Heleopera (from Ancient Greek helos 'a bog' and pera 'a bag')[1]: 162  is a genus of testate amoebae belonging to the order Arcellinida. It is the sole genus within family Heleoperidae and infraorder Volnustoma, which in turn belong to the suborder Glutinoconcha. It is characterized by a conspicuous slit-like test aperture.

Heleopera
Heleopera petricola
Scientific classification Edit this classification
Domain: Eukaryota
Phylum: Amoebozoa
Class: Tubulinea
Order: Arcellinida
Suborder: Glutinoconcha
Infraorder: Volnustoma
Lahr et al. 2019[3]
Family: Heleoperidae
Jung 1942[2]
Genus: Heleopera
Leidy 1879[1]: 162 
Type species
Heleopera sphagni
Leidy 1879[1]: 162 

Description

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Heleopera is a genus of testate amoebae, a type of unicellular amoeboid protists that are enclosed in a shell known as the test. In particular, it belongs to the order Arcellinida, which includes testate amoebae with lobose (round, blunt-ended) pseudopods.[4] The genus is characterized by an ovoid, laterally compressed test composed of a cancellated chitinoid membrane with a reticulate appearance of mostly dotted lines, often incorporating particles of sand. The test opening, or 'mouth', is large, elliptical and has a terminal position. Through this opening, the organism extends numerous digitiform pseudopods.[1]: 162 

The conspicuous slit-like (laterally compressed) terminal opening found in this genus is what distinguishes the infraorder Volnustoma from other groups of Arcellinida. In addition, the tests are reinforced with mineral particles.[3]

Systematics

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Taxonomy

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The genus Heleopera was described by American paleontologist Joseph Leidy in his 1879 book Fresh-water rhizopods of North America. He constructed the generic name from the Greek words helos, meaning bog, in reference to swamps, its frequent habitat; and pera, meaning bag, in reference to the shape of its test. He transferred the species Nebela sphagni to this new genus and assigned it as the type species, but also changed the specific epithet to picta, thus modifying its name to Heleopera picta.[1]: 162  In the 1909 volume of The British freshwater Rhizopoda and Heliozoa, British naturalist James Cash reinstated the epithet sphagni,[5]: 143  arguing that the original epithet of a given species should be conserved if it is not preoccupied by an earlier name.[5]: 112  Consequently, the current accepted name of the type species is Heleopera sphagni.[6]

In 1942, a family was proposed to accommodate this genus, Heleoperidae.[2] The validity of this family was questioned during the first years of molecular phylogenetic analyses of testate amoebae, because the genus itself was apparently paraphyletic. As a consequence, Heleopera was considered an incertae sedis taxon within the order Arcellinida, containing most lobose testate amoebae.[6][4] In 2019, with better phylogenetic resolution, the order was divided into various monophyletic suborders and infraorders, and Heleoperidae was placed in its own infraorder Volnustoma. It remains the only family in this infraorder, which in turn belongs to the suborder Glutinoconcha.[3][7]

Species

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The genus includes 11 accepted species:

=Difflugia lucida Penard 1890[10]: 145 
= Difflugia (Nebela) sphagni Leidy 1874[14]: 157 
= Nebela sphagni Leidy 1876[15]: 119 
= Heleopera picta Leidy 1879[1]: 162 

References

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  1. ^ a b c d e f g Leidy, Joseph (1879). Fresh-water rhizopods of North America. Department of the Interior. Report of the United States Geological Survey of the Territories. Vol. XII. Washington: Government Printing Office. pp. 1–324, plates I–XLVIII. LCCN 08006737.
  2. ^ a b Jung, W. (1942). "Südchilenische Thekamöben (Aus dem südchilenischen Küstengebiet, Beitrag 10)" [Southern Chilean thecamoebae (From the southern Chilean coastal area, post 10)]. Archiv für Protistenkunde (in German). 95 (3): 253–356.
  3. ^ a b c Lahr, Daniel J.G.; Kosakyan, Anush; Lara, Enrique; Mitchell, Edward A.D.; Morais, Luana; Porfirio-Sousa, Alfredo L.; et al. (2019). "Phylogenomics and Morphological Reconstruction of Arcellinida Testate Amoebae Highlight Diversity of Microbial Eukaryotes in the Neoproterozoic". Current Biology. 29 (6): 991–1001. doi:10.1016/j.cub.2019.01.078. hdl:11380/1301486. PMID 30827918. S2CID 72333352.
  4. ^ a b Kosakyan, Anush; Gomaa, Fatma; Lara, Enrique; Lahr, Daniel J.G. (2016). "Current and future perspectives on the systematics, taxonomy and nomenclature of testate amoebae". European Journal of Protistology. 55 (B): 105–117. doi:10.1016/j.ejop.2016.02.001. PMID 27004416.
  5. ^ a b c d Cash, James; Hopkinson, John (1909). Rhizopoda, part II. The British freshwater Rhizopoda and Heliozoa. Vol. II. London: Printed for the Ray Society. pp. i–xviii, 1–166, pls. XVII–XXXII. doi:10.5962/bhl.title.927. LCCN 06007330. OCLC 6063003. BHL page 869209.
  6. ^ a b Lara, Enrique; Heger, Thierry J.; Ekelund, Flemming; Lamentowicz, Mariusz; Mitchell, Edward A.D. (2008). "Ribosomal RNA genes challenge the monophyly of the Hyalospheniidae (Amoebozoa: Arcellinida)" (PDF). Protist. 159 (2): 165–176. doi:10.1016/j.protis.2007.09.003. PMID 18023614.
  7. ^ González-Miguéns, Rubén; Todorov, Milcho; Blandenier, Quentin; Duckert, Clément; Porfirio-Sousa, Alfredo L.; Ribeiro, Giulia M.; Ramos, Diana; Lahr, Daniel J.G.; Buckley, David; Lara, Enrique (2022). "Deconstructing Difflugia: The tangled evolution of lobose testate amoebae shells (Amoebozoa: Arcellinida) illustrates the importance of convergent evolution in protist phylogeny". Molecular Phylogenetics and Evolution. 175: 107557. doi:10.1016/j.ympev.2022.107557. hdl:10261/281619. PMID 35777650.
  8. ^ Soler-Zamora, Carmen; González-Miguéns, Rubén; Guillén-Oterino, Antonio; Lara, Enrique (2021). "Arcellinida testate amoebae as climate miner's canaries in Southern Spain". European Journal of Protistology. 81: 125828. doi:10.1016/j.ejop.2021.125828. PMID 34487957.
  9. ^ Porfirio-Sousa, Alfredo L.; Tice, Alexander K.; Morais, Luana; Ribeiro, Giulia M.; Blandenier, Quentin; Dumack, Kenneth; et al. (2024). "Amoebozoan testate amoebae illuminate the diversity of heterotrophs and the complexity of ecosystems throughout geological time". Proceedings of the National Academy of Sciences. 121 (30): e2319628121. bioRxiv 10.1101/2023.11.08.566222v2. doi:10.1073/pnas.2319628121.
  10. ^ a b c Penard, Eugène (1890). Ètudes sur les rhizopodes d'eau douce [Studies on the freshwater rhizopods]. Mémoires de la Societé de Physique et d'Histoire Naturelle de Genève (in French). Vol. XXXI(2). Genève [Geneva]: Imprimerie Aubert-Schuchardt. pp. 1–230, plates I–XI.
  11. ^ Wailes, G. H. (1912). "Freshwater Rhizopoda and Heliozoa from the States of New York, New Jersey, and Georgia, U.S.A.; with Supplemental Note on Seychelles Species". Zoological Journal of the Linnean Society. 32 (214): 121–161. doi:10.1111/j.1096-3642.1912.tb01773.x.
  12. ^ Bonnet, L.; Thomas, R. (1955). "Étude sur les thécamoebiens du sol (I)" [Study of the soil thecamoebae (I)]. Bulletin de la Société d'Histoire naturelle de Toulouse (in French). 90: 411–428.
  13. ^ Penard, Eugène (1910). "Rhizopodes nouveaux" [New rhizopods] (PDF). Revue Suisse de Zoologie (in French). 18: 929–940. doi:10.5962/bhl.part.16676. BHL page 10712423.
  14. ^ Leidy, Joseph (1874). "Notice of some Rhizopods". Proceedings of the Academy of Natural Sciences of Philadelphia. 26: 154–157. BHL page 1687078.
  15. ^ Leidy, Joseph (1876). "Remarks on the Rhizopod Genus Nebela". Proceedings of the Academy of Natural Sciences of Philadelphia. 28: 115–119. BHL page 26298840.
  16. ^ Ribeiro, Giulia M.; Useros, Fernando; Dumack, Kenneth; Porfírio-Sousa, Alfredo L.; Soler-Zamora, Carmen; Alcino, João Pedro Barbosa; et al. (2023). "Expansion of the cytochrome C oxidase subunit I database and description of four new lobose testate amoebae species (Amoebozoa; Arcellinida)". European Journal of Protistology. 91: 126013. doi:10.1016/j.ejop.2023.126013. hdl:10261/352010.
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