Does breeding tarantulas reduce their lifespan?

Over the past 10 or so years, the authors have bred many species but there seems to be a pattern emerging when it comes to certain African species, particularly Ceratogyrus and Pterinochilus spp. This pattern involves the adult female spiders dying not long after they have successfully produced spiderlings.

On average in captivity, females of Ceratogyrus and Pterinochilus live around 8 - 10 years but we have noticed on many occasions that once the female has produced her offspring, it is not uncommon for them to die within the next few months (or even weeks). This has even been noted in relatively young, yet sexually mature, females of around 2 - 3 years.

Diary notes (G. Tansley):

P. murinus (rcf): During 2003, 3 captive bred females were successfully mated. 1 seemingly healthy female died within four weeks of mating, never producing an eggsac, 1 female died within 8 weeks after the spiderlings were separated from the female (all food was refused and the spider spent many hours sitting hunched in one corner). Female 3 has recently moulted and is doing well after producing a successful eggsac during February '04.

P. murinus: During 2003 and 2004, 3 captive bred females were mated and all produced successful eggsacs. No eggsacs were removed from the females but all eventually died in the following months after the spiderlings were separated. 2 of the 3 females were around 3" legspan and would be considered young adults. In both cases, the females refused to eat and died before their next moult.

Diary notes (P. Messenger):

C. meridionalis: 2 females mated both resulting in spiderlings, female 1 refused to feed after spiderlings emerged and died 8 weeks later.

C. marshalli and 2 C. darlingi, all wild caught. All produced eggsacs but the only one still alive is one C. darlingi that ate the eggsac. The other 3 died with in 8 weeks of the eggsacs developing into spiderlings.

P. murinus: Since January 2003, 6 produced spiderlings. 2 out of the 6 females died, one at 8 weeks after the nymphs moulted into spiderlings and the other at 10 weeks after nymphs moulted into spiderlings. These were all captive bred specimens ranging from 2 years old at 2.5" legspan to 4 years old at 4 - 5" legspan yet it was one small and one large female that died.

P. murinus (rcf): Since January 2003, 2 young (3" legspan), captive bred females produced spiderlings, 1 died within 10 weeks of the nymphs moulting into spiderlings.

So why is this happening? Maybe with young females (though sexually mature), maybe they are being bred too young and it takes too much effort out of them and weakens them to the point of death (Some of the oldest and largest specimens in the authors' collections have never been mated). This could also be the case for older females. Often when the females begin refusing food and then die, the eggsac has been removed from them for artificial incubation. Does the spider become over-stressed at this intervention and then simply give up? Or does the female die to maybe help her offspring somehow? Maybe in the wild, where prey is scarce, the absence of the female will benefit the spiderlings? Symptoms seem to appear after the eggs have developed into spiderlings, the adult female will be reluctant to feed or moult. Is this a sign of inbreeding our stock over many years? Maybe tarantulas become weaker over the course of many generations and are less able to resist complications and problems that may occur after eggsac production. Or are these observations simply coincidence? There seems to be no common denominator for the results listed above, a combination of old and young specimens, captive bred and wild caught females dying with no real explanation.


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