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

Despite my very wide interests (my career with animals has, quite literally, spanned ants to elephants!), I’ve always been partial to newts and salamanders. I focused on them from my earliest days working for the Bronx Zoo, and had the good fortune to author two books on their care and breeding. As pets and zoo specimens, they range from nearly impossible to keep to being among the longest lived of all captive herps (to age 50+, for the Fire and Japanese Giant Salamanders). The following points, drawn from a lifetime of working with these wonderful creatures in zoos, the field, and at home, are useful to consider before embarking on your amphibian-keeping venture.

 

Note: The terms “newt” and “salamander” do not always correspond with taxonomic relationships. All newts may be correctly called “salamanders”, but generally we consider newts to be those species that spend most of their time in water and salamanders to be more terrestrial. However, the term “salamander” is also used for many completely aquatic animals, such as the mudpuppy and hellbender…so call them what you wish!

 

As the care of different species varies greatly, please post below if you have specific questions, or would like a link to an article on a certain species.

 

Newts and Salamanders are “Hands-Off” Pets

Fire Salamanders, Tiger Salamanders, Ribbed Newts and some others are often responsive to their owners, and will readily feed from the hand. However, they should be picked-up only when necessary, and then with wet hands. All amphibians have extremely delicate skin, and even microscopic tears will allow harmful bacteria to enter and cause havoc.

 

Also, all produce toxic secretions designed to repel predators. The toxins of several North American salamanders have caused temporary blindness when rubbed into handlers’ eyes, and the ingestion of California Newts (apparently some sort of college ritual) has resulted in fatalities. Severe irritations are to be expected if these toxins find their way onto broken skin or mucus membranes. Obviously, this is a special consideration for those with young children at home.

 

Well-cared-for newts and salamanders will reward you by exhibiting fascinating behaviors…but not if you disturb them with unnecessary handling!

 

Clean Terrariums and Excellent Water Quality are Essential

Newts and salamanders absorb water through the skin, and along with that water comes any associated pollutants. The most common of these is ammonia, which is excreted with the waste products. Most newts and salamanders are as or even more sensitive to water quality than are tropical fishes, since they absorb water over a greater surface area.

 

Ammonia test kits, partial water changes and strong filtration are critical to success in keeping amphibians. Substrate needs the same attention as does water, as terrestrial species can be poisoned by ammonia-soaked moss or soil.

 

Newts and Salamanders Need a Varied Diet

No species will thrive long-term on a diet comprised solely of crickets. Earthworms can be used as a dietary staple for most newts and salamanders; it would be wise to locate a source and perhaps set up a colony before purchasing your pet (please see the article linked below). I’ve done well by relying upon wild-caught invertebrates during the warmer months. Moths, beetles, tree crickets, harvestmen, “smooth” caterpillars and a variety of others are accepted – usually far more enthusiastically than are crickets! Please see these articles for tips on collecting insects.

 

Useful invertebrates that you can buy include roaches, butterworms, calciworms, silkworms, and sow bugs.

 

Newts are simpler to feed than are terrestrial species, as nearly all (i.e. Red-Spotted, Crested, Paddle-tailed, Ribbed) will accept Zoo Med Aquatic Newt Food and Reptomin. These foods can anchor the diet, with live blackworms (sold in many pet stores as tropical fish food), guppies, chopped earthworms and small crickets being offered on occasion.

 

Spotted Salamanders, Red Efts and other terrestrial species will accept live food only.

 

Many Newts and Salamanders are Heat Sensitive

Average household temperatures are too warm for the vast majority of newts and salamanders. Even those native to seasonally hot regions, such as the Spotted and Marbled Salamanders of the American Southeast or North Africa’s Fire Salamanders, live in cool micro-habitats (often below-ground). Sustained temperatures above 75 F (and, for many, above 70 F) weaken the immune system and increase susceptibility to bacterial and fungal skin infections. A cool basement is the ideal location for most species.

 

If you must keep your pets in a warm room, several of the more tolerant newts should be considered. Please post below for further information.

 

The “It Doesn’t Do Anything” Factor

Ideally, the new amphibian owner will be interested in her or his pet for its own sake. But most of us also wish to see how it lives, what it does, and so on. Many amphibians are about as active as the infamous “pet rock”…and are nocturnal to boot!

 

If you favor an active pet, consider a diurnal newt that forages for rather than ambushes its food, and keep it in a large, naturalistic aquarium. Six Fire-Bellied Newts in a well-planted 20 gallon tank will provide you with infinitely more to observe than will an equal number of Marbled Salamanders housed in a terrarium of the same size.

 

Some nocturnal species may adjust to daytime schedules once they settle into their new homes. Tiger and Fire Salamanders are especially accommodating in this regard. Red night-viewing bulbs will greatly increase your ability to observe Slimy Salamanders and other strictly nocturnal species.

 

 

 

Further Reading

Earthworm Care and Breeding

Newt Care

Fire Salamander Care

Tulane University researchers have published an important study concerning captive frog nutrition that should be of interest to all amphibian and reptile keepers. A colony of Strawberry Poison Frogs (Oophaga pumilio) was maintained on a diet comprised of fruit flies. When carotenoids were added to the fruit fly diet, the frogs produced significantly more eggs, and a greater number of tadpoles survived through metamorphosis. The Vitamin A deficiency found among some of the animals was also reversed.

 

Nutritional deficiencies are common in both private and public amphibian collections, partly because of the limited dietary variety we are able to provide. Adding carotenoids (which are pigments produced by plants) to the diet of feeder insects may be a simple means of improving health and reproductive output – especially important in these times of unprecedented amphibian declines. Please see also the links under “Further Reading” for other articles I’ve written on supplementing cricket diets with carotenoids and Vitamin A deficiency in frogs.

 

Carotenoid Function and Sources

Various plant pigments known as carotenoids are responsible for the yellow-orange color of egg yolks and skin among a huge array of animals. They also play a role in neonatal health, benefit the immune system by acting as antioxidants and function in the reproductive system. Animals cannot manufacture carotenoids but rather must obtain them from their diet.

 

In the Tulane University study (Zoo Biology, V32, N6), the fruit fly medium’s carotenoid content was increased by the addition of Spirulina, red phaffia yeast and powdered marine algae. Studies have also shown that the provision of fruits and vegetables increases the carotenoid content of crickets; please see links below.

 

Effects on Reproduction and Survival

Sixty-two pairs of Strawberry Poison Frogs were included in the study. The increased tadpole survival was attributed to higher quality eggs being produced by female frogs. Infertile eggs, which are deposited by females as food for their tadpoles, were also believed to be of higher nutritional value following carotenoid supplementation.

 

A number of the animals were found to suffer from a Vitamin A deficiency. This condition was reversed over the course of the study. Many animals convert carotenoids to Vitamin A, so it is theorized that the addition of carotenoids to the fruit fly medium was responsible. As many frog enthusiasts know, the all-too-common condition known as “Short Tongue Syndrome” has been linked diets low in Vitamin A. If your frogs or toads are having difficulty catching insects, please see the link below, or post here for further information on this disorder.

 

Further Reading

Adding Carotenoids to Cricket Diets

 

Carotenoid Supplementation may Brighten Frog Colors

 

Do Your Frogs have Trouble Catching Insects?

The discovery of a new frog is always an exciting event, but the species revealed in this month’s issue of Zoo Keys is especially so. The colorful, entirely-aquatic Telmatobius ventriflavum was found in a small stream along a major highway 3,900 feet up in the Peruvian Andes. It is related to a unique group of frogs, the best known being the bizarre, “push-up performing” Lake Titicaca Frog (Telmatobius culeus).   I was fascinated by the huge, baggy-skinned Lake Titicaca Frogs resident at the Bronx Zoo (the only ones in captivity) as a child – and due to their 30 year lifespans, I was lucky enough to work with those same individuals once I began my zoo-keeping career!

(Please see the article linked below for more on this amazing frog). The Lake Titicaca Frog’s newly-discovered relative promises to be just as interesting – and, it seems, is similarly threatened with extinction.

 

A Strange Frog in a Harsh Habitat

The new found frog sports the odd (some say “un-nerving”) upwardly-directed eyes typical of the other 62 members of the genus Telmatobius (similar, in my mind, to those of the more familiar Buddget’s Frog) and a beautiful, bright yellow to orange abdomen.

 

The only known population occupies a narrow stream of the Huaytara River, located in a valley on the Pacific slope of the Peruvian Andes. Herpetologists were surprised by its discovery because the site is near a major highway, and in a region that has been well-studied. The frog’s bright coloration might also have been expected to draw attention. Furthermore, a completely aquatic frog was not expected in this habitat – a dry, shrub-studded alpine grassland known as the Puna. The region receives a bit of rain from January to March, after which it remains bone-dry, and it has few resident amphibians.

 

Threats: Chytrid, Dams and Isolation

Because the stream in which T. ventriflavum lives is separated from other suitable habitat by desert-like grasslands, the species is assumed to be endemic to the immediate area. The stream has dammed, but it is not known if this negatively affects the population (but it’s a pretty safe bet that it does!).

Unfortunately, some of the frogs and tadpoles that have been examined were found to harbor Chytrid fungus, which has been responsible for scores of amphibian extinctions worldwide. So far, nothing is known of the fungus’ impact on the population, but herpetologists are not optimistic. In Ecuador, 3 related species have been wiped out by chytridiomycosis, the disease associated with this fungus.

 

As T. ventriflavum is already at risk due to its tiny range and the damming of its home stream, careful study of the population, especially as regards Chytrid infection, is being considered.

 

 

Further Reading

Lake Titicaca Frog Conservation

Original Article Describing the New Aquatic Frog

 

 

 

Read More »

Newts of all kinds are very popular with amphibian keepers. Although most in the trade are quite small, one of the hardiest and most personable is a true newt giant. The attractive Spanish Ribbed Newt (Pleurodeles waltl) can reach 12 inches in length, and is stoutly-built. They are easy to breed – an important consideration as wild populations are threatened – and quickly learn to feed from the hand. And, as you’ll see below, they employ on of the animal world’s most unique defensive strategies (pets, however, become so tame that they never feel the need to defend themselves!).

 

Newts and salamanders have always held a special fascination for me. Beginning in childhood, I sought to breed as many species as possible, and I focused on their husbandry and conservation when I entered the zoo field. In time, I wrote a book summarizing my experiences. The passage of so many years has not dulled my enthusiasm for any of these fascinating amphibians, but the Ribbed Newt has always been a personal favorite.

 

A Note on the term “Newt”

The term “newt” is usually applied to small, semi-aquatic salamanders in the family Salamandridae. The group’s 80+ species range throughout North America, Asia, Europe and parts of North Africa. The Ribbed Newt may reach 12 inches in length, but most newts top out at 4-6 inches.

 

Description

Spanish Ribbed Newts are generally grayish-brown in color, but some exhibit yellow or green hues, while others are nearly black. Rows of yellow to orange “warts” (poison glands) line the upper edge of the body. Amazingly, distressed individuals will contract their bodies and force the ribs right through the back’s skin, directly over these glands. The toxins contained therein are thus in a position to thwart most predators.

 

Neotenic adults (bearing gills and totally aquatic, but able to reproduce) have been found in the wild and reported by hobbyists and lab caretakers. A strain of leucistic (white in color) Ribbed Newts has been developed by private breeders.

 

The largest Ribbed Newt I’ve encountered was built like a well-fed Tiger Salamander, and measured just over 12 inches in length. Most adults top out at 8-9 inches.

 

Two related species, rarely if ever seen in the pet trade, are classified in the genus Pleurodeles.

 

Range and Habitat

The Spanish Ribbed Newt is limited in range to Spain, Portugal and Morocco, and is generally found in arid habitats. Highly aquatic, it favors temporary and permanent ponds, swamps, canals, and other stagnant or slow-moving bodies of water. In Morocco, Ribbed Newts have been found living in cave waterways 100 feet below-ground.

 

Behavior

Ribbed Newts are always nosing about for food, exploring, and interacting with tank-mates. They see well and may swim to the aquarium’s side when you enter the room, in anticipation of a meal.

 

Handle newts only when necessary, and with wet hands, so that the skin’s protective mucus covering is not removed.

 

Housing

Ribbed Newts are almost entirely aquatic, but do need a place to haul out and rest. The water in their aquarium can be deep, provided that egress is simple…cork bark, turtle platforms, and floating live or plastic plants all serve well as resting spots.

 

Newts are perfectly suited to aquariums stocked with live plants, and spectacular displays can be easily arranged. Plants help maintain water quality, and the complex environments they create make life more interesting for both newt and newt-owner alike.

 

Substrate

Smooth, rounded gravel of a size that cannot be swallowed is ideal; rough stones will injure the delicate skin.  Bare-bottomed tanks, which are easily kept clean, may also be used.

 

Water Quality

In common with other amphibians, Ribbed Newts have porous skin that allows for the absorption of harmful chemicals. Careful attention to water quality is essential.

 

An aquarium pH test kit  should always be on hand. Ribbed Newts fare well at a pH of 6.5 to 7.5, with 7.0 being ideal.

 

Ammonia, excreted as a waste product and produced via organic decomposition, is colorless, odorless and extremely lethal to all amphibians; a test kit should be used to monitor its levels.

 

Chlorine and chloramine must be removed from water used for any amphibian. Liquid preparations  are highly effective and work instantly.

 

Copper may be leached by old water pipes; a test kit should be used if you suspect its presence.

 

Filtration

Undergravel,  sponge,  and most other filters designed for use with fish, reptiles and amphibians can all be used in Ribbed Newt aquariums. Even with filtration, regular partial water changes are essential in keeping ammonia levels in check.

 

As Ribbed Newts are not strong swimmers, water outflow from the filter should be mild; plants, rocks and movable outflow attachments can be used to reduce current strength.

 

Light and Heat

Newts do not require UVB exposure. UVA light is not essential, but may encourage natural behaviors.

 

Ribbed Newts fare best when kept fairly cool, i.e. 60-68 F., although temperatures to 72 F are usually well-tolerated. Temperatures consistently above 75 F may weaken the immune system or cause other health problems. Temperature tolerance seems to vary among populations, and may be linked to the portion of the range from which the animals originated.

 

Feeding

Zoo Med Aquatic Newt Food and Reptomin Food Sticks can be used as the basis of the diet. Freeze-dried shrimp, “gelled insects”, and frozen fish foods (i.e. mosquito larvae) should be offered regularly.

 

A variety of live foods will help ensure a balanced diet. Blackworms, bloodworms, earthworms, guppies, small crickets and similar foods will be eagerly accepted. Stocking the aquarium with live blackworms and guppies will keep your pets active and occupied.

 

Breeding

Ribbed Newts reproduce quite regularly in captivity, and provide an excellent introduction to amphibian breeding. Breeding sometimes occurs spontaneously but results will be improved if you manipulate water temperatures and day length somewhat. Unlike many amphibians, Ribbed Newts may even breed following a 1-day change in water temperature. Please post below for detailed information on inducing reproduction and rearing the young.

 

 

 

Further Reading

Please check out Newts and Salamanders, a book I’ve written on their care and conservation.

 

Newt Toxins: personal observations

 

While working at the Bronx Zoo, I had the good fortune to breed Kihansi Spray Toads – an endangered species that gives birth to fully-formed toadlets – and the amazing skin-brooding Surinam Toad. Yet these are but two examples of the amazing diversity of odd frog breeding strategies, none of which resemble what might be called “normal” frog behavior! Among the world’s 6,400+ frog species, we find tadpoles that eat bark, their mother’s eggs and even their father’s skin, along with parents that carry eggs or young in skin pouches, vocal sacs and even stomachs. None, however, were known to give birth to live tadpoles. As you’ll see below, a herpetologist’s extremely lucky catch, at just the right moment, changed that recently – one can only guess at what will come next!

 

Strange Frog in a Strange Land

The Indonesian island of Sulawesi, located between Borneo and the Philippines, is home to some of the world’s most unique and (to most of us) unexpected animals. From invertebrates to mammals, the island’s fauna is “rule-breaking” and astonishing (take a look at the Sulawesi Black “Ape”, pictured here). So the UC Berkeley biologists working there recently were well-used to surprises. But when a herpetologist grabbed at a frog and came up with a handful of tadpoles as well, he knew that new ground had been broken.

 

Fanged Frogs

The frog in question, Limnonectes larvaepartus, had been collected before, but has only now been recognized as a new species. Endemic to Sulawesi, it belongs to a little-studied group known as the Fanged Frogs. Armed with sharp bones that project from the lower jaw (similar to the odontoids borne by Horned Frogs and African Bullfrogs), male Fanged Frogs battle one another, presumably for mates and territory.

 

Internal Fertilization and Live Birth

But where Limnonectes larvaepartus is concerned, peculiar dentition is only the beginning of the story. Following the timely capture of a female in the process of giving birth, it was determined that this new species also employs a new (to us, anyway!) form of reproduction. It is the only frog known to produce live tadpoles rather than eggs or small frogs. What’s more, fertilization is internal – a strategy used by only 8-10 of the world’s 6,455 frog species (including the USA’s Pacific and the Rocky Mountain Tailed Frogs; please see photo). The new species is described in the journal PLOS One (12-31-14, Iskander et al; see link below).

 

This discovery may help herpetologists to understand the evolution of the amazing diversity of Fanged Frogs on Sulawesi and elsewhere in Southeast Asia. Many more than the currently described 62 species are expected to be found, and as with all creatures on Sulawesi, they likely hold wonderful surprises for us.

 

Natural History of the New Species

We know very little about Limnonectes larvaepartus. There is some speculation that males may guard the tadpoles, but this remains to be confirmed. Females seem to rely upon small forest pools in which to deposit their tadpoles. This may be an attempt to reduce the threat of predation by larger relatives that inhabit nearby streams, but further research is needed.

 

Learning More About Amphibian Breeding Strategies

I can’t seem to stop writing about the amazing breeding strategies of frogs, caecilians and salamanders. Please see the articles below for more on wood-eating tadpoles and others. The article first describing Limnonectes larvaepartus is also linked.

Tree-Dwelling Tadpoles that Feed Upon Bark

Skin-Eating Tadpoles

Novel Reproductive Mode in a New Species of Fanged Frog