Peripatopsidae

Peripatopsidae
Systematics
Master's group: Urmünder (Protostomia)
over trunk: Skin animals (Ecdysozoa)
trunk: Stummelfüsser (Onychophora)
class: Udeonychophora
order: Euonychophora
family: Peripatopsidae
scientific name
Peripatopsidae
kinds (selection)
  • Florelliceps
  • Paraperipatus
  • Metaperipatus
  • Peripatoides
  • Peripatopsis
  • Tasmanipatus

as Peripatopsidae one designates a family of Stummelfüssern (Onychophora). The animals, whose appearance reminds of worms with legs, exclusively live in the moderate zone of the Southern Hemisphere. Contrary to the other Stummelfüssergruppe, which Peripatidae gives, it a set of kinds, which do not bring living boys to the world, but eggs put, thus ovipar are.

The family was described for the first time in the year 1907 and designated after the type kind Peripatopsis.

Table of contents

structure

Peripatopsidae kinds exist in numerous colors, are most frequent however schillerndes a cyan. With a length between 0,5 and 8 centimeters they are usually shorter than the Peripatidae kinds and have even fewer legs; the number of these stummelförmigen appendices of body is always constant and varied within a kind between 13 and 29 pairs. The last pair of legs is also not even present sometimes diminished, occasionally apparent.

General anatomy corresponds to a large extent to that all Stummelfüsser and is in detail discussed in the appropriate article; in the following therefore primarily special characteristics of the Peripatopsidae are. In addition belong for example the nerve supply of the heart, which takes place differently than with the Peripatidae exclusive via a back nerve strand, in addition, the simple structure of the salivary glands, which do not possess a reservoir, in which the saliva buffered become could.

Cruraldrüsen, special organs, which lie within the stub legs, often into the body cavity in-rich and probably primarily communication between the sexes serve, occur in principle with both sexes. As also with the Peripatidae, with which they are however only with the males, but them by openings at the belly-lateral leg beginning, the Cruralpapillen, chemical messenger materials, pheromones so mentioned, off. Coxalsäcke, structures, which probably serve the water absorption with other Stummelfüssern, are not within the Peripatopsidae.

The genital aperture, which always lies with the Peripatidae between the next to last pair of legs, is with the Peripatopsidae behind or between the last received pair of legs, which supports the thesis already addressed that a further pair of legs was lost in the process of the master history of the Peripatopsidae.

Also at the reproduction organs some characteristics show up: Thus the eggs lie in the ovaries of the females exogenously, that means that the follicles in the contact with the body cavity, for which Hämocoelom stand and can from this nutrients take up to develop about in order Dotter. A Plazenta, as it is with many Peripatidae kinds, does not occur against it in principle.

With the males likewise some special adjustments exist. Thus for example kinds of the kind Paraperipatus possess a proper Penis; its employment with a Kopulation could not be observed however so far. Some mobile structures, which can be found at the head of the males of numerous Australian kinds, are still more unusual. It probably concerns modifications of the Sinnespapillen, which are trained as thorns, occurring with all Stummelfüssern on the skin, claws or Stiletten here and probably serve the transmission of sperm cells packages. With the kind Florelliceps stutchburyae exists for example an individual long thorn, which can be put forward from a skin fold, which runs forward for instance from eye level.

spreading and habitat

the Peripatopsidae live in the moderate zones of the Southern Hemisphere and exhibit thereby a zirkumaustrale spreading in such a way specified: They are in the east and southwest, locally also in the central south of Australia, in Tasmanien, new Guinea and in New Zealand, besides also in Chile and in two close coastal strips of South Africa, on the one hand south the Cape fold mountains, on the other hand beyond the eastern Great escarpment on the precipitation-rich sea side.

The geographical distribution of the kinds testifies the origin of the group on the former southern supercontinent Gondwana; they were transported from there with their current habitat in the course continental drift into its present circulation areas.

Like all Stummelfüsser also the Peripatopsidae is dependent on a high air humidity. They live therefore only in damp surrounding field, particularly in forests, approximately under stones, in or under Totholz as umgestürzten trunks or in the leaves layer of the soil. In southwest and south Australia they occur also in the drying forest, in South Africa even on otherwise unbewachsenem grass country. A South African kind, Peripatopsis alba, lives in caves.

Likewise in South Africa so far the largest well-known population density was determined within the family; there are isolated up to 10 individuals per square meter soil.

From Australia, whose stub foot he fauna was so far best examined, is well-known, which frequently genetically from each other definable kinds divide the same habitat, which could refer to a sympatrische kind formation, thus the development of two or several kinds without geographical isolation.

reproduction

all Peripatopsidae kinds reproduce themselves sexually. The genetic variety within a population is often not very large however at least with the particularly well examined Australian kinds, which suggests frequent mating among brothers and sisters or to otherwise closely used animals, in individual cases also on strong stabilizing selection.

Nearly everywhere the fertilization of the females takes place vaginal. With living-bearing kinds from the fact the problem results that the growing up embryos obstruct pregnant women of the female the way of the sperm cellses to the ovaries in the Uterus. For this reason fertilization finds supposed with most kinds before the sex-ripe instead of. Within the female the sperm cellses can remain lebensfähig in special pouches for more than nine months and fertilize the eggs in this way at a later time. In all cases the pouches do not serve however the long-term storage of the seed - sometimes only few days lie between insemination and fertilization, so that more comes to them the function of a short time memory.

The mode of the sperm cells transmission is different with the different kinds: As previously mentioned Paraperipatus a penisartige structure occurs within the kind, which could not be observed however yet in function, while with many Australian kinds with the males special structures at the head exist, which seem to likewise serve the sperm cells transfer. More exact observations are only present from the kind Florelliceps stutchburyae from new South Wales: Here a special thorn apparent serves the positioning of a sperm cells package (Spermatophore) in the Vagina of the female; possibly it is there also already opened by this and the contained sperm cellses is set free in such a way. During Kopulation the male presses its head firmly against the genital opening (Gonopore) of the female, who supports its partner thereby by seizing and clasping the Hautpapillen of the male present on the top with the claws of the last pair of legs. Both animals are so firmly connected in this mating position that even the handling did not lead by the examining scientists to a task of the mating position. However the animals implement slow, but coordinated movements, with which obviously the female in front present leads. How the Spermatophore from that arrives to genital aperture of the male at its head, is still unsettled. Possibly this unusual mating variant developed as adjustment to close habitats, like it for instance within died trunks prevails - there it concerns a very effective transmission path for the sperm cellses.

Two South African kinds, Peripatopsis hit completely different way capensis and Peripatopsis sedgwicki. At both fertilization does not take place by the Vagina; accordingly also no pouches exist for the storage of the sperm cellses. Instead the male in the diameter about a sperm cells package at the flanks or on the back of the female, large, puts down a millimeter. Special Amöbozyten cells mentioned, which are contained in the blood of the female, separates thereupon enzymes off, which dissolve aimed the skin at the same time underneath the sperm cells package and its covering. As consequence sperm cellses by these arrive produced “wound” into the body concavity of the female and penetrate from this from to the ovaries, whose wall they penetrieren. In this way they arrive at the Eizellen, which can be fertilized now. This after the scientific name for the outside, dead Hautschicht cuticular fertilization mentioned is to that extent unusual, normal skin injuries lead with Stummelfüssern by bacterial infections usually very fast to death - it must exist thus a mechanism, which prevents such infections in case of the “mating wound” effectively.

Although the mating often already begins with the females before the sex-ripe, quite further Kopulationen are possible in the further process of the life. Females of the Australian kind Euperipatoides rowelli are apparent fertilized in the process of its life by several partners, so that it can happen that new generation of different fathers grows up at the same time in the female.

Most Peripatopsidae is living-bearing - like all animals of its group of sisters, the Peripatidae -; there are however some egg-laying (ovipare) kinds. In the eggs surrounding large with 1,3 to 2.0 millimeters by a chitinhaltigen bowl is then an accordingly large quantity of Dotter, of which the growing up embryos nourish themselves. The remaining kinds divide themselves in egg-living-bearing (ovovivipare) and genuinly living-bearing (vivipare) forms, whereby a vivipare way of life is only with few kinds. Differently than with many Peripatidae kinds also in principle no Plazenta exists with them.

It is considered as probable that the original reproduction mode of the Peripatopsidae ovovivipar was; both Oviparie and Viviparie probably secondarily developed thus.

The development time of the embryos is at between six and seventeen months. With the living-bearing kinds come in each case to two young animals to the world, which are usually somewhat more brightly colored as their parents, but already have the leg number correct for their respective kind.

At males the first mating takes place after approximately nine to eleven months; it is well-known that they exhibit a higher mortality than the females. These pairs of itself depending upon kind for the first time at the age of 9 to 24 months. The first birth and/or oviposition takes place accordingly after approximately two to three years; the average descendant number varies again kind-dependently between 6 and 23 young animals per year.

endangerment

many Peripatopsidae into the 1990er years were only discovered there and besides many regions could be examined as for instance new Guinea still hardly scientifically, are present only few reliable information about the actual endangerment of most kinds.

A kind, Peripatiopsis leonina, became extinct, however together with Opisthopatus roseus at present threatened of that internationally union for Conservation OF Nature and Natural Resources still as critical from becoming extinct was possibly already estimated. Both kinds originate from South Africa. In addition Tasmanipatus come leonina from Tasmanien, which are considered as threatened, and four further kinds, which are classified as endangered: These are in detail Peripatopsis clavigera and Peripatopsis alba from South Africa as well as Peripatoides indigo and Peripatoides suteri from New Zealand.

The protection status is different depending upon state. While in South Africa all Stummelfüsser is legally protected and both is necessary for the a collecting and for the export of the animals special permission, no special regulations are well-known from Chile. In Australia exist no collecting, probably however export restrictions. As unusually particularly a regional project aligned to two tasmanische kinds, Tasmanipatus may be considered anophtalmus and to Tasmanipatus baretti, which velvet so mentioned worm conservation flat, which dedicates an attention to these which can be found only rarely with eddyless animals two groups.

master and discovery history

the Peripatopsidae are fossil not delivered, so that their master history from the knowledge of the modern kinds and its geographical spreading must be opened.

They separated probably already before breaking the southern supercontinent Gondwana open approximately 130 million years ago from its presumed group of sisters, the Peripatidae. The fragmentation of the Stummelfüsser took place thus probably already in the earth-history epochs from Trias or law. But also 100 million a years old chalk-temporal stub foot he fossil , Cretoperipatus speaks burmiticus, which already belongs to the family Peripatidae.

The further master history of the family can be opened among other things by an Retrovikarianz analysis in such a way specified: This is based on the principle that geographically neighbouring kinds are related more closely with one another than such, which are domestic in far from each other distant circulation areas. It becomes nontrivial by the fact that during geological periods the movement of the continents must be considered to each other. An Retrovikarianz analysis can in each case a rough estimate supply and may not not with a phylogenetischen analysis which is based on morphologic or molecular-genetic characteristics be confounded. In the concrete case the following picture results:

Peripatopsidae |--South African kinds |--N. N.
   |--Chilean kinds  |--Kinds of New Zealand  |--Australian kinds (inclusive Papua New Guinea)

the separation between the South African kinds and all different the ursprünglichste is thus supposed - she took place probably in late law or the early chalk time , as still another land connection between Africa, South America and Australia via Antarktika existed. Also the splitting off of a first group egg-laying (more oviparer) kinds probably decreases/goes back to this time.

The Chilean stub foot he fauna is relatively closely related to fauna of New Zealand and the Australian. The latter forms however probably even no monophyletische group - some Australian kinds apparent find their closest relatives in New Zealand. Settling Australia took place probably from Tasmanien and southeast Australia, whereby the latter was in the meantime flooded and secondarily rekolonisiert then.

In the Eozän probably about 37 million years ago, at one time, at which Australia was isolated from all other continents already, the second line of development of oviparer kinds there then probably originated in. The settlement of new Guinea can have taken place only after the Pliozän, since the area was before under water. It is obvious to assume that the animals over the land bridge from Australia, existing during the ice ages of the Pleistozäns, immigrated - molecular-biological realizations contradict however at present this assumption.

systematics

whether it with the Peripatopsidae around a natural (monophyletische) group does not act, which covers all descendants of its common moving forward is undisputedly, is considered however as good working hypothesis, even if isolated arguments for a classification of the Peripatidae into the Peripatopsidae speak.

By extensive taxonomische work in Australia from there most are that altogether 37 kinds well-known, which cover 92 kinds. Many of it cannot be differentiated however outwardly. This therefore also as kryptisch designated kinds instead defined by molecular-biological aids such as Allozym - electrophoresis from each other.

The following overview lists the well-known kinds with their circulation area in alphabetical order:

  • Acanthokara (new South Wales, Australia)
  • Aethrikos (new South Wales, Australia)
  • Akthinothele (Queensland, Australia)
  • Anoplokaros (new South Wales, Australia)
  • Austroperipatus (Queensland, Australia)
  • Baeothele (new South Wales, Australia)
  • Centrorumis (new South Wales, Australia)
  • Cephalofovea (new South Wales, Australia)
  • Critolaus (Queensland, Australia)
  • Dactylothele (Queensland, Australia)
  • Dystactotylos (Queensland, Australia)
  • Euperipatoides (new South Wales, Australia)
  • Florelliceps (new South Wales, Australia)
  • Hylonomoipos (Queensland, Australia)
  • Konothele (Queensland, Australia)
  • Lathropatus (southeast Australia)
  • Leuropezos (Queensland, Australia)
  • Mantonipatus (south Australia)
  • Metaperipatus (South America)
  • Minyplanetes (Queensland, Australia)
  • Nodocapitus (Queensland and new South Wales, Australia)
  • Occiperipatoides (southwest Australia)
  • Ooperipatellus (south Australia)
  • Ooperipatus (Victoria and southeast Australia)
  • Opisthopatus (South Africa)
  • Paraperipatus (new Guinea)
  • Paropisthopatus ?
  • Peripatoides (New Zealand)
  • Peripatopsis (South Africa)
  • Phallocephale (new South Wales, Australia)
  • Planipallipus (new South Wales and Victoria, Australia)
  • Regimitra (new South Wales, Australia)
  • Ruhbergia (new South Wales, Australia)
  • Sphenoparme (Queensland, Australia)
  • Symperipatus ?
  • Tasmania (Tasmanien, Australia)
  • Tasmanipatus (Tasmanien, Australia)
  • Tetrameraden (new South Wales, Australia)
  • Vescerro (Queensland, Australia)
  • Wambalana (new South Wales, Australia)

the supposed masterhistorical Verwandtschaftsverhältnisse of the kinds derived from molecular-genetic data are shown in the following diagram to each other. The kinds Florelliceps and Tasmania are not yet contained in it for lack of phylogenetischer information; the kind Ooperipatus is considered as para or even polyphyletisch and is specified as non-natural group therefore only for the sake of the form here.

Peripatopsidae |--Tasmanipatus|--N. N.
   |--Peripatoides   |--N. N.
      |--N. N.
      |  |--Ooperipatellus parvus      |  |--N. N.
      |     |--Ooperipatellus (other kinds)     |     |--N. N.
      |        |--Opistopathus     |        |--N. N.
      |           |--Peripatopsis     |           |--N. N.
      |              |--Metaperipatus     |              |--Paraperipatus     |     |--N. N.
         |--Euperipatoides         |--N. N.
            |--Occiperipatoides            |--N. N.
               |--Centrorumis               |--N. N.
                  |--Minyplanetes                  |--N. N.
                     |--Nodocapitus                     |--N. N.
                        |--Acanthokara                       |--Share-emergency-heal                        |--Austroperipatus                        |--Baeothele                        |--Cephalofovea                        |--Critolaus                        |--Dactylothele                        |--Dystactotylos                        |--Hylonomoipos                        |--Konothele                        |--Leuropezos                        |--Mantonipatus                        |--Ooperipatus                        |--Phallocephale                        |--Planipapillus                        |--Ruhbergia                        |--Tetrameraden                        |--Vescerro                        |--Wambalana                        |--Wambalana                        |--N. N.
                        |  |--Regimitra                       |  |--Anoplokaros                        |                       |--N. N.
                           |--Aethrikos                          |--Sphenoparme

the molecular-genetic and from the Retrovikarianzanalyse of derived realizations cover themselves only very inaccurately, in both areas exist thus further research need.

literature

  • D. A. Briscoe, N. N. Tait, Allozyme evidence for extensive and ancient radiation in Australia Onychophora, Zoological journal OF the Linnean Society, 114, 1995, page 91
  • D. A. Briscoe, N. N. Tait, genetics deviation within new Zealand Onychophora and their relationships ton the Australian fauna, Zoological journal OF the Linnean Society, 114, 1995, page 103
  • A. L. Reid, Review OF the Peripatopsidae (Onychophora) in Australia, with COMMENT on Peripatopsid Relationships, Invertebrate Taxonomy, 10, 1996, 663
  • N. N. Tait, J. M. Norman, Novel mating behaviour in Florelliceps stutchburyae towards. Nov., frame. Nov. (Onychophora, Peripatopsidae) from Australia, journal OF Zoology, 253, 2001, page 301
 

  > German to English > de.wikipedia.org (Machine translated into English)