Belonging to the phylum Onychophora, meaning 'claw-bearers', velvet worms are small, land-dwelling worms that range from about 2-10 cms in length. There are over 70 species of velvet worms that have been identified. At first glance, these worms appear to be docile, however, in reality they are voracious feeders that relish on tiny spiders, woodlice, etc.
In terms of color, they vary from black, dark brown, red, white, blue, pink, orange, etc. The two antennae protruding from their head, give them a snail-like appearance, while the 14 or more tiny, stumpy legs give them a caterpillar-like look.
Although the name includes the term 'worm', these creatures aren't exactly worms, but appear more like caterpillars, with their antennae and clawed appendages adorning the whole length of their bodies.
These worms are quite reclusive in nature and are often found dwelling in moist places, like rotting tree barks, leaf litter, etc. Found mostly in the southern hemisphere, these worms are highly sensitive to light and exhibit photonegative behavior.
Velvet worms have permanently open, tiny holes called trachea distributed all across the body. Since these holes cannot be closed, water content is oft lost without any control. This is why these worms can easily dry out, and need moist and humid areas to survive. Dry habitats are a total no!
Source of oxygen
In velvet worms, the tubular heart does not play any role in pumping or supplying oxygen. In fact, these worms receive oxygen via the pores on their skin.
Velvet worms use the 'sticky method' to get hold of their prey. They squirt a sticky, slimy substance from their slime glands (situated at the base of the two antennae), onto the prey's face. The slime temporarily blinds the prey, thereby, enabling them to overcome the opponent. The captured insect gets entangled in the slime, and its body begins to soften.
Next, the velvet worm bites out a hole in the body of the insect captured, and sucks out its internal juices, etc. Moreover, with the help of its 6, tiny, finger-like protrusions lining the mouth, it devours the prey.
Self defense moves
The same 'firing slime method', is used for self-defense as well. The slime squirted out falls on the predators face and eyes, temporarily blinding it. This gives the worm the opportunity to scurry away from the danger zone as soon as possible.
In velvet worms, reproduction takes place when the male worm releases packets of sperms on the back or sides of the female's body. However, some even release the sperm packs on the genital opening of the female.
The skin of the female on which the sperm pack is laid dissolves, thereby enabling the sperms to wiggle their way into the ovaries of the female, to fertilize the ovas. While some species lay large, yolk-filled eggs, others lay small eggs, devoid of a yolky food source.
These creatures are truly fascinating, and once again remind us of the great wonders of the animal kingdom!