Crotoniidae

Heminothrus targionii, copyright R. Penttinen.

Belongs within: Holonota.
Contains: Camisia, Crotoniinae.

Heminothrus is a genus of oribatid mites in which the posterior margin of the notogaster bears distinct seta-carrying protuberances.

The camisiids: cryptic inhabitants of soil and wood
Published 15 July 2019
Various views of Camisia biverrucata, copyright Pierre Bornand.

The animal in the above pictures is a typical representative of the Camisiidae, a widely distributed family of oribatid mites. Members of this family can be found in soil, on the trunks of trees, or hidden among mosses and lichens. They are slow-moving animals and are often concealed from potential predators by an encrusting layer of dirt and organic debris. Carrying this encrusting layer may be related to a reduction in the offensive chemical-producing glands that are used by many other oribatids for defense (Raspotnig et al. 2008). In members of the genus Camisia, the openings of these glands are completely covered by dirt, but in the genera Platynothrus and Heminothrus the openings still protrude above the encrustation. The recently described Paracamisia osornensis, which does not carry an encrusting layer, retains a large offensive gland (Olszanowski & Norton 2002).

Close to 100 species have been assigned to this family; though found in most parts of the world, camisiids are most diverse in the Northern Hemisphere. One species in particular, Platynothrus peltifer, is almost global in distribution and the range of habitats in which it has been found includes soil, litter, peat and even aquatic habitats (Norton & Behan-Pelletier 2009) When one is as small and metabolically undemanding as these animals are, there may be surprisingly little difference between being out in the air or immersed in water, and even primarily terrestrial oribatids may survive submersion almost indefinitely. Genetic studies of P. peltifer have identified a high level of within-species divergence and it has been calculated on this basis that this species may have survived almost unchanged in external appearance for some 100 million years (Heethoff et al. 2007).

The ubiquitous Platynothrus peltifer, copyright Centre for Biodiversity Genomics.

The Camisiidae are closely related to another oribatid family, the Crotoniidae, that is found in South America and Australasia. One of the more significant differences between the two families is that whereas the camisiids appear to be entirely parthenogenetic, crotoniids reproduce sexually. Recent analyses, both molecular and morphological, indicate that the ‘camisiids’ are paraphyletic with regard to the crotoniids, leading Colloff & Cameron (2009) to treat the latter as a subfamily, Crotoniinae, of the former. This re-classification has been accepted by other authors though the law of priority requires that the combined family should be known as the Crotoniidae, not Camisiidae. The nested position of the sexual crotoniines within the asexual ‘camisiids’, with other related oribatid families also being asexual, has led to the suggestion that the crotoniines have somehow re-evolved sexuality. This would be fascinating if true, seemingly violating the usual principle that complex features can’t be re-evolved once lost. Personally, I tend to be sceptical of claims like this. I would like to see evidence beyond simple phylogenetic position to indicate if this is a true re-evolution rather than an historical bias towards loss of sexuality giving a misleading image.

Systematics of Crotoniidae
<==Crotoniidae [Camisiidae, Crotonides, Crotonioidea]C10a
    |  i. s.: Eocamisia sukatshevae Bulanova-Zakhavatkina 1974S93
    |--Heminothrus Berlese 1913C10a, S04 [Heminothrinae]
    |    |--H. (Heminothrus) [incl. Paulonothrus Kunst 1971]S04
    |    |    |--*H. (H.) targionii (Berlese 1885)S04 (see below for synonymy)
    |    |    |--H. (H.) apophysiger Hammer 1979S04
    |    |    |--H. (H.) exaggeratus Hammer 1979S04
    |    |    |--H. (H.) glaber Mahunka 1984S04
    |    |    |--H. (H.) interlamellaris Jacot 1939 [=H. longisetosus interlamellaris]S04
    |    |    |--H. (H.) leleupi (Balogh 1958) [=Platynothrus leleupi]S04
    |    |    |--H. (H.) longisetosus Willmann 1925 [=H. paolianus longisetosus]S04
    |    |    |--H. (H.) microclava Hammer 1966S04
    |    |    |--H. (H.) minor Aoki 1969S04
    |    |    |--H. (H.) ornatissimus (Berlese 1910) [=Angelia ornatissima]S04
    |    |    |--H. (H.) oromii Morell & Subías 1991S04
    |    |    |--H. (H.) paolianus (Berlese 1913)S04, SC19, S04 [=Nothrus (H.) paolianusS04]
    |    |    `--H. (H.) similis Fujikawa 1998S04
    |    `--+--H. (Capillonothrus Kunst 1971) [incl. Ovonothrus Kunst 1971, Paracamisia Olszanowski & Norton 2002]S04
    |       |    |--H. (*C.) thori (Berlese 1904)S04 (see below for synonymy)
    |       |    |--H. (C.) capillatus (Berlese 1914)S04, SC19, S04 [=Angelia capillataS04]
    |       |    |    |--H. c. capillatus (see below for synonymy)S04
    |       |    |    |--H. c. kikonaiensis (Fujikawa 1982) [=Platynothrus capillatus kikonaiensis]S04
    |       |    |    `--H. c. peltiferinus (Winkler 1957) [=Platynothrus capillatus peltiferinus]S04
    |       |    |--H. (C.) fluviatilis (Hull 1913)S04 (see below for synonymy)
    |       |    |--H. (C.) meakanensis (Fujikawa 1982) [=Platynothrus meakanensis]S04
    |       |    |--H. (C.) nevadensis (Pérez-Íñigo 1969) [=Platynothrus nevadensis]S04
    |       |    |--H. (C.) numatai (Aoki 1965) [=Platynothrus numatai]S04
    |       |    |--H. (C.) osornensis (Olszanowski & Norton 2002) [=Paracamisia osornensis]S04
    |       |    `--H. (C.) yamasakii Aoki 1958S04
    |       `--Platynothrus Berlese 1913SC19, S04 [incl. Neonothrus Forsslund 1955S04, Sigmonothrus Chakrabarti & Kundu 1978S04]
    |            |--*P. peltifer (Koch 1839)S04 (see below for synonymy)
    |            |    |--P. p. peltiferS04 (see below for synonymy)
    |            |    `--P. p. japonensis Fujikawa 1972 [=Heminothrus (Platynothrus) japonensis]S04
    |            |--P. altimontanus Hammer 1958 [=Heminothrus (Platynothrus) altimontanus]S04
    |            |--P. banksi (Michael 1898)NB-P09, S04 (see below for synonymy)
    |            |--P. biangulatus Hammer 1962 [=Heminothrus (Platynothrus) biangulatus]S04
    |            |--P. bicarinatus Jacot 1938 [=Heminothrus (Platynothrus) bicarinatus]S04
    |            |--P. bistriatus (Chakrabarti & Mondal 1978) (see below for synonymy)S04
    |            |--P. brevisetosus Lee 1985 [=Heminothrus (Platynothrus) brevisetosus]S04
    |            |--P. carinatus (Banks 1910) [=Nothrus carinatus, Heminothrus (Platynothrus) carinatus]S04
    |            |--P. castaneus Hammer 1961 [=Heminothrus (Platynothrus) castaneus]S04
    |            |--P. fossatus (Kramer 1898) [=Nothrus fossatus, Heminothrus (Platynothrus) fossatus]S04
    |            |--P. hooki Piffl 1966 [=Heminothrus (Platynothrus) hooki]S04
    |            |--P. humicola (Forsslund 1955)S04 [=*Neonothrus humicolaBB92, Heminothrus (Platynothrus) humicolaS04]
    |            |--P. lapponicus Trägårdh 1910S62
    |            |--P. major Hammer 1966L85
    |            |--P. novaezealandicus Balogh & Balogh 2002 (see below for synonymy)S04
    |            |--P. ovatus (Kundu & Mondal 1978) [=Sigmonothrus ovatus, Heminothrus (Platynothrus) ovatus]S04
    |            |--P. praeoccupatus Subías 2004S04 (see below for synonymy)
    |            |--P. punctatus (Koch 1879) (see below for synonymy)S04
    |            |--P. quadristriatus Hammer 1958 [=Heminothrus (Platynothrus) quadristriatus]S04
    |            |--P. reductus Balogh & Balogh 1986 [=Heminothrus (Platynothrus) reductus]S04
    |            |--P. robustior (Berlese 1916) [=Heminothrus (Platynothrus) robustior]S04
    |            |--P. sibiricus Sitnikova 1975 [=Heminothrus (Platynothrus) sibiricus]S04
    |            |--P. skottsbergi Trägardh 1931T31 [=Heminothrus (Platynothrus) skoettsbergiS04]
    |            |    |--P. s. skottsbergiS04
    |            |    `--P. s. expansus Wallwork 1966 [=Heminothrus (Platynothrus) skoettsbergi expansus]S04
    |            |--P. tenuiclava Hammer 1966 [=Heminothrus (Platynothrus) tenuiclava]S04
    |            |--P. traversus (Hammer 1966) [=Heminothrus (Platynothrus) traversus]S04
    |            `--P. yamasakiiT92
    `--+--CamisiaC10a
       `--CrotoniinaeC10a

Heminothrus (Capillonothrus) capillatus capillatus (Berlese 1914) [incl. Platynothrus maior Willmann 1956, P. capillatus septentrionalis Sellnick 1944]S04

Heminothrus (Capillonothrus) fluviatilis (Hull 1913)S04 [=Hermannia fluviatilisS04, Nanhermannia fluviatilisWH58, Platynothrus fluviatilisL87a]

Heminothrus (*Capillonothrus) thori (Berlese 1904)S04 [=Angelia thoriS04, Platynothrus thoriL87b; incl. Nothrus crinitus Warburton & Pearce 1905S04]

*Heminothrus (Heminothrus) targionii (Berlese 1885)S04 [=Nothrus targioniiS04, Angelia targioniiM98; incl. N. (Heminothrus) princeps Berlese 1916S04]

Platynothrus banksi (Michael 1898)NB-P09, S04 [=Nothrus banksiS04, Heminothrus (Platynothrus) banksiS04, N. furcatus Banks 1895 non Koch 1844S04]

Platynothrus bistriatus (Chakrabarti & Mondal 1978) [=Sigmonothrus bistriatus, Heminothrus (Platynothrus) bistriatus]S04

Platynothrus novaezealandicus Balogh & Balogh 2002 [=Heminothrus (Platynothrus) novaezealandicus; incl. P. maior Hammer 1966 non Willmann 1956]S04

*Platynothrus peltifer (Koch 1839)S04 [=Nothrus peltiferS04, Camisia peltiferaT05, Heminothrus (*Platynothrus) peltiferS04, Neoliodes peltiferT31]

*Platynothrus peltifer peltifer (Koch 1839)S04 [incl. Heminothrus abchasicus Tarba 1990S04, Nothrus bicristatus Haupt 1882S04, N. cirrosus Canestini & Fanzago 1876S04, Platynothrus grandjeani Sitnikova 1975S04, Acarus infusionem Schrank 1803 (n. d.)S04, Nothrus palliatus Koch 1839S04, Angelia palliataM98, Hermannia palliataM98, Platynothrus palliatusS22, N. spirofilus Haupt 1882S04]

Platynothrus praeoccupatus Subías 2004S04 [=Heminothrus (Platynothrus) praeoccupatusS04, *Sigmonothrus quadristriatus Chakrabarti & Kundu 1978 non Platynothrus quadristriatus Hammer 1958BB92]

Platynothrus punctatus (Koch 1879) [=Nothrus punctatus, Heminothrus (Platynothrus) punctatus; incl. Hermannia carinata Kramer 1897, Hem. valentianus Hull 1916]S04

*Type species of generic name indicated

References

[BB92] Balogh, J., & P. Balogh. 1992. The Oribatid Mites Genera of the World vol. 1. Hungarian Natural History Museum: Budapest.

[C10] Colloff, M. J. 2010. The Gondwanan relict oribatid genus Crotonia (Acari: Oribatida: Crotoniidae) from rainforests in Queensland and northern New South Wales: new species show a mixed pattern of short-range and long-range endemism. Zootaxa 2649: 1–51.

Colloff, M. J., & S. L. Cameron. 2009. Revision of the oribatid mite genus Austronothrus Hammer (Acari: Oribatida): sexual dimorphism and a re-evaluation of the phylogenetic relationships of the family Crotoniidae. Invertebrate Systematics 23: 87–110.

Heethoff, M., K. Domes, M. Laumann, M. Maraun, R. A. Norton & S. Scheu. 2007. High genetic divergences indicate ancient separation of parthenogenetic lineages of the oribatid mite Platynothrus peltifer (Acari, Oribatida). Journal of Evolutionary Biology 20: 392–402.

[L85] Luxton, M. 1985. Cryptostigmata (Arachnida: Acari)—a concise review. Fauna of New Zealand 7: 1–106.

[L87a] Luxton, M. 1987a. The oribatid mites (Acari: Cryptostigmata) of J. E. Hull. Journal of Natural History 21: 1273–1291.

[L87b] Luxton, M. 1987b. The British oribatid mites (Acari: Cryptostigmata) of Warburton and Pearce. Journal of Natural History 21: 1359–1365.

[M98] Michael, A. D. 1898. Oribatidae. In: H. Lohmann (ed.) Das Tierreich. Eine Zusammenstellung und Kennzeichnung der rezenten Tierformen vol. 3. Acarina pp. 1–93. R. Friedländer und Sohn: Berlin.

[NB-P09] Norton, R. A., & V. M. Behan-Pelletier. 2009. Suborder Oribatida. In: Krantz, G. W. & D. E. Walter (eds) A Manual of Acarology, 3rd ed., pp. 430-564. Texas Tech University Press.

Olszanowski, Z., & R. A. Norton. 2002. Paracamisia osornensis gen. n., sp. n. (Acari: oribatida) from Valdivian forest soil in Chile. Zootaxa 25: 1–15.

Raspotnig, G., E. Stabentheiner, P. Föttinger, M. Schaider, G. Krisper, G. Rechberger & H. J. Leis. 2008. Opisthonotal glands in the Camisiidae (Acari, Oribatida): evidence for a regressive evolutionary trend. Journal of Zoological Systematics and Evolutionary Research 47 (1): 77–87.

[SC19] Schaefer, I., & T. Caruso. 2019. Oribatid mites show that soil food web complexity and close aboveground-belowground linkages emerged in the early Paleozoic. Communications Biology 2: 387.

[S22] Schweizer, J. 1922. Beitrag zur Kenntnis der terrestrischen Milbenfauna der Schweiz. Verhandl. Naturf. Ges. Basel 33: 23–112, 4 pls.

[S93] Selden, P. A. 1993. Arthropoda (Aglaspidida, Pycnogonida and Chelicerata). In: Benton, M. J. (ed.) The Fossil Record 2 pp. 297–320. Chapman & Hall: London.

[S62] Seyd, E. L. 1962. The moss mites of Kinder Scout, Derbyshire (Acari: Oribatei). Journal of the Linnean Society of London, Zoology 44 (300): 585–591.

[S04] Subías, L. S. 2004. Listado sistemático, sinonímico y biogeográfico de los ácaros oribátidos (Acariformes, Oribatida) del mundo (1758–2002). Graellsia 60 (número extraordinario): 3–305.

[T05] Trägårdh, I. 1905. Monographie der arktischen Acariden. In: Römer, F., & F. Schaudinn (eds) Fauna Arctica. Eine Zusammenstellun der arktischen Tierformen, mit besonder Berücksichtigung des Spitzbergen-Gebietes auf Grund der Ergebnisse der Deutschen Expedition in das Nördliche Eismeer im Jahre 1898 vol. 4 pp. 1–78. Gustav Fischer: Jena.

[T31] Trägårdh, I. 1931. Acarina from the Juan Fernandez Islands. Natural History of Juan Fernandez and Easter Islands 3 (4): 553–628.

[T92] Travé, J. 1992. La chaetotaxie du palpe des nothroides (oribates). Acarologia 33 (4): 377–385.

[WH58] Woolley, T. A., & H. G. Higgins. 1958. A revision of the family Nanhermanniidae (Acari: Oribatei). In: Becker, E. C. (ed.) Proceedings of the Tenth International Congress of Entomology vol 1 pp. 913–923. Montreal: Canada.

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