[Guest]

i have a total noob question...

for frogs that like laying eggs in bomelaids, why is this natural? i imagine that if you didn't remove them (as everyone seems to do) the tadpoles would end up in this tiny cup of water unless displaced to a larger body of water. and i would think that this tiny body of water's quite unstable in a natural environment (wind, animals, etc could easily brush by it and knock the eggs/tadpoles and water out).

so in their natural environment, do frogs use bromelaid-type watering holes for laying their clutch, or is this just something that the hobby has taken to?

thanks,
sam

 

[Schism]

Its much easier for a frog to keep an eye on their tads/eggs if their in a little brom, not a pond. Its predator free, and the odds of an animal are much less of it knocking the tad out and something eating the tad in a big pool. The tads are normally transported by a parent to a bigger body of water once its necessary. Then, their on their own.

 

[bbrock]

As Bill Duellman, reknowned herpetologist, writes in the introduction to several of his books. The typical life history of frogs that lay eggs in ponds and then leave the eggs to fate is not really so typical. The majority of frog species live in the tropics and in wet environments, there are many benefits to laying eggs on land and either transporting the tadpoles or allowing them to drop in a suitable body of water which is small and predator free as the previous post explained. Dart frogs actually carry their tadpoles on their backs and haul them to suitable places to grow. Often these suitable places are those tiny cups of water you are wondering about. In the grand world of frogs. Dart frogs are not so strange afterall. It's those bullfrog that are weirdos.

 

[Guest]

wow.. that's fascinating behaviour... so that explains why they only seem to lay a few eggs per clutch.. because they actually care for their young afterwards? that's some pretty unusual behaviour for such small reptiles...

pretty cool... so do people with water features (such as a pond) actually get to witness this behaviour? and the tadpoles can mature on their own in the pond?

it's pretty frustrating for me right now b/c i'm dying to get started on my terrarium, but my old tank's back home and i won't be able to pick it up for a few months before i get cracking... but this forum definitely is helping me prepare before i dive in..

thanks
sam

 

[bbrock]

It gets much more fascinating than just toting tads around. You will here people talking about egg feeders. These frogs are difficult to breed but they take parental care to the ultimate in amphibians. After the tads are carried to water, the female visits the tads every few days and deposits an unfertilized egg which is almost the only food the tads are known to eat. Then there are the facultative egg feeders where the male places a tad and continues to court the ladies at the edge of a tadpole's little pool. If he is successful getting a female to lay an egg, the tadpole gets a nutrient rich meal. If the tadpole had died, the male cares for the egg and gets a new tadpole out of the deal.

As for witnessing this behavior in captivity. Yes, if the vivarium is set up right, they can do the whole show right in front of your eyes. In fact, the egg feeding behavior was discovered by observing frogs in vivaria. Any question why these guys are so addictive?

 

[Ed]

I thought the ultimate parental care in anurans was by Nectophrynoides liberiensis and N. occidentalis in which the eggs are retained until they hatch and are then subsequently fed via oviductal secretions.

Obligate egg feeding does not look to be that rare and has evolved in a number of genera.

Ed

 

[bbrock]

I thought the ultimate parental care in anurans was by Nectophrynoides liberiensis and N. occidentalis in which the eggs are retained until they hatch and are then subsequently fed via oviductal secretions.

Obligate egg feeding does not look to be that rare and has evolved in a number of genera.

Ed

Hmm, we have a challenger and I see I slipped. Normally I say that obligate egg feeding is the most "complex" parental care known in amphibians. For complexity I would still give the egg feeders the nudge. But "ultimate" yep, that's open for another interpretation and the Nectophrynoides are probably at least a tie if not on top. You do keep people on their toes Ed.

 

[Ed]

There is at least one frog that has obligate egg eating tadpoles that doesn't exhibit the complexity of care that obligate egg feeding Dendrobatids demonstrate. Female Osteocephalus oophagus returns in amplexus to the same bromeliad as the first egg clutch was deposited and deposits clutches of eggs at 5 day intervals. The tads are kept in groups and apparently only one deposition site is used by the female. Each tadpole can swallow and slowly digest over 100 eggs.

Ed (grins)

 

[*GREASER*]

Frogs from the tropics have developed many unique ways to raise and develope there young because of the large # of different species all competeing for mating sites. The amount af amphibian diversity is alot stronger in tropical regions then it is in the states so,mass breeding sites in ponds that we are very familier with woldnt be very practical for that many amphians all breeding in the same waters. Frogs depositing tads in little pockets of water is just one of the many alternative ways for raising young frogs have developed tp compinsate. Some take tadpoles into there mouths and the tads develope into froglets right inside the vocal sack of the male. Others have pockets in there back tads are raised in. Others build foam nests to keep there eggs moist. And there is a species that builds a little hut out of mud to keep there eggs and tads moist and there are even species that uses straight development where the tad stage is completed within the egg and a fully developed froglet comes out of the egg.