Breeding Haplopelma albostriatum

I only started keeping H. albostriatum (Simon, 1886) in recent years so when I was offered a mature male (from Chris Sainsbury), I checked my three specimens to find them all female and probably large enough to attempt a pairing.

All Haplopelma spp. in captivity are fossorial in nature requiring enough substrate in their enclosures to allow them to dig their deep burrows. Of the three females, one was housed in custom-made fossorial tank based on an original idea by von Wirth and Huber (VON WIRTH, V. & M. HUBER (2004): Housing specimens of Haplopelma and other tube-dwelling tarantulas. British Tarantula Society Journal 19(4): 107-113), the second was in an adapted sweet jar and the third in a cereal tub. Due to their defensive temperament, caution is advised when attempting to pair members of this genus as often males are misidentified resulting in either death of the male or hybridisation between species. H. albostriatum, from Myanmar, Thailand and Cambodia, is easily distinguished from others in the genus by characteristic white stripes to the patella and tibia of all the legs. There can be some colour variation and some specimens can be quite dark. Males are similar in colour but overall slimmer in appearance.

Female A, housed in a custom-made tank:

28/08/05: Moulted.

11/09/05: Mated. Courtship was a very deliberate affair with the male beginning courtship almost immediately on contact with the females silk. The female responded by appearing at her burrow entrance and drumming her first pair of legs in response to the male. They remained calm throughout as the male secured the females chelicerae (H. albostriatum don't have tibial hooks or spurs but rather a blunt-ended protrusion that sits at the base of the females' fang in order to lift her into position). Palp insertions were brief and followed by characteristic epigynum rubbing by the female. The reason Ornithoctoninae females show this post-mating behaviour is somewhat of a mystery. After mating the female is often seen to frantically rub her underside (around the epigastric furrow) with her third and fourth pair of legs while moving the chelicerae in a 'chewing' motion (much like a speeded up version of cleaning). Explanations include massaging the uterus externus back into position or displacement activity - a conflict between mating behaviour and prey capture (the male as prey). In such a case the behaviour "jumps over" to a completely other behaviour complex (cleaning), because she is not only rubbing her genital region but the complete abdomen, spinnerets and the chelicerae (von Wirth, 1996).

Over the following four months, temperatures remained on average around 70-75oF and the substrate remained moist at lower levels of the enclosure and dry at ground level. Feeding wasn't increased and prey was offered approx. once a month consisting of crickets and lobster cockroaches Nauphoeta cinerea with the occasional deaths head cockroach Blaberus discoidales.

28/01/06: Found with eggsac. Burrow entrance left open (no noticeable silk or substrate across the entrance). As with most females that are incubating an egg-sac, feeding was suspended and the container disturbed as little as possible. The egg-sac could clearly be seen through the side of the enclosure (fossorial tanks are ideal for viewing the spider inside its burrow chamber). The female was often seen to move the egg-sac up and down the burrow and sometimes at the front of the container at ground level (warming the egg-sac at the point closest to the heat source).

13/04/06: Found with nymphs that spent their time at ground level, again, probably at the warmest part of the enclosure (they would bolt down the females burrow at the slightest disturbance). The egg-sac had been discarded at burrow entrance and was opened to find several black eggs and moulted skins of the surviving nymphs. These eventually moulted into spiderlings - some at ground level, some in the females' burrow chamber.
01/05/06: Separated spiderlings, 50 in total.

The other two breedings were similar:

Female B, housed in a sweet jar:

19/09/05: Mated - this was the smallest female but very eager to mate, male using both palps.

14/04/06: Found with egg-sac.

01/05/06: Egg-sac discarded, destroyed by mould.

Lack of adequate air-flow through the lower section (the only air holes were in the lid) of this container probably resulted in the egg-sac being destroyed by mould. Lack of visibility into the container so no evidence of the female moving and warming the egg-sac at the burrow surface.

15/09/05: Mated (similar to female A).

23/01/06: Found with eggsac - again, burrow entrance un-silked and no traces of it being plugged by substrate. Due to poor visibility of the cereal tub, it was difficult to note if the female spent any time on the surface with the egg-sac.

18/03/06: Nymphs were discovered in the container (burrow chamber). These were seen to gather on the surface but would quickly run down the burrow if disturbed.

13/04/06: Found all nymphs had moulted into spiderlings. These would gather at the far reaches of the container, probably warming themselves at the point closest to the heat source.

01/05/06: Spiderlings separated, 113 in total (no bad eggs found).

This was the most successful of the three egg-sacs without any apparent losses. No doubt, there are slight environmental differences between the three enclosures (temperature but, more importantly, humidity and air-flow) which are contributing factors to a successful egg-sac.


In conclusion I would guess that the taller the enclosure for this species (and indeed, all similar species) is beneficial to egg-sac production. A deeper substrate within a taller tank gives a much wider range of environmental conditions (cooler and more humid in the burrow chamber, warmer and drier at the burrow surface). This gives the female a choice of incubation position for the egg-sac and this is something that only she can sense - an advantage of leaving the eggsac with the female for the full term.



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