A Focus on Aquatic Amphibians

When I was boy (what seems like centuries ago), I had a 10 gal. freshwater tropical fish tank. I had the usual assortment of inexpensive and reasonably foolproof fish—mollies, angelfish, guppies and the like. That tank was a good educational tool, as it taught me about responsibility, care and the cycle of life.

In all honesty, though, the real reason I had that tank was for the aquatic amphibians. Again, the population was typical faire—Firebellied newts, Eastern newts and local tree frog tadpoles that I had caught were pretty much it. These were all animals that would co-habit well with the fish and required very little in the way of individual care.

But, whereas the fish were constantly and mindlessly in motion, the amphibians were placid and still. With them, movement was the reward for very patient observation. A quick dash to the surface for a gulp of air or a saunter over to a bit of food… this passed for excitement in their (and my) day. Maybe not as exciting to the eye as the fish, but each movement seemed fraught with meaning. I am certain I was in the minority for this, but I have built my career on catering to clients with similar inclinations.


Changes in the Hobby

I have seen the possibilities for what is available for aquatic tanks to expand and contract in the intervening years. Right now, we are in a period of extreme contraction. The big reason for that contraction is a fungal disease that has spread worldwide and effects a wide swath of amphibians.

It is called Chytrid, and the disease is Chytridiomycosis. It literally poses the threat of extinction for entire families of amphibia. In the animal business, it is our moral imperative to preserve wildlife, and we all need to get on board with putting the animals themselves ahead of our profit motives. Thus, in the last few years, we have seen the entire complex of Firebellied newts become impossible to acquire. The same goes for Sirens, Axolotls, Eastern newts, Amphiumas and Caecilians. I am, and you should be, fine with that. They deserve to be honored and protected. Of course, in many parts of the country, aquatic amphibians are native, and as long as folks obey state laws and limits regarding their capture, the possibility still exists for some of us that they could be active, thriving members of our in-home aquatic communities.

The other possible resource within state limits would be those folks keeping and breeding exotic salamanders and newts. In my shop, for instance, we have a tank of Spanish Ribbed Newts that we are hopeful will reproduce, and some of our customers breed and sell us their amphibia, as well. We have always been all about the encouragement of private breeding, as it not only fuels our businesses, but the hobby has often led the way to knowledge that then benefits the work of zoos and agencies of conservation.


Frogs in the Pond

So, in terms of exotic species, what are we left with? There are three or four species of African and Asian frogs still available that will thrive in aquatic and semi-aquatic environments. These are not widely available from reptile wholesalers but rather turn up in the inventories of tropical fish dealers. They tend to be, in keeping with my childhood experience, inexpensive and readily available.

Perhaps the most ubiquitous is the African Dwarf Frog (Xenopus boettgeri). These are tiny things—they rarely exceed an inch in length—and are exclusively aquatic. They are bottom scavengers, and will eat up excess fish food and live tubifex worms. Zoo Med makes an excellent granular diet designed specifically for aquatic frogs, and I have found they are not shy in their appreciation of it. (We also recommend the same pellets for raising up dart frog tadpoles).

In the past few years, I have started to see albinos available at a slightly higher price. The good news is that it means they are being "farm-raised" rather than being pulled directly from the wild. This inevitably produces healthier animals and reduces the negative effects of wild harvesting.

But, because they are so minute, I would think twice about introducing them into a community tank with any kind of larger or even remotely aggressive fish. There is some evidence that they are somewhat social and do better in small groups than kept alone. That said, their lifespan is not long, and I would not expect more than three years or so out of them. Give them a well planted tank as they like cover. I have seen them from time to time drift up to the surface where they seem to float languidly, and for no obvious reason. I have heard this behavior called "burbling" but have never seen an explanation for why they do it. They prefer relatively still water.

If one of your Dwarf Frogs seems to be breaking the rules and growing well past the limits of dwarfdom, you have unwittingly acquired a different species, the African Clawed Frog (Xenopus laevis). This is an entirely different kettle of fish, as it were. They get large—4 in. or more is not uncommon—and will turn tables on every other living thing in your tank, as they are impressive predators with enormous appetites. Their adaptability to a variety of circumstances has garnered them verboten status in a number of states, where, like bullfrogs and red-eared sliders, they eat up and out-compete almost all wildlife around them. Beware!

How to tell the difference? Clawed frogs have no webs on their front feet, round rather than pointed snouts and eyes atop their heads as opposed to on the sides. They can be delightful pets on their own, but will turn everything else you try to keep with them into dinner.

Our next community tank friend is the delightful Indonesian Floating Frog (Occidozyga lima), which happily coexist with tank mates by simply ignoring them. Commonly found in rice paddies, their gaze is pretty exclusively on what might drop onto the water’s surface, with live bugs being their specialty. I particularly enjoy keeping them in tanks heavily overgrown with duckweed, in which they act like little crocodiles. As crickets walk across the weed, they pounce!

Floaters get about 2 in. long and are variably colored with olive to brown bodies, often decorated with a back and yellowish stripe running down their backs. They should be provided a small rocky outcropping as they spend some of their time terrestrially.

Even more semi-terrestrial, but still adaptable to a largely aquatic tank, is the Fire-Bellied Frog (Bombian orientalis). It is more seasonal than the aforementioned species, but certainly the most attractive of the common freshwater aquarium amphibians. Typically bright lime green with a spattering of black spots, and afforded a startling bright orange red belly (they are living traffic signals, blending in to thwart off predators for above, while sternly warning predators below!), they get about 2 to 3 in. in length, and behave much like the Floaters.

Again, this is a rice paddy dweller, but I find they spend a bit more time terrestrially than others mentioned here, and to that end you will need to provide them with a viable land portion to the tank. Be aware: an animal that is comfortable on land is also an animal more prone to walking away. Make sure your tank has no escape routes, because a frog set loose in your home is very much like a fish out of water.

They are an excellent choice to keep in small groups, as they engage in remarkable shenanigans over food, harmlessly biting each other, wrestling, tumbling and generally carrying on. When not feeding, they call with a chorus that sounds like a pack of distant little dogs. To that end, I always sell these with both a single price and a discounted price for groups of five or more.

We are living in unprecedented times. Our current pandemic has been devastating, but for our business, sales are going through the roof. It seems everybody who is stuck at home is now wanting to fill a bit of that void with pets. Long term, some of those new to the hobby will stay with it, and so it behooves us to provide a gentle and rewarding introduction. One of the best ways you can accomplish that is with a tropical fish tank…plus something extra.  PB

Owen Maercks has enjoyed being immersed in the world of professional herpetoculture for nearly 40 years. His store, the East Bay Vivarium in Berkeley, Calif., is one of the oldest and largest herptile specialty stores in the U.S.