Where did they go?

Leucistic Tank

Small tank

Well, it is a sure good thing that the axolotls were separated! The big tank now has four or five, maybe six, axolotls. The leucistics are hard to keep up with because they are still small and speedy, but I would estimate about ten now. The little tank has about three or four that I can see. All of them are small.The question now is why the axolotls remaining in the large tank are so large why the rest are so tiny comparatively. The immediate answer that comes to mind is cannibalism: eat the most, grow the most. However, there are no axolotls in the little tank where cannibalism has occurred with sizes comparable to the axolotls in the large tank. None of the leucistics have outstanding size either. Perhaps the size of the tank is a factor in the growth rate of the axolotls. Another potential food source is being experimented. Frozen beef liver cut in strips are eaten well by the larger axolotls, but not quite as readily by the small ones. It is also a great treat for the full-grown axolotls.

A few of the large axolotls

Moving up!

Gimongo! And two small ones for size comparison

It has been such an interesting few weeks! The superstars have emerged, especially the wild type we have named "Gimongo." There are noticeably fewer axolotls in the tanks; cannibalism definitely took its toll. However, many of the ones that are left are huge in comparison to before. Some are still smaller than the rest. The big tank has more, larger axolotls, whereas the smaller one has fewer, smaller ones. The wild types are definitely emerging as a power over the poor leucistics. The leucistic population is much smaller than it was during the last post. Since we want to ensure some leucistic axolotls survive, we took the father out of the small holding tank and sent him home to free up a third tank especially for the white babies. They were separated from the wild types and placed in this tank. The bloodworms ran out over spring break, so we tried feeding them amphibian pellets (the regular diet of the full grown axolotls). They recognized them as food and ate them. This means that they are nearing the adoption stage! It seems like they have grown so quickly.

Little Leucistic Tank

Big Changes!

The axolotls are growing so large! This past week has been a monumental one. The axolotls got moved to a larger, cleaner tank. In the move, we found six dead axolotls. These are the first known deaths. The survivors got their first taste of food that is not brine shrimp: live blackworms! These worms are really thin and long, so it was a formidable task for the baby axolotls to eat them. It would be like a human, unable to bite, slurping a string of wriggling spaghetti that is three times their size! The next day, fourteen of the larger ones were separated and a chunk of frozen bloodworms was placed in the container. When they thaw, these are about the size of a smaller baby axolotl. They also do not move,which means that the axolotls must hunt by smell, not by sight.

I haven't seen one of them completely eat a bloodworm yet, but some have tried, which is a definitely good sign. The brine shrimp hatchings have not been extremely successful, but now that the axolotls are taking larger prey, we can use store bought food. One bad thing about this growth, howpoint. I haven't seen them completely eat one another, but there have been reports. I have seen them nip at each other, however. It is sad, but we have to ever, is cannibalism. The baby axolotls start eating each other after a certain keep in mind Darwin's theories of evolution. I will try and separate the superstar ones today to ensure the optimal group of survivors.

Moving (with new legs)

The axolotls are growing healthily! Their water needed changing, and their tank was too small, so we decided to move them to a larger, cleaner tank. After siphoning water from the adult axolotls' tank and painstakingly capturing and releasing baby axolotls for hours, the job was complete. The babies are excited to be in their new tank; it is awesome to watch them eating (whereas the last tank was too crowded) and being able to see the entire population without stirring the water. The white ones are even relatively transparent!I know of one death and only a few eggs that haven't hatched. This is an extremely healthy, strong, orange-bellied group of neotenic amphibians.
On some, we can already see little front legs budding. This exciting milestone also begins one of the most treacherous examples of Darwin's research, however. Before reaching maturity, axolotls enter a cannibalistic stage in which they feed on their weaker brethren. We are currently debating whether to and how to split them up. It is the cruelty of the natural world. Hopefully, since we are keeping them very well fed, there will not be too many casualties. We are beginning an adult brine shrimp culture in another tank to keep up with our rapidly growing axolotls. Using a dark blue bottle, a tank of warm salt water, and our current brine shrimp hatching expertise, we should be growing brine shrimp within the next week.

Wait... white?

A speckled hatchling

This past week while feeding the babies, we noticed something. Some of the hatchlings were white, or at least lighter than the others. We didn't expect it; both the parents are wild type, or brown, axolotls. This means they must be heterozygous, or, they carry the white gene, which is recessive. Since the wild type gene is dominant over the white gene, the white

A white (leucistic) full grown axolotl

axolotls must have gotten two white genes instead of a white and a wild, like their parents. Using our knowledge of genetics, about one fourth of the babies should be white and half able to have white children. We are excited about the variety! The hatchlings are also growing quickly. They may be able to eat larger brine shrimp soon - we have been feeding much and often. They are growing healthily and are much larger and more outgoing than when they hatched. We think that some may have front leg buds already. Hopefully we will be able to catch one with some and take a picture under the microscope soon. They are so fast, and the more developed ones are faster.

Feed Me!

The babies are very healthy. Most have bright orange bellies, meaning they are full of brine shrimp.We usually feed them two large feedings a day so they will grow quickly. It is hard work to be sure they won't eat the eggs or shells of the shrimp, which could be fatal. We always have two cultures going, one new and one that is a day or two old. This ensures that if a culture fails, we will have a backup. We haven't changed the water in the tank - and aren't planning on it... the water in Lake Xochimilco has never been changed, the sponge filter is bubbling nicely, the water is chemically balanced, and there is no need to stress out the hatchlings. Some are getting quite large! We hope to see leg sprouts sometime early next week. Unlike frogs, axolotls grow their front legs first.   There is a variety of colors; we may even have some speckled hatchlings! Until next time, watch a video of the feeding frenzy that ensues after the brine shrimp are poured into the tank.

Half Hatched

Over the weekend, about half of the eggs hatched. Now, little axolotls are swimming around the tank. It is hard to see them unless you look really well because of all the leaves. They make them feel secure, though, so we'll leave them in for now. (no pun intended) I was able to round one up in a cup and put it under the microscope. Isn't it adorable? If you looked really closely, you could see the blood pulsing in its gills.

A baby axolotl under the microscope

Because of the new hatchlings, we decided that the goldfish bowl setup just would not do. Instead, we filled two bottles about halfway with fresh water and placed them on top of coiled heating wire. After letting the eggs hydrate for about half an hour, we added two tablespoons of aquarium salt. Then, we placed the aquarium tubes on the bottom. We have started one successful culture with this method and are hatching another. This morning, we put a few droplets of brine shrimp in the tank with an eyedropper.It was cool to see them swimming around with the axolotls! There are still occupied eggs in the tank; we are hoping for the rest of the axolotls will hatch today or tomorrow. Then we can have a lot of little baby brine shrimp swimming around and being eaten by a lot of little baby axolotls!

The new brine shrimp setup