Antilles Pink Toe, Black Horse Spider, Martinique Red Tree Spider, Trinidad Chevron, Haitian Brown and Caribbean Bird Eater are just a few of the many tarantula species found throughout the Caribbean with over 800 species found world-wide. As we wrote last month, tarantulas are venomous. However, their venom is only mildly irritating to most humans and there has never been a death recorded due to a tarantula bite.
Being ‘shot’ with the urticating, venom tipped hairs from the abdomens of some New World tarantulas is more likely to cause a trip to the doctor for treatment of intense itching and rash. In fact, some of our older readers may remember a substance called itching powder that was used by practical jokesters on unsuspecting victims. Among the ingredients in itching power were urticating hairs taken from New World tarantulas.
Ranging in length from 1 inch to over 11 inches and possibly up to 13 inches, all 800+ species of tarantulas share the same anatomical features and all are carnivorous; feeding upon bugs, other spiders, lizards, birds, and sometimes bats. There is evidence that the females of some species may live over 30 years with males living 10-15 years. While tarantulas are generally brown or black, some are beautifully colored with tiger-like stripes, iridescent purples and cobalt blue or bottle green, red or blonde bodies and legs, pink or red abdomens, and curly white or grey hairs. Like other spiders, tarantulas cannot see much other than light, dark, and vague shapes; however, their very sensitive body hairs more than make up for their lack of sight by picking up vibrations.
Tarantulas have exoskeletons rather than internal skeletons. In order to accommodate growth they shed their exoskeletons at least once a year until the males reach adulthood between 3-10 years, depending upon the species, at which time their molting usually ceases while females continue to molt throughout their life times. As the new exoskeletons develop within the old ones, new lungs, stomach linings, missing limbs, and in females, new genital tracts also develop. When the new bodies have fully developed and are ready to come forth, the tarantulas increase their circulatory pressure forcing blood into the space between the skeletons which causes the old skeleton to split and allows the “new” tarantulas to emerge.
As do other spiders, tarantulas have silk glands in their abdomens; however, unlike other spiders, tarantulas do not spin webs to catch prey. Tarantulas produce silk for use in nests, when mating, or as trip wires to signal when prey is nearby.
Mating amongst tarantulas can be a dicey prospect for the males. Rarely seen during the day because tarantulas are nocturnal, in mating season males can often be seen during daylight hours wandering about looking for a receptive female. Once a female is located reproduction begins with the males spinning a compact web on which they deposit sperm from their abdomens. The male then picks up the sperm with his pedipalps; shortened limbs located on his head, and after flipping the female onto her back, inserts the pedipalps into her genital tract. Before the female rights herself, the male makes a quick exit or risks being eaten since tarantulas are cannibalistic.
The fertilized female spins a protective cocoon in which she deposits anywhere from 50 to 1,000 eggs before sealing it with her silk. Some of the New World tarantulas place their urticating hairs on the outside of the egg cocoon as a deterrent to other insects that might attempt to feed upon the developing eggs. The female tarantula guards the egg cocoon for 6 or 7 weeks until her tiny tarantulas emerge. For approximately 2 weeks the young stay very near the cocoon before heading off in all directions to live solitary lives.
Tarantulas live in ground burrows, in trees, under rocks or tree bark, and on the faces of cliffs and buildings. They spin their silk into nests and will often leave trails of silk outside their dwellings to signal the approach of possible prey which stumbles across the delicate silken threads. Burrowing tarantulas line their underground habitats with fine silk and extend the silk along the rim of the burrow in a webbed pattern in order to conceal the opening.
The myths perpetuated during the Middle Ages regarding horrid deaths from tarantula bites and big screen horror films about invading, deadly spiders are purely fiction yet they have caused totally unfounded fears and paranoia. When a tarantula was recently dug up in my yard two gardeners immediately jumped forward with shovels and machetes to kill it. Fortunately, my landlord and I were quicker. After allowing it to explore our arms and hands we carefully released it and neither of us had to perform the Tarantella…what a sight that would have been although we would certainly have enjoyed ourselves!