Chordeumatida

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Chordeumatida
Chordeumatida New Zealand.jpg
Two unidentified species from New Zealand
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Myriapoda
Class: Diplopoda
Subterclass: Eugnatha
Superorder: Nematophora
Order: Chordeumatida
Pocock, 1894
Suborders

Chordeumatidea
Craspedosomatidea
Heterochordeumatidea
Striariidea

Contents

Diversity
c. 50 families, 1200 species
Synonyms

Ascospermophora Verhoeff, 1900
Craspedosomatida Jeekel, 1971

Chordeumatida (from the Greek word for "sausage") is a large order of millipedes containing some 1200 species with a nearly worldwide distribution. Also known as sausage millipedes, [1] they grow and develop through a series of moults, adding segments until they reach a fixed number in the adult stage, which is usually the same for a given sex in a given species, at which point the moulting and the addition of segments and legs stop. [2] This mode of development, known as teloanamorphosis, distinguishes this order from most other orders of millipedes, which usually continue to moult as adults, developing through either euanamorphosis or hemianamorphosis. [2] [3]

Description

Chordeumatidans are relatively short-bodied, with only 26 to 32 body segments (including the telson) behind the head. They range in length from 4–25 mm (0.16–0.98 in). A key feature is the presence of 6 large bristles (setae) on the dorsal surface of each body segment. The first segment (collum) is relatively narrow, giving the appearance of a distinct "neck" in many species. The body tapers towards the rear, and the rearmost tip (telson) contains silk-producing organs (spinnerets). A dorsal groove runs down the length of the body, and some species possess paranota, lateral extensions of the exoskeleton. Paranota are also found in some other millipedes, notably Polydesmida, from which Chordeumatidans can be distinguished by having a dorsal groove. Unlike most other helminthomorph (worm-like) millipedes, chordeumatidans lack ozopores. [4] [5]

Most chordeumatidan species have 30 body segments (including the telson) as adults, and adult females in these species have 50 leg pairs. [2] [6] In adult males in this order, two leg pairs (pair 8 and pair 9) are modified into gonopods, leaving 48 pairs of walking legs in the typical adult male chordeumatidan. [7] [2] Many species in this order, however, deviate from this typical body plan.

Many chordeumatidan species deviate from the usual 30 segments: A few species have 26 segments as adults (e.g., Chamaesoma broelemanni and Opisthocheiron canayerensis ), many species have 28 (e.g., Lipseuma josianae [8] ), one genus features 29 ( Tianella , in which all but two species have 29 [9] ), one species ( Metamastigophorophyllon martensi ) features 31, and many species have 32 (e.g., Altajosoma kemerovo [10] ). [2] Some species also deviate by featuring sexual dimorphism in segment number, specifically, adult males with two segments fewer than adult females, for example, in the family Buotidae (males with 26, females with 28), [11] in Xystrosoma beatense (males with 28, females with the usual 30), [2] and in the family Peterjohnsiidae (males with the usual 30, females with 32). [12]

With these deviations from the usual 30 segments, the number of leg pairs in adults changes, usually with two leg pairs added or subtracted for each segment added to or subtracted from the typical number. [6] For example, in Chamaesoma broelemanni, with only 26 segments (four fewer than the typical number), adult females have only 42 leg pairs, and adult males have only 40 pairs of walking legs (excluding two pairs of gonopods). [13] [2] Adult females with 32 segments (two more than the typical number) have 54 leg pairs (e.g., in the family Peterjohnsiidae [12] ), which is the maximum number fixed by species in the class Diplopoda. [14]

Many species deviate from the expected number of walking legs, however, because they deviate in terms of sex-linked modifications to their legs. For example, many species involve another leg pair in addition to pairs 8 and 9 in the gonopod complex in adult males. In the family Speophilosomatidae, leg pair 7 in adult males is modified as part of the gonopod complex. [15] In many species, the gonopod complex instead includes leg pair 10 in addition to pairs 8 and 9 (e.g., Branneria carinata , [16] Reginaterreuma monroei, [12] Golovatchia magda , and Hoffmaneuma exiguum [17] ). The family Chordeumatidae exhibits the most extensive modifications, including five leg pairs (pairs 7 through 11) in the gonopod complex. [7] [2] Some species also deviate from the usual body plan by reducing or eliminating leg pairs in the adult female. In the family Chordeumatidae, for example, adult females feature a legless sternite (the "platosternite") where a third pair of legs would otherwise be. [7] [2] [6] In other species (e.g., the genus Kashmireuma and the species Vieteuma longi ), adult females instead exhibit modifications to the second pair of legs, which are reduced to small nubbins. [18]

Distribution

Chordeumatidans have a large distribution, occurring on all continents except Antarctica. They are present in Madagascar but absent from sub-Saharan Africa and, aside from southern Chile, are largely absent from South America. They occur in the tropics of Central America, Southeast Asia, and Oceania, and as far south as Tasmania, New Zealand, and Chiloé Island, Chile. [19] They are abundant in cold, rocky, mountainous areas of Europe and central Asia, and range northward to Scandinavia, Siberia, and in North America up into Canada and southwest Alaska. [19]

Classification

Chordeumatida contains approximately 1200 species, [20] [21] classified in four suborders and approximately 50 families, although several families contain only one to five genera. [22]

Suborder Chordeumatidea Pocock 1894
Suborder Craspedosomatidea Cook, 1895
Suborder Heterochordeumatidea Shear, 2000
Suborder Striariidea Cook, 1896

Related Research Articles

<span class="mw-page-title-main">Millipede</span> 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 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 tight ball. Although the name "millipede" derives from Latin for "thousand feet", no species was known to have 1,000 or more until the discovery in 2020 of Eumillipes persephone, which can have over 1,300 legs. 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.

<span class="mw-page-title-main">Polydesmida</span> Order of millipedes

Polydesmida is the largest order of millipedes, containing approximately 3,500 species, including all the millipedes reported to produce hydrogen cyanide (HCN). Polydesmids grow and develop through a series of moults, adding segments until they reach a fixed number in the adult stage, which is usually the same for a given sex in a given species, at which point the moulting and the addition of segments and legs stop. This mode of development, known as teloanamorphosis, distinguishes this order from most other orders of millipedes, which usually continue to moult as adults, developing through either euanamorphosis or hemianamorphosis.

<span class="mw-page-title-main">Xystodesmidae</span> Family of millipedes

Xystodesmidae is a family of millipedes. Its members often have very small distributional areas, with many species only known from a single locality. They are found across the northern hemisphere, with peak diversity in the Appalachian Mountains, where one-third of the 300 or so species occur. They are particularly abundant in deciduous broadleaf forests in the Mediterranean Basin, Africa, Asia, Central and North America, and Russia. Information on basic taxonomy is scant for this family; for example, it is estimated that the genus Nannaria contains over 200 species, but only 25 were described as of 2006. By 2022, 78 species in Nannaria have been described.

Branneria is a genus of small millipedes in the order Chordeumatida and the only genus in the family Branneriidae. Individuals reach about 4 mm (0.16 in) long. There are two species known, found in the southeastern USA: Branneria bonoculus is found in Arkansas and eastern Texas while B. carinata occurs from North Carolina to Florida and Mississippi. The adult B. bonoculus millipede has 28 body segments, and the adult B. carinata millipede has 26, both fewer than the 30 usually found in the order Chordeumatida. In both species, the gonopod complex in adult males includes three leg pairs rather than just the two that are usually modified into gonopods in this order.

Siphonophoridae is a family of millipede in the order Siphonophorida. There are about 12 genera and more than 110 described species in Siphonophoridae.

<span class="mw-page-title-main">Haplodesmidae</span> Family of millipedes

Haplodesmidae is a family of millipedes in the order Polydesmida. Species occur in East Asia, Southeast Asia, and Oceania, although some species have been introduced to the New world tropics. Species are small bodied, often with elaborate sculpturing on the tergites, and some species are capable of rolling into a near-complete ball.

<span class="mw-page-title-main">Cleidogonidae</span> Family of millipedes

Cleidogonidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 28, 29, or 30 segments. This family includes the genus Tianella, notable for featuring adult millipedes with 29 segments, a number not found in the adults of any other chordeumatidan species. All Tianella species have adults with 29 segments except for two in which adults have only 28 segments. In the Tianella species with 29 segments, adult females have 48 pairs of legs, as one would expect in adult female chordeumatidans with one segment fewer than the 30 usually found in this order. There are seven genera and at least 140 described species in Cleidogonidae.

<span class="mw-page-title-main">Striariidae</span> Family of millipedes

Striariidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 30 segments. There are at least 3 genera and about 13 described species in Striariidae.

Tingupidae is a family of millipedes in the order Chordeumatida. Adult millipedes in this family have 28 or 30 segments. There are 2 genera and 13 described species in Tingupidae.

<i>Rhinotus</i> Genus of millipedes

Rhinotus is a genus of millipedes in the family Siphonotidae. There are at least 20 described species in Rhinotus.

<span class="mw-page-title-main">Metopidiotrichidae</span> Family of millipedes

Metopidiotrichidae is a family of millipedes in the order Chordeumatida. These millipedes range from 4 mm to 17 mm in length. Adult millipedes in this family have 32 segments, not the 30 segments usually found in this order. Adult males in this family often feature a reduced or vestigial leg pair 10 as part of the gonopod complex, in addition to the two leg pairs typically modified into gonopods in this order. There are about 9 genera and at least 70 described species in Metopidiotrichidae.

Trichopolydesmidae is a family of millipedes belonging to the order Polydesmida. This family includes two genera notable for featuring sexual dimorphism in segment number: adult females in these genera have the 20 segments usually found in this order, but adult males have only 19. This family also includes the species Deharvengius bedosae, notable for being among the very few species in this order to feature adults with only 18 segments rather than the 20 segments usually found in polydesmids.

Chordeumatidae is a family of millipedes belonging to the order Chordeumatida. These millipedes range from 7 mm to 18 mm in length and are found in Europe. Adult millipedes in this family have either 28 or 30 segments. This family features distinctive sex-linked modifications to the legs in adults: In the adult female, a legless sternite replaces the third pair of legs, and in the adult male, five pairs of legs are modified in the gonopod complex. These modifications are more extensive than those found in other adult males in this order, which often have only two leg pairs modified into gonopods. With the more extensive modifications to the legs in this family, species with the usual 30 segments feature adult females with only 49 leg pairs and adult males with only 45 pairs of walking legs, and species with only 28 segments feature adult females with only 45 leg pairs and adult males with only 41 pairs of walking legs.

Speophilosomatidae is a family of millipedes belonging to the order Chordeumatida. These millipedes are found in Japan and range from 4 mm to 6 mm in length. Adult millipedes in this family are notable for being among the few in this order with only 26 segments instead of the 30 usually found in chordeumatidans. The adult males in this family are also notable for involving three leg pairs in the gonopod complex rather than the two pairs typically modified into gonopods in this order.

Peterjohnsiidae is a small family of millipedes belonging to the order Chordeumatida. The family was first described in 1987 by Jean-Paul Mauriès. These millipedes range from 3 mm to 8 mm in length and are found in Australia. Species in this family exhibit sexual dimorphism in segment number: adult males have 30 segments, but adult females have 32 segments. In adult males in this family, the gonopod complex involves three leg pairs rather than just the two usually modified into gonopods in this order.

Diplomaragnidae is a family of millipedes belonging to the order Chordeumatida. These millipedes range from 9 mm to 24 mm in length and are found from the Volga River region in Russia to Japan and Taiwan. All known adult females in this family have 32 segments rather than the 30 segments typically found in this order; in most species, adult males also have 32 segments, but in some species, adult males have only 30 segments.

Haaseidae is a family of millipedes belonging to the order Chordeumatida. Adult millipedes in this family range from 4.5 mm to 12 mm in length and have either 28 or 30 segments. For example, Orobainosoma hungaricum orientale, a subspecies of Haasea hungarica, has only 28 segments in adults rather than the 30 usually found in chordeumatidan adults, with only 46 pairs of legs in adult females and only 44 pairs of walking legs in adult males.

Golovatchiidae is a family of millipedes belonging to the order Chordeumatida. This family contains a single species, Golovatchia magda. This species ranges from 15 mm to 17 mm in length and is found in the Russian Far East. Adult millipedes of this species have 30 segments. In the adult male of this species, the gonopod complex involves three leg pairs rather than just the two that are usually modified into gonopods this order.

Kashmireumatidae is a small family of millipedes belonging to the order Chordeumatida. These millipedes range from 5 mm to 14 mm in length and are found in East Asia. Adult millipedes in this family have only 26 or 28 segments rather than the 30 segments usually found in this order. In the species Vieteuma topali, adults have 26 segments, whereas in all other species in this family, adults have 28 segments.

Opisthocheiridae is a family of millipedes belonging to the order Chordeumatida. These millipedes range from 5 mm to 16 mm in length and are found from Belgium to Morocco. Adult millipedes in this family have 26 or 30 segments. This family includes the cave-dwelling species Opisthocheiron canayerensis, notable as one of few chordeumatidan species with only 26 segments. The adult female of this species has only 42 pairs of legs, and the adult male has only 40 leg pairs, as one would expect for adult chordeumatidans with four fewer segments than typically found in this order.

References

  1. ↑ Henen, Derek; Brown, Jeff. Millipedes of Ohio (PDF). Ohio Division of Wildlife. pp. 3, 24.
  2. 1 2 3 4 5 6 7 8 9 Enghoff, Henrik; Dohle, Wolfgang; Blower, J. Gordon (1993). "Anamorphosis in Millipedes (Diplopoda) — The Present State of Knowledge with Some Developmental and Phylogenetic Considerations". Zoological Journal of the Linnean Society. 109 (2): 103–234. doi:10.1111/j.1096-3642.1993.tb00305.x.
  3. ↑ Fusco, Giuseppe (December 2005). "Trunk segment numbers and sequential segmentation in myriapods". Evolution & Development. 7 (6): 608–617. doi:10.1111/j.1525-142X.2005.05064.x. PMID   16336414. S2CID   21401688 . Retrieved 25 August 2020.
  4. ↑ "Millipede Body Organization". Milli-PEET: The class Diplopoda. The Field Museum, Chicago. 9 February 2012. Archived from the original on 31 October 2013. Retrieved 18 March 2014.
  5. ↑ "Putative apomorphies of millipede clades" (PDF). Milli-PEET: Millipede Systematics. The Field Museum, Chicago, IL. 26 September 2006. Archived from the original (PDF) on 26 December 2015. Retrieved 20 March 2014.
  6. 1 2 3 Enghoff, Henrik; Golovatch, Sergei; Short, Megan; Stoev, Pavel; Wesener, Thomas (2015-01-01). "Diplopoda — taxonomic overview". Treatise on Zoology - Anatomy, Taxonomy, Biology. The Myriapoda, Volume 2: 363–453. doi:10.1163/9789004188273_017. ISBN   9789004156128.
  7. 1 2 3 Blower, J. Gordon (1985). Millipedes : keys and notes for the identification of the species. Linnean Society of London, Estuarine and Brackish-water Sciences Association. London: Published for the Linnean Society of London and the Estuarine and Brackish-Water Sciences Association by E.J. Brill. ISBN   90-04-07698-0. OCLC   13439686.
  8. ↑ Golovatch, Sergei I.; Geoffroy, Jean-Jacques; Mauries, Jean-Paul (2006). "Four new Chordeumatida (Diplopoda) from caves in China". Zoosystema. 28 (1): 75–92.
  9. ↑ Mauriès, Jean-Paul (1988). "Myriapodes du Népal. II. Diplopodes Craspedosomides nouveaux de l'Himalaya et de la région indo-malaise (Craspedosomidea et Chordeumidea)". Revue suisse de zoologie (in French). 95: 3–49. doi: 10.5962/bhl.part.79638 . ISSN   0035-418X – via Biodiversity Heritage Library.
  10. ↑ Shear, William A. (1990). "On the Central and East Asian milliped family Diplomaragnidae (Diplopoda, Choredeumatida, Diplomaragnoidea)". American Museum Novitates (2977). hdl:2246/5072.
  11. ↑ Shear, William A. (2009-11-16). "Buotidae, a new family for the minute North American milliped Buotuscarolinus (Chamberlin) 1940 (Diplopoda, Chordeumatida, Striarioidea)". Zootaxa. 2290 (1): 41–49. doi: 10.11646/zootaxa.2290.1.4 . ISSN   1175-5334. S2CID   4833397.
  12. 1 2 3 Mauries, Jean-Paul (1987). "Craspedosomid Millipedes Discovered in Australia: Reginaterreuma, Neocambrisoma and Peterjohnsia, New Genera (Myriapoda: Diplopoda: Craspedosomida)". Memoirs of the Queensland Museum. 25 (1): 107–133 – via Biodiversity Heritage Library.
  13. ↑ David, Jean-Francois (1989). "Le cycle biologique de Chamaesoma broelemanni Ribaut et Verhoeff, 1913 (Diplopoda, Craspedosomatida) en forêt d'Orléans (France)". Bulletin du Muséum National d'Histoire Naturelle, Section A (in French). 4:11 (3): 639–647. doi: 10.5962/p.288286 . S2CID   132547501 – via Biodiversity Heritage Library.
  14. ↑ Fusco, Giuseppe (2005). "Trunk segment numbers and sequential segmentation in myriapods". Evolution & Development. 7 (6): 608–617. doi:10.1111/j.1525-142X.2005.05064.x. ISSN   1520-541X. PMID   16336414. S2CID   21401688.
  15. ↑ Shear, William A.; Tsurusaki, Nobuo; Tanabe, Tsutomu (1994). "Japanese chordeumatid millipeds. I. On the genus Speophilosoma Takakuwa (Diplopoda, Chordeumatida, Speophilosomatidae)" (PDF). Myriapodologica. 3 (4): 25–36.
  16. ↑ Shear, William A. (2003-07-04). "Branneria bonoculus, n. sp., a second species in the North American milliped family Branneriidae (Diplopoda: Chordeumatida: Brannerioidea)". Zootaxa. 233 (1): 1–7. doi:10.11646/zootaxa.233.1.1. ISSN   1175-5334 – via ResearchGate.
  17. ↑ Shear, William A. (1992). "Golovatchia, new genus, and Golovatchiidae, from the Far East of the Russian Republic, with a comment on Hoffmaneumatidae (Diplopoda: Chordeumatidae)" (PDF). Myriapodologica. 3 (4): 25–36.
  18. ↑ Shear, William A. (2002). "Five New Chordeumatidan Millipeds from China: New Species of Vieteuma (Kashmirieumatidae) and Nepalella (Megalotylidae)". Proceedings of the California Academy of Sciences. 53 (6): 63–72 – via Biodiversity Heritage Library.
  19. 1 2 Shelley, R. M. & Golavatch, S. I. (2011). "Atlas of myriapod biogeography. I. Indigenous ordinal and supra-ordinal distributions in the Diplopoda: Perspectives on taxon origins and ages, and a hypothesis on the origin and early evolution of the class". Insecta Mundi. 158: 1–134.
  20. ↑ Sierwald, Petra; Bond, Jason E. (2007). "Current Status of the Myriapod Class Diplopoda (Millipedes): Taxonomic Diversity and Phylogeny". Annual Review of Entomology. 52 (1): 401–420. doi:10.1146/annurev.ento.52.111805.090210. PMID   17163800.
  21. ↑ Brewer, Michael S.; Sierwald, Petra; Bond, Jason E. (2012). "Millipede Taxonomy after 250 Years: Classification and Taxonomic Practices in a Mega-Diverse yet Understudied Arthropod Group". PLOS ONE. 7 (5): e37240. Bibcode:2012PLoSO...737240B. doi: 10.1371/journal.pone.0037240 . PMC   3352885 . PMID   22615951.
  22. ↑ Shear, W. (2011). "Class Diplopoda de Blainville in Gervais, 1844. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness" (PDF). Zootaxa. 3148: 159–164. doi:10.11646/zootaxa.3148.1.32.
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