Siren setup for burrowing

[eyrops]

I have been interested for some time in constructing a setup for Siren lacertina that facilitated burrowing behavior. I’ve made several attempts with mixed results. My latest try appears to be working fine so far, so I’m writing about it here.
I used a 29 gallon (110 liter) tank. I installed an undergravel filter assembly. I covered this with a filter pad that was about ½” (1.5 cm) thick. My goal was to send water down one of the airlifts and let it upwell through the sand. I used a powerhead water pump to do this. I installed plastic film for a few inches around the airlift so the water wouldn’t upwell right next to the airlift. I used silicone sealant to hold the filter pad in place, to seal the water tube connections, and to plug the unused airlifts. When the sealant was cured, I added about 4 inches (10 cm) of fine sand, and filled the tank with water.
The water does upwell through the sand, making little “springs”. The location of these springs changes, but right now they are concentrated on the end of the tank opposite the airlift. The “springs” float the sand, and this unconsolidated substrate gives the siren an easy place to enter the sand. It does enter the sand and burrow through it. Sometimes it is hidden, sometimes both had and tail stick out, and quite often just the head and limbs stick out as in the attached photo. It also spends some time totally above the substrate.
I believe that some form of accessible substrate may be a good thing for keeping sirens. Burrowing is something they do in the wild, and it may cut their stress level in captivity if they are able to burrow. I don’t think the way I set this tank up is the only or necessarily the best way to do it. I’d be interested in hearing from others that have attempted to address this issue. I believe mud substrates have been used. I did not try this, mostly because I could imagine several ways it could fail spectacularly. I’m most interested in ideas based on experience with aquatic burrowers, but all ideas are welcome!

 

[Kaysie]

Would it be possible for you to post pictures/diagrams of your apparatus? I'd be most interested in seeing how that was set up.

 

[taherman]

Can't they burrow in normal sand substrate without suspending it with flow from a powerhead?

 

[eyrops]

Without the upwelling, I have had mixed results. Smaller sirens usually seem to be able to burrow in fine sand or coarse sand in my setups, especially if they have some rocks to use for leverage as they get started. The larger animals seem to have trouble. I don't know quite what to think about this but maybe a smaller sharper wedge cuts better than a larger blunter one, as a knife requires less force than an ax. The upwelling does seem to make it easy for the siren to get into the sand.

 

[SludgeMunkey]

The resulting liquefaction from the power head seems like a darn good idea to me! Occam's razor for success!

I wonder if there is a suitable neutral buoyancy substrate that could work as an alternative. You have the gears in my head grinding on this one. I think I have to do some experimenting...

 

[taherman]

You could try mixing in some ground up oak leaves, peat moss, coco pith, or other organic matter. I know some of the aquatic plant gurus have great success layering sand, clay, sphagnum, and peat moss.

 

[eyrops]

Would it be possible for you to post pictures/diagrams of your apparatus? I'd be most interested in seeing how that was set up.

OK - I'll try. Pardon my draftsmanship here. I should have taken pictures as I built it.

 

[Kaysie]

Looks very interesting. I might have to try this out!

Currently I use a large number of PVC tubes to simulate 'burrows', but these are far from perfect.

 

[eyrops]

I've thought about tubes, but haven't tried them. Do the sirens use them? --or-- Do they ever come out? I made a setup once with water seeping over an artificial cliff with some nooks and crannies for hiding. Unfortunately the siren figured out how to get behind the whole cliff. Then it would come out for its food only, so I rarely saw it. I built a little funnel type "minnow trap" and baited it with a worm to catch it and get it out of there. I really liked how that setup looked, but functionally it was a disaster.

-Steve Morse

 

[Kaysie]

I have a fair number of 'elbows' connected together, as well as two 1-foot long pieces of 2" pvc. These are their favorite hides, and I may get more.

They are fairly active, especially at dusk, and move between the tubes regularly. I also have a large amount (although I'd like more) silk foliage, mostly kind of leafy vines, that they hide in frequently.

I'm working on getting them a larger tank. Right now I'm keeping two (15") in a 55 gal. It's adequate, but hardly ideal. I'll be upgrading them to a 75 gal in the near future. That should hold them for a bit.

 

[SludgeMunkey]

I have been muddling this over in my head for a few days now. I ordered some stuff to test out the neutrally buoyant idea with. I don't know if it will work, but it will be fun to try.

 

[fishkeeper]

Another neat thing about this setup is it keeps the substrate from becoming funky.

I've used sodium bentonite clay in terraria design...it holds it shape well out of water so long as it stays moist...when it dries up it cracks and so alot of the less well kept areas of my background are bare now(need to redo them).

In water, however, it is a goopy consistency that may be perfect for sirens to burrow in(hardly any resistance). It will cloud up the water if constantly moved about but a layer of sand above it may help. The water area in my paludarium has quite a bit of it and it stays put for the most part. I have no idea how safe this would be for your filter so test first.