larval axolotl feeding in wild..

[lims]

I was just wondering,, when one feeds larval axolotls with hatched plankton and the like, there is a high desity of food in the tub with them, so obviously they have no problems finding it.
In the wild, do they find areas of water with equally dense food suppy or do they move around alot more, getting what odd bits of food they can?

I ask this as I was wondering if axie larvae could be raised in a large natural setup, where I could forget about them and just drop food in, hoping they find it and keep eating..

 

[Bellabelloo]

Hi,
I accidently left some eggs in a tank of water ( newish ) and when I eventually got around to cleaning up I found a gang of larvae still alive, be it very small( this must have been a good 2 months later). I then decided to transfer them to a larger tank that I was using for their siblings food, this contained mosquito larvae and much later bloodworm and daphnia. Whilst their siblings where very light at this point ( yellow) all the ones out side where very dark . I had also noticed that the egg sacks when left in the water would 'catch' water insects..it appeared to be very sticky..these insects stayed alive until the larvae came to them and dined. I personally suspect that in the following days when the newly hatched larvae are less mobile the discarded sack plays quite an important role.

 

[oceanblue]

I think you can succeed with a large natural setup in a pond in the UK. Bellabelloo's experience describes early larvae. I was given 6 larvae 15-20mm long and they looked unhappy with curled tails in small containers, despite apparently suitable temperature and water temperatures, before I let them loose in pairs in 10 L outdoor tubs containing dwarf water lilies and lots of algae and at first daphnia and mosquito larvae. They thrived and grew through the summer at about 1mm a day. I was puzzled what they were eating as their bellies were full without supplementation until I examined their droppings which were very rich in planorbis snails.

Be careful that your large natural setup is a closed environment. Under UK law garden ponds are not the wild but rivers and streams are. Releasing axolotls into the wild is illegal under the wildlife and countryside act.

 

[Daniel]

I was puzzled what they were eating as their bellies were full without supplementation until I examined their droppings which were very rich in planorbis snails.

That's very interesting - could you give any further information on the observations you made?

As for the wild: I think that there certainly are areas where food density is quite high, for instance in shallow parts where the water is warmer - I assume that dapnia or similar little food will thrive there. Additionally in shallow water it's more difficult for carnivores to get a bite on the larvae...

 

[Jennewt]

Early stage larvae don't really need much to eat. If 3 or 4 daphnia swim by in a day, that's enough to keep them growing. When they get a bit older and need more to eat, either they are lucky and end up in an area with lots of plankton, or they cannibalize. The few that survive get the benefit of the food energy stored up in their siblings. It's a cruel world for larvae, but that's why axolotls lay 100s of eggs.

 

[oceanblue]

The snails are Planorbis planorbis, the smaller of the two common native ramshorn species "Common and widespread in most lowland areas of Britain and Ireland" - I suspect they range across Europe too. The books say they may reach 12mm diameter but mine rarely exceed 4mm.

They originated with gravel from a local stream used to setup a demonstration tank (for fish not axolotls) about 15 years ago: they are present in every tank or tub I keep. I used to view them as a problem to live with (they drop off plants if disturbed, hide in the gravel and breed small, all of which makes elimination by hand removal impossible - I tried years ago) but now regard them as an asset. The tubs used were rich in algae, daphnia and mosquito larvae for several weeks but then appeared to be devoid of obvious food. I had six larvae so I put out two first to see what would happen and after a couple of weeks they looked so much better than the others and had grown faster so I put the other four out.

I was worried they needed supplementary feeding but the axolotls continued to look healthy and rounded with lots of dark intestinal contents visible in the leucistic ones. I caught two axolotls and waved small lengths of worm in front of them but they either ignored them or spat them out. I kept one in a small container overnight and crushed the droppings. They were full of shells. I returned them to the tub.

The two largest axolotls are now in a very heavily planted tank which has a muddy bottom, no filtration and excellent water chemistry that used to contain 30 Platies before I evacuated them to make room for the axolotls.(photograph attached) It has a 1% water change every day with artificially hardened water. I had given up crushing snails in this tank so there were lots present.

I didn't feed the axolotls at all in the tank for the first two weeks and the snails became scanty (They grew from 10cm long to 11.5cm in this time) Their droppings disintegrated into piles of white shells. I'm now feeding heavily with worms and the snails are still present in small numbers. The two largest axolotls are now about six months old and 18cm long: The smallest (in a different tank) is only 9cm.

The great outdoors is not without its problems, two of my axolotls disappeared: It could be a heron (Ardea cinerea) but it was stupid of me to leave my net next to the least planted tub and I think a glass jam jar also vanished so I suspect humans! In an artificial system without fish predators deep water might be better than shallow. Predation is from above.

An outdoor "wild" setup will almost certainly raise a lot fewer axolotls than a high density "fish farm" type setup for reasons such as Jennewt explains, but if all you want is a few adults it will probably be successful. Once my larvae were over 10cm or so they cleared chopped worms dropped into the tank very easily, I see no reason why they won't in a pond. I suggest lots of water-weed and don't worry if the water is thick with algae as it is plants and algae that provide the surface for bacteria and the sink which mops up the ammonia/nitrite/nitrate in the wild environment.

 

[lims]

wow, I thought this thread had died after bellaboos comment, interesting cheers people..