Alternatives For Raising Obligate Egg-Feeding Tadpoles

Over the years I have been trying to come up with solutions for artificially raising obligate egg-feeding tadpoles, specifically the O. histrionica and O. 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 histrionica 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.  Several years ago I had an idea or theory I had that O. histrionica tadpoles could be raised by O. pumilio.  O. 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.  O. histrionica are unfortunately still very rare in the hobby.  In addition O. histrionica are not nearly as prolific in captivity as O. pumilio.  My thought was that if you could take a prolific and somewhat widely available egg-feeder like O. pumilio and have them raise the tadpoles of the “not so prolific” and very unavailable O. histrionica, you may be able to increase the production of O. histrionica in captivity to a level greater than that gained by simply letting the O. histrionica adults handle all of the parental duties.  At the very least the O. histrionica 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. My first attempts were to try simple surrogate parenting of two different morphs of O. pumilio.  The first hurdle in my mind was to see if O. 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 brought me to experiments using this technique to raise more of the Blue Jeans morph of O. pumilio, which in my experience so far has proven less prolific in captivity than the bastimentos morph.  It is worth noting that in addition to bromeliads I use plastic ½ to 1-ounce condiment cups glued to driftwood and other items in the enclosure for the O. pumilio to raise tadpoles.  I use bromeliads also, but have trouble keeping them healthy and retaining water in the terrariums so I started using “cup trees” or simply placing these cups in the terrariums, and this has proven quite successful for me.  I also have several tanks where 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.

It should be noted that I have had different degrees of success with different species and even different morphs within species, so when I say I have had success, it doesn't mean with all morphs or species.  I will list the different morphs and degree of success later in this document.

Using Other Dart Frog Eggs

The first method that has proven fairly successful is using the eggs of other dart frogs.  Prior to obtaining a good number of pumilio and other obligate egg feeder pairs I had several tinctorious tribe frogs.  Among these were d.tinctorious, d. auratus and d. truncatus.  I would pull recently laid clutches and "de-nucleate" the eggs for feeding of pumilio and histrionica tads.  I would use the end of a pippet to catch the yolk and kind of scrape the yolk from the gel as the tads in general could not get to the yolk if the gel was left intact.  This proved to be more difficult in some species and morphs than others, but d. tinctorious (infer-alanis) and the yellow form of d. truncatus were some of the easier to work with.  Occasionally you will break a yolk and it pretty much dissappears, you'll see.  I would feed maybe 2 or 3 eggs a week depending on the size of the tad.  I lost a lot of tadpoles in the first couple of weeks, many would bloat up and then die.  I did however morph a few pumilio during this time period.  Once I had a good number of pumilio and histionica pairs clutching eggs, I switched to starting the tads on the smaller pumilio and histrionica eggs, preferably eggs from the parents themselves.  Then when the tad had some size, say after a month, I would use the tinc eggs if I didn't have other eggs to feed.  This proved to be much more successful in the number of froglets morphed.  I have to thank the guys at Black Jungle for this tip.  I basically feed as much as the tads will eat though it is more dictated by what frogs are clutching and how many eggs I can harvest.  I have had dry spells where I have gone weeks without any eggs and so far when this happens the tads will morph eventually (when the food returns) but the froglets aren't as robust and usually don't make it very far.  When I have a good supply of eggs the froglets morph out strong and seem to do well.  I have had many grow to adults are now several years old.  As stated before, it depends on the species and morph as to whether or not I had success.  I have had good success with blue jeans pumilio, bastimentos pumilio, carmel or saddle back histrionica, and lita sylvatica.  I have not had any success with bullseye histrionica.  The bullseyes would always morph with spindly or no front legs at all.  In general if the animals are producing young on their own, I don't try to raise additional animals as there are usually tads of species/morphs that are not producing that I will try to work with.  The exception was with blue jeans as when I started all of this the parents were producing a couple of froglets a year already.  I managed to produce 12 in the same timeframe. It is worth noting that when artificially feeding pumilio and sylvatica 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 histrionica 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.

Using Surrogate Parents

The second method I have used is surrogacy.  Basically this is having a "good parenting" frog such as bastimentos pumilio, surrogate a tad that is not their own.  In the beginning I didn't have much success but after several attempts, all of the surrogates were morphing out successfully, with the exception being bullseye histrionica.  In order to do this you need access to the parents deposition site.  This is where the plastic cups come in handy.  Much easier to see the tads and access them as opposed to being in a bromeliad.  I would use a pippet to transfer/swap out the tads.  In general I would have to sacrifice a tad for the surrogate but also had one instance where I replaced a morphing froglet with a new tad and the parents took to the new tad and raised it to a froglet.  I also tried several times to manually place a tad on the back of both male and female potential surrogates, but this didn't really pan out.  The tads never really latched on and they eventually were lost in the substrate.  Again, success depends on individual tads/species/morphs, but I have had success with bastimentos raising blue jeans pumilio and el dorado pumilio raising lita sylvaticus as well as other mixes of species and morphs.

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.  More tads need to be attempted to really draw a conclusion but the results are promising.  Furthermore I have proven that O. pumilio can raise O. histrionica or O. sylvatica 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 can successfully 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 but I've never counted.  Typically it is dictated by what I have on hand and I pretty much feed as much as I can harvest.  If I had to guess I would say average 8-10 pumilio sized eggs a week.

Updated 1/10/2011

Forward

The information contained in this article comes from my own experience with several forms of O. histrionicus and O. sylvaticus as well as the experiences of several other breeders who have successful bred and propogated other forms of O. histrionicus as well as O. lehmanni and O. speciosus.  These are things that have worked for me and what I have used to attain a bit of success with these animals.  The information contained here is by no means the only way to have success, just what works for me and has worked for others.  The reason I separate breeding and propogation is that it is fairly easy to get O. histrionicus to breed and lay fertile clutches.  The problems come in getting the females to properly raise the tads to froglets and then keeping the froglets alive for more than a months or even weeks. 

If you have any information that supports or refutes the information or theories contained in this article, or would like to contribute your own experiences with the histo group, please send information to

Breeding and Propogation of Oophaga Histrionica and Sylvatica

One of the most sought after dart frogs in the hobby is O. histrionicus.  It is one of the few dart frogs that has not been captively bred in large numbers.  Most animals that end up in the hobby are smuggled wild caught animals that require a great deal more care than most dart frogs.  As with most wild caught frogs, they usually come in stressed and loaded with problems.  Even wild caught animals are hard to come by these days because many of the histo forms come from areas in Columbia, with the exception of some found in Ecuador.  Even smugglers are afraid to take the risks associated with going into the jungles of Columbia because of the drug dealers and civil unrest in that area of the world.  It should be noted that O. sylvaticus, O. lehmanni and O. speciosous are very closely related to O. histrionicus.  In this article when I mention behaviors or husbandry techniques of O. histrionicus, in general they also apply to O. sylvaticus, and to a lesser degree O. lehmanni and O. speciosus.

The primary reason there are not large numbers of captive born animals is that O. histrionicus tadpoles are mandatory egg feeders.  After deposting tadpoles into a suitable body of water, usually the axil of a bromeliad, the female will periodically visit the tad, depositing a "food egg" into the axil for it to feed on.  This "food egg" is basically an infertile egg that lacks the protective gel covering found on fertilized eggs.  This is the only thing histo tadpoles will eat.  Other dendrobatid species exhibit similar behavior, O. lehmanni, O. speciousus, O. pumilio, R. reticulatus and O. granuliferus to name a few.  Of these egg feeders, R. reticulatus tadpoles are the only ones that in captivity will feed on other food items such as fish flakes.  R. reticulatus and the frogs in the imitator "tribe" are considered non-obligate egg feeders, meaning that the parents will raise the tadpoles in a similar manner, but the tads may also be raised on food other than eggs from the mother.  It should be noted that O. pumilio have been successfully propogated in fairly large numbers in captivity.  However, the techniques applied in successfully propogating O. pumilio do not necessarily ensure success with O. histrionicus. 

Terrarium Setup

Perhaps the most important thing in setting up a terrarium for O. histrionicus is the most obvious, bromeliads.  The animals need a place to deposit tadpoles that has standing water.  In the wild, the axil of bromeliads is the nursery of choice.  It is my opinion that there should be more than just one bromeliad in the tank so that the male has many choices.  The theory being that the more choices, the more likely he will find a suitable axil, and the more tads he will transport.  Hopefully then the female will raise more tads to froglets.  The rest of the terrarium setup is the same as any other dart frog enclosure (see article for more info on general setups)  Egg laying may occur on the leaves of the bromeliads, but in my experience all clutches were laid in an empty film canister or in a petri dish under a simple breeding hut.  In recent years I have been using 1oz. condiment cups for my pumilio to raise their tads and all have taken to using them like a bromeliad.  I have not tried this technique with histrionicus but would imagine they would use them as well.  Some people use misting systems to frequently mist their tanks in order to keep humidity at a maximum.  When I had productive Ecuadorian histrionicus I never misted the tank and they reproduced quite well.  I use a misting system now on my pumilio tanks but do not mist heavily.  I mist just enough to keep the cups from drying out, which winds up about 3-4 times a week and only for a minute each misting.  I have found that simply keeping an inch or so of standing water in the tank keeps the humidity at acceptable levels.  I don't think misting hurts anything but in histrionicus and pumilio I am not convinced that it really helps.  I now have most of my egg feeders on a misting system mainly for convenience.  One note on using condiment cups or other artificial deposition sites: I don't believe that bromeliads need to be flushed out necessarily or purposefully.  Usually simply adding water to the bromeliad or using a misting system will keep the water from stagnating too badly.  If you use condiment cups though, be careful and replace the water a couple of times during the tadpoles growth as you will find that fruit flies will build up in them and can cause the tad to die if it gets too bad.

One thing I have learned is that even if you have a pair, it doesn't mean they will be productive.  I believe that in a best case scenario the frogs get to choose their mates, and this mate may not be the one you decide for them.  I do not recommend putting these frogs in anything other than pairs.  Even with a large enclosure you will find that same sex frogs will battle.  I had 2.2 O. sylvaticus in a 340 gallon enclosure with plenty of bromeliads and visual barriers.  After about a year and a half I split them up as the males started constantly fighting once settled in to the enclosure.  I believe the larger the enclosure the better, but I have had success in 35 gallon enclosures as well as larger ones.  I know others who have had success in 10 gallon tanks.  As with many things in husbandry there is often more than one right answer.  One thing I do recommend is that new animals are put in tanks that have not been previously inhabited by other animals.  The reason is that some believe these animals to be more sensitive to the bacterias, toxins, etc of other darts/animals.  I addition once you have animals set up in a suitable enclosure, do not move them... ever.  If you give them to another breeder, give them the tank with the frogs, don't move them.  For whatever reason these animals are sensitive to being moved into new enclosures.  Once you get a suitable pair, expect fertile clutches of between 9 and 12 eggs approximately every two weeks.  This of course will vary by species and morph.  Some of my pairs are more seasonal than others.  This is similar to most of my other captive darts.  Most often all of the eggs hatched into tads and soon after the male would start transporting tads to the bromeliads.  I don't know exactly how many are successfully transported but I was only ever able to find two or three at any one time.  Froglets emerge in a similar timeframe to other darts, about two to three months before you see tads with front and back legs.  In any one period of time I will have between one and three tadpoles that would morph into froglets.  Others have had similar success rates in terms of number of neonates successfully raised by the females.

Raising Juveniles

This is perhaps one of the hardest parts of propogating histrionica.  In the case of my ecuadorian sylvaticus, over the course of about a year and a half, my female rasied a total of six young from tadpole to froglet.  The neonate histos are very tiny when they emerge, not much bigger than a neonate R. reticulatus.  I'm not sure how large histo froglets are in the wild, so I don't know if this small size is normal or not.  I raised my neonates on springtails until they were large enough to take small fruit flies dusted with vitamins and calcium.  The neonates survived in ranges from two weeks to six months.  None survived past six months.  Early on I would always pull the froglets as soon as they emerged from the water.  Now as with all my egg feeders I leave them in the tank with the adults until they are nearly full grown.  This has let to much greater success and to date I have successfully raised quite a few different histrionica and sylvatica.

There are several theories as to what can be done to further increase the survivability of the neonates.  Most have to do with diet, of both the adults and the neonates.  I can say that feeding the adults and neonates only springtails and fruitflies, dusted with a good vitamin powder, is actually enough to ensure some degree of success.  There are several other food options available that may help success rates.  These include parasitic wasps, small wax worms and pinhead crickets.  The key may lie in variety of food for both the adults and the neonates.  It is believed that the stronger and healthier the adults are, the stronger and more viable the tadpoles will be.  For whatever reason though, leaving the froglets in with the adults has seemed to make the biggest difference in terms of survivability.

Keeping Adults Alive

Another problem that I have had and others have experienced is the relatively short life span of these frogs in captivity.  Note that I am referring to wild caught animals only.  It seems that wild caught histos are particularly prone to problems even long after they have been through an initial quarantine period.  My adult wild caught histos lasted for about five or six years with no apparent problems.  The female was the first to go and the male about a year and a half later.  I had other males at the time that lived for a few years longer.  Some I wound up giving to others working with the same type.  Being wild caught I have no idea how old they were, but I have heard enough similar stories from others that it is probably not just old age that kills them.  One thing that may help is a longer quarantine period and annual "checkups".  Perhaps periodically sending stool samples to a vet to check for worms, protozoa, bacteria, etc.  One theory is that all potential foods in captivity and in the wild carry some types of protozoa and/or bacteria.  In the wild, these frogs have a variety of foods to choose from, but in captivity, we usually limit them to only a couple of different foods supplemented with vitamins.  Feeding them the same food type all the time may cause a build up of whatever bacteria or protozoa is present in that particular food.  Perhaps histos over time can be overcome by that build up.  Keep in mind this is only a theory and there is no empirical evidence to back it up.  In the future someone will hopefully be able to back this up or dismiss it.  Regardless, I believe that varying the diet of these and other dart frogs in captivity as much as possible is helpful.  I have also recently talked to others who have lost animals and they too have heavier losses in females than males.  One theory is that perhaps the females are not able to replace the nutrients given up during egg laying and/or egg feeding.

I have also had issues with CB adults dying after a year or so if not setup in a decent enclosure with a mate.  I have lost many adult cb animals that were set up alone in 10 gallon tanks for extended periods of time.  More recently I have tried to setup in pairs or trios in large (40 gallon or more) enclosures and eventually try to get down to m-f pairs. 

Food Substitutes for Tadpoles

It is my belief that finding an alternate food source for the tadpoles may be the key to raising larger numbers of these frogs in captivity.  Many people have done experiments with different foods and have had limited success.  Egg yolk from chicken eggs will sometimes be consumed by the tads but they never grow much and never morph into a froglet on this diet.  Experiments with eggs from D. auratus have yielded similar results.  Eggs were collected from D. auratus and the protective egg sack removed.  The inner yolk was then fed to the tads, who readily accepted the food, but again never developed into froglets.  Eggs from other frogs such as tree frogs were used in a similar experiment, however the tads refused to eat them.  So it appears that there is some key ingredient contained in the food eggs deposited by the females.  I would like to get an analysis done on these food eggs and get a breakdown of all the components and chemicals that are contained within them.  With that information perhaps we could come up with a viable food alternative.   One technique I have had great success with is using harvested pumilio and histo eggs to raise tadpoles.  Prior to having a lot of pumilio pairs I would use tinc and auratus eggs and had limited success.  Now that I have more pumilio and histrionica eggs available I have had good success with certain morphs.  Read more about this and using surrogates under the Alternatives for Obligates tab.

O. sylvatica (Ecuadorian Valley)

In the pictures above you can see a few of the neonates that I was able to produce in working with the Ecuadorian form of D. histrionicus.  Only one of six neonates came out with spindly legs.  The others looked quite healthy and fed on springtails and actively pursued and ate drosphila melanogaster when they were large enough.  As I said before, none lasted more than about 6 months.  In addition my female died about 6 months after the last froglets emerged. These were produced in the early 90's and were my first attempts at raising histrionicus (now these are classified as sylvaticus).

Bullseye O. histrionica raised with alternate egg feeding.

Bullseye O. histrionica raised with alternate egg feeding. Notice the frog is spindly.

Spindly leg bullseye.

Carmel or saddleback O. histrionica rasied by parents.

O. sylvatica San Juan froglet raised by parents.

CB adult O. histrionica saddleback/carmel.

O. histrionica bullseye raised by parents.

O. sylvatica Lita raised by O. pumilio El Dorado.

My name is Robb Melancon.  I have been working with dart frogs since the early 90's.  Prior to darts I kept several types of snakes, mainly boas and pythons.  I still love large constrictors but just don't have the time or room or to keep them.  I have redone this website to provide as much information as I can on keeping some of the more difficult species of dart frogs.  When I started keeping dart frogs almost 20 years ago, information was hard to come by and today it is almost information overload on the internet.  The problem is that with the advent of the internet and particularly internet forums, it seems everybody is an expert and knows the right way to do things.  The truth is there are several right ways to do things and sometimes what is claimed to be true, is just not so.  Not that this is constrained to the internet but it is more pervasive as anyone can easily and anonymously claim to be an expert.  What works for some people may not work for you and unfortunately a lot of what you learn will be trial and error.  I encourage you to do as much research as you can on the animals you intend to keep.  Just keep in mind that your source may not be the expert they claim to be.  I don't claim to be an expert either.  I learn new things all the time.  I do have a lot of experience and this site is a compilation of my husbandry techniques and what works for me.  Some of the things I say are facts and others are opinions.  I try to state this when possible, just keep in mind that many claim their opinions as fact.  Others will claim facts based on something that may have worked for them that may simply be mere coincidence.  If you know this going in, you will hopefully take a broader approach to your research.  I mean no disrespect to any other hobbyists or any of the internet forums, I just see bogus claims often enough to warrant giving my opinion.  I guess like with the old saying "don't believe everything you read" when researching on the interenet, look for recurring infomation, things that you read in several different places.  Good luck with whatever species you decide to keep and remember that as with any "pet", there is a commitment that you should be making to insure the well being of the animals you keep.  If there is one thing that seems to be a constant with good husbandry I would have to say it's consistency.  Be consistent in your husbandry routines and you will likely be successful.