Tarantula Reproductive Cycle
Arachnids, spiders in general differ in their mating techniques with mammals’ life primates and humans. Once a male tarantula reaches a reproduction maturity, they seek out the females and this can seem as they are migrating. This is because, these spiders are mostly solitary creatures and the next available mate can be hundreds of meters away.
Spiders have pedipalpi which are two six segments appendages connected to the thorax. The terminal part of the pedipalpi of males functions as part of the reproductive system. The males have special spinnerets (this are flexible tube-like structures from which the spiders spin exude their silk which hardens upon contact with air) around their genitals to which the sperm web is spun from. The males spin this web(silken) unto which they release the semen from the glands in their opistoma. The sperm web platform is laid on the ground during this process. They insert the pedipalps into the semen which absorbs it and keeps it viable for a period until a mate is found.
Spiders exude chemicals when they are ready to mate and a male can tell off if the female is of its species by the chemicals it gives off. Males search for those females that have newly molted as they can be particularly aggressive after mating which can result in the death of the male. Careful selection enables not only a successful copulation but self-preservation.
Upon finding a female though scent left by her substratum, the male tests her receptiveness by tapping near her burrow entrance or web. The male will them carefully enter the burrow and meet up with the female. If the female is not ready, she will either pay no attention or attack him in which case the male will rapidly run away to prevent being the devoured as the next meal. If the female is ready for mating, she might not show interest upon which the male will have to perform a special mating ritual. He will lower his front and raise his abdomen. Having extended his forelegs and pedipalps moving backward outside the burrow. This attracts the female and to keep the attraction going on, he stops from time to time moving his forelegs and pedipalps from left to right shuddering his body.
When they reach out outside, the male is free to move and unlike the courtship of other spiders, the tarantula males approach the females carefully and touches her with the tips of the front legs and pedipalps with repeated breaks to make sure that that behavior does not pose danger to him. If the female is passive after this, the male will approach her, hook his front legs between her pedipalps and chelicerae which move in readiness for mating. He then lifts her prosoma stroking her abdomen lower surface. If the female is ready for mating now, the male unbounds the pedipalps embolus containing the semen and inserts it in the female gonopore. This takes place for a fraction of a minute after which the male runs away because the female’s appetite grows and may eat him. This enables him to mate with other females if he keeps his life. Also the females are able to mate with different males for a season.
Fertilization occurs in the womb within a determined period after the copulation which can be as short as 1 month or 8 months which depends upon several factors such as, the female’s last molt, season, presence of food or even humidity. The female lays eggs entwined with the cocoon. Unlike the other spiders, the female takes care of the eggs, turning them periodically and also moving them depending on the temperature and humidity. The amount of eggs laid by the female depends on the species, the size and age of the female. It can range from 50 up to 2000 eggs.