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.

General Considerations

In general, omnivorous tadpoles should be provided with as many of the following foods as is practical.  As we do not know much about the natural diets of filter-feeding tadpoles, they too should be given a wide variety of finely-ground commercial foods.  Horned Frog (Ceratophrys spp.) and other carnivorous tadpoles do best when high protein foods such as freeze-dried bloodworms, shrimp and pre-killed minnows are added to a Reptomin-based diet. 

I’ve found that nearly all tadpoles relish kale, and experience has shown it to be a very beneficial addition to their diet.  I have, as an experiment, successfully raised American Bullfrog, Lithobates catesbeianus, and Green-and-Gold Bellfrog, Litoria aurea, tadpoles on a diet comprised solely of kale and tropical fish flakes.  Soak kale in hot water for 10 minutes or so before using, so as to improve its digestibility. 

Reptomin Floating Food Sticks (Tetrafauna)

If I had to choose a single food that fits the needs of most tadpoles, I’d go with Reptomin Floating Food Sticks, which I have relied upon in zoos and my own collection for decades.  I’ve had excellent results using this product as 50-75% of the diets of a variety of tadpoles, including American and African Bullfrogs, Green Frogs, European Edible Frogs, American Toads, Wallace’s Flying Frogs, Australian Bell Frogs and Ornate Horned Frogs.

Reptomin contains a variety of animal and plant ingredients, including shrimp, algae and fish meal, wheat, corn and potato.  The floating sticks soften quickly, but not so much as to become unavailable to larger tadpoles, sink after becoming water-logged, and can also be ground up and offered to filter feeders.  Reptomin is also an excellent food for many adult aquatic frogs, newts, turtles, and invertebrates…I even use it to gut load feeder crickets and roaches.  It has crossed over from the pet trade and is now a staple in zoos worldwide.  Please see this article for further information on this valuable food item.

Canned and Sun-Dried Freshwater Shrimp (ZooMed)

Shrimp are very numerous in many freshwater environments, and likely play a role in tadpole diets.  While marine shrimps and krill have long been available as tropical fish food, freshwater species are difficult to find.  I was, therefore, pleased to learn that Zoo Med is now using a fresh water shrimp, Macrobrachium nipponense, in its Canned Shrimp and Sun Dried Red Shrimp products.

Excellent as a high-protein addition to the diets of most tadpoles and very important for carnivorous species, both products are easy to use.  Canned Shrimp, being quite “meaty”, is ideal for the voracious tadpoles of African Bullfrogs, Horned Frogs and similar species.  Sun Dried Shrimp can be crushed to meet the needs of smaller tadpoles and filter feeders.  You can read more about these products here.

Tropical Flakes Fish Food (TetraMin)

As with ReptoMin, tropical fish flakes are highly nutritious and an ideal food for a wide variety of tadpoles.  I’ve relied most heavily upon TetraMin’s original Tropical Flakes, and cannot recall any species that has refused it.  Developed in 1950, this product can be ground into a powder fine enough even for the tiny filter feeding tadpoles of the Dwarf African Clawed Frog, Hymenochirus curpites, but is also taken by American Bullfrogs and other large species.  I also provide it to feeder insects, snails, millipedes, and shrimp (and fish!). 

Other flake foods developed for fishes with specific dietary needs (i.e. algae feeders, Cichlids) may also be used to add variety to tadpole diets.

Spirulina Discs (Wardley)

Wardley Spirulina Discs contain blue algae meal, spinach powder and other plant-based ingredients important to the health of nearly all tadpoles.  As carnivorous species likely consume some plant material in the wild, I add Algae Discs to both their diets and those of omnivorous/herbivorous tadpoles.  Many other foods formulated for plant-eating fishes are also useful tadpole foods.

Earthworm Fish Food Flakes (Zoo Med)

I’ve long championed earthworms as a herp food, and so was interested in trying out Zoo Med’s new Earthworm Flakes.  The flakes also contain salmon, shrimp meal and plankton, and are readily consumed by most tadpoles.  Further thoughts on this exciting new product can be found here.

Repto Treat Delica Bloodworms (TetraFauna)

Bloodworms, the larvae of midges (or “gnats”, Family Chironomidae), are one of the few small insects available to tadpole keepers. 

TetraFauna’s Repto Treat supplies bloodworms encased within a vitamin-enriched gel.  

Bloodworms and other aquatic insects form the basis of the food chain in many tadpole habitats, and are almost certainly an important food item.  Also, tadpoles consuming Repto Treat will be eating the entire organism, an important consideration if research on adult amphibians is any guide.  You can read more about the use of bloodworms as an amphibian food here.

There are many other tadpole food options…please post your ideas and experiences below, and I’ll be sure to share them with my readers and colleagues.

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,
Frank Indiviglio

Further Reading

Breeding the Malayan Leaf Frog

Rearing African Clawed Frog Tadpoles

Arboreal, Wood-Eating Tadpoles

Tadpole image referenced from wikipedia and originally posted by Rainforest Harley

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Best Tadpole Foods (Based on my Experiences) – Seeking Additional Suggestions

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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.

Captive Behavior

The frogs settled in nicely, but, despite their size, one had to search long and hard to find them. Although wild adults reportedly bask in the sun, ours rarely left the water by day (I wonder now if UVB would have been helpful…please see below).  At night, however, they became quite active – prowling the shoreline and gobbling up Leopard Frogs, their favorite food. I watched them overnight on several occasions, and a bird keeper who lived in the basement of the building (long story!) also kept tabs on their nocturnal wanderings. Unfortunately, breeding behavior was never observed, and this seems to remain true today.

Although field research indicates that invertebrates form 60% of the Goliath Frog’s natural diet, those I cared for favored other frogs over all else.  I suspect that crayfish would have been accepted, but these were not regularly available back then.

Webbed Fingers and Toes

The frogs under my care were dark brown above (some field reports describe adults as greenish-brown, and juveniles as greener in color) and white, tinged with light yellow, below. The feet were fully webbed and tabs of skin fringed the fingers, perhaps to assist in swimming or grasping rocks buffeted by swift currents. 

Natural History

Size

With a snout-vent length of 13 inches and legs of the same length, the Goliath is by far the longest of all frogs. It also vies for the title of heaviest, although African Bullfrogs and Marine Toads occasionally tie or even exceed the Goliath record of approximately 8 pounds. Considering how few have been accurately measured, even bigger individuals may be out there…if they are not eaten! (please see below).

Range and Habitat

The Goliath Frog occupies an 80 to 100 mile-wide range in Cameroon and the Republic of Equatorial Guinea, West Africa (please see map).  Within this tiny area, it is limited to swift, unpolluted, rocky streams bordered by dense equatorial rain forest.

Diet

Field studies are scarce, but indicate that invertebrates comprise at least 60% of the diet.  Freshwater crabs, spiders, scorpions, snails, beetles, millipedes and toads (2 species) have been recorded as prey 

Goliath Frog tadpoles, which are quite “normal” in size, are believed to feed upon a single plant species for much of their lives.

Reproduction

Limited observations indicate that several hundred eggs are attached to aquatic vegetation in quiet pools among the rapids. The tadpole stage lasts for 2.5 to 3 months.

In common with certain other frogs that inhabit noisy, rushing streams, Goliath Frogs produce no mating calls. It is not known whether they communicate via body posture or hand signals, as do Panamanian Golden Frogs.

Behavior

Juveniles spend most of their time in the water, with just the head exposed. Adults sit on rocks within streams, often in direct sunlight, and seem to adjust their exposure to the sun by changing positions. This apparent basking behavior lasts for up to 35 minutes, after which the frogs spend some time in the water before returning to the rocks.

Goliath Frogs hunt along stream borders at night. There is some evidence that adults maintain distinct hunting territories of 60 to 130 square feet.

Conservation

Collection for the food trade is thought to be the greatest threat, especially now that traps have replaced capture by hand. Logging and stream siltation are also concerns. One recent study documented a 50% decline in the adult population over a 15 year period. 

In years past, Goliath Frogs were exported for use in zoos, the pet trade and even frog-jumping contests. I recall seeing an individual that had been entered into one such contest in California. Given their high-strung nature, I was not surprised to note that its snout was bleeding and showed evidence of past injuries.

Goliath Frogs are classified as Endangered by the IUCN. Part of their range lies within Equatorial Guinea’s Monte Alen National Park, but information as to what protection this affords is difficult to come by.

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio

Further Reading

Goliath Frog Video and Facts

Goliath Frog Photos and Information

Goliath Frog Field Study

Goliath Frog image referenced from wikipedia and originally posted by Ryan Somma
Zambian Landscape image referenced from wikipedia and originally posted by Florence Devouard

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The World’s Largest Frog – Working with the Massive Goliath Frog

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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).

Aerobic bacteria starter cultures may be purchased (i.e. Nutrafin Cycle) or obtained from the filter materials in a well-established tank. Always leave a bit of old material in your filter when changing carbon or filter pads, so that aerobic bacteria will seed the new filter medium.

Suspended solids and chemicals are removed from the aquarium through mechanical and chemical filtration.

Live Plants

Aquatic plants will assist filters in maintaining water quality and amphibian health. Pothos, Peace Lilies and other terrestrial plants that adapt to watery environments can also be used. Please do not discount the effects of live plants…I and many others can attest that they can make a real difference.

Water Changes

The use of a filter does not eliminate the need for regular water changes, as ammonia will accumulate even in well-filtered enclosures. 

Undergravel Filters

Yes, they are largely ignored today, but I believe this to be serious error. I have used undergravel filters to successfully keep a wide range of delicate amphibians, and have included them in several of the large zoo exhibits I’ve designed. 

Undergravel filters transform the entire aquarium substrate into a biological filter. Water drawn through the gravel nourishes beneficial aerobic bacteria and inhibits the growth of harmful anaerobic species.  The return tubes can be cut so that even a small pool in a terrarium can be filtered. 

Undergravel filters are especially useful when rearing eggs, larvae and tadpoles, because they will not injure animals with suction and strong currents.  Please see this article for detailed information on their use.

Corner or Box Filters

These “old-fashioned” inside-the-tank filters are actually quite effective if powered by sufficient airflow. I maintain a number of tanks using corner filters alone.  In addition to providing mechanical and chemical filtration, these filters support aerobic bacteria that assist in ammonia detoxification.

Ideally, a corner filter should have low and high intake ports, so that water will be pulled from the very bottom of the tank and at a slightly higher level I recommend the Lee Triple Flow; most others lack low intakes.  As a corner filters outflow is directed upwards, strong currents that might disturb eggs, larvae or weak-swimmers are avoided.

Corner filters can be easily hidden with plants.  Live Java Moss is ideal for this purpose.

Sponge Filters

Sponge filters provide mechanical and biological filtration, and are ideal for use with amphibian eggs and larvae, and delicate specimens. They work well with African Clawed Frog tadpoles and other filter-feeders, as minute food particles are not rapidly removed from the water.  This is also a consideration when salamander larvae are being reared, as many feed upon Daphnia, brine shrimp and other tiny creatures that may be pulled into more powerful filters.  

The filter should be periodically cleaned by rinsing it in cool water (hot water will kill beneficial bacteria).  Chemical filtration is not provided, so regular water changes are especially important. 

Zoo Med Turtle Clean Canister Filter

This powerful filter is designed with turtle-keepers in mind (please see this article for information on filtering turtle tanks).  In common with fish canister filters, the Turtle Clean has ample chambers for carbon, filter pads and aerobic bacteria colonies, and is simple to clean.  It is placed next to (not below) the tank, and can be used to create a waterfall effect. 

Despite its size and power, the Turtle Clean Filter can operate in as little as 2 inches of water, rendering it ideal for use in terrarium ponds or in shoreline-type setups housing American Bullfrogs, Leopard Frogs and similar species.

A powerful motor enables this filter to handle the copious wastes produced by Mudpuppies, Sirens, Amphiumas, Surinam Toads and other large amphibians.  However, water can also be returned to the aquarium via a spray bar, so that newts and other small amphibians can also be maintained.

Supreme Ovation Submersible Power Jet Filter

The Supreme Ovation is first submersible, combined pump and filter to be marketed in the USA; my original unit operated continuously, under great strain, for approximately 20 years! 

The four models currently available are extremely powerful, but are equipped with a movable outlet tube and a spray bar so that strong currents can be avoided. The largest (Model 1000) circulates 265 gallons per minute, yet is compact and easy to service. 

Other Filters

Nearly all filters designed for use with tropical fishes can be of use to amphibian keepers. Although certain modifications may be required, many are worth investigating as a great deal of research has gone into their development.

You can check out 50+ aquarium filters options here. Please be sure to post your ideas, experiences and questions below. 

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.  

Please also post your questions and comments here…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio

Further Reading

Undergravel Filters in Terrariums and Aquariums

Ammonia Toxicity in Amphibians

Amphibian Lab Filtration Techniques

Filtering Turtle Tanks

NutraFin Cycle: Bacteria in a bottle
 

Axolotls image referenced from wikipedia and originally posted by ZeWrestler
Tadpoles image referenced from wikipedia and originally posted by MarJon

Post from: That Reptile Blog


The Best Filters for Axolotls, Clawed Frogs, Newts and Other Amphibians

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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).

As the contents of external aquarium filters are not in direct contact with the water, they will not immediately add to the pollution problem.  However, these filters should be disconnected, because when electric power is restored they will flood the tank with ammonia and other toxins.  Amphibians lack the protection offered by fish scales, and so succumb to ammonia poisoning quickly when water conditions deteriorate (scale-less fishes, such as eels, loaches, and certain catfishes, are also sensitive).  

When Power Returns

Before being re-connected, the filtration material in internal and external filters should be replaced or rinsed. 

Under normal circumstances, you can re-seed a newly-cleaned filter with aerobic bacteria by leaving in a bit of used filter material; alternatively, you can replace only a portion of the material when the filter is serviced.  After a power outage, however, your filters will not contain living bacteria.  Nutrafin Cycle can be used to reintroduce live beneficial bacteria to your filters.  A colleague of mine who works at a major frog-breeding laboratory vouches for this useful product.  Upon his recommendation, I’ve begun to use Nutrafin in water bowls and after regular filter changes as well (please see this article).

“Insurance”: Check Valves

Check valves are an inexpensive (as in “less than $2”) yet often over-looked means of limiting damages during power failures.  These simple devices prevent water from flowing up airline tubing and out of the tank when pumps shut down. 

Parasite and Disease Concerns

Spiking ammonia levels depress amphibian immune systems, as does the often rapid rise in temperature once power returns. Cold temperatures are generally less of a concern than is the case for reptiles, but this will vary by species. I’ve observed Fire Salamanders moving about normally at 38 F (while trying to induce dormancy), and my Red, Marbled and Tiger Salamanders feed throughout the winter at 55 F. Temperature reduction can even be used as a medical treatment; please see this article for some interesting observations. 

Temperatures that are too cold for a particular species, or a rapid temperature change, can stress the immune system.  Parasites and pathogens are always present in the aquarium, even when conditions are ideal.  Healthy frogs and salamanders can fight off many common invaders, but often become ill when their immune systems are not working at full throttle. 

One of the most common parasites to afflict immune-depressed fishes is the protozoan Ichthyophthirius multifiliis, which causes the infection widely known as “Ich”.  Many have long suspected that this micro-organism also infects amphibians, and indeed this was confirmed in 1999 (please see this article).  Fish medications have proven useful, but should be administered to amphibians gradually, beginning with half the recommended dose.  I’ve had great results using Methylene Blue to treat ailing amphibians, and as a prophylactic step; please see this article. 

Other problems may develop, even after conditions are back to normal. For example, food consumed prior to the outage may remain undigested and lead to a serious infection. Please post any questions you may have below. 

Oxygen Deprivation

The water’s oxygen content drops rapidly once pumps shut down.  Commonly-kept aquatic amphibians that rely primarily upon their gills (Mudpuppies, Axolotls) or skin (Hellbenders) for respiration can also take in oxygen at the water’s surface, via the lungs.  However, this is stressful to secretive species that generally remain in underwater retreats.  Tadpoles and salamander larvae may, depending upon their stage of development, be able to gulp air at the surface. 

Aerators and Oxygen Tablets

There are a number of things you can do to provide oxygen for your aquatic amphibians during power failures.  Battery-operated aerators are very effective.  The Penn Plax Silent Air B-11 is especially useful, as it turns on automatically when electricity fails.  Oxygen Stones – tablets that create bubbles as they dissolve – should also be on hand.  

Plants, Manual Aeration, Water Changes

Live plants, especially those that do well in low-light conditions, can make a real difference in oxygen levels and water quality.  Java Moss lives quite well in my aquatic insect tanks, which receive only ambient room light, and survived 6 days in near total darkness in my larger aquariums.

Don’t forget manual aeration.  By simply scooping up some water and pouring in into your tank from above, you can significantly raise oxygen levels. 

Partial water changes will add oxygen while reducing toxin levels.  Water leaves my tap at 60 F, which is fine for many amphibians.  Water changes will go a long way in helping your animals to survive.

What’s Next…What Can I Do?

Even after all is back to normal, watch your pets carefully for signs of the concerns mentioned above.  Please write in for more information on hurricane-related issues.

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio

Further Reading

Turtleback Zoo Tends to People and Animals during Hurricane

First Documentation of “Ich” in Frogs 

Nutrafin Cycle

Extreme Cold Hardiness in Amphibians

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Amphibian Care during Power Outages – Bacteria, Disease and Oxygen

The post Amphibian Care during Power Outages – Bacteria, Disease and Oxygen appeared first on That Reptile Blog.

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). 

But pollutants turned out not to be the whole story…a parasite also played a role. The creature involved needs to infect both a frog and a wading bird in order to complete its life cycle. Amazingly, it lives within a tadpole for a time and “re-programs” the development of the hind legs as metamorphosis occurs. The newly-transformed frog develops extra rear legs and, unable to jump very well, is likely to be caught by a heron – just as the parasite “intended”! 

Actually, many parasites cause incredible changes in their hosts’ behaviors – one “directs” an ant to climb into the canopy and raise its now red-colored abdomen skyward in imitation of a tasty berry (so that it is eaten by the next essential host, a bird), another causes the host spider to build a silken shelter before dying, so that the parasite has a safe place in which to emerge, and so on…

Are Pathogens Changing?

Amphibians evolved some 300-400 million years ago, long before the dinosaurs, and they’ve likely been battling parasites similar to those described above for much of that time. The same can be said of other fungi, bacteria and viruses that attack them. 

Yet it seems that certain pathogens and diseases, despite being around for centuries, are now causing unprecedented amphibian population declines and extinctions.  For example, Chytrid fungus, first identified as a serious threat in 1999, may be responsible for the disappearance of nearly 200 species. Although termed an “emerging disease”, it was likely present all along, but is now spreading more rapidly, and having a more devastating effect on its victims. This trend is seen among frogs worldwide (salamanders and caecilians are not as well-studied) – many pathogens are more common now than in years past, are spreading to new habitats, and are causing unusually high mortality rates.

The Role of Stress

According to the article referenced above, multiple stresses may be weakening amphibian immune systems, rendering them unable to battle common illnesses.  We see this in captivity all the time – animals that are assailed by inappropriate temperatures, hostile tank-mates or poor diets often fall victim to parasites and diseases that would have been handled by the immune system had conditions been ideal.  

One stress factor can depress the immune system (in zoos, birds moved to a new exhibit often succumb to Aspergillosus infections, an ever-present fungus that typically causes no problems).  Currently, many amphibians are exposed to pollution, climate change, introduced species, habitat fragmentation and other stressors simultaneously. Small wonder that at least 2,500 species are believed to be in decline.

Permeable skins that allow for the passage of harmful chemicals, and the typical need for two distinct habitats, predispose amphibians to difficulties when environmental changes occur. However, there is evidence that similar processes are at work among other groups as well (please see this article on snake declines). 

What’s Next…What Can I Do?

Please be on the alert for deformed amphibians and signs of population declines, and post your observations here.  I can help you to get the information to organizations that can put it to good use.  Also, a colleague of mine is now involved in Amphibian Ark, a fine conservation group which can provide guidance if need be.

Please see the articles linked below for information on IUCN surveys and other efforts that utilize volunteers.

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio

Further Reading

Frog Leg Trade Helps Spread Amphibian Disease  

Amphibian Study Seeks Volunteers  

Deformed Frogs Found in Minnesota

Bacteria may offer Chytrid Immunity

 Global Amphibian Declines (excellent overview)

Chytridiomycosis image referenced from wikipedia and originally posted by Forest Brem

Post from: That Reptile Blog


Amphibian Declines – Pollution Worsens Disease and Parasite Attacks

The post Amphibian Declines – Pollution Worsens Disease and Parasite Attacks appeared first on That Reptile Blog.

Natural History

Argentine Horned Frogs inhabit savannas (grasslands) in Argentina, Uruguay and Brazil. In some regions, they become dormant during cool, dry periods.

Seven related species have been described.  Of these, the Cranwell’s or Chaco Horned Frog (Ceratophrys cranwelli) is most frequently seen in the pet trade.  The following information can be applied to its care.  The Surinam Horned Frog (C. cornuta) bears the longest “horns” of all (please see photo). 

Horned Frog tadpoles communicate with one another by sound…the only vertebrate larvae known to do so.  The calls may prevent the carnivorous tadpoles from preying upon relatives…at least until other food runs out! (please see video below).

Hunting Behavior and Diet

Due to their size and aggressive personalities, Horned Frogs, known locally as Escuerzos, are the subject of many tales within their native range.  They are, for example, erroneously thought to be venomous and to attack livestock.  They are, however, formidable predators.  Studies indicate that other frogs comprise up to 80% of the diet, with invertebrates, birds, snakes and rodents making up the balance. 

They are assisted in hunting by huge mouths, powerful jaws and bony “teeth”, known as odontoid structures, that project from the lower jaw.  Although they bite readily in self defense, these stout beasts are rather clumsy and may safely be grasped behind the front legs (more on handling below).

Housing

Setting up the Terrarium

The ultimate “sit and wait” predator, a Horned Frog rarely moves unless necessary.  A 15-20 gallon tank will accommodate an adult.

Horned Frogs produce copious waste products, and ammonia poisoning is the most common cause of pet death.  Fortunately, they are quite comfortable in simple, easy-to-clean terrariums.  Ease of maintenance is the main consideration when setting up a Horned Frog habitat.

A bare-bottomed aquarium, tilted on one side to create a small water section, is ideal, as it can easily be dumped and cleaned.  Alternatively, a water bowl can be utilized. 

Horned Frogs do not require plants or other furnishings, and are unusual among frogs in that they are quite content without a hiding spot. 

Substrate

Horned Frogs swallow whatever enters their huge mouths along with meals, and are prone to intestinal blockages from gravel and other substrates.  Bare-bottomed terrariums or washable cage liners are best.  I’ve used Sphagnum moss with success, but please see cautions under “Feeding”. 

Light, Heat and Humidity

Horned Frogs do not require UVB light, and humidity is not a concern if they have access to a water bowl. 

A temperature range of 72-85 F suits them well.  An incandescent bulb or ceramic heater can be used to warm the terrarium, but be careful of their drying effects. 

Companions

Juveniles have insatiable appetites and invariably try to swallow even like-sized tank-mates.  They are best housed singly. Same-sized adults may co-exist, but should be fed separately as bites can occur at feeding time.

Feeding

Given the high proportion of vertebrates in their natural diet, it follows that Horned Frogs require a great deal of calcium.  Whole fishes and pink mice are ideal calcium sources; crickets alone, even if powdered with supplements, are not sufficient.

Horned Frogs do well on relatively simple fare…fish, earthworms and crickets can make up most of their diet.  Minnows, shiners or guppies should be offered, with pink mice should be used less often (once each 7-10 days).  While some success has been had by feeding adult mice and even small rats to Horned Frogs, over-use of rodents may lead to liver problems and fur impactions (please see this article). 

Crayfishes, roaches, waxworms, butterworms, silkworms and other commercially-available species should also be provided regularly.  Where practical, feeders should themselves be provided a nutritious diet before being given to your pets (please see these articles on cricket and earthworm care) To increase dietary variety, try wiggling canned grasshoppers, snails and silkworms in front of your frog (using tongs, not your fingers!).

Food (other than pinkies and fish) should be powdered with Zoo Med ReptiCalcium plus D3 or a similar product.  Vitamin/mineral supplements such as Reptivite  should be used 2-3 times weekly.

Youngsters do best when fed daily or every-other-day.  Adults require only 1-2 feedings per week, or can be provided smaller, more frequent meals. 

If you use moss or other substrates, food is best offered via tongs or in a separate, bare-bottomed enclosure to limit substrate ingestion. 

Water

Water should be changed daily and treated with a chlorine/chloramine remover.  Ammonia, released with waste products, is colorless and odorless at low concentrations.  It is rapidly absorbed by frog skin and can prove fatal in short order.  Please see this article.

Special Considerations

Horned Frogs have powerful jaws equipped with sharp, tooth-like structures, and can inflict painful bites. Even after years in captivity, an instinctive feeding response will cause them to bite fingers moved about within range. 

Fortunately, it is a simple matter to safely pick up a Horned Frog by grasping it behind the front legs. Amphibians should be handled only when necessary, and then with wet hands, so that you do not remove the protective mucus from their skin. Wash well after handling any animal. 

Please check out my posts on Twitter and Facebook.  Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable.  I look forward to hearing about your interests and experiences as well, and will use them in articles when possible.

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio

Further Reading

Video: vocal tadpoles

Argentine Horned Frog Natural History

Other Horned Frogs (all species)

Surinam Horned Frog Facts

Ornate Horned Frog image referenced from wikipedia and originally posted by Melanie Mae Brown
Suriname Horned Frog image referenced from wikipedia and originally posted by H Zell
Albino Ornate Horned Frog image referenced from wikipedia and originally posted by Grosscha

Post from: That Reptile Blog


Argentine/Ornate Horned Frog Care: the “Pac Man Frog” and its Relatives

The post Argentine/Ornate Horned Frog Care: the “Pac Man Frog” and its Relatives appeared first on That Reptile Blog.

Amphibian Declines

The threat currently facing amphibians are unprecedented. At least 200 species have become extinct in recent years, prompting some to compare this “Sixth Extinction Crisis” to the disappearance of the dinosaurs. 

Although dedicated biologists continue to battle the spread of Chytrid epidemics and other dangers, traditional conservation measures are not up to the task at hand. Imaginative new approaches, such as the recent cooperative agreements between some zoos and private animal owners (please see article below) are essential.

Breeding Frogs to Fund Conservation

Wikiri is a private company based in Ecuador, a frog diversity hotspot where hundreds of species are at risk of extinction. Its strategy represents, in many ways, a radical departure from traditional thinking on the topic. Wikiri devotes profits from the sale of captive-reared frogs, husbandry products and educational materials to amphibian research and conservation. 

Amphibian biologists based at the Centro Jambata for Amphibian Research and Conservation assist the organization in both captive care and field research.  As a result, Wikiri’s efforts incorporate the latest information available, and are conducted in accordance with local and international laws. The endorsement of Amphibian Ark a major US conservation organization, bears witness to the quality of Wikiri’s work.

Husbandry Advances and Captive-Bred Frogs

Wikiri has made significant advances in the breeding of endangered frogs, the maintenance of Chytrid-free environments and the formulation of healthful diets.  Especially impressive is the focus on eliminating metabolic bone disease in captive amphibians.

Some very interesting species are bred in an environmentally friendly manner and offered for sale. Included among these are the Little Devil Frog, Dendrobates (Oophaga) sylvaticus, the Pacific Horned Frog, Ceratophrys stoltmanni, and the Andean Marsupial Frog, Gastrotheca riobambae.

Other species destined for re-introduction programs are also being produced at Wikiri. Indoor facilities are used, but I’m especially interested in the organization’s reliance upon “enriched natural habitats” as frog-rearing sites.  Complete details have yet to be published, but it seems that frogs are being raised outdoors, on tracts of previously degraded land. Improving the habitat for frogs and their prey shows great promise.

Field Research and Conservation

Wikiri is actively working at several sites in Ecuador, and supporting the work of biologists in others. Chief among these is the Otokiki Tropical Rainforest Reserve, north of the capital city of Quito. Lumbering, agriculture and gold mining have greatly affected surrounding areas, and researchers are at risk from foreign paramilitary forces and drug traffickers. Never-the-less, new strides in amphibian research and conservation are being taken, funded in part by the sale of captive-bred frogs. 

Several at-risk frog species are being actively managed to a degree rarely seen in field situations. Included among these are the Gliding Leaf Frog, Agalychnis spurrelli, the Splendid Treefrog, Cruziohyla calcarifer (an astonishingly-beautiful frog), the Imbabura Treefrog, Hypsiboas picturatus and Little Devil Frog, Dendrobates (Oophaga) sylvaticus. Genetic monitoring techniques are being developed.

Towards a Pet Trade-Conservation Coalition

My involvement in conservation projects that have included both private keepers and professional herpetologists has convinced me that the future of many species lies in cooperative ventures. Zoos do not have the space and funds to do all that is required; please see Herp Hobbyists: Hindering or Helping Conservation? for some examples. Please write in with your own ideas and experiences…many species face a bleak future, and time is short!

Frogs produced by Wikiri will, initially, likely be more expensive than those from other sources. However, profits will be plowed back into conservation and also into research that will benefit pet keepers (i.e. the development of techniques to address Chytrid and MBD). In addition, the high death rates and other problems associated with legal and illegal collection will be eliminated. Please support the work of this and similar organizations. 

Please check out my posts on Twitter and Facebook. Each day, I highlight breaking research, conservation news and interesting stories concerning just about every type of animal imaginable. I look forward to hearing about your interests and experiences as well, and will use them in articles when possible. 

Please also post your questions and comments below…I’ll be sure to respond quickly. 

Thanks, until next time,

Frank Indiviglio

Further Reading

Wikiri’s Frogs and Husbandry Products

Video and Info: Marsupial Frog

The Frog Leg Trade, Chytrid and other Threats

Wikiri’s Conservation Projects

Imbabura Treefrog Natural History

Marsupial Frog image referenced from wikipedia and originally posted by Patomena
Little Devil Poison Frog image referenced from wikipedia and originally posted by PLoS Biology

Post from: That Reptile Blog


Pet Trade Frogs Fund Conservation – Wikiri’s Unique Strategy

The post Pet Trade Frogs Fund Conservation – Wikiri’s Unique Strategy appeared first on That Reptile Blog.