Wow, that is very interesting.
This was written in approx. 1990SPINDLY-LEG SYNDROME
Dendrobatid breeding has been plagued by the spindly-leg syndrome in recent years, in the U.S.A. and Europe as well as in Britain. Breeders have been very disappointed to find, after spawning their frogs and carefully rearing the tadpoles, that they develop this condition, necessitating euthanasia immediately after metamorphosis. The symptoms are small and ineffective forelimbs, though usually these are perfectly formed. Conversely, the hind limbs are normal. The causes of this condition have been debated and many varying reasons for its occurrence have been suggested. The have included a lack of some factor in the diet of either the parent frogs or the tadpoles, an incorrect environmental parameter, or genetic problem. I have discounted the possibility of the syndrome being genetic in origin as it has occurred in clutches from frogs producing previously healthy larvae, occurring only after intensive breeding. I have also discounted the environmental factor, as I find it hard to believe an environmental parameter occurring in breeder's vivarium but not in the wild state, to result in such handicapping condition. As the forelimbs are the last to develop in the process of metamorphosis, this implies a lack or depletion of some factor that has been exhausted in the previous developmental stages. The larval diet consists generally of good-quality fIsh-food. Whilst not a natural diet mimic, this food should provide all possible nutrients including minerals or all but one. The natural larval diet of non egg-feeders must consist of decaying plant and insect matter (detritus feeders), these items falling into the water body in which the larvae are living, be this a living bromeliad in the treetops, mud puddle on the forest floor or the water in a discarded Coke can. It is possible that the female frog supplies the necessary developmental factors since the adult diet is far less restricted an, thus vital vitamins and minerals may be passed on via the egg yolk. I do not feel a lack of vitamins is responsible since I as well as others who have experienced this syndrome dust livefood will multi-vitamin preparations. My search for a missing factor led me back to my biology text books. The development and metamorphosis of the tadpole into a frog involves complex, morphological changes that are controlled by hormones. These hormones promote the development of certain cells to produce the new limbs and organs of the frog. The main hormone concerned with this cell differentiation is thyroxine, produced by the thyroid gland. Thyroxine contains iodine. If the diet of the parent or the tadpole were deficient in iodine, then there would be a deficiency of thyroxine, the hormone responsible for metamorphosis. There may be enough thyroxine for development up to a point, but not enough for the later developmental stage, that of forelimb growth. I have started to use the iodine nibbles used for cage birds, added to the tadpoles' water and also dusted on the food for adult frogs. In a batch of D. tinctorius that had previously shown 100% offspring with spindly-leg, those tadpoles that had not started to develop limbs prior to iodine addition have developed into perfect frogs. I am still investigating iodine deficiency and would like to show recurrence of the syndrome when iodine is discontinued. However, the immediate correction after the addition of iodine suggests strongly that iodine deficiency is the cause of spindly-leg syndrome. STEVE HALFPENNY
In my colony of D. auratus West Coast I must lose some 60% of larvae to spindly leg. It is particularly frustrating because this insidious condition only shows itself during what amounts to be the last five minutes of tadpole's development. It is sad enough to have to dispose of a young tadpole but I find having to dispose of a young frog just a it is showing its first beautiful colours even more distressing. I have tried everything I can think of to try to counteract the effects of this condition. Frozen foods for tropical fish; live foods; dried foods; mineral supplements as well as plain cuttlefish. Bearing all this in mind, then, I'm afraid Steve Halfpenny's idea of iodine supplement did not come as an earthshattering revelation to me. I rang one or two people up to discuss the idea with them and, not surprisingly, they shared my scepticism. However, not wanting to put a damper on things before giving it a fair trial, I proceeded to try out Steve's idea on my current batch of ten larvae. They were a couple of weeks old, from two different spawnings, but still do not have their hind legs. They seemed ideal candidates for the trial. I looked after the tadpoles exactly as before except that, after each daily water change, I added to each container a couple of droppers-full of ground iodine block as manufactured for cage birds, mixed with a little water (Johnson's Iodised Condition Pek [sic]). Some of this sank to the bottom in a fine powder, while it seemed clear that a proportion had dissolved. The food was, as before, TetraMin flake (type: Staple food, yellow drum, dark brown lid); the Tradescantia shoots were still present as before. I kept rigidly to this regime... and waited... and waited. I finally got to the point where the first larvae were due to push through their front legs. Up to this point, their development had been completely as it had been in hundreds of larvae before them. Good appetites. Good growth rates. In other words, text book offspring. Out of ten larvae, I expected to lose at least six. Imagine my surprise when, one by one, the larvae developed absolutely normal, healthy front legs. I have a 50% success rate with these at the moment, and don't doubt for one minute that I will have similar successes with the remainder. I have several batches of eggs incubating at the moment, and can't wait for another chance to try this technique, just to make sure it isn't just
a fluke. I'm now sure in my own mind that it is not. Suffice it to say that my thanks must go to Steve for his observations - but I can't help but ask myself: having tried just about everything I could think of, why did I not think of iodine myself. Just goes to show... JOHN SKILLCORN
Ed, you obviously know a lot about frogs (amphibians in general) so I must ask, where do you work? My guess is a zoo.Okay I'll go over the break down and you can see how we narrowed it down to the filter.
Kyle, where do you get your RO Right?I have since switched to reconstituted RO (RO Right) and have had great results.