Successful Breeding of Avicularia  auranticum (formerly magdalena)

By Carl Portman

There are many Avicularia species around these days, and it seems like a veritable minefield when it comes to correct identification. In my experience, too many people are selling  “Avic. auranticum” when clearly they are not. Let me state now that I am a million miles away from being an expert but I have consulted educated people such as Mark Titterton who clearly has substantial knowledge on the subject of theraphosids. I write this article as an enthusiastic amateur who would like to share an experience with other BTS members and hopefully members will be able to gain something from it.

The species Avicularia auranticum is readily identified for having striking yellow banding on the first three leg joints, but especially between the tarsus and metatarsus. The spider is light brown with reddish setae. In sunlight the spider shows much Olive colouring on the legs.

A. auranticum can be found in Colombia, and is in my opinion one of the most beautiful tree spiders in the Avicularia genera.

My female is kept in a medium sized tank with a mixture of peat and vermiculite for substrate. A suitable piece of cork bark is sited for the spider to rest on. The temperature was 75°F and humidity ranges between 70 and 80 per cent.

I procured my female on 4th October 1996, knowing that she was a wild caught specimen.

I originally thought it was Avicularia juruensis as they do look similar, but this proved not to be the case, as when compared together, A. auranticum is, for one thing much yellowier overall.

Soon after this purchase I was lucky enough to obtain a male of the species, which I had never seen before. He was of the same colouring as the female until his final maturing moult in June 1996 when he metamorphosed into a superb jet-black spider with bright yellow/golden banding on the legs. He was introduced to the females’ chamber in early June. She still had her moulted skin in the tank.

Mating itself took some time with both parties being very nervous of each other. When nothing had happened for two hours, my wife Susan and I made the decision to leave him in with her overnight. We don’t always do this but when we are confident that conditions are right we simply let nature take its course. Next morning we arose to find the female eating the remnants of the male. (So much for our analysis!) This was a real blow for two main reasons;

            a) We did not know if they had mated and if they had not there would not now be another opportunity.

            b) We could not loan him to other colleagues for important breeding purposes.

However, we always stand by our decisions and had no choice now but to wait and see.

We kept the female well fed and ensured she was kept at a constant temperature with MINIMUM disturbance from light or vibration. She was becoming very large so we knew she had a good chance of being gravid.

On the morning of August 4th I took my daily glance at the tank and sure enough there was the female with a very large egg sac.

Several weeks passed until I noticed the mother was wandering about her tank. The egg-sac was still there, and intact but she was unusually restless. In these circumstances I personally try to figure out whether the spider is merely stretching its legs, seeking food/water or even making sure there are no predators about for the imminent arrival of her offspring.

Once again, gut feeling came into play and I had to decide whether to leave the egg-sac in or remove it and finish incubation myself. I have no mind-bending theories for this and eventually decided (always quite reluctantly) to extract the egg-sac. This is always a tense affair because I respect the fact that the parent has spent so much effort and sacrificed much to get this far only to have it all taken away so suddenly. However, once again I state that when one has made a decision about such issues then there must be no regrets.

The egg-sac was duly removed after a momentous struggle from the female to hang on to it.

Incidentally we then tried the old trick of substituting the egg-sac for a ball of cotton wool to dupe the mother into thinking it was her egg-sac. I should say that we never usually try this because even if the female was tricked, she would still at that stage have felt the young moving in the egg sac and now there would be nothing, therefore possibly distressing her even more. Additionally the female actually DID discard the cotton wool within the hour so she knew what was real and what was not.

It only took several days for the spiderlings to emerge from the egg-sac. I have been known to make a small incision in the egg-sac to assist the young in their task but had not done so on this occasion.

There were an awful lot of spiderlings. Unfortunately, they emerged just before we had to leave the UK, so we did not have time to count them all before giving them to a friend to look after. We were disappointed not to have got the exact count as this is a major item of information but we reckon there were approximately 170 spiderlings.

All spiderlings were soon split into jars in denominations of five and ten. Some others were put singly. This may give us information on communal habits etc.

So that is it! I    have spoken to several people who fancy a go at breeding tarantulas but feel they have not enough experience etc. To them I say make sure you know the reasons WHY you are breeding, then have a go. Make as many notes as you can and do not be afraid to talk to experienced people about it. The best way to learn is to have a go!