Comparative anatomy of slime glands in onychophora (velvet worms)

  title={Comparative anatomy of slime glands in onychophora (velvet worms)},
  author={Alexander Baer and Georg Mayer},
  journal={Journal of Morphology},
Onychophorans use a unique hunting and defense strategy, which involves the ejection of an adhesive slime secretion produced by a pair of specialized glands. So far, a comparative study on the anatomy of these glands has not been carried out among different species. In this article, we compare anatomical features of slime glands in representatives of two major onychophoran subgroups, the Peripatopsidae and the Peripatidae, from different parts of the world. Our data show that the musculature of… 

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

It is suggested 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 allPeripatids.

Structure and functional morphology of the acid-secreting pygidial glands in the whipscorpion Mastigoproctus giganteus (Lucas, 1835) (Arachnida: Thelyphonida)

The first description of gland structure in the North American vinegaroon, Mastigoproctus giganteus is provided, revealing that vinegaroon pygidial glands are unlike most other arachnid exocrine glands in their structure, methods of secretion, and mechanisms of discharge.

Capture of Prey, Feeding, and Functional Anatomy of the Jaws in Velvet Worms (Onychophora).

The elemental analysis reveals an increased incorporation of calcium at the tip of each blade, which might provide rigidity, whereas there is no evidence for incorporation of metal or prominent mineralization in the jaws of onychophorans.

A new giant egg-laying onychophoran (Peripatopsidae) reveals evolutionary and biogeographical aspects of Australian velvet worms

A peculiar new species of Ooperipatellus from Tasmania that can exceed twice the length of other representatives of this taxon is presented and the results of the molecular phylogenetic analyses support the recognition of O. nickmayerisp.

Functional morphology of a lobopod: case study of an onychophoran leg

Locomotory movements of individual lobopods of E. rowelli proved far more diverse than previously thought and might be governed by a complex interplay of 15 muscles, including one promotor, one remotor, one levator, one retractor, two depressors, two rotators, one flexor and two constrictors as as muscles for stabilization and haemolymph control.

Adhesive defence mucus secretions in the red triangle slug (Triboniophorus graeffei) can incapacitate adult frogs

Evidence of adhesive mucus secretions in the red triangle slug (Triboniophorus graeffei) as an adaptation against predation is provided, appearing to be the first description of defensive mucus production in this slug species and one of the first natural observations of the use of adhesive defence secretions to incapacitate a predator.

Peculiar salivary glands in a silk‐producing mite Bakericheyla chanayi (Cheyletidae)

The detection of axon profiles in the gland body suggests a neural control for the glandular cell function, and two possible ways of secretion are suggested: 1) exocytosis into the acinar cavity and 2) direct passage via the central processes.

Slime protein profiling: a non-invasive tool for species identification in Onychophora (velvet worms)

It is suggested that the slime protein profiling is a valuable, non-invasive method for identifying the onychophoran species, and might help to discover potentially new species of OnyChophora, given that the ~200 described species most likely underrepresent the actual diversity of the group.

Neuronal tracing of oral nerves in a velvet worm—Implications for the evolution of the ecdysozoan brain

The overall innervation pattern of the oral lip papillae in E. rowelli is incompatible with the interpretation of the onychophoran brain as a modified circumoral ring, which shows a collar-shaped, circumoral organization in cycloneuralians but a ganglionic architecture in panarthropods.



The Musculature of Peripatus and Its Innervation

A unique innervation pattern was found, consisting of a combination of muscle arm to nerve contacts, which appear to be the commonest, and nerve on muscle fibre synapses, which are markedly different from both arthropod and annelidan neuromuscular synapses.

Metaperipatus inae sp. nov. (Onychophora: Peripatopsidae) from Chile with a novel ovarian type and dermal insemination

A distinct separation into a sterile and a fertile ovarian portion suggests that the novel type of onychophorans from Chile might be derived from an ovary with stalked oocytes characteristic of the Peripatopsidae and South-East Asian peripatidae.


  • M. Locke
  • Biology
    The Journal of cell biology
  • 1965
The most common type of specialized adhesive site between invertebrate epithelial cells has been characterized by Wood as a "septate desmosome" but recently it has been possible to obtain sections tangential to the surface in the region of these desmosomes which suggest a modification of the original interpretation of the structure.

Position and development of oocytes in velvet worms shed light on the evolution of the ovary in Onychophora and Arthropoda

Embryological data and an outgroup comparison with arthropods suggest that the exogenous Ovary is the ancestral condition in velvet worms and a synapomorphy of Onychophora and Arthropoda and the assumption that the pseudoendogenous ovary is derived from an exogenous type and the similarities with the endogenous ovary are superficial.

Feeding behaviour and prey choice in Macroperipatus torquatus (Onychophora)

  • V. M. S. J. ReadR. Hughes
  • Environmental Science
    Proceedings of the Royal Society of London. Series B. Biological Sciences
  • 1987
Macroperipatus torquatus feeds nocturnally on crickets and a few other invertebrates on the floor of the Trinidadian rain forest and grew better when fed on them in the laboratory, whereas juveniles grew better on smaller prey.

Studies on the Onychophora. II. The Feeding, Digestion, Excretion, and Food Storage of Peripatopsis with Biochemical Estimations and Analyses

The material for this work consisted of several hundred specimens of Peripatopsis obtained in South Africa in 1933 and brought to England alive and used as extensively as possible for other purposes.

Analytische Untersuchungen des Wehrsekretes von Peripatopsis moseleyi (Onychophora) / Analytical Investigations of the Defensive Secretion from Peripatopsis moseleyi (Onychophora)

The defensive secretion of Peripatopsis moseleyi (Onychophora) consists of 84% water and 16% protein and free amino acids and the elastic properties of the secretion threads indicate a micellar structure.

Review of the Peripatopsidae (Onychophora) in Australia, with comments on peripatopsid relationships

The results indicate that the Australian Peripatopsidae may not be monophyletic, and Ovoviviparity appears to be the ancestral state in the Onychophora, with oviparity arising in at least two Australian lineages.

Composition of the Blood in Onychophora

The primitive terrestrial arthropods of the Class Onychophora are of especial zoological interest and it seems worth recording some measurements of the blood ion- levels in Peripatopsis moseleyi and the composition of a satisfactory physiological saline based on these ion-levels.