Possible Alternatives For Raising Obligate Egg-Feeding Tadpoles  

(updated 3/1/2007)  

Over the years I have been trying to come up with solutions for artificially raising obligate egg-feeding tadpoles, specifically the d. histrionicus and d. pumilio groups.  There have been many documented attempts of raising these tadpoles on everything from chicken yolk to the yolk of other dendrobate eggs to American bullfrog eggs.  All of these methods have resulted in very small percentages of successful healthy froglets being produced.  There is nothing more frustrating than having a clutch of 12 healthy looking histrionicus tadpoles, then having only one raised by the adults and the other 11 simply going to waste.  I don’t think that there has ever been research done to determine the percentages of tadpoles that actually get raised in the wild by the adults.  My guess is that the percentage in the wild would be higher simply because the terrarium environments we create and the foods taken in captivity can never match that of animals in the wild.  In the past few years I have acquired several pairs of D.pumilo.  My idea was to test a theory I had that D. histrionicus tadpoles could be raised by D. pumilio.  D. pumilio have recently become fairly well established in the hobby in the US and in particular the bastimentos morph has proven to be quite prolific and the parents are capable of producing a fair number of young frogs in a years time.  D. histrionicus are unfortunately still very rare in the hobby.  In addition D. histrionicus are not nearly as prolific in captivity as D. pumilio.  My thought was that if you could take a prolific and somewhat widely available egg-feeder like D. pumilio and have them raise the tadpoles of the “not so prolific” and very unavailable D. histrionicus, you may be able to increase the production of D. histrionicus in captivity to a level greater than that gained by simply letting the D. histrionicus adults handle all of the parental duties.  At the very least the D. histrionicus adults will raise a certain number of young and the alternate methods may fail producing no additional young, so nothing is really lost in trying.

            Unfortunately histrionicus tadpoles are hard to come by so I decided to try simple surrogate parenting of two different morphs of D. pumilio.  The first hurdle in my mind was to see if D. pumilio would attempt to raise a tadpole that was not their own.  As suspected tadpoles of a different morph of the same species so far have had better results than tadpoles of a completely different species.  I believe that this is still worth pursuing, as there are some pumilio morphs that are not as productive as others.  This brings me to my current experiments using this technique to raise more of the Blue Jeans morph of D. pumilio, which in my experience so far has proven less prolific in captivity than the bastimentos morph.  It is worth noting that I use plastic ½ to 1-ounce condiment cups glued to driftwood and other items in the enclosure for the D. pumilio to raise tadpoles.  I have used bromeliads in the past but had trouble keeping them healthy and retaining water in the terrariums so I switched to the “cup trees” which have proven quite successful for me.  I also have several tanks wehre I simply silicone the cups to the sides of the enclosures.  It also makes it a whole lot easier to manipulate and inspect tadpoles during the parenting process.  I can also see exactly when to pull the neonate (I raise them individually outside of the parents enclosure) so that I don’t have to tear apart the enclosure looking for it.

Update 1/31/2005 - I have since morphed out another surrogate froglet and it is alive and well.  I have also morphed out several on the "alternate egg" plan.  So far the alternate egg plan has yielded about 20% successful froglets and of those about half survived.  This is actually better than the 75% mortality of the froglets that the parents have raised.

Update 7/30/2005 - more BJ surrogates and artificial rearing

Recently I morphed a total of 6 out of 6 pumilio using artificial means.  One surrogate blue jeans and three blue jeans, one bastimentos (the one replaced for surrogacy), one Chiriqui River all raised on mostly auratus eggs.

I have also moved the original WC blue jeans pair into a 65 gallon enclosure with many bromeliads.

Update 7/30/2005 - Histrionicus tadpoles surrogate attempt

Recently I was able to test the surrogate parent method with three D. histrionicus tadpoles.  I replaced one bastimentos tadpole and two "man creek" pumilio tadoles with histrionicus tadpoles.  Within the first week the tadpole with the bastis had died.  In the following week I lost the other two tadpoles.  Intersting to note is that I also lost all the tadpoles of the pumilio parents that were deposited in the same time frame.  Could be coincidence and I'm not sure what caused the deaths.  Normally in these pumilio pairs, most if not all of the deposited pumilio tads make it to froglets.  What is encouraging is that the pumilio did in fact deposit eggs for the histo tads.  Though I am not sure if the histrionicus tads ate any of them.

I also spoke with another hobbyist whom I had heard attempted similar things with histrionicus and pumilio.  What he did was take a fertile clutch of histrionicus eggs and place them in with a fertile clutch of pumilio eggs.  Several months later he had a histrionicus froglet along with several pumilio froglets.  So the pumilio transported the histrionicus tad and raised it to a froglet.

Update 7/6/2006 - Moving the WC blue jean pair into the 65 gallon enclosure hasn't seemed to help.  They have raised 1 tad to froglet in the last year.  Meanwhile I have raised 4 or 5 using surrogates and other dart eggs.  For some reason I am having a lot more success lately with using auratus eggs.  I am probably up to about 50% success with using auratus eggs.  As I have been more busy with my primary occupation my record keeping has gone down but I have certainly been more successful lately than when I first started.

Update 3/1/2007 - Histrionicus tadpoles and other breeders attempts - I have recently been doing some more experimentation with histrionicus tadpoles.  I have also been in contact with several other breeders who have been trying similar techniques.  Richard and Michael of Black Jungle have noted that if they start pumilio froglets on strictly pumilio eggs for the first week or so, then switch to auratus or tinc eggs they have much better success than using just auratus and tinc eggs.  Rich Frye of Frye Brothers Frogs has successfully morphed "Cristobal" pumilio by using surrogate "Bastimentos" pumilio parents.  I also know of another breeder working with several other obligate egg feeder species who is trying different methods of raising young.  I will be posting his results as they become available.  Thanks to all for sharing your experiences.  Anyone wishing to add to this document can contact me at the email address below. 

Recently I took two newly hatched histrionicus tadpoles and placed one in surrogate care of a pair of Chiriqui River pumilio.  The other I placed in a 4 oz cup and started feeding histrionicus eggs as well as tinctorious and auratus eggs.  After one month the surrogate tad is only a quarter the size of the alternate egg tad.  I have seen eggs deposited by the pumilio but don't know if the histrionicus tad is consuming them or not.  Early on I supplemented a few eggs of histrionicus, auratus and tinctorious as it was obvious the alternate egg tad was outgrowing the surrogate.  After the month period I pulled the surrogate and started feeding alternate eggs as it was obvious that the surrogate was not growing at the rate it should.  The alternate egg tad at a little over six weeks has full back legs and the fronts are looking to pop out any day.  The surrogate has grown but we'll see if it recovers and morphs out in the next month or so.

It is worth noting that when artificially feeding pumilio tads they display the same behavior, what most refer to as "the tadpole dance", when being fed by human hands as they do when being fed by pumilio parents.  However, I have not noticed the dance as much in histrionicus tadpoles.  In fact I don't recall seeing it at all in the last two tadpoles.  Perhaps this is contributing to the lack of success of surrogates with this species.

Surrogate parenting of Blue Jeans tadpole by a Basitimentos pumilio

7/6/2006 - As noted in other places in this document I have successfully surrogated about a dozen pumilio froglets.  All have done well and I have several that are now adults.  I have only had one or two instances where the tad did not make it, but it is likely that these would not have made it even if left with the original parents.  There have been no other instances of spindly in both surrogate and alternately fed tads.  To date I have had blue jeans tads raised by both Bastimentos and Chiriqui River pumilio.

6/5/2004 – One of the BJ tads being raised by the BJ parents morphs out.  It is hard to tell if this one is spindly also but there is definitely something wrong with the froglet.  There is some green fungus or something growing on it’s back.  I tried rinsing it off but it is pretty well attached.  The body just doesn’t appear to be well formed.  The froglet that was raised by the bastis looks a whole lot better even though it has spindly.

6/4/2004 – BJ tad with basti parent completely morphed out.  It appears to have spindly leg.  I have had spindly in the past with tads raised by the BJ parents so it could be coincidental.  The tads from same clutch being raised by BJ parents are almost ready to morph out.

6/3/2004 – Placed another BJ tad (5/22/2004) that has to date been raised on d. auratus eggs in the same cup where the spindly froglet resided.  Tad is only slightly larger than when it hatched.

5/13/2004 – At the time I put the BJ tad in with the bastis the BJ parents transported 2 tads of their own from the same clutch.  The tad being raised by the bastis seems to be developing at the same rate as the tads being raised by the BJs.  No other basti tads noticed at this point.

4/21/2004 - Blue Jeans tadpole deposited into cup that was currently housing a basti pumilo almost completely morphed.  Morphed basti removed and BJ tad deposited in the morning.  In the afternoon of the same day I noticed the basti female had already deposited a group of food eggs in the cup.

Manual placement of Blue Jeans tadpoles

5/22/2004 – Made my first attempt at manually attaching a BJ tad to a basti female using an eyedropper.  I put the female in a small Rubbermaid box with just a bit of water.  I then sucked up the tad into the eyedropper and dripped it onto the bastis back.  It took several attemps but I was able to get it placed.  It wound up being more towards her head than her back but it looked like it would stay.  I was wrong though, when I moved her back into her enclosure it fell off, so obviously it wasn’t truly attached.  Not surprisingly I could not find the tadpole.  Next time I will wait longer once it is place to see if the tad will really take hold.

5/22/2004 – Placed two BJ tads in film canister used by bastis as an egg laying site.  After three days I checked the canister and found only one tadpole.  I checked all of the cups and no tad had been transferred so I am assuming it died and disintegrated.  The remaining tad was transferred to a container to be raised on D. auratus eggs.

5/23/2004 – Second attempt at manual attachment of BJ tad to basti female.  This time I got it on the back and waited about 20 minutes.  When I came back the tad was in the film canister I had captured her in that was placed in the Rubbermaid.  There was a small amount of water in the canister but I don’t know if she placed the tad or it simply fell off.  Third attempt I got it on her back, waited a couple of minutes and got her back in the enclosure without the tad falling off.  15 minutes later the tadpole was not on her back but amazingly I found it on a piece of wood in the enclosure.  I managed to pick it up off the wood using the eyedropper and I deposited it into one of the cups that was most used over the past year for rearing young.  As of 6/2/2004 I have not yet seen eggs deposited in the cup for this tadpole.  Does not appear that the tadpole is really grabbing hold when manually placed.  Next I may try with the male or with a different female, although I am out of tadpoles at this point so I will have to wait for the next clutch.

8/15/2004 – Bastis have laid a clutch of eggs that appears to be infertile.  I put a BJ tad in the canister with the eggs.  After a week the tad has not been deposited.

9/24/2004 – BJ tad #10 from 9/3 currently being raised on alternate eggs moved into cup in Almirante enclosure.  The Almirante tad died but there were still eggs in the cup.

11/2/2004 – Surrogate BJ tad #10 morphing has all 4 legs, looks good so far.  Does not appear spindly.

11/2/2004 – BJ tad #17 moved to almirante cup where #10 just morphed from

Conclusion – After successfully using the surrogate technique for about a dozen pumilio and having a success rate of almost 100% I think that this is a viable alternative at least for pumilio.  In addition I have raised 6 or 8 pumilio tads using D. auratus and other dendrobatid eggs.  The success rate using other eggs is currently around 50%.  More tads need to be attempted to really draw a conclusion but the results are promising.  Furthermore I have proven that d. pumilio will attempt to raise d. histrionicus tadpoles or likely any other species tadpoles provided they display the behavior (ie - tadpole dance) that egg feeding tadpoles display.  Obviously a few tadpoles is again not really enough to draw conclusions but it shows that pumilio do make the attemp to raise other species tadpoles.  It is likely that the case of spindly had little to do with the fact that surrogate parents raised the tadpole and more to do with the host of other parameters that can cause spindly.  I have also had three tadpoles (2 basti and one BJ) raised by a single basti female and the 2 bastis morphed out perfect but the BJ morphed with spindly.  This, to me, gives a lot of weight to my theory that spindly has more to do with the parents than any diet or other parameter of raising the tads. 

F.A.Q

Q. Are the eggs that you feed fertile?

A. Maybe, maybe not, I pull them as soon as possible after being laid and remove the yolk from the egg case and feed them immediately after (or freeze).

Q. Can you freeze the eggs for later?

A. I have fed frozen eggs but never exclusively.

Q. How many eggs does it take to morph a pum?

A. Would depend on the type of host eggs I'm using and I've never counted.