Larvae Illness

I have some larvae that are about half a week old and exhibiting signs of some stange illness.

First, their gills shrink down to stubs, and then they develop a weird bump or bubble on thier underside between their head and chest. Sometimes this causes them to roll onto thier sides. Some of them also developed fungus, but I can't tell if this is post mortem or not. If their gills start shrinking, they are usually dead by next morning. I am not sure if the disease is contagious or not, but I separate ones looking ill as a precaution. Some of the larvae also hatched looking slightly underdeveloped with very large bubbles in the same place. They swam on thier sides and managed to live a few days before dying. These are eggs from my female's first clutch, and I've heard they have a higher mortalitly that most, but I'm not sure if its supposed to be like this.

They are being kept in small containers of water from my adult axolotls tank(water parameters look fine), about five larvae to container. Every day I change 100% of thier water and scrub the inside of the containers with hot water. I have tried salt baths on a few, and fridging on some other ones. Niether of these have seemed to help much. None of the afflicted eat very much either. I know this isn't the same thing as larvae that float because they haven't started eating, I've seen that before with the last batch of eggs I raised.

I'm just wondering if anyone has seen anything like this before?

P.S. I also have one "spinner", his entire body is curled slightly and he only swims in circles. Has there been any solutions for little guys like this?

Thanks For Your Help!

Hi Gamachii,

Internal bubbles can be caused by not allowing degassing (aging) of fresh water before it is used for water changes. Can also be caused by bubbles in the digestive tract (either ingested, or forming there by other causes). If the bubbles are in the digestive tract, the larva will often expel the air and recover. Move the affected larva to very shallow water with lots of aquatic plants so that it can rest comfortably.

Floating – Sometimes larvae will float, even in the absence of visible internal bubbles. This is probably a symptom of stress.

Fungus – If the larvae start to get fuzzy BEFORE they die, consider the possibility of fungal attack. However, fungus rarely attack larvae unless they are under stress from other causes.

Spinners – This is caused by an occasional genetic defect. Some spinners turn in circles, while others swim in corkscrew fashion. It is possible in some cases to raise a spinner to adulthood, but they are likely to eat poorly, and likely to drown at metamorphosis, so it is probably better to euthanize them.

This link will provide you with a lot of detailed answers.

http://www.caudata.org/cc/articles/why_larvae_die.shtml

Also consider a variety of microfood due to different feeding habits of different larvae. That may help with the more inappetant ones. http://www.caudata.org/cc/articles/microfoods.shtml

Cheers

This being the female's first clutch could be a factor. The type/amount of food may also be a factor (you didn't say if this occurred before you even started adding food). I would also say to try keeping some of them in fresh dechlorinated (and aged) water, rather than the tank water.

I would also suggest a possible alternative rearing method. Set up a tank or tub with a substantial amount of live plants, plus various rocks or ornaments from the adult tank. Put a few larvae in there and let them go with minimal care, just a bit of food.

If one rearing method doesn't work for you, my advice is to try other things until you hit on a method that works for you. Bubbles and high mortality are indicators that something isn't right, but it's hard to say what.