Peripatopsis alba

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Peripatopsis alba
Peripatopsis alba (10.3897-subtbiol.36.60162) Figure 1 (cropped).jpg
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Onychophora
Family: Peripatopsidae
Genus: Peripatopsis
Species:
P. alba
Binomial name
Peripatopsis alba
Lawrence, 1931

Peripatopsis alba, the white cave velvet worm, is a species of velvet worm in the family Peripatopsidae. [1] 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 . [2] [3] The white cave velvet worm is rare [2] [3] and limited to one cave system on Table Mountain in South Africa. [4]

Contents

Discovery

This species was first described by the South African zoologist Reginald F. Lawrence in 1931 based on four specimens, including two type specimens, an adult male and a subadult female. [5] The male measures 48 mm in length, whereas the female is smaller, only 32 mm long. [6] Lawrence collected these specimens from Wynberg Cave near the top of Table Mountain, including some from the main gallery, about 100 feet (30 m) below the surface. [5] [6] [7] These velvet worms were found under stones or climbing up the wet walls of the cave. [5]

Description

This species has no eyes and lacks pigmentation. The body of this species is a striking white, with a thin opaque stripe running from the head down the back but fading near the posterior end of the body. This species has 18 pairs of clawed legs, with the last pair reduced. In the male, the penultimate pair is also smaller than the preceding pair. The soles of the feet feature three pads with the middle pad two or three times as broad as the proximal pad. The claws are a dirty white tipped with brown. LIke other velvet worms in the genus Peripatopsis , this species has three distal papillae on each foot, two anterior and one posterior. [6] [5]

The feet are elongated, and the legs are notably longer and more slender than in other species of Peripatopsis. [5] [6] In the larger male type specimen, for example, the legs in the middle of the body measure 2.1 to 2.6 mm in length, and the feet are 0.8 to 0.9 mm long. [5] Long legs reflect an adaptation to life in the dark, where the velvet worm can use these legs to explore its surroundings, much as a blind person might use a cane. [8] This species also features longer antennae, another characteristic common among troglobitic species. [7] The other troglobitic species of velvet worm, S. spelaeus, for example, also lacks pigment, has no eyes, and features legs and antennae that are unusually long. [6]

Phylogeny

As noted by Lawrence, this species resembles its close relative P. balfouri , both in terms of the number of legs and the conical papillae on the integument. [5] [6] He describes P. alba as an eyeless version of P. balfouri, but with longer legs and lacking pigment. [5] The species P. balfouri is also close in terms of geography, living just outside the cave where P. alba was discovered. [6] Phylogenetic analysis using molecular data confirms that P. alba is part of the P. balfouri species complex but maintains P. alba as a separate species. [9] An analysis of the molecular evidence places P. alba in its own clade on a branch of a phylogenetic tree with a sister group formed by two other clades, one belonging to P. balfouri and the other comprising P. bolandi and P. purpureus . [10]

Distribution and habitat

Peripatopsis alba is known only from two caves, Wynberg Cave and Bats' Cave, both part of a cave system about 750 m above sea level on Table Mountain in South Africa. [2] [3] This cave system is the third largest sandstone cave system in the world, and Wynberg and Bats' caves are the most frequently visited of the Table Mountain caves. Wynberg Cave measures 300 m in length and reaches a maximum depth of 50 m, whereas Bats' Cave is shorter (only 60 m long) but deeper. [3]

The walls of Wynberg Cave is an extensive labyrinth of horizontal galleries with surfaces kept damp by water seeping in through fissures in the rock. [3] [5] [6] The only vegetation in this cave is a greyish lichen. [5] [6] Bats' Cave is similarly humid with a perennial pool in a small deep zone chamber. [3] Like other deep caves with small entrances, these caves maintain a fairly constant temperature and humidity over the course of the day and through the year. [7]

The white cave velvet worm preys on cave crickets, [8] but prey is not plentiful, so the population density is low. [7] This velvet worm is found only in the deep zone of the caves under stones or on damp walls where moisture is plentiful. [3] [6] This species is so sensitive to its environment that all attempts to keep them alive outside the cave system have failed. [3] Lawrence collected two live specimens and kept them under conditions that would have sustained other Peripatopsis species, but both died 24 hours later. [5]

Conservation

This species is listed as Vulnerable on the IUCN Red List in light of its restricted distribution, small population, and the threat of collection by humans and disruption by cavers. [1] [6] This species is so scarce that a survey conducted from 1995 to 1996 found P. alba to be the rarest of all the Table Mountain troglobites. [3] Furthermore, this species is so stenotopic and the ecosystem of this cave system is so fragile that even small changes in the environment could be disastrous and cause the extinction of this species. [3] [7]

Related Research Articles

Opisthopatus roseus is a species of velvet worm in the Peripatopsidae family. As traditionally defined, this species is rose pink with 18 pairs of legs. Known as the pink velvet worm, it is found only in the Weza Forest, a Mistbelt Forest in South Africa.

<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.

Speleoperipatus is a monospecific genus of velvet worm in the Peripatidae family, containing the single species Speleoperipatus spelaeus. This species is a pale greenish yellow, almost white, with 22 or 23 pairs of legs and no eyes. Specimens range from 27 mm to 34 mm in length. The minimum number of leg pairs found in this species (22) is also the minimum number found in the neotropical Peripatidae. This velvet worm is viviparous, with mothers supplying nourishment to their embryos through a placenta.

<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 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 intermedia is a species of velvet worm in the Peripatopsidae family. This species is about 33 mm long and has 19 pairs of legs: 18 pregenital leg pairs plus a last pair of much reduced legs. The type locality is in South Africa. Although some authorities doubt the validity of this species and deem it to be a junior synonym of P. balfouri, others consider these two to be separate species, citing the distance between their type localities.

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 sedgwicki is a species of velvet worm in the Peripatopsidae family. Also known as the Tsitsikamma velvet worm, this species has a narrow geographic distribution in South Africa but is especially abundant in the indigenous forest of the Tsitsikamma mountains. Recent phylogenetic analysis using molecular data finds that Peripatopsis sedgwicki as traditionally understood based on morphology is a species complex that contains four different species: P. sedgwicki s.s., P. orientalis, P. collarium, and P. margaritarius.

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

Peripatopsis overbergiensis, the Overberg velvet worm, is a species of velvet worm in the Peripatopsidae family. This species usually has 19 pairs of legs: 18 pregenital leg pairs plus one last pair that is strongly reduced and without claws or spinous pads. Some individuals, however, have only 18 leg pairs. This species is limited to the Overberg region of 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.

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 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. 1 2 3 Hamer, M. 2003. Peripatopsis alba. 2006 IUCN Red List of Threatened Species. Downloaded on 5 August 2007.
  2. 1 2 3 Barnes, Aaron; Daniels, Savel R. (2022). "Refining species boundaries among velvet worms (Onychophora, Peripatopsidae), with the description of two new species of Opisthopatus from South Africa". Invertebrate Biology. 141 (2). doi:10.1111/ivb.12368. ISSN   1077-8306.
  3. 1 2 3 4 5 6 7 8 9 10 Sharratt, Norma J.; Picker, Mike D.; Samways, Michael J. (2000). "The invertebrate fauna of the sandstone caves of the Cape Peninsula (South Africa): patterns of endemism and conservation priorities". Biodiversity & Conservation. 9 (1): 107–143. Bibcode:2000BiCon...9..107S. doi:10.1023/A:1008968518058. ISSN   1572-9710.
  4. ↑ Daniels, Savel R.; Picker, Mike D.; Cowlin, Ross M.; Hamer, Michelle L. (2009-04-21). "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. doi:10.1111/j.1095-8312.2009.01205.x. ISSN   0024-4066.
  5. 1 2 3 4 5 6 7 8 9 10 11 Lawrence, R.F. (1931). "A new peripatopsid from the Table Mountain Caves". Annals of the South African Museum. 30: 101–107 – via Biodiversity Heritage Library.
  6. 1 2 3 4 5 6 7 8 9 10 11 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 [289, 293–296].
  7. 1 2 3 4 5 Newlands, G.; Ruhberg, H. (1978), Werger, M. J. A. (ed.), "Onychophora", Biogeography and Ecology of Southern Africa, Monographiae Biologicae, Dordrecht: Springer Netherlands, pp. 677–684, doi:10.1007/978-94-009-9951-0_17, ISBN   978-94-009-9951-0 , retrieved 2024-03-04
  8. 1 2 "Introductory series: Dark caverns and blind critters". www.wwf.org.za. Retrieved 2024-03-05.
  9. ↑ Daniels, Savel R.; McDonald, Dane E.; Picker, Mike D. (2013). "Evolutionary insight into the Peripatopsis balfouri sensu lato species complex (Onychophora: Peripatopsidae) reveals novel lineages and zoogeographic patterning". Zoologica Scripta. 42 (6): 656–674. doi:10.1111/zsc.12025. ISSN   0300-3256.
  10. ↑ Lawrence, Julian A. Nieto; Daniels, Savel R. (2024-02-07). "Sample design in biodiversity studies matters: a fine-scale study of Lawrence's velvet worm, Peripatopsis lawrencei (Onychophora: Peripatopsidae), reveals hidden diversity". Invertebrate Systematics. 38 (2): 13. doi:10.1071/IS23051. ISSN   1447-2600. PMID   38744496.
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