number only])
CHIOC 17852 (paratype) (Gomes et al., 2019:589 [accession number only])
Non-type Brazilian specimens:
CHIOC 4144 (Vieria et al., 2008)
CHIOC 38100 (Gomes et al., 2019:589)
Mexican specimens:
The Global Biodiversity Information Facility (GBIF) has six Mexican records of the species collected between 1973–1979: https://www.gbif.org/occurrence/search?taxon_key=2499513
Media
References
Original scientific description:
Machado-Filho, D. A. (1950). Revisão do gênero Prosthenorchis Travassos, 1915 (Acanthocephala). Memórias do Instituto Oswaldo Cruz 48: 495-545.
Other references:
Corrêa, Pilar, Bueno, Cecília, Vieria, Fabiano Matos and Muniz-Pereira, Luís Cláudio. (2016). Helminth parasites of Galictis cuja (Carnivora, Mustelidae), from localities in the Atlantic forest of Brazil. Braz. J. Vet. Parasitol., Jaboticabal 25(4): 407-413. https://doi.org/10.1590/S1984-29612016077
Corrêa da Silva, Pilar. (2015). Estudo da Helmintofauna de Galictis cuja (Molina, 1872) (Carnivora, Mustelidae) atropelados na rodovia BR-040, no trecho entre Rio de Janeiro, RJ e Juiz de Fora, MG. Master's thesis, Fundação Oswaldo Cruz.
García-Prieto, L., García-Varela, M., Mendoza-Garfias, B. and Pérez-Ponce de León, G. (2010). Checklist of the Acanthocephala in wildlife vertebrates of Mexico. Zootaxa 2419(1): 1-50. https://doi.org/10.11646/zootaxa.2419.1.1
García-Prieto, L. et al. (2012). Helminth parasites of wild Mexican mammals: list of species, hosts and geographical distribution. Zootaxa 3290(1): 1-92. https://doi.org/10.11646/zootaxa.3290.1.1
Gomes, Ana Paula Nascimento. (2019). Morphological, molecular and ecological intergrative taxonomy of Acanthocephala (Archiacanthocephala) parasite of Brazilian wildlife mammals. PhD thesis, Instituto Oswaldo Cruz, Rio de Janeiro. [automatic download]
Gomes, Ana Paula Nascimento, Amin, Omar M., Olifers, Natalie, Bianchi, Rita de Cassia, Souza, Joyce G. R., Barbosa, Helene S. and Maldonado, Arnaldo Jr. (2019). A New Species of Pachysentis Meyer, 1931 (Acanthocephala: Oligacanthorhynchidae) in the Brown‑Nosed Coati Nasua nasua (Carnivora: Procyonidae) from Brazil, with Notes on the Genus and a Key to Species. Acta Parasitologica 64: 587-595. https://doi.org/10.2478/s11686-019-00080-6
Lamothe-Argumedo, R., Pineda, R. and Meave, O. (1981). Infección natural de Paragonimus mexicanus en Didelphis virginiana californica en Colima, México. Anales del Instituto de Biología, Universidad Nacional Autónoma de México 52: 45-50.
López-Forment, W. and Urbano, G. (1979). Historia natural del zorrillo manchado pigmeo, Spilogale pygmaea, con la descripción de una nueva subespecie. Anales del Instituto de Biología, Universidad Nacional Autónoma de México, Serie Zoología 50: 721-728.
Monet-Mendoza, Anne, Osorio-Sarabia, David and García-Prieto, Luis. (2005). Helminths of the Virginia Opossum Didelphis virginiana (Mammalia: Didelphidae) in Mexico. J. Parasitol. 91(1): 213-219.
Muniz-Pereira, Luís C., Corrêa, Pilar, Bueno, Cecília and Vieira, Fabiano M. (2016). Rediscovery of Pachysentis gethi (Acanthocephala: Oligacanthorhynchidae), a parasite of wild lesser grison Galictis cuja (Carnivora: Mustelidae) from Brazil / Redescubrimiento de Pachysentis gethi (Acanthocephala: Oligacanthorhynchidae), parásito del grisón menor silvestre Galictis cuja (Carnivora: Mustelidae) de Brasil. Revista Mexicana de Biodiversidad 87(4): 1356-1359. https://doi.org/10.1016/j.rmb.2016.10.010
Salgado-Maldonado, G. (1979). Acantocéfalos de mamíferos I. Hallazgo de Pachysentis gethi (Machado, 1950) Schmidt, 1972, parásito de Spilogale pygmaea en México. An. Inst. Biol. UNAM. Ser. Zool. 50(1): 51-61. [Abstract]
Schmidt, G. D. (1972). Revision of the Class Archiacanthocephala Meyer, 1931 (Phylum Acanthocephala), with emphasis on Oligacanthorhynchidae Southwell et Macfie, 1925. Journal of Parasitology 58: 290-297. https://doi.org/10.2307/3278091
Vieria, Fabiano M., Luque, José L. and Muniz-Pereora, Luís C. (2008). Checklist of helminth parasites in wild carnivore mammals from Brazil. Zootaxa 1721: 1-23.