Monday, July 13, 2015

#38 - BREEDING TARANTULAS #1 - POECILOTHERIA

This entry will cover a formula for increased success with breeding Poecilotheria. Nobody is 100% successful and the spiders have their own ideas. Although we talk about breeding, we really mean mating (or "pairing) and also doing the best we can both beforehand and afterward to encourage the female to produce a fertile eggsac. This "beforehand" and "afterward" is what I will refer to as "pre-conditioning" and "post-conditioning". It may be a pedantic semantic argument, but when you say "I bred my Poecilotheria metallica" you actually mean that you paired a male and a female and they mated. I presume you didn't actually breed with a spider. And while I am being pedantic, you're spider is not "gravid" even if it has an enlarged abdomen that is not due to feeding and is likely to produce an eggsac. "Gravid" means containing fertilized eggs and your spider will (hopefully) be fertilizing them as they are laid.

Since we are discussing definitions let us begin with the aforementioned "pre-conditioning" and "post-conditioning". "Pre" is anything you do prior to mating to prepare your female for mating and the production of a fertile eggsac. "Post" is anything you do after mating to maximize the possibility of a fertile eggsac being produced and encourage the female to lay her sac. Both are important, but our "formula" for Pokies is going to focus on post-conditioning. But first let's talk about the best case scenario for getting both male and female ready for mating (pre-conditioning). However, before I begin elaborating on my method for optimal success I need to interject something.

This blog is about maximizing success. It does not detail the only method of having success. In fact, many people do nothing special and successfully breed Pokies. It is not unusual for experienced breeders to have poor results with a tarantula species and beginners to hatch the same species. Tarantulas often thrive with what has been called "benign neglect". And I know keepers who hatch Pokies without any pre- or post-condition of either sex. But the "formula" described herein is based on data from the hundreds of Pokie eggsacs that myself and my former Tarantulas.com colleague Alex Orleans have hatched. We have combined to produce as many Pokie offspring as anyone, and our best success has been using the methods, especially with regards to post-conditioning females, that I will disclose in this blog. In fact, I must credit him as co-author of this blog as the detailed records I inherited at Tarantulas.com and discussions with Alex over the years have resulted in my Pokie success method. To maximize success we follow a formula for post-conditioning females that results in the most fertile eggsacs.

Pre-conditioning Males
Timing is everything when it comes to tarantula breeding. You want a male to mature and have some time to have a couple post-molt meals and produce a sperm web (or multiple sperm webs) at the same time your female is at the right point of her molt cycle (covered below). Of course, this assumes you have both male and female of the species. Often this is not the case, and that is why the breeding loan has become such an integral part of tarantula breeding. However, for the purposes of this discussion, we will say that you are breeding Poecilotheria regalis (the "classic" Pokie) and you have at least one male and female. Hopefully you have multiple females as timing really is everything. We'll come back to that soon, but first let's finish discussing timing as it applies to males and how to prepare them for mating.

As a tarantula breeder (pretending that you have all of your own needed males) you will usually find yourself either wanting to slow down or hold off maturity in males or the opposite. It will become important to positively determine sex early on so that you can adjust feeding frequency and meal size to grow your females "quickly" and either retard or accelerate the growth rate of your males. I have tubs of male Pokies in 32 oz. deli cups that I don't need yet and they only get fed once every few weeks. I try to check on them and "water" as necessary each week, but they aren't fed once a week like most females. If I do need a male, or I have a surplus of males and want some to mature for potential breeding loans, then they are removed from the tubs and placed on the shelves beside females. They are then fed and watered on the same schedule as the female so that they mature as soon as possible.

Pre-conditioning Females
Although environmental manipulation can be a big part of post-conditioning females (see below), the pre-conditioning in Poecilotheria is simply a matter of keeping the females well-fed on healthy prey and ensuring that the spiders receive optimal care. "Healthy prey" means feeder insects that have been gut-loaded and well-hydrated with "cricket quencher" and/or greens or fruits. I don't do anything special for females before mating other than pamper them as much as possible. If a female is approaching a molt (based on previous records (i.e., date of last molt) or behavior/appearance I may feed and water her as often as possible to try to get her to molt as soon as possible. Again, this is based on timing and when I will have a male ready.

Post-conditioning Males
There isn't much to post-conditioning males except for getting a few meals into them and watching for sperm web production. Some males have good appetites while others may seem disinterested. It may take some persistence and offering smaller prey than usual to get males to eat. If a male does have a good feeding response I usually will feed him one cricket every day until he refuses. He may lose interest in food once he starts being introduced to one or more females and I want him in good shape. Sperm webs may be destroyed after they are used so if you are not inspecting the male's enclosure often you may miss knowing whether one has been built. I often like the male to be matured for 30 days before I try to use him. In this time it is likely that he will build a sperm web. If the first time I pair him he seems disinterested in mating, I may return him to a gallon jar or similar container for another couple weeks. A piece of cork bark or cut piece of cork tile angled in the jar may help him to construct his sperm web.

Pairing
I am assuming that anyone reading this first read Blog #37 - Casa de Tarantula #2 where I describe an ideal enclosure (modified cereal container) for Poecilotheria breeding and end with a photograph that shows a male and female's container side by side in a "breeding arena". If you haven't please go read that blog entry and then return to this spot.

Poecilotheria females are normally not aggressive to males. The exceptions are P. fasciataP. ornata and, to a lesser extent, P. rufilata and P. striata. Not surprisingly, these are the four Pokie species that are the most defensive in general. More often than not, a mature male and female Poecilotheria will cohabitate indefinitely if left to do so.

If you are using a larger enclosure such as a vertically-oriented 10 gallon aquarium or an ExoTerra mini terrarium you may "shark tank" a male that is housed in a 32 oz. deli cup by placing the cup in the female's enclosure for a few nights. "Shark tank" refers to keeping the male protected from the female, but putting the pair in each other's presence so that pheromones are sensed and courtship behavior like tapping can occur. After a few nights the lid can be removed from the cup and the pair introduced to each other. Many keepers will observe and confirm mating with "good insertions" takes place and then separate the pair. To be honest, I normally just leave the male for a week. However, I suggest using the cereal container enclosures and "breeding arena tub" detailed in Blog #37 to pair Pokies. This set-up allows the male plenty of space to escape the female if she is unreceptive or is aggressive after she has been receptive. You may pair repeatedly or offer multiple males. Any subsequent matings can only increase the chances of a fertile sac. However, eventually the male is best removed so that the female is undisturbed and you can concentrate on feeding her well and beginning the post-conditioning described below.

Post-conditioning Females
This is the "formula". I prefer to pair Poecilotheria females that are 30-90 days from their last molt with 45-60 days being ideal. I want her to be freshly molted so there is no worry about molting herself "sterile" before eggsac production, but I also want time for her to "recover" from molting and feed heavily for four or five weeks. At 75-90 days I cool the female for 30-45 days and keep her dry. I am not talking about a drastic reduction in temperature. My spider rooms have normally been in the upper 70s with occasional temps as high as 82-83ºF. I tend to mist the enclosures and/or rehydrate the substrate once a week and 78ºF is the usual temperature. A couple weeks before I begin cooling I stop misting to dry the cage a bit and then place the enclosure in an area where the temperature is maintained at about 68ºF and continue to abstain from watering. At tarantulas.com we had a small room that was air-conditioned to maintain this temperature. It was kept dark and dry. All that was kept in it was female Pokies that had been mated. We would move their enclosures from the warm and humid breeding room to the air-conditioned cooling room and leave them for 30-45 days or so. Then we would return them to the breeding room and its daily temperatures of 75-82ºF and begin to mist/spray their enclosures often. In my new home my spider room is 76-80ºF and I can move spiders to my basement in order to cool them for four to six weeks to simulate a cool and dry period prior to the warmth and moisture of my simulated monsoon.

This post-conditioning is simulating the monsoon weather that is found in India and Sri Lanka. Poecilotheria are found solely in these two countries and they lie north of the equator. Sri Lanka is only 6-7º north of the equator and could be considered equatorial, but India ranges from 8º to 37º north. So there is some seasonal difference in temperature, especially to the north of the genus' range in India. However, it is the wet and dry seasons influenced by monsoons that affect these "tiger spiders" the most. Moving mated Poecilotheria females from a warm area with humidity in the range of 60-70% to a cooler and drier area for even 30 days gives them the environmental cue or trigger that contributes to maximized breeding success. Once gradually returned to warmth and "rained on" a few times a week to bring humidity to 75-85%, while at the same time being offered frequent meals, the female is stimulated to produce her eggsac. If she has a dark retreat such as described in Blog #37 and is left undisturbed the sac is likely to hatch. The sac can be pulled at 30-40 days when development will have reached the postembryo stage or perhaps 1st instar and incubated outside of the cage. I like to leave my sacs with the females until they hatch, but this does result in the very labor intensive task of finding all the spiderlings in the cage and potential escapees. Therefore, most people will pull their eggsacs and 30 days after the sac is produced is a good time.

Incubation
Near the end of my Tarantulas in the Terrarium film I show how I make an incubator cup for Poecilotheria. It is much easier explained with video than here and I suggest you click here to go to the 1:16:26 mark to begin viewing.

Conclusion
Following the above formula for pairing and then cooling/drying the female and warming her back up while supplying elevated humidity will increase your success with Poecilotheria. Using the cereal container enclosures described in Blog #37 will often lead to greater success especially for less experienced keepers. It is much easier to keep an eye on your Pokies in these containers and the spider will feel more secure and have a dark retreat that is more like the tree hole it would use in nature. Finally, I should note for those who are unaware that most Poecilotheria become "spiderlings" at 2nd instar like the majority of other tarantulas. However, P. metallicaP. tigrinawesseliP. miranda and P. formosahave an additional development stage and are not "spiderlings" until 3rd instar. That is, they require one more molt before they are fully colored, independent tarantulas that will begin feeding. And Poecilotheria formosa has been known to require yet one more molt before spiderling.

Good luck breeding! MJ


1 comment:

Unknown said...

Hi Micheal, this is very informative and helpful! I just have 1 question, can i still use my mature male p.regalis that already made his final molt 6months ago?