Onychophorans (Velvet Worms): Natural History and Conservation of a Vulnerable Invertebrate Taxon in the Caribbean Islands
Kenneth W. McCravy1,* and Ivo de Sena Oliveira2,3
1Department of Biological Sciences, Western Illinois University, 1 University Circle, Macomb, IL 61455, USA. 2Department of Zoology, Institute of Biology, University of Kassel, Heinrich-Plett-Straße 40, D-34312 Kassel, Germany. 3Departamento de Zoologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, Brazil. *Corresponding author.
Caribbean Naturalist, Special Issue No. 2 (2019)
Onychophorans, or velvet worms, are an enigmatic group of soft-bodied, terrestrial invertebrates. These organisms are of keen interest in investigations comprising a variety of topics, including animal evolution, biogeography, and conservation, given their close affinities with the arthropods and remarkable distribution pattern, as well as the point-endemism of almost all species. Onychophorans are found in moist habitats in tropical and subtropical forests, but given their nocturnal activity and cryptic behavior, relatively little is known about the biology and conservation status of the ~200 valid described species. Onychophorans are subdivided into 2 major subgroups: the Peripatidae (81 species) inhabiting the Neotropics (= Neopatida), equatorial Africa, and Southeast Asia, and the Peripatopsidae (120 species) occurring in the Australasian region, Chile, and southern Africa. The Caribbean islands house 22 described species of Peripatidae—over 25% of the diversity known for this subgroup. Only 3 species are of recognized conservation concern and included on the International Union for Conservation of Nature Red List: Macroperipatus insularis (endangered), Plicatoperipatus jamaicensis (lower risk/near threatened), and Speleoperipatus spelaeus (critically endangered). The restricted geographic ranges of onychophoran species, together with their occurrence in insular habitats subject to natural and/or anthropogenic disturbance, suggest that onychophorans might be at risk in the Caribbean islands. Herein, we present a short review of Onychophora, with particular attention to Caribbean species and discuss how these organisms, despite embodying the challenges and difficulties inherent in conservation of cryptic and poorly known invertebrates, may still be used as flagship species for habitat conservation.