25.03.2022

How to get cocoons out of Haplotanks

The attached film shows some of our female Asian tarantulas currently having a sack. So it is not a film that was recorded in nature, but a recording in our Haplotanks made with an endoscope. The Haplotank is a type of terrarium developed by Volker von Wirth in the late 1980s specifically for burrowing species. It offers the animals the opportunity, similar to nature, to create a tube, but at the same time to be able to be observed and controlled by the owner. We keep our tube dwellers, such as Haplopelma, Ornithoctonus, Selenocosmia or Aphonopelma, exclusively in such Haplotanks. HERE you can see how the Haplotank is set up and how it works.

In this context, however, the question arises again and again how to get to the cocoons of the female tarantulas when they sit with the cocoon in a tube in a haplotank. The cocoons are mostly guarded by the females deep at the end of the tube, as you can see in the video below.

However, there is a trick to get to the cocoons without destroying the tubes of the females or without digging out the cocoons.

Many tarantulas in nature like to keep their cocoons out of the tube in the morning hours. Especially when there are already prelarvae inside. Thus it was reported to us by friends that they could discover many white "ping pong balls" in the middle of the green vegetation of a road embankment in the Peruvian Andes when they walked along it in the morning. On closer inspection these "ping pong balls" were in reality cocoons of tarantulas which were placed by the mothers apparently for warming at the tube entrance, which probably supports the development of the brood by the warmth. This interesting behavior can also be observed in terrarium keeping. The Pic 1 show an Ornithoctonus aureotibialis mother, which was placed with her now 5 weeks old cocoon on the sunny windowsill. It did not take long and the mother came out of the depth of her tube with her cocoon to the entrance and held it towards the sunrays. As a keeper you can take advantage of this moment and take the cocoon from the mother with a well-aimed grip with tweezers to control it and to incubate it further if necessary. In this case it is interesting how the mother holds the cocoon. She holds the cocoon with her rear legs a little bit under the abdomen (Pic 2). Possibly she does this to push the cocoon quickly under her body in case of a disturbance, e.g. by a predator, and to rush back into the tube with it. If, on the other hand, the cocoon was held out of the tube with the front legs as if in a lurking position, it would lie in front of the mother in the event of a disturbance and would thus be at the mercy of the predator. However, this is pure speculation and would have to be tested under the same (laboratory)conditions under numerous cocoon-carrying females of one species.

Reference:

von Wirth, V. & M. Huber (2002). Einige Praxis-Tipps zu Haltung von Haplopelma Arten und anderen Röhrend bewohnenden Vogelspinnen. DeArGe Mitteilungen 7 (11), 14-23

von Wirth, V. & M. Huber (2004). Housing Specimens of Haplopelma and Other Tube-Dwelling Tarantulas. BTS Journal, 19 (4), pp. 107-113

von Wirth, V. (2011): Vogelspinnen. Graefe und Unzer Verlag, München