Mycobates

Mycobates conitus, copyright Monica Young.

Belongs within: Ceratozetoidea.

Mycobates is a genus of oribatid mites found in the Holarctic region (Subías 2004).

Mites from a land of ice and snow
Published 16 April 2016
Mycobates sarekensis, from Siepel & Dimmers (2010).

The Arctic tundra is not an inviting place. Cold winds sweep through a forebidding landscape, unhindered by forest. In places, patches of bare rock can be seen, with no vegetation able to retain a foothold other than hardy lichens. And yet even here you can find an entire ecosystem in place if you look closely enough.

The animal shown at the top of this post is an oribatid mite of the genus Mycobates, a group of about 35 species belonging to the family Punctoribatidae (sometimes referred to as Mycobatidae). These are sturdy, stocky oribatids with a body that is oval in cross-section, with a length generally around the half-millimetre mark (Seniczak et al. 2015). Characteristic features of Mycobates include pteromorphs (triangular outgrowths of the body wall that hang down over the bases of the legs) that are hinged by a line of weaker cuticle so they can be moved up and down, a convex pedotectum I (another protruding shelf, this time on the underside of the body shielding the base of the first pair of legs) and overlapping lobes at the back of the body where the dorsal shield (the notogaster) overhangs the edge of the venter (Behan-Pelletier 1994). Their legs are curved inwards towards the body, and the dorsal setae are usually smooth, without barbs, and flexible (Seniczak et al. 2015).

SEM of Mycobates beringianus from Behan-Pelletier (1994). Note the cluster of pores visible as a lighter patch on the side of the notogaster; these are secretory or respiratory structures.

Many of these features are suited to the preferred habitat of a number of species in the genus: burrowing through the thalli of lichens (which are both home and food). Mycobates species are found in cooler boreal and alpine habitats. Species found in more Arctic habitats, such as the tundra-dwelling M. sarekensis, are found close to ground level (in the tundra, there’s not many other levels to be found at). In more temperate regions, they are often arboreal, crawling about on the trunks and branches of trees. Some species have been found in association with mosses as well as lichens; many of the northern species are able, snuggled as they are in their moss or lichen hosts, to live in microhabitats too dry for many other invertebrates.

Systematics of Mycobates

Characters (from Balogh & Balogh 1992): Rostrum rounded or bidentate. Prodorsum with lamellae and translamella present, lamellae converging, translamella much longer than cuspides; anterior tectum of notogaster overhanging bothridium, with interlamellar setae originating under tectum. Notogaster with ten pairs of setae or setal alveoli; four pairs of areae porosae; pteromorphae movable. Six pairs of genital setae; one pair of aggenital setae; two pairs of anal setae; three pairs of adanal setae.

<==Mycobates Hull 1916S04
    |--M. (Mycobates)S04
    |    |--*M. (M.) parmeliae (Michael 1884) (see below for synonymy)S04
    |    |--M. (M.) acuspidatus Behan-Pelletier, Eamer & Clayton 2001S04
    |    |--M. (M.) austroamericanus Hammer 1958S04
    |    |--M. (M.) cambricus (Hull 1916)S04 [=Melanozetes cambricusS04, Oribates cambricusL87]
    |    |--M. (M.) carli (Schweizer 1922) [=Oribata carli]S04
    |    |--M. (M.) corticeus Bvehan-Pelletier, Eamer & Clayton 2001S04
    |    |--M. (M.) debilis Mihelčič 1957S04
    |    |--M. (M.) exigualis Behan-Pelletier 1994S04
    |    |--M. (M.) ezoensis Fujikawa 1982S04
    |    |--M. (M.) flabelliger (Berlese 1908) [=Sphaerozetes flabelliger]S04
    |    |--M. (M.) hylaeus Behan-Pelletier 1994S04
    |    |--M. (M.) integer Mihelčič 1957S04
    |    |--M. (M.) minor Subías, Kahwash & Ruiz 1990S04
    |    |--M. (M.) monodactylus Shaldybina 1970S04
    |    |--M. (M.) perates Behan-Pelletier 1994S04
    |    |--M. (M.) rileyi (Haller 1884) (n. d.) [=Oribata rileyi]S04
    |    |--M. (M.) royi Palacios-Vargas & Vázquez 1988S04
    |    |--M. (M.) tridentatus Weigmann 1976S04
    |    `--M. (M.) yukonensis Behan-Pelletier 1994S04
    `--M. (Calyptozetes Thor 1930) [incl. Permycobates Strenzke 1954]S04
         |--M. (*C.) sarekensis (Trägardh 1910) [=Oribata sarekensis; incl. M. consimilis Hammer 1952]S04
         |--M. (C.) alpinus (Willmann 1951) [=Calyptozetes alpinus]S04
         |--M. (C.) altus Behan-Pelletier 1994S04
         |--M. (C.) angulatus (Koch 1839) [=Oribata angulata]S04
         |--M. (C.) azaleos Behan-Pelletier 1994S04
         |--M. (C.) beringianus Behan-Pelletier 1994S04
         |--M. (C.) bicornis (Strenzke 1954)S04 [=*Permycobates bicornisB65]
         |--M. (C.) brevilamellatus Behan-Pelletier 1994S04
         |--M. (C.) conitus Hammer 1952S04
         |--M. (C.) cribelliger (Berlese 1904) [=Oribata cribelliger]S04
         |--M. (C.) dryas Behan-Pelletier 1994S04
         |--M. (C.) hammerae Behan-Pelletier 1994S04
         |--M. (C.) incurvatus Hammer 1952S04
         |--M. (C.) monocornis Aoki 1973S04
         |--M. (C.) occidentalis Behan-Pelletier 1994S04
         |--M. (C.) patrius Shaldybina 1970S04
         |--M. (C.) punctatus Hammer 1955S04
         `--M. (C.) tridactylus Willmann 1929S04

*Mycobates (Mycobates) parmeliae (Michael 1884) [=Oribata parmeliae; incl. Sphaerozetes (Trichoribates) lenicomus Berlese 1910, Mycobates nadiji Paulitchenko 1991]S04

*Type species of generic name indicated

References

[B65] Balogh, J. 1965. A synopsis of the world oribatid (Acari) genera. Acta Zoologica Academiae Scientiarum Hungaricae 11 (1–2): 5–99.

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

Behan-Pelletier, V. M. 1994. Mycobates (Acari: Oribatida: Mycobatidae) of America north of Mexico. Canadian Entomologist 126: 1301–1361.

[L87] Luxton, M. 1987. The oribatid mites (Acari: Cryptostigmata) of J. E. Hull. Journal of Natural History 21: 1273–1291.

Seniczak, S., A. Seniczak & S. J. Coulson. 2015. Morphology, distribution and biology of Mycobates sarekensis (Acari: Oribatida: Punctoribatidae). International Journal of Acarology 41 (8): 663–675.

[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.

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