Tarantulas reproduce by laying and subsequently incubating eggs. The eggs are small, circular and most commonly white or off-white in color. The number of eggs laid can vary significantly between species, with some producing 50-100 eggs, while others may produce over 1,000 at once.
When Do Tarantulas Lay Eggs?
Tarantulas do not get “pregnant” in the traditional sense. Instead, mating involves the male inserting his sperm into the reproductive organs of the female. These organs are known as the “spermatheca”. It can be thought of as a “purse” for holding sperm until egg laying starts. Only as the eggs are laid are they fertilized with the stored sperm.
Female tarantulas are capable of laying fertile eggs at almost any time after mating. In captivity it is normal for some months to pass between breeding and egg laying but this waiting time may last up to a year.
Normally a female tarantula will wait until she is satisfied with conditions – the volume of food she has eaten recently, the temperature and humidity all potentially having an impact.
Some tarantula keepers deliberately try to adjust these conditions to “trigger” a female tarantula to lay eggs. One example would be regularly misting the cage of Poecilotheria tarantulas to simulate the wet season in India and Sri Lanka.
Do Tarantulas Lay Infertile Eggs?
Tarantulas can lay infertile eggs. These are often brown or yellow in color, or may become so during incubation. In many cases only a proportion of the eggs laid are infertile. However there are cases where an entire clutch is infertile.
Some captive female tarantulas are known to produce “phantom eggsacs” – an entire batch of infertile eggs even if they haven’t mated with a male.
How Do Tarantulas Lay Eggs?
Tarantulas spin a thick matt of webbing on the ground. The female then deposits her eggs onto the centre of the web, and carefully rolls up the web. This produces a silken bag with the eggs safely contained within. These are typically known as “eggsacs” in the hobby.
Which Tarantulas Lay the Most Eggs?
Possibly the largest number of eggs produced by any known tarantula is the Salmon Pink Birdeater (Lasiodora parahybana). Their eggs may total more than a thousand from a single mating, and helps to explain why this species is so reasonably priced as a pet.
Another tarantula producing almost as many eggs is the Brazilian White Knee (Acanthoscurria geniculata), which again tends to be a reasonably-priced tarantula pet.
Which Tarantulas Lay the Least Eggs?
The goliath birdeaters tend to produce relatively small clutches of eggs, though the resultant baby tarantulas are also much larger than the average spiderling.
Do Tarantulas Care For Their Eggs?
Once an eggsac has been laid it remains with the female tarantula until hatching. Many tarantulas will stop feeding while caring for their eggs, only resuming feeding once the eggs have hatched.
Many species of tarantula carry their eggsac in their mouth, so they are able to gently turn the eggs and move them to an area of suitable temperature and humidity. Some other tarantulas produce a “sling” of silk to which the eggsac is attached.
Whatever the case female tarantulas maintain watch over their eggsacs until they hatch.
How Long Do Tarantula Eggs Take to Hatch?
The time that tarantula eggs take to hatch can vary from species to species, as well as in response to environmental conditions. Warmer conditions can lead to eggs hatching sooner.
In captivity it is normal for keepers to leave eggs with their mother for roughly 30 days. At this point the eggs are removed and then incubated artificially. It is normal for the final stages of development to take some further weeks.