Food web

[clover]

I'm curious about food webs for captive salamanders, both terrestrial and aquatic, and whether anyone has much experience with setting up a full food web for them. It seems more fulfilling and stimulating for them to hunt a portion of their food and to be human fed as only a part of their diet.

For terrestrial salamanders/newts the only things I'm really aware of are springtails (which would only be a good food source for the smallest animals anyways) as well as ispods and maybe roaches. I have concerns about roach populations getting out of control. Am I missing any terrarium additions that wouldn't make the soil foul like worms might?

How about aquatic? I know there are a limited number of different animals you can keep with aquatic newts or salamanders for safety and temperature reasons but it seems like black worms, ramshorn and MTS, shrimp, and aquatic ispods might all be good additions that could provide safe and stimulating prey. Would you add daphnia or scuds to an aquarium without larva in it? Would scud populations get out of control if newts/salamanders are the only predators? Anything else?

 

[minorhero]

Sooooooo while this is technically possible to set up it is not practical. The reason being space limitations. You can't set up a tank with prey species in a normal size tank without the newts eating them faster than they reproduce. Maybe if you had a 120 gallon tank for a single newt you could keep enough aquatic options available for it to hunt most of it's food... But that's the kind of size you would need. Certainly 20 gallons for a single newt would not be big enough.

Realistically you need to feed them yourself.

 

[clover]

I was definitely going to feed them But wanted to add things that were safe and stimulating so they could still hunt and engage in some natural behaviors. Just not 100% human feeding, like if they saw a yummy looking isopod crawling around then it might be a good time for a snack vs being in a pristine tank where they don't get to engage in that type of behavior.

 

[minorhero]

In that case for terrestrial tanks isopods and earth worms. For aquatic tanks, snails, shrimp, and scuds. Blackworms are frankly the best but they won't last long.

 

[Niels D]

Tubifex worms can be "cultured" in a newt tank if the conditions are good.

 

[clover]

Oh goodness I didn't get an email about your comment! Everything I've seen about tubifix worms says they like a "polluted" environment so wouldn't an environment that's good for them be bad for the newts?

 

[Niels D]

Tubifex worms inhabit the mud, silt, and sludge of aquatic environments, particularly in areas with moderate water flow. They primarily feed on organic debris, but they do not require a polluted environment, such as one contaminated with chemicals or heavy metals. Tubifex can be easily cultured in a controlled space, though they are also capable of reproducing within your aquarium substrate. They burrow into the substrate but periodically surface to "wave" and catch debris. Newts can essentially "graze" on the tubifex worms from the substrate. While the environmental conditions must be suitable, if the water parameters are optimal for your newts, they will also support tubifex worms. In most cases, however, newts tend to consume them more quickly than they can reproduce.

 

[Lordosteous]

I've also been exploring in-situ feeder culturing for Salamanders. A lot of the "clean up crew" types are easy to breed in my experience, but a lot of predators don't like them as much as crickets or mealworms. Sure they will eat Millipedes and isopods if theres nothing else, but they're unlikely to get enough nutrition from them even if enough are breeding.
Roaches are usually a better fit, but picking the right species is very important. Some are way too big, some need it dry or hot. But, there are smaller, prolific species like Pycnoscelus that need no heat, don't mind moisture, are the right size, parthenogenic, and will eat mostly detritus. There are even Semi-aquatic roaches like Epilampra maya, though I haven't worked with these yet.
Springtails and many worms are of course very happy in a vivarium as well and provide additional prey.
But ultimately, as minorhero said, size is the ultimate constraint. I have a 270 gal enclosure, and after lots of work and experimentation, I'm convinced it's still too small to produce enough prey even for a small species like Cynops. I think a vivarium a little bigger than mine (~300 gal) probably could produce enough prey for a small colony of small newts if well designed, but it poses a fascinating challenge regardless.

 

[clover]

With mine I definitely intend to feed things like blood worms and nightcrawlers and more just want to supplement them because they are hunters and I think it's good to be able to hunt. I hadn't heard about semi aquatic roaches but I added aquatic isopods to my aquarium and they're great. I have a very large terrarium (for plants only) that I discovered I brought some slugs in from the yard on. They're an invasive species so I can't release them so I've been catching them with yeast and feeding the small enough ones to my efts and that seems like a good food. Doesn't move too fast and they're pretty meaty. You could definitely make a slug culture and feed them as an additional food source.

 

[Lordosteous]

Very cool, I've never considered slugs as a major prey item for them!
How do the aquatic isopods fair in your tanks? Do they breed succesfully? or go after plants? I've never kept them before but I'm super curious.

 

[clover]

The isopods are great. They're pretty docile and breed really well. I haven't seen them go after plants but you could drop in an algae wafer or shrimp food every few days to be sure. My newts are too small to be in the aquarium right now so the isopods are out running around all the time. It's possible they hide with a predator around but I highly recommend looking into getting some.