Tarantula Life Cycle
The life cycle of the tarantula begins as eggs hatched by the female. The embryo hatches into the postembryo instar while inside the eggsac here, it is capable of moving its appendages but it is not a mobile stage. The nutrients are provided by the internal York located in the enlarged abdomen.
The postembryo begins its first true molt a stage formally known as the first instar. The total number of molts depends on the species, sex and the individual of the tarantula during its life.
After hatching, the stage of the spider before reaching sexual maturity is called penultimate instar which is followed by the adult (ultimate instar). All the male spiders except for a few exceptions do not molt after reaching their adulthood. Tarantulas and some other female spiders however can continue to molt after reaching the adulthood (Ultimate instar). Its first true molt after reaching the ultimate instar is called first postultimate instar and so forth. The term larva and nymph do not apply to spiders.
Factors affecting the rate of the spider development are mainly temperature and availability of food. In the wild, tarantulas in the warmer regions take a shorter time to mature than those in the colder regions. Tarantulas in the captive as pets or specimen in the laboratory however are affected by the availability of food. The life expectancy of the tarantulas ranges from 6 months to a record of 50 years. Males live for 10- 12 years with the females living for twice this much.
The tarantulas will go on to grow between a length of 2.5 cm to 11cm depending on the species. They will also weigh between 80gm and 170gm. The largest tarantula has fangs reported to reach 1.5 inches. The differentiating characteristics between the female and the male is the color and the size. Females have bigger stocky bodies covered in brown hair while the males have thinner bodies covered with black hair. However, the color of these tarantulas can range from cobalt blue to green with black and white stripes.
The tarantulas are predatory and ambush feeders. Although low in acute vision, they feed on grasshoppers, crickets, small birds and even snakes which have much better vision. They however cannot chew their prey and therefore inject them with venom which contains digestive enzymes that liquefy them and in the process feed on the “soup” from them. Apart from injecting their prey with venom, the tarantulas can also tear the prey apart and roll the pieces into balls and liquefy them. This simplifies the capture of multiple prey items instead if securing them one at a time.
The tarantulas are not short of enemies with the greatest being the wasp family of prompilidae also called the tarantula hawks. These track and kill tarantulas. They have a reputation of injecting the underside of tarantulas’ cephalothorax making use of the thin membrane. This paralyzes the spider and it drags it to a burrow, depositing its eggs inside its body which provide the wasp larva with flesh when it hatches.
The tarantulas have special hairs that they use for defense against the predators. These hairs are irritating upon contact. Most tarantulas in the wild die of because predation and the males in particular because of the attacks by the females after copulation. Some tarantulas are endangered as their natural habitat is encroached by man and also the environmental changes. Also due to being traded as exotic pets, their numbers are increasing at home and can pose as a threat to the ecosystem in cities and towns notwithstanding the allergic reactions they pose to those with low immunity.