Peripatopsis sedgwicki

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Peripatopsis sedgwicki
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Onychophora
Family: Peripatopsidae
Genus: Peripatopsis
Species:
P. sedgwicki
Binomial name
Peripatopsis sedgwicki
Purcell, 1899
Synonyms
  • Peripatus dewaali(Weber, 1898)

Peripatopsis sedgwicki is a species of velvet worm in the Peripatopsidae family. [1] [2] [3] Also known as the Tsitsikamma velvet worm, [4] this species has a narrow geographic distribution in South Africa but is especially abundant in the indigenous forest of the Tsitsikamma mountains. [5] [6] Recent phylogenetic analysis using molecular data finds that Peripatopsis sedgwicki as traditionally understood based on morphology (sensu lato) is a species complex that contains four different species: P. sedgwicki s.s. (sensu stricto, that is, as more narrowly defined), P. orientalis , P. collarium , and P. margaritarius . [7]

Contents

Discovery

This velvet worm was first described under the name Peripatus dewaali by the Dutch zoologist Max Weber in 1898 based on specimens he collected near the town on Knysna in the Western Cape province of South Africa. [8] In 1899, the South African zoologist William F. Purcell provided a more detailed description based on a male and eleven females that he found in 1896 in rotten wood in the forest and under heaps of weeds on farms near the town of Knysna. [9] [5] He named this species Peripatopsis sedgwicki for the British zoologist Adam Sedgwick. [9] Although Peripatopsis sedgwicki is a junior synonym of Peripatus dewaali, authorities favor the name Peripatopsis sedgwicki based on its long usage, deeming Peripatus dewaali to be a nomen oblitum and designating Peripatopsis sedgwicki a nomen protectum . [2] [3]

Taxonomic revision and distribution

In 2024, the zoologists Aaron Barnes and Savel R. Daniels conducted a phylogenetic study using molecular data from a large sample of specimens of Peripatopsis sedgwicki (sensu lato). They find that this species complex contains four clades, each representing a different species. Type specimens of each species are deposited in the South African Museum. Each of these species has a different geographic distribution within the range of this species complex in South Africa. [7]

The species P. sedgwicki s.s. (that is, as narrowly understood) is endemic to a small area confined to the Afrotemperate forest of the Western Cape province near the original type locality Knysna. Given the absence of any original type material, Barnes and Daniels designate a female specimen as the neotype and three other female specimens as paraneotypes. These specimens were collected from the Diepwalle forest in Knysa. Other specimens in the same clade were collected in three nearby localities (the Homtini River in Rheenendal as well as Harkerville and the Garden of Eden in Plettenberg Bay). [7]

The species P. orientalis has the broadest distribution within this species complex, ranging from Nature's Valley to Grahamstown in the Eastern Cape province. Barnes and Daniels base the original description of this species on a female holotype and six paratypes (including two males and two females). These specimens were collected in Nature's Valley. The specific name refers to the relatively eastern distribution of this species. [7]

The species P. collarium is a point endemic found only in the Van Stadens Wild Flower Reserve in the Eastern Cape province. Barnes and Daniels based the original description of this species on a female holotype and two paratypes (one male and one female) found there. The molecular data indicate that this species is most closely related to P. orientalis and that these two species form a sister group for P. sedgwicki s.s. [7]

The species P. margaritarius is a point endemic found only in the Fort Fordyce Nature Reserve on a high plateau in the interior of the Eastern Cape province. Barnes and Daniels base the original description of this species on a female holotype and 25 paratypes (including thirteen females and eight males) found there. Phylogenetic analysis of this species complex places this species on the most basal branch of a phylogenetic tree, with the other three species forming a sister group. This species is named in honor of the biologist Margaretha Hofmeyr of the University of the Western Cape. [7]

Description

Although Purcell originally described Peripatopsis sedgwicki with 20 pairs of legs, [9] which was long considered characteristic of this species, [5] more recent studies find that velvet worms in the P. sedgwicki species complex can have as few as 19 or as many as 23 leg pairs. [10] Leg number is diagnostic for the Fort Fordyce species P. margaritarius, which features 21 to 23 leg pairs, as only 19 or 20 leg pairs are recorded elsewhere in the rest of the species complex. For example, P. sedgwicki s.s. can have either 19 or 20 leg pairs in most localities. Although 20 leg pairs are usually observed in P. orientalis, some localities (four out of 17 localities sampled) yielded samples of this species with 19 pairs as well as 20 pairs. Finally, P. collarium is known from only a small sample in one locality, with 20 leg pairs recorded in four specimens (two males and two females). [7]

All specimens of P. collarium feature a prominent white head collar that is absent in the other three species. The name P. collarium refers to this diagnostic trait. [7] Color is otherwise highly variable in this species complex, even within a single clade, with the ventral surface varying from white to light pink and the dorsal colors ranging from dark blue, grey, or brown to bright orange or red. [6] [7] [10] Thus, coloration proves to be generally unreliable as a basis for distinguishing among clades within this species complex. [7]

Although gross morphology is of limited use in identifying individual species within this species complex, scanning electron microscopy reveals diagnostic differences beyond those noted above. For example, each species features a different number of scale ranks on the dorsal primary papillae, with seven in P. margaritarius, eight in P. sedgwicki s.s., nine in P. orientalis, and ten in P. collarium. [7] In terms of gross morphology, however, the velvet worms in this species complex generally share the features associated with P. sedgwicki (sensu lato) as described below.

These velvet worms are relatively large: [9] Females range in size from 12 mm to 68 mm in length, whereas males range from 10 mm to 46 mm in length. [5] The outer blade of the jaw may have only one accessory tooth or no such tooth, and rarely may have two such teeth. The inner blade of the jaw features four to seven accessory teeth. [11] The male genital opening is cruciform, and the female genital opening is a horizontal and small vertical slit. [7]

The last leg pair (the genital pair) features claws, [10] like those on the pregenital pairs, and is well developed compared to those in some other species in the genus Peripatopsis . [9] The last leg pair, however, is smaller than the preceding leg pair and reduced more in the male than in the female. [5] [9] Each leg feature three or four spinous pads except for the last leg pair, which feature only one to three pads on each leg. [5] [11] The feet also feature three distal papillae (two anterior and one posterior). [11]

These velvet worms share many traits with other species in the genus Peripatopsis. These shared traits include features considered characteristic for the genus, such as the reduced last (genital) leg pair, feet with three distal papillae (two anterior and one posterior), the cruciform genital opening in the male, and variable color. [12] In 2009, a phylogenetic analysis of Peripatopsis species using molecular data found P. sedgwicki (sensu lato) to be most closely related to P. moseleyi , [6] which has also since been found to be a species complex. [12] Like the velvet worms in the P. moseleyi species complex, those in the P. sedgwicki species complex do not curl up into a spiral when initially exposed. [5] [12]

The velvet worms in the P. sedgwicki species complex can be distinguished from their close relatives in the P. moseleyi species complex based on marked differences in the last leg pair. This leg pair in the P. sedgwicki species complex is relatively well developed and features claws in both sexes, [5] whereas this leg pair in the P. moseleyi species complex is rudimentary and reduced to mere tubercles. At most, this leg pair in the P. moseleyi species complex may feature a single claw (never two) on one or two of these legs in the female. [12]

Reproduction and life cycle

Like other velvet worms in the genus Peripatopsis, those in the P. sedgwicki species complex exhibit matrotrophic viviparity, that is, mothers in this genus retain eggs in their uteri and supply nourishment to their embryos, but without any placenta. Females in the P. sedgwicki species complex produce eggs with almost no yolk, and embryos develop large "trophic organs" or "trophic vesicles" that may function as means to absorb nourishment from the mother. [13] The female gives birth to her first batch of young when she is about two years old. About a month before the birth of each batch, the next batch of eggs are fertilized. The young reach their maximum size when they are about three years old. These velvet worms have a life span of about six to seven years. [5]

Related Research Articles

<i>Peripatopsis</i> Genus of velvet worms

Peripatopsis is a genus of velvet worms in the Peripatopsidae family. These velvet worms are found in the KwaZulu-Natal, Western Cape, and Eastern Cape provinces of South Africa. This genus was proposed by the British zoologist Reginald I. Pocock in 1894 with Peripatopsis capensis designated as the type species.

<span class="mw-page-title-main">Peripatopsidae</span> Family of invertebrate animals

Peripatopsidae is one of the two living velvet worm families. This family includes more than 140 described species distributed among 41 genera, but some authorities deem only 131 of these species to be valid. The French zoologist Eugène Louis Bouvier proposed this family in 1905 with Peripatopsis as the type genus.

Metaperipatus is a genus of velvet worms in the family Peripatopsidae that contains two species found in Chile, including Metaperipatus inae. This genus was created by the American zoologist Austin Hobart Clark in 1913 to contain the type species, M. blainvillei. Authorities believe M. blainvillei is a species complex, however, and some consider M. blainvillei a nomen dubium.

Peripatopsis balfouri is a species of velvet worm in the Peripatopsidae family. This species has 18 pairs of clawed legs. Also known as the blue velvet worm, this species ranges from 9 mm to 22 mm in length. The type locality is in South Africa.

Peripatopsis birgeri is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. moseleyi species complex. The number of legs in this species varies from 21 pregenital pairs to 22 pregenital pairs. Live animals are light green, brown, or black with a distinct pale head collar; the ventral surface is creamy white. Males range from 23 mm to 40 mm in length; females range from 28 mm to 40 mm in length. Also known as the Mount Currie velvet worm, this species is known only from the Mount Currie Nature Reserve in South Africa.

Peripatopsis bolandi is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. balfouri species complex and ranges from 18 mm to 22 mm in length. Also known as the Boland velvet worm, this species is found in the Hottentots Holland Mountain region in South Africa.

<i>Peripatopsis capensis</i> Species of velvet worm

Peripatopsis capensis is a species of velvet worm in the Peripatopsidae family. This species has 18 pairs of legs: 17 pregenital leg pairs with claws plus one strongly reduced last pair without claws or spinous pads. Females of this species range from 9 mm to 70 mm in length, whereas males range from 6 mm to 54 mm. The native range of this species is limited to the Cape Peninsula of South Africa.

Peripatopsis cederbergiensis is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. balfouri species complex. Males of this species have 17 clawed legs with the last pair highly reduced, whereas females have a complete foot with claws on the reduced leg. This species is charcoal black in color and ranges from 9 mm to 15 mm in length. Also known as the Cederberg velvet worm, this species is endemic to the Cederberg Mountains of South Africa.

Peripatopsis hamerae is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. moseleyi species complex. The original description of this species is based on one specimen of each sex, each measuring 22 mm in length with a black dorsal surface and creamy white ventral surface. The male of this species has 22 pairs of pregenital legs and one pair of genital legs; the female has 23 pairs of pregenital legs and one pair of genital legs. Also known as the Kamala velvet worm, this species is known only from Groot Bruintjieshoogte in South Africa.

Peripatopsis janni is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. moseleyi species complex. The original description of this species is based on male specimens ranging from 15 mm to 30 mm in length. Live animals are dark green on the dorsal surface but greyish white on the ventral surface. The number of legs in males of this species varies from 21 pregenital pairs to 22 pregenital pairs. Also known as the Amathole velvet worm, this species is found in the Amathole mountains in South Africa.

<i>Peripatopsis lawrencei</i> Species of velvet worm

Peripatopsis lawrencei is a species of velvet worm in the Peripatopsidae family. This species has 17 pairs of legs, with the last pair reduced in size but featuring two claws on each leg. This species is restricted to the Theewaterskloof-Overstrand region of South Africa.

<i>Peripatopsis moseleyi</i> Species of velvet worm

Peripatopsis moseleyi is a species of velvet worm in the Peripatopsidae family. Males of this species have 20 to 24 pairs of legs with claws ; females have 19 to 23 pairs of legs with claws. Females range from 11 mm to 75 mm in length, whereas males range from 9 mm to 50 mm. The type locality is in South Africa.

Peripatopsis purpureus is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. balfouri species complex. Males of this species have 17 clawed legs with the last pair highly reduced, whereas females have a complete foot with claws on the reduced leg. Specimens range from 17 mm to 25 mm in length. Named for its purple-blue color, this species is found in the Western Cape Province of South Africa.

Peripatopsis storchi is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. moseleyi species complex. The number of legs in this species ranges from 21 pregenital pairs to 23 pregenital pairs. Males of this species range from 12 mm to 22 mm in length, and females range from 22 mm to 36 mm in length, but live animals can stretch to 50 mm while walking. Also known as the Katberg velvet worm, this species is known only from the Katberg forest in South Africa.

<i>Peripatopsis alba</i> Species of velvet worm

Peripatopsis alba, the white cave velvet worm, is a species of velvet worm in the family Peripatopsidae. This species is notable as one of only two species of velvet worm known to be troglobitic; the only other velvet worm known to be a troglobiont is Speleoperipatus spelaeus. The white cave velvet worm is rare and limited to one cave system on Table Mountain in South Africa.

Peripatopsis mira is a species of velvet worm in the family Peripatopsidae. This species is a clade in the P. clavigera species complex. This species has 17 pairs of legs, varies from slate black to charcoal, and is found on the south-facing slope of the Outeniqua mountain range in Western Cape province in South Africa.

Peripatopsis aereus is a species of velvet worm in the family Peripatopsidae. This species is known only from the Riviersonderend Mountains in South Africa. This velvet worm was discovered living in sympatry with another species in the same genus, P. lawrencei. These two sympatric species can be distinguished based on the number of legs: The species P. aereus has 18 pairs of legs, whereas the species P. lawrencei has only 17 leg pairs.

Peripatopsis collarium is a species of velvet worm in the Peripatopsidae family. This velvet worm is a point endemic known only from a small sample found in the Van Stadens Wild Flower Reserve in South Africa. The species name of P. collarium refers to a distinctive white head collar present in all specimens of this velvet worm. This species was discovered as a clade within the Peripatopsis sedgwicki species complex.

Peripatopsis orientalis is a species of velvet worm in the Peripatopsidae family. This species was discovered as one of four clades within the Peripatopsis sedgwicki species complex. Each clade represents a separate species, each with a different geographic distribution in South Africa. The species P. orientalis has the broadest distribution among the four species in this species complex. The specific name refers to the relatively eastern distribution of this species within this species complex.

Peripatopsis margaritarius is a species of velvet worm in the Peripatopsidae family. This velvet worm is a point endemic found only in the Fort Fordyce Nature Reserve in South Africa. This species was discovered as a clade within the Peripatopsis sedgwicki species complex. This velvet worm can have from 21 to 23 pairs of legs, unlike the other three species in the P. sedgwicki species complex, which have only 19 or 20 leg pairs.

References

  1. ↑ Oliveira, I. S.; Hering, L. & Mayer, G. "Updated Onychophora checklist". Onychophora Website. Retrieved 24 November 2016.
  2. 1 2 Oliveira, Ivo; Read, V. Morley; Mayer, Georg (2012-07-25). "A world checklist of Onychophora (velvet worms), with notes on nomenclature and status of names". ZooKeys (211): 1–70. Bibcode:2012ZooK..211....1O. doi: 10.3897/zookeys.211.3463 . ISSN   1313-2970. PMC   3426840 . PMID   22930648.
  3. 1 2 Oliveira, Ivo de Sena (2023-11-16). "An updated world checklist of velvet worms (Onychophora) with notes on nomenclature and status of names". ZooKeys (1184): 133–260. Bibcode:2023ZooK.1184..133O. doi: 10.3897/zookeys.1184.107286 . ISSN   1313-2970. PMC   10680090 . PMID   38023768.
  4. ↑ "Tsitsikamma Velvetworm (Peripatopsis sedgwicki)". iNaturalist. Retrieved 2023-03-07.
  5. 1 2 3 4 5 6 7 8 9 Hamer, M.L.; Samways, M.J.; Ruhberg, H. (1997). "A review of the Onychophora of South Africa, with discussion of their conservation". Annals of the Natal Museum. 38 (1): 283–312 [285, 289, 305-306].
  6. 1 2 3 Daniels, Savel R.; Picker, Mike D.; Cowlin, Ross M.; Hamer, Michelle L. (2009-05-01). "Unravelling evolutionary lineages among South African velvet worms (Onychophora: Peripatopsis) provides evidence for widespread cryptic speciation". Biological Journal of the Linnean Society. 97 (1): 200–216 [201, 209]. doi: 10.1111/j.1095-8312.2009.01205.x . ISSN   0024-4066.
  7. 1 2 3 4 5 6 7 8 9 10 11 12 Barnes, Aaron; Daniels, Savel R. (2024). "Molecular and Morphological Evidence for the Description of Three Novel Velvet Worm Species (Onychophora: Peripatopsidae: Peripatopsis sedgwicki s.s.) from South Africa". Diversity. 16 (9): 566. doi: 10.3390/d16090566 . ISSN   1424-2818.
  8. ↑ Weber, M. (1898). "Wetenschappelijke Vergadering". Tijdschrift der Nederlandsche Dierkundige Vereniging (in Dutch). 5 (4): VII–IX – via Biodiversity Heritage Library.
  9. 1 2 3 4 5 6 Purcell, W.F. (1899). "On the South African species of Peripatidae in the collection of the South African Museum". Annals of the South African Museum. 1: 331–351 [345–347] – via Biodiversity Heritage Library.
  10. 1 2 3 Daniels, Savel R.; Dreyer, Megan; Sharma, Prashant P.; Daniels, Savel R.; Dreyer, Megan; Sharma, Prashant P. (2017-12-04). "Contrasting the population genetic structure of two velvet worm taxa (Onychophora : Peripatopsidae : Peripatopsis) in forest fragments along the south-eastern Cape, South Africa". Invertebrate Systematics. 31 (6): 781–796. doi:10.1071/IS16085. ISSN   1447-2600. S2CID   49530457.
  11. 1 2 3 Ruhberg, Hilke (1985). Die Peripatopsidae (Onychophora) : Systematik, Ökologie, Chorologie und phylogenetische Aspekte (in German). Stuttgart: E. Schweizerbart. pp. 102–104. ISBN   3-510-55023-4. OCLC   14872354.
  12. 1 2 3 4 Ruhberg, Hilke; Daniels, Savel R. (2013-05-24). "Morphological assessment supports the recognition of four novel species in the widely distributed velvet worm Peripatopsis moseleyi sensu lato (Onychophora : Peripatopsidae)". Invertebrate Systematics. 27 (2): 131–145 [134]. doi:10.1071/IS12069. ISSN   1447-2600.
  13. ↑ Mayer, Georg; Franke, Franziska Anni; Treffkorn, Sandra; Gross, Vladimir; de Sena Oliveira, Ivo (2015), Wanninger, Andreas (ed.), "Onychophora", Evolutionary Developmental Biology of Invertebrates 3, Vienna: Springer Vienna, pp. 53–98, doi:10.1007/978-3-7091-1865-8_4, ISBN   978-3-7091-1864-1 , retrieved 2023-02-15
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