We are excited to share that we have finally been able to start our breeding project with this species after many years of keeping these guys (luckily they have a very long life span when taken care of properly in captivity, 10 to 20 years!) We were very excited to receive our first couple of eggs from one of our pairs on February 15, 2022, and what a great Valentine's Day present that was!
I wanted to share a post about the development stages of the egg, which can take as long as 25 days, and as short as 14 days, depending on the specific dart-frog species that you are working with, and the temperatures at which you keep them. Our Robertus Dart Frog eggs takes 21 days to hatch. The temperatures we keep ours at is 75F-77F during the day and 72F or 73F at night. They are kept on a shelf that receives a regular day and night light cycle.
It can be very exciting and also nerve-wracking to watch the tadpoles grow inside the clear egg-gel as a first-time breeder, so I wanted to make this post to help put people at ease during this time-period of your breeding project!
On Day 2, there is no visible changes to the eggs that can be seen by the naked eye, but usually by day 2 you will know whether or not the eggs are viable. If they are not, then they will turn gray, and start losing their round shape, when compared to the rest of the eggs in the clutch:
There are no other changes that are visible to the naked eye until Day 7 here at PanTerra Pets. On day 7 you can see the beginnings of the development of a line across the sphere of the egg, which will eventually grow into the tadpole, so this is the very beginning of the tadpole's body forming:
We have made a lot of progress between Day 7 and Day 9. In the picture below, you can see the tail has really started to grow, as well as the external gills (lungs). In the wild, Tinctorius dart frogs lay their eggs in oxygen poor conditions, so the long filamentous gills are necessary, to ensure that there is enough time for CO2 and O2 to diffuse across the lining of gills to the jelly, while the tadpole is still forming in the egg:
On Day 11, you can start to see the familiar shape of a tadpole face beginning to form, and the eyes beginning to form. The external gills are still elongating and branching out, but soon they will start to atrophy, as the tadpole will eventually need to switch to internal respiration to breath:
Not much difference to the naked eye between Day 11 and Day 13, except the external gills seem to finally be beginning to shrink a bit, and the tail is still getting longer:
On Day 15, something is beginning to look off with the tadpole on the right. While the one on the left's body seems to be taking the shape you would expect from a tadpole, the shape of the one on the right has not changed much since Day 13. Also, the external gills seem to be much too small, in comparison to the one on the left:
On Day 19, it became clear that the tadpole on the right did not make it, as the body is beginning to gray and decompose a bit inside of the egg gel. The tadpole on the left continued to grow and take on the familiar shape of a tadpole between Day 15 and Day 19:
On Day 21, it is clear that the remaining tadpole has begun to hatch, as the egg is starting to look like a deflated balloon around the tadpole. Dart frog tadpoles hatch by releasing an enzyme from a specialized gland that causes the wall of the egg to dissolve, making it easier for the tadpole to free itself from the egg:
Day 22, the tadpole has hatched, as you can clearly see the remnants of the egg gel beside it in the petri dish:
At this point you still want to leave the tadpole in the petri dish for a few days, and place a small piece of Indian Almond leaf in there, just in case they start wanting to munch. However, they do not move much or eat for 3 to 5 days after they hatch. Once the tadpole becomes more active, you can move it to it's own grow out container.
We use 24 oz deli cups for our grow out containers, with an inch and a half of water. The water should be spring water or RO water, and should be "steeped" with an piece of Indian almond leaf for at least a week prior to putting the tadpole in there. Steeping the water with Indian Almond leaves is beneficial to the tadpole, as the tannins from the leaf inhibits fungal and bacterial growth in the water, while also allowing algae to grow on the leaf, to create a natural food source for the tadpole! The only other thing we put in our tadpole grow out containers is a sprig of java moss.