T. marmoratus larvae problems

I've got loads and loads of T. marmoratus larvae at the moment and about two weeks ago I moved two large ones (with small hind legs) into little containers with shallow water. They are doing well. About a week ago, I fished out some smaller ones (no hind legs) and also put them into individual tubs. They get a water change every day with water from the tank. I feed them artemia. The bigger ones also get little worms. All of these are doing well. The smaller ones turned lighter colour within a day or so after being taken out of the tank into the much lighter environment.

Then a couple of days ago I took more of the smaller larvae out of the tank and put them into the tubs with the previous batch so now there were two larvae per tub (I did this to get better use of the artemia and would separate them later). They fed well on the artemia, afterwards I did a water change (same water as the tank they came out of). The next morning three were dead. They still looked very dark. The light ones from before - in the same tubs - were fine. Since then I moved all of these back into the tank because they were all looking unwell. I'm not sure if they can recover but hopefully this gave them a chance.

Does anyone have an explanation for this? Despite being the same size, the second batch just couldn't cope with the change. In it self I wouldn't find it so strange because it is a huge change for such a tiny creature. But there is the other group, fished out of the tank just a couple of days earlier, in the same environment, feeding on the same food, which adjusted with no problems.

I've always found T.marmoratus to be quite delicate larvae. I'm not a big fan of raising newts in small shallow containers as there's not enough water to buffer slight changes in chemistry. I understand that when feeding BBS you need as much control over the feeding and water as possible, small containers help this.

I've lost many a larva through water changes so now my favorite method is to remove the parents once they've finish laying and leave the larvae in a large, mature setup with lots of plants. You'll get fewer losses. I even hesitate to do water changes when raising larvae in a single large tub, just the occasional top up if required. This method probably isn't ideal for BBS feeding though so you'll need a source of daphnia, tubifex etc.

When in raise my T. Marmoratus. I use water from their parents tank and feed them daphnia until they can feed on mosquito larvae and tubifex. This works for me most of the time. Also i don't do water changes regularly

When I reared a large number of Alpine newt larvae, I had similar problems when trying the small-tub method. In the end I used RUBs with lots of plants etc set up as stable aquaria. I fed BBS in these tanks and just hoovered out excess with an airline siphon or turkey baster. The dead BBS tend to stick together so it only takes about 5 mins per tub. It actually worked out as much less effort as well being a more successful rearing ,method. Some of the larvae stayed in this setup until adulthood!

Thank you for the answers. After the incident described all the remaining larvae are doing well.

Chris, did you notice a lot of missing limbs etc. when you raised the larvae together?

The last batch I raised was in a tub with maybe 2' of water and lots of plants. The water came from the parent tank and was topped up from there too. I topped up food with microworm, brine shrimp and various watery insect from the pond. I did do daily spot cleans of any dead insects as they did tend to clump together. When big enough they had white worm and then chopped earthworms
I didn't notice many missed limbs, but they are cannibalistic so lost a few from that.

Just to be clear, I was talking about alpine newts, but I only had issues with limb loss if I was late with feeding, and only in younger larvae, which have spindlier legs, rather than in older ones that have more adult-like legs.

It sounds like Julia's approach is essentially the mature-tank method. I think the addition of lots of plants does help a lot, as well as having just enough water to avoid swings in chemistry with rotting food and then sudden replacement with fresh water (even if it is from the parental tank).

C

Hi,
Has anyone tried vinegar eels?
I like to feed them to fish fry. They are better than microworms or BBS because they don't die in the water. Nutrition is not the same, I use BBS later.
Inever tried them with amphibia larvae.

Best,
João

Sorry I don't know anything about vinegar eels.
I am raising the larvae in small tubs mostly to avoid limb losses. I had no problems with this method last year but one of the individuals didn't regrow two toes so this year I am planning to separate them more. I have noticed a lot of missing legs and toes in the individuals left in the large tank. Unfortunately I don't have access to daphnia so I only feed the small larvae BBS and the larger ones white worms, defrosted bloodworms and small earthworms.

T. marmoratus have such long digits and limbs, so it makes sense that they get nibbled on more than in alpines - that and the 'cristatus group' voracity! I hope you get these guys through ok.