Onychophora Newsletter

No. 6 / March 1997

Editor and publisher: J. Monge-Nájera.

Editorial Board: B. Morera, C.E. Valerio, J.A. Vargas

It is hard to believe that I have been publishing the Onychophora Newsletter for eight years... Well, anyway, this fifth number is almost fully dedicated to presenting an updated directory of the growing number of people interested in the "velvet worms". Of course you will also find some general news as well as a summary of what some active researchers are doing. I hope you will find this new edition useful. Until next time, best wishes to everyone.

J. Monge-Nájera


Tenth anniversary and the Internet

This may be the last Onychophora Newsletter to appear in printed form. Forthcoming issues will be exclusively available on the Internet. A temptative address to look for it is the Tropiweb section in: www.ots.duke.edu, but if you fail to find it there in the following months, look for Onychophora Online through yahoo, magellan, altavista or any other web searcher. I think that a good way to celebrate the tenth anniversary of the newsletter is by placing it in the web, thus making it available worldwide at a lower cost. I thank all of you who have been with me throughout these years and specially the onychophora fans who have contributed material for this newsletter. Other findings that mark the anniversary are the breaking of the world size record for onychophorans (note below) and the discovery of amber preserved specimens (they are housed at the University of Oregon and we are still waiting for a satisfactory description as only a brief note in Science has been published).

Until next time, best wishes from sunny tropical Costa Rica!

J. Monge-Nájera


Onychophoran Systematics: Where Do Onychophorans Belong

As usual, every new year brings a variety of papers about the "correct" systematic position of onychophorans. As a rule, they claim to have identified the errors in previous studies and to finally offer a sound answer to the question. Papers based on biochemical analysis usually differ widely in the final outcome, both among themselves and from the traditional morphological view. For a change from the DNA series, I recently received a copy of a paper with a cladogram based on 13 morphological characters that places Onychophora as sister group of Arthropoda and relates both with the Clitellata. You can see it in Zoologica Scripta 24 (pages 269-301).

The Lost E.H. Tailor Onychophorans: Found!

Years ago I heard a rumor about onychophorans, probably of Phillipine origin, collected by the late herpetologist E.H. Taylor of Kansas. This was particularly important because the occurrence of the phylum there, albeit expected for biogeographical reasons (Zool. J. Linn. Soc. London 114: 2160) and reported in early literature, has not been substantiated by museum specimens that I know of.

I am glad to inform that a jar of specimens, donated thirty years ago by Taylor to Costa Rican entomologist Alvaro Wille, was found in the Museum of Zoology, University of Costa Rica. The specimens, however, were identified only by numbers stamped on metalic plates.

After a long search in which the assistance of botanist Luis Diego Gómez, and of R. Krishtalka, A. Resetar (Field Museum) and John E. Simmons (Kansas) was instrumental, I obtained locality data: Nr. 432 Turrialba, Limón, 4190, 6043 and 4263 Moravia de Chirripó, 4461 Volcán Irazoe, Cartago, 4502 and 4641 BataÆn, Limón, 8453 Finca Los Diamantes, Limón (no data for 8975). I also have the dates. All the localities are in Costa Rica, so if Dr. Taylor did collect onychophorans in the Phillipines, they are still lost and might appear in his large Kansas collection, because his custom (Dr. Wille told me) was to place onychophorans in the same jars with reptiles.

Onychophorans Hunting On Foliage

Onychophorans have long been considered soil animals. However, in 1911, a young Costa Rican biologist who was studying the communities of bromeliad tanks for his doctoral dissertation in the Paris Sorbonne reported that he had found one onychophoran in the dry part of a bromeliad tank in Limón, Caribbean of Costa Rica.

After almost a century, two or three more recent reports confirmed that they climb trees. A similarly surprinsing report, onychophorans living and hunting in foliage, as observed by American herpetologist William Lamar, was mentioned in a 1993 paper (Rev. Biol. Trop. 41(3): 689-696).

Then, in a letter written in October 1994, Peruvian herpetoloigst Javier Icochea reported that he had found, in Cordillera del Cóndor, near the border with Ecuador, an onychophoran that had glued an insect to a leaf and was feeding on it. He preliminarily identified it as Oroperipatus quitensis and sent an excellent photograph documenting his finding. If some of you have further reliable observations on the subject, I would like to see them.

Do Isopods Prey On Onychophorans?

Istvan Pajor from South Africa collected two Peripatopsis moseleyi in the Drakensberg (about 1840 m a.s.l.) and placed them in his two-year old terrarium, taken over by isopods. After some time he could only find one.

In his own words: "The next day I could see this only Peripatopsis in a burrow facing the glass panel of the terrarium It seemed to be half-active, moving a bit back and forth. There were a number of these large wood lice around it, some even on top of it, but it did not make any attempt to "shake" them off.

Then I noticed that it had a few lesions, white spots on its back, and one of the wood lice chewing-off bits of skin. I did not think too much about it then; maybe that these scavenging Crustaceans were just nibbling-off dead skin.

When I had a look a few hours later, the onychophoran was at a different location, now surrounded by numerous wood lice, a number of which were gnawing on it. It was really in a bad state already, not moving at all. I removed it quickly and saw that it had already lost not only even more bits from its "skin", but also one of the antennae and a few legs and was oozing from its wounds.

I placed it into a smaller dish with enough humidity and shelter and it moved a little bit. But then it died the next day. I do not know whether this would happen in its natural habitat".

Similar but less conclusive observations have been published (Rev. Biol. Trop. 41(3): 689-696) and only hard to do field work will give a definitive answer, but if you have pertinent information please speak out.

Review Of Australian Onychophorans

A cladistic review of Australian onychophorans, A.L. Reid's Ph.D. thesis, has been published in Invertebrate Taxonomy (vol. 10, 1996, p. 663-936). It includes 41 new species and 22 new genera, increasing the number of named Australian onychophorans to 54. She suggests that (1) the oldest taxa, more closely related with other peripatopsids,.are those from southeastern Australia, (2) oviparity is a derived (not ancestral) character! and (3) that species inhabiting the continent may not be monophyletic. Only time will tell how this extensive erection of new taxa will be received by colleagues, but many may miss the use of the termination "patus" in her new genera.

Onychophorans In Publications

Photographs of onychophorans have appeared in recent books or will appear soon:

  1. Monge-Nájera, J. (ed.). 1995. Sustainable development: the view from the less industrialized countries. Universidad Estatal a Distancia, San José, Costa Rica. Epiperipatus biolleyi appears in the cover. the photograph was donated by Hilke Ruhberg of Hamburg.
  2. A forthcoming University of California Invertebrate textbook will feature an undescribed species of Macroperipatus from the Caribbean of Costa Rica

Could The Fossil Onychophoran Xenusion Have Been So Large?

In a paper currently under preparation, Hou and Monge-Nájera estimate individual weights of extinct onychophoran species. These might have had weights ranging between 100 mg in the case of Luolishania longicruris (the weight of an Epiperipatus biolleyi of similar size) and more than 5000 mg in the case of the 20 cm long Xenusion . Until recently one of the largest onychophorans, Epiperipatus torquatus, was known to reach 15 cm and 4000 mg, but some had doubts that an onychophoran, with its soft body and many legs, could exceed that size. Perhaps Xenusion was not at all an onychophoran? Well, the note below provides an answer.

Gigantic Onychophoran Discovered In The Caribbean

A recently discovered and still undescribed Costa Rican species from Cartago Province in the Caribbean of Costa Rica measures 20 cm in length, equal to the fossil Xenusion. It was collected by Costa Rican herpetologist Alejandro Solórzano, who documented the finding with several photographs. When he came to my office with the animal, I thought he had a small snake in the jar he was proudly showing me: then I was astonished to realize what it really was!

The original specimen, as well as others collected afterward by Solórzano are deposited in the University of Costa Rica until formal description. This proves that onychophorans can indeed be the size of the ancient Xenusion, supporting the interpretation that it was indeed an onychophoran.

Assistance Needed

The production of this newsletter has always been done without financial assistance from any institution, and thus the extent and contents of the newsletter are very limited. If you are able to assist with a small donation, please do so: it will be used to improve the Internet onychophoran site. I would specially like to incorporate a comprehensive bibliography (I have one that covers the XIX and early XX centuries, handwritten by Dr. E.H. Taylor but need funds to have it typed) and a photographic catalogue of living specimens but have no funds for copying and scanning.

How To Be Part Of This Newsletter

If you have information, notes, requests and other material for this newsletter, send it to the editor at rbt@biologia.ucr.ac.cr or to J. Monge Nájera, Revista de Biologia Tropical, Oficina 15 Biología, Universidad de Costa Rica, 2050 Costa-Rica; rbt@biologia.ucr.ac.cr

Onychophorans On Cd Rom

D.D. Williams (University of Toronto) has announced Invertebrate Phylogeny, a CD ROM with a phylogenetic tree of invertebrates where students can click on specific branches for information, photographs and videos. Dr. Williams is looking for onychophoran photographs. Coincidentally, I also received a request from T.H. Carefoot from the University of British Columbia for a similar material. I suggested that they use photos from the Onychophora Online gallery, which I will soon include in the WWW through the OTS website, but if some of you out there have good material to share with them, just let me know.