That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Breeding frogs and rearing tadpoles is one of the most enjoyable aspects of our hobby, and becoming ever more important to the survival of many species.  In the course of working with numerous species at home and in zoos, I’ve compiled a list of commercial foods that have proven especially useful as tadpole foods.  The variety of new food items that have appeared and the many frog species that have been recently bred by hobbyists have convinced me that it’s time to reach out see what new “wonder products” or ideas folks have tried. I have, therefore, highlighted some of the foods I’ve come to rely on, and would greatly appreciate hearing of your experiences with them and others. Thank you.

The Amazing Specialists

While the tadpoles of many commonly bred frogs (i.e. White’s Treefrog, Litoria caerulea) are omnivorous and take a variety of foods, others are specialists and will not survive unless their exacting requirements are met.  The tadpoles of African Clawed Frogs, Xenopus laevis and Malayan Leaf Frogs, Megophrys nasuta, for example, are filter feeders, while those of the African Bullfrog, Pyxicephalus adspersus, are as carnivorous as their pugnacious parents.  Poison Frog tadpoles of several species feed upon unfertilized eggs deposited by their mother, Goliath Frog, Conraua goliath, tadpoles consume a single species of algae, Fringe-Limbed Treefrog (Ecnomiohyla rabborum) tadpoles eat their father’s skin,  Brown Leaping Frog (Indirana semipalmata) tadpoles gnaw on wood (high up in trees!) …the list is fascinating.  Please post below if you would like information on these or other species. Read More »

As a child, my information on the Goliath Frog, Conraua goliath, was limited to a few brief sentences hidden away in various books, but this was enough to spark my interest.  Eventually, a life-sized sculpture of one at the American Museum of Natural History (please see photo) gave me some idea of just how impressive a creature it was, and my desire to learn more intensified.  Happily, I found a job at the Bronx Zoo shortly after a group of Goliath Frogs arrived there from Cameroon, and I was able to indulge my passion.  One of my new charges spanned 25 inches with legs extended…nothing, not even the enormous African Bullfrogs and Marine Toads (or, for that matter, Leatherback Turtles!) that I had already handled prepared me for the sight of that amazing animal.

The Goliath Frog Exhibit

I first started working with Goliath Frogs in 1983, at which time we knew little about their natural history or captive needs. Unfortunately, not much has changed since, although field research completed in 1985 (Sabater-Pi, Contribution to the Biology of the Giant Frog, Amphibia-Reptilia, 6(2), 143-153) has filled in some of the blanks.

The new Goliath Frogs, collected as adults in Cameroon, were shy and high strung, and prone to wild, injury-producing leaps when disturbed. We assumed, therefore, that the zoo’s noisy, crowded Reptile House would not prove an ideal location for their exhibit. Therefore, the curator commandeered an exhibit at the relatively-ignored Aquatic Bird House. Goliath Frogs are habitat specialists, so their exhibit was arranged accordingly, and outfitted with a waterfall and a swift, rocky stream bordered by dense thickets of live plants. In keeping with what little information was available, the water was maintained at a slightly acidic pH. Read More »

With their highly-permeable skins, amphibians absorb ammonia and other pollutants over a greater surface area than do fishes.  Surinam Toads, Axolotls, tadpoles and other aquatic amphibians are most at risk from poor water quality, but even terrestrial species such as toads and Fire Salamanders can quickly succumb to water-borne toxins while soaking in terrarium pools. Keeping their water clean, both visibly and chemically, can be quite a challenge.

General Considerations

Natural History

Your pet’s natural history will determine the type of filter that should be used.  For example, newts and Dwarf Clawed Frogs will be stressed by fast currents, Hellbenders are extra-sensitive to water quality, many species are prone to bacterial attack in highly-oxygenated waters, and so on.  Please post below if you need help in selecting a filter.

Types of Filtration

Biological filtration, wherein aerobic bacteria convert ammonia to less harmful compounds (nitrites and nitrates), is the most important of the three basic filtration processes. Ammonia enters the water via dead animals and plants, uneaten food and the occupants’ waste products. The organisms involved in the process, Nitrosomas and Nitrobacter bacteria, live on substrates that are bathed with oxygenated water (i.e. gravel, filter pads). Read More »

Hurricane Sandy, which hit the Northeastern USA in October of 2012, caused losses to both private herp keepers and zoos.  My own collection, home to a 32+ year-old Red Salamander and several others aged 20+, thankfully fared very well.  The zoos and aquariums for which I consult are working to limit losses; I’ll provide updates via Twitter.

Reptile care during power outages is well-understood by most, so today I’ll focus on amphibians, as their unique needs can be easily over-looked.  Most of the points mentioned below also apply to semi-aquatic species.

Filter Care and Bacteria Die-offs

When power fails, submersible, corner, and other internal filters should be removed from the aquarium.  When oxygenated water is flowing through a filter, ammonia is converted to less toxic nitrites and nitrates by beneficial aerobic bacteria.  Once the flow of water stops, the resident beneficial bacteria perish and your filter becomes a source of decomposing organic material, poisoning the already-stressed aquarium inhabitants.  Fish keepers are well aware of these processes, which are part of the nitrogen cycle.  An understanding of the nitrogen cycle will enhance your ability to keep and breed amphibians; (please see this article). Read More »

In 1990, the IUCN’s Declining Amphibian Populations Task Force, to which I belonged, was one of the few large scale efforts addressing what is now known as the “Disappearing Amphibian Crisis”.  Today, with legions of biologists and hobbyists at work on the problem, we still do not fully understand why nearly 200 species have become extinct in the last 20 years – a rate 200x that of what might be “expected”.  But we do have some insights, one of which was highlighted in a recent journal article (Philosophical Transactions of the Royal Society (Biology) .  It appears that stress, much of which is in response to what we are doing to amphibian habitats, is worsening the effects of normal pathogens and diseases.

Parasites and Insecticides: a Confusing Scenario

As the reality of worldwide amphibian declines became apparent, herpetologists and private citizens began noticing increasing numbers of deformed and dead frogs. In 1995, school children in Minnesota made headlines when they found dozens of deformed frogs in a local pond. Since several chemicals are known to cause growth abnormalities, researchers began focusing on pollutants. At the Bronx Zoo, I worked with a veterinarian who studied African Clawed Frogs, and was amazed to see ovaries develop in males that had been exposed to Atrazine (a common insecticide). Read More »