
10/25/2024
Asheville Wildside Creature Feature!
Barbados Velvet Worm
(Epiperipatus barbadensis)
500 million years ago our planet would be unrecognizable to us. Gondwana, a landmass of joined continents dominated the southern hemisphere, with the smaller continent and islands of Laurentia along the equator. The Panthalassa was a vast uninterrupted global ocean that dominated much of the Earth's surface. Carbon dioxide levels were high, and oxygen a limited and valuable resource. Massive macroalgaes thrived along the coastline and biofilms and microbial mats would litter the coastal lowlands and tidal flats where moisture from the ocean would keep them alive. The rest of the interior landmass was a punishing desert of rock and sunbaked soil. Plants as we know them, wouldn't begin to develop for millions of years, but during this time Earth witnessed something incredible. The development of multicellular organisms and the Cambrian explosion. When life began in earnest on our little waterlogged planet. Animals with mineralized shells, chitinous exoskeletons, sponges, echinoderms, trilobites, and arthropods flourished across this virgin world and rapidly diversified into new ecological niches that had never before been occupied.
While most living organisms would remain in the oceans, a few pioneering forms began to probe the surface of the world, most remained close to the coastlines where moisture made life more agreeable. Early hexapodal insect precursors, arachnids, and myriapods were successful groups that would form the evolutionary basis for all their descendants going forward. Yet another small, strange, terrestrial group of animals developed alongside them. So bizarre in physiology and evolutionary history they earned their own Phylum. We are talking today about Phylum Onychophora, the wonderful little Velvet Worms. Closely related, and sharing characteristics of both Tardigrades (water bears) and arthropods, these fascinating little invertebrates have managed to survive on Earth from the very beginning. Weathering every mass extinction event, and surviving shifts in climatic conditions, tectonic plate movement, and the evolution of more advanced organisms.
Velvet Worms are predatory, segmented invertebrates with primitive characteristics and features recognized in other animals. They possess a pair of sensory organs analogous to antennae, but the structures are diverged from the labrum and do not correspond with arthropods antennae development. They have small simple eyes to detect light intensity and are highly photosensitive. They have small conical shaped baggy legs that end in small stubby feet with chitin coated claws for gripping irregular surfaces. Velvet Worms maintain a rigid hydrostatic skeleton of internal pressure that their simple musculature can push against during locomotion. On the third head segment is a small mouth opening, and on each side are a pair of oral papillae which connect to a large slime gland. From these papillae, Velvet Worms can spray a sticky glue like substance which ensnares small arthropods and can be deployed defensively against predators. Their outer skin is a thin layer of cuticle formed predominantly of proteins and chitin. Under this is a single layer of epidermis, followed by tiny muscle layers. The outer cuticle is covered in fine papillae, some of these house clusters of sensitive hair-like bristles and small fuzzy scales, lending them the soft ‘velvety’ appearance and origin of their common name.
This species, Epiperipatus barbadensis is native to the Caribbean island of Barbados. Across Earth, some 200 recognized species exist and are restricted to tropical conditions at the equator and southern hemisphere. Fossilized specimens have been found in amber deposits in the northern hemisphere, indicating a larger range when conditions on the planet were more conducive to survival. Velvet Worms are highly photosensitive and recoil from light sources. They are also easily dessicated and prefer habitats with high moisture and humidity. These little predators can be found hunting at night in leaf litter and other forest floor debris and often cluster together under wet rotting wood, moss covered stones, and even small caves or burrows during the day.
Epiperipatus barbadensis is typical of other Velvet Worms, reaching lengths of 2 to 3.5” and typically clad in aposematic orange or red coloration. This genus of Velvet Worms are viviparous, developing a placenta-like structure on the uterine wall that nourishes the embryonic young during development. These are fascinating animals and have traditionally been difficult to raise in captivity. This species seems to be the easiest to keep long term, using habitat designs and methods commonly seen with small species of sensitive amphibians. With luck, we can continue to work with these incredible living fossils and perhaps with time more species will find success in captive care. Animals like these are often underrepresented and escape the attention of the broader hobby or nature enthusiasts. Despite the fact that Velvet Worms, along with the other Cambrian descendants are this planet's true royalty. They have called our world home from the very beginning. The moment this planet could support multicellular organisms, animals like this rose to prominently stake their claim and plant their flag on the very frontier of life itself. Then quietly survived against all odds, while millions of other species rose and fell, while dynasties changed, and the surface of the planet transformed, these original land dwelling organisms stood proudly on the foundations established by their ancestors, half a billion years ago.