Sphaeromimus

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Sphaeromimus
Sphaeromimus andohahela.jpg
Sphaeromimus andohahela
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Brandt, 1833
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Genus:
Sphaeromimus

Species

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Sphaeromimus (Latin: sphere mimic), [1] or the chirping giant pill millipedes, is a genus of giant pill millipedes (order Sphaerotheriida) endemic to southeastern Madagascar. [2] Though described in 1902, [3] the genus was up to 2005 known from a single male specimen, whose appearance was so unusual that the authors suspected a mislabeled giant pill-millipede from India. [4] Their unusual and distinct morphology includes well-developed stridulation organs, probably as devices for courtship. These are the male ‘harp’ and the female ‘washboard’, which contain more stridulation ribs than in other members of the order Sphaerotheriida. [5] They have a closer affinity with the Indian genus Arthrosphaera than to other Malagasy genera, though all belong to the Arthrosphaeridae. [5]

Contents

Relationships

It belongs to the family Arthrosphaeridae, which besides Sphaeromimus includes the Malagasy genera Zoosphaerium and Microsphaerotherium , and the Indian genus Arthrosphaera . [6] Recent research has shown that Sphaeromimus is more closely related to the Indian genus Arthrosphaera than to the other Malagasy genera. [6]

Habitat

All populations inhabit the leaf litter of the Malagasy rainforests, except for one recently described species (2014) which was found in a cave and the type species S. musicus which has only been found in the dry spiny forest. Recent research has shown that Sphaeromimus populations are highly endemic, since individuals are not able to travel between forest patches. Movement between populations is becoming more limited, as forest is being destroyed at a rapid rate on Madagascar.

Habits

Like other giant pill-millipedes, Sphaeromimus individuals can roll up into a ball for protection. The size of this ball is typically equal to that of a ping-pong ball and can sometimes even be larger. Males have a structure on their anterior telopod, known as the harp, which has several stridulation ribs and is able to produce sounds when rubbed against a sclerotized knob on the leg. They probably use this structure during courtship in order to prevent females from rolling up into a ball. [7] When a female is receptive, it is believed that males use the posterior telopod in order to hold females down for copulation. Females, on the other hand, have a structure on their subanal plate called the washboard, which, like the male harp, contains stridulation ribs and produces sounds. The harp and washboard are present in all species of the family Arthrosphaeridae but are especially well developed in Sphaeromimus, with males having 3–7 ribs on each harp, and females 8–16 ribs on each washboard. [2]

Species

Three color morphs of Sphaeromimus musicus: red (upper left), brown (upper right), and "normal" (lower right), which resembles Zoosphaerium blandum (seen at lower left) Sphaeromimus musicus morphs.jpg
Three color morphs of Sphaeromimus musicus: red (upper left), brown (upper right), and "normal" (lower right), which resembles Zoosphaerium blandum (seen at lower left)

Until 2014 only three species of Sphaeromimus were known. A further seven species were described in 2014, some of which are microendemics. [1] [2] [5]

2014

Related Research Articles

Millipede Class of arthropods

Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name being derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a ball. Although the name "millipede" derives from the Latin for "thousand feet", no known species has 1,000; the record of 750 legs belongs to Illacme plenipes. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures.

Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mechanism is typically that of one structure with a well-defined lip, ridge, or nodules being moved across a finely-ridged surface or vice versa, and vibrating as it does so, like the dragging of a phonograph needle across a vinyl record. Sometimes it is the structure bearing the file which resonates to produce the sound, but in other cases it is the structure bearing the scraper, with both variants possible in related groups. Common onomatopoeic words for the sounds produced by stridulation include chirp and chirrup.

Pill millipede Order of millipedes

Pill millipedes are any members of two living orders of millipedes, often grouped together into a single superorder, Oniscomorpha. The name Oniscomorpha refers to the millipedes' resemblance to certain woodlice (Oniscidea), also called pillbugs or "roly-polies". However, millipedes and woodlice are not closely related ; rather, this is a case of convergent evolution.

Gonopod

Gonopods are specialized appendages of various arthropods used in reproduction or egg-laying. In males, they facilitate the transfer of sperm from male to female during mating, and thus are a type of intromittent organ. In crustaceans and millipedes, gonopods are modified walking or swimming legs. Gonopods may be highly decorated with elaborate structures which may play roles in sperm competition, and can be used to differentiate and identify closely related species. Gonopods generally occur in one or more pairs, as opposed to the single (un-paired) reproductive organs such as the aedeagus of insects or the penis of harvestmen.

Andohahela National Park

Andohahela National Park, in south-east Madagascar, is remarkable for the extremes of habitats that are represented within it. The park covers 760 km2 (293 sq mi) of the Anosy mountain range, the southernmost spur of the Malagasy Highlands and contains the last humid rainforests in the southern part of Madagascar.

Sphaerotheriidae Family of millipedes

Sphaerotheriidae is a family of giant pill millipedes of the class Diplopoda. Millipedes of this family are distributed in southern Africa.

<i>Procyliosoma</i> Genus of millipedes

Procyliosoma is a genus of pill millipede found in Australia and New Zealand. Formerly classified in the family Sphaerotheriidae, in 2009 Procyliosoma was reclassified as the only genus in the family Procyliosomatidae.

Glomerida Order of millipedes

Glomerida is an order of pill-millipedes found primarily in the Northern Hemisphere. They superficially resemble pill-bugs or woodlice, and can enroll into a protective ball. They have twelve body segments, 17 to 19 pairs of legs, and males have enlarged rear legs involved in mating. The order includes about 30 genera and at least 280 species, including Glomeris marginata, the common European pill-millipede. The order contains members in Europe, South-east Asia and the Americas from California to Guatemala. Although historically considered closely related with the similar sphaerotheriidans that also enroll, some DNA evidence suggest they may be more closely related to glomeridesmidans, a poorly known order that does not enroll.

Tsimanampetsotsa National Park

Tsimanampetsotsa National Park also spelt Tsimanampetsotse, and known as Tsimanampetsotsa Nature Reserve is a 432 km2 national park on the south-west coast of Madagascar in the region Atsimo-Andrefana. The park is 90 kilometres (56 mi) south of Toliara and 950 kilometres (590 mi) south of the capital, Antananarivo. Route Nationales (RN) 10 to Faux Cap passes the park and the nearest airport is at Toliara. The national park contains and is named after Lake Tsimanampetsotsa.

Sphaerotheriida Order of millipedes

Sphaerotheriida is an order of millipedes in the infraclass Pentazonia, sometimes known as giant pill millipedes. They inhabit Southern Africa, Madagascar, South and Southeast Asia, Australia and New Zealand. Like the Northern Hemisphere pill millipedes of the order Glomerida, these millipedes can roll into a ball when disturbed. When they are rolled-up, most sphaerotheriidans reach a maximum size of a cherry or golf ball, but some species from Madagascar can even reach the size of an orange. When rolled-up, predators are unable to unravel giant pill millipedes since the margins of their second and last dorsal plates fit perfectly into one another, creating a sealed ball. A few giant pill millipede species are able to produce sound, the only millipedes known to do this. This order of millipedes is also unique in that some African species are used for medicinal purposes.

Zephroniidae Family of millipedes

Zephroniidae is a family of giant pill millipedes in the taxonomic order Sphaerotheriida. They occur in southeast Asia from the Himalayas and China south and east to Sulawesi and to Australia, and also inhabit some Philippine islands.

Arthrosphaeridae Family of millipedes

Arthrosphaeridae is a family of giant pill millipedes that are found in Madagascar, the Western Ghats of India, and Sri Lanka. The largest pill-millipede in the world, Zoosphaerium neptunus belongs to this family and is known to swarm at certain times of the year.

<i>Zoosphaerium neptunus</i> Species of millipede

Zoosphaerium neptunus is the largest pill-millipede in the world, reaching lengths of 90 mm (3.5 in). Endemic to Madagascar, it is known to swarm at certain times of the year.

Arthrosphaera attemsi, is a species of pill millipedes in the family Arthrosphaeridae. It is native to India and Sri Lanka.

The Tanzanian Pill Bug Millipede,, is a species of pill millipedes in the family Arthrosphaeridae. It is found in many African countries, Asian countries such as India and Sri Lanka. It is about 3–4 cm in length. Adult is pale brown color with black lines in between the segments, whereas juveniles are dark brown. It is one of widely used exotic pill bug species in the world.

Arthrosphaera corrugata, is a species of pill millipedes in the family Arthrosphaeridae. It is endemic to Sri Lanka

Arthrosphaera noticeps, is a species of pill millipedes in the family Arthrosphaeridae. It is endemic to Sri Lanka.

Arthrosphaera pilifera, is a species of pill millipedes in the family Arthrosphaeridae. It is endemic to Sri Lanka.

Arthrosphaera ruginosa, is a species of pill millipedes in the family Arthrosphaeridae. It is endemic to Sri Lanka.

Pachybolidae Family of millipedes

Pachybolidae, is a family of Round-backed millipedes of the order Spirobolida. The family includes 49 different genera. Two subfamilies recognized.

References

  1. 1 2 de Lazaro, Enrico (June 23, 2014). "Seven New Species of Chirping Giant Pill-Millipedes Discovered in Madagascar". Sci-News.com. Retrieved 15 July 2014.
  2. 1 2 3 T. Wesener & P. Sierwald (2005). "The giant pill-millipedes of Madagascar: Revision of the genus Sphaeromimus with a review of the morphological terminology (Diplopoda, Sphaerotheriida, Sphaerotheriidae)" (PDF). Proceedings of the California Academy of Sciences. 56: 557–599.
  3. H. de Saussure and L. Zehnter (1902). Myriapodes de Madagascar. Vol. 27 of Alfred Grandidier, Histoire, physique, naturelle, et politique de Madagascar. Paris: Imprimerie Nationale. pp. i–vii, 1–356, pl. 13, 14, 15.
  4. C. A. W. Jeekel (1999). "A new pill-millipede from Madagascar, with a catalogue of the species hitherto described from the island (Diplopoda, Sphaerotheriida)". Myriapod Memoranda. I: 5–21.
  5. 1 2 3 Wesener, Thomas; Le, Daniel; Loria, Stephanie (6 June 2014). "Integrative revision of the giant pill-millipede genus Sphaeromimus from Madagascar, with the description of seven new species (Diplopoda, Sphaerotheriida, Arthrosphaeridae)". ZooKeys (414): 67–107. doi:10.3897/zookeys.414.7730. PMC   4086051 . PMID   25009417.
  6. 1 2 T. Wesener & D. Vanden Spiegel (2009). "A first phylogenetic analysis of Giant Pill-Millipedes (Diplopoda: Sphaerotheriida), a new model Gondwanan taxon, with special emphasis on island gigantism". Cladistics . 25 (6): 545–573. doi:10.1111/j.1096-0031.2009.00267.x. S2CID   86041765. Archived from the original (PDF) on 2013-01-05.
  7. U. Haacker (1969). "Das Sexualverhalten von Sphaerotherium dorsale (Myriapoda, Diplopoda)". Verhandlungen der Deutschen Zoologischen Gesellschaft. 3: 454–463.