Unexplored Character Diversity in Onychophora (Velvet Worms): A Comparative Study of Three Peripatid Species

Low character variation among onychophoran species has been an obstacle for taxonomic and phylogenetic studies in the past, however we have identified a number of new and informative characters using morphological, molecular, and chromosomal techniques. Our analyses involved a detailed examination of Epiperipatus biolleyi from Costa Rica, Eoperipatus sp. from Thailand, and a new onychophoran species and genus from Costa Rica, Principapillatus hitoyensisgen. et sp. nov.. Scanning electron microscopy on embryos and specimens of varying age revealed novel morphological characters and character states, including the distribution of different receptor types along the antennae, the arrangement and form of papillae on the head, body and legs, the presence and shape of interpedal structures and fields of modified scales on the ventral body surface, the arrangement of lips around the mouth, the number, position and structure of crural tubercles and anal gland openings, and the presence and shape of embryonic foot projections. Karyotypic analyses revealed differences in the number and size of chromosomes among the species studied. The results of our phylogenetic analyses using mitochondrial COI and 12S rRNA gene sequences are in line with morphological and karyotype data. However, our data show a large number of unexplored, albeit informative, characters in the Peripatidae. We suggest that analysing these characters in additional species would help unravel species diversity and phylogeny in the Onychophora, and that inconsistencies among most diagnostic features used for the peripatid genera in the literature could be addressed by identifying a suite of characters common to all peripatids.This study was supported by a Ph.D. fellowship of the Conselho Nacional de Desenvolvimento Cientı´fico e Tecnolo´gico (CNPq: 290029/2010-4) and by a SYNTHESYS grant (financed by the European Community Research Infrastructure Action - FP7 Integrating Activities Programme: http://www.synthesys.info/) to ISO. GM is a Research Group Leader supported by the Emmy Noether Programme of the German Research Foundation (DFG: Ma 4147/3-1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

An updated world checklist of velvet worms (Onychophora) with notes on nomenclature and status of names

Gefördert durch den Publikationsfonds der Universität Kasse

Phylum Onychophora Grube, 1853

Mayer, Georg, Oliveira, Ivo De Sena (2013): Phylum Onychophora Grube, 1853. Zootaxa 3703 (1): 15-16, DOI: 10.11646/zootaxa.3703.1.

Phylum Onychophora Grube, 1853. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness

MAYER, GEORG, OLIVEIRA, IVO DE SENA (2011): Phylum Onychophora Grube, 1853. In: Zhang, Z.-Q. (Ed.) Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness. Zootaxa 3148 (1): 98, DOI: 10.11646/zootaxa.3148.1.13, URL: http://dx.doi.org/10.11646/zootaxa.3148.1.1

Revision of Tasmanian viviparous velvet worms (Onychophora : Peripatopsidae) with descriptions of two new species

The restricted distribution of viviparous onychophorans in Tasmania has long been a subject of discussion, but their evolutionary history remains unclear. We applied morphological, molecular and karyological methods to assess the taxonomy and phylogenetic relationships of the four viviparous species reported from Tasmania, including Tasmanipatus barretti, T. anophthalmus and two undescribed species previously referred to as 'Tasmania' sp. 1 and sp. 2. We demonstrate that all four species can be unambiguously distinguished based on independent character sets. The two 'Tasmania' species, which were previously thought to be cryptic, proved to exhibit a set of distinct morphological characters. Molecular phylogenetic analyses revealed that the four species belong to a major clade that includes Peripatoides from New Zealand, and that species from the two landmasses show reciprocal monophyly within this clade. Within the Tasmanian clade, T. anophthalmus is more closely related to the two 'Tasmania' species than to T. barretti. Based on this relationship and the lack of morphological and/or karyological characters supporting the Tasmanian viviparous clade, we erect two new genera to accommodate the two 'Tasmania' species (Diemenipatus, gen. nov.) and T. anophthalmus (Leucopatus, gen. nov.). An emended diagnosis followed by a redescription of T. barretti is provided and 'Tasmania' sp. 1 and sp. 2 are formally described as D. taiti, gen. et sp. nov. and D. mesibovi, gen. et sp. nov., respectively.This study was supported by grants from the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq Brazil: 290029/2010–4) and the Zentrale Forschungsförderung of the University of Kassel (ZFF: 1970/2016) to ISO and the German Research Foundation to GM (DFG: Ma 4147/3–1, 7–1) and HR (Ru 358/2–5)

The role of ventral and preventral organs as attachment sites for segmental limb muscles in Onychophora

Background: The so-called ventral organs are amongst the most enigmatic structures in Onychophora (velvet worms). They were described as segmental, ectodermal thickenings in the onychophoran embryo, but the same term has also been applied to mid-ventral, cuticular structures in adults, although the relationship between the embryonic and adult ventral organs is controversial. In the embryo, these structures have been regarded as anlagen of segmental ganglia, but recent studies suggest that they are not associated with neural development. Hence, their function remains obscure. Moreover, their relationship to the anteriorly located preventral organs, described from several onychophoran species, is also unclear. To clarify these issues, we studied the anatomy and development of the ventral and preventral organs in several species of Onychophora. Results: Our anatomical data, based on histology, and light, confocal and scanning electron microscopy in five species of Peripatidae and three species of Peripatopsidae, revealed that the ventral and preventral organs are present in all species studied. These structures are covered externally with cuticle that forms an internal, longitudinal, apodeme-like ridge. Moreover, phalloidin-rhodamine labelling for f-actin revealed that the anterior and posterior limb depressor muscles in each trunk and the slime papilla segment attach to the preventral and ventral organs, respectively. During embryonic development, the ventral and preventral organs arise as large segmental, paired ectodermal thickenings that decrease in size and are subdivided into the smaller, anterior anlagen of the preventral organs and the larger, posterior anlagen of the ventral organs, both of which persist as paired, medially-fused structures in adults. Our expression data of the genes Delta and Notch from embryos of Euperipatoides rowelli revealed that these genes are expressed in two, paired domains in each body segment, corresponding in number, position and size with the anlagen of the ventral and preventral organs. Conclusions: Our findings suggest that the ventral and preventral organs are a common feature of onychophorans that serve as attachment sites for segmental limb depressor muscles. The origin of these structures can be traced back in the embryo as latero-ventral segmental, ectodermal thickenings, previously suggested to be associated with the development of the nervous system.17 page(s

Strategien der Natur als Vorbild für nachhaltige Biomaterialien

Gefördert im Rahmen des Projekts DEA

Suppl_movie_3

Supplementary Movie 3. Muscles involved in hydrostatic pressure control, stabilisation and claw movements in E. rowelli