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

Lengthening days and warmer temperatures are beginning to register on amphibian pets nationwide, stirring long-dormant breeding urges.  Last week I was please to find that a 2 year old female axolotl (Ambystoma mexicanum) which I paired with an older male had produced eggs for the first time.  A week or so earlier a reader informed me of another spontaneous axolotl breeding.

Mexican axolotls are an ideal choice for the prospective amphibian breeder, and are becoming ever more popular each year.  With spring upon us, I thought I might pass along some photos of my pair and their eggs, along with a few tips.

The Aquarium and Filter

The eggs pictured here are set up in a PLA House Plastic Cage equipped with a Small World Filter.  PLA House Cages are available in 6 sizes, and their light weight allows for easy water changes.  I have found them indispensible in my collection, and always have a number on hand.

The Small World Filter is ideal for use with amphibian larvae, as the water return is directed upwards and so does hamper weak swimmers.  Sponge filters work equally well.  I use an air pump that provides just enough aeration to keep the eggs slightly in motion.

Providing Cover
Axolotl eggs are typically attached to plants or other structures, as seen in the accompanying photo.  Once they begin to hatch, I’ll add additional plants, nearly filling the tank so as to separate the larvae a bit and reduce cannibalism.  Plastic plants set in bases are very useful, as they provide shelter throughout the water column. The Cypress Mat  provides excellent cover on the bottom of the aquarium, where the larvae will be spending most of their time.

Feeding Axolotl Larvae
Finely chopped live blackworms form the basis of my diet for newly hatched larvae…a worm feeder lessens the likelihood of the worms clumping together (larvae often choke while trying to swallow large balls of worms).  A brine shrimp hatchery is also useful, and larvae can sometimes be induced to accept freeze dried daphnia and other invertebrates as well.

Further Reading
Pleased see my article Breeding Mexican Axolotls  for additional breeding recommendations.

 

ReptoMin Floating Food sticks have long been recognized as a valuable dietary staple for many aquatic reptiles, amphibians and invertebrates, and are used in zoos and private collections worldwide.  A new version, ReptoMin Select-A-Food, contains the original food sticks as well as freeze dried plankton and shrimp.  The size of the individual food items is geared towards smaller creatures, and each ingredient is housed in its own compartment, allowing for careful control of your pet’s food intake.

My Experience

ReptoMin Food Sticks are unique in that they form a nearly complete diet for quite a few species…the addition of freeze dried invertebrates increases the product’s value immensely.  I have used Reptomin Foods Sticks while caring for herps in the Bronx Zoo’s collection, as well as for my own pets, since its introduction, and most other professional zookeepers do the same.  Following is a brief summary of those species for which I have used it as a major component of the diet.

Amphibians

50-75% of the diet of African clawed frogs (several species) and of fire-bellied, red-spotted, California, ribbed, alpine and crested newts, among others.

80-90% of the diet of Mexican axolotls and of larvae over 1 month old.

50-75% of the diets of the larvae of numerous salamanders, including spotted, marbled, tiger and fire salamanders.

50-75% of the diets of numerous tadpoles, including American and African bullfrogs, green frogs, edible frogs, American toads, Wallace’s flying frogs, Australian bell frogs and horned frogs (several species).

Turtles

Except for live food specialists such as the mata mata, nearly every aquatic and semi-aquatic turtle relishes ReptoMin and freeze dried shrimp.  Due to the high calcium needs of growing turtles, I tend to supplement their diets quite frequently with whole fishes and crayfish as well.  I vary the percentage of ReptoMin with the species and situation, but usually rely upon it heavily.

I have used ReptoMin for 50-75% of the diets of hatchling red-eared sliders and snapping turtles, and 30-40% of the diets of spotted, painted, musk, Asian box, Bornean pond and many other turtle species.

Invertebrates

Reptomin is eagerly accepted by crayfishes, fresh water shrimp and most aquatic snails, as well as a number of terrestrial invertebrates – millipedes, roaches, snails, crickets and sow bugs.

Larger Animals

For those pets that require larger food items as they grow (i.e. the huge African clawed frog pictured here) you can offer the same basic nutrients by switching from Select-A-Food to a combination of ReptoMin Food Sticks, ReptoTreat Suprema Food Sticks (krill)  and ReptoTreat Gammarus Shrimp.

Further Reading

For a look at another very useful food item for aquatic animals, please see my article Zoo Med’s Canned Shrimp .

 

 

Breeding season aggression is a potentially serious concern for owners of male green iguanas.  Spurred by reproductive hormones, mature males, even those which have been placid for years, may suddenly become dangerously aggressive.  This most often, although not necessarily, occurs in the late winter to early spring in the USA, so I thought that a word of caution might be in order at this time.

The Results of an Iguana Bite

If you are caught off-guard, an iguana attack can be quite severe.  A former coworker of mine, well-seasoned in reptile care, was surprised by an aggressive male who had been living without incident in the collection for over 10 years. The animal latched onto his throat and then fell to the floor, leaving a wound that required 18 stitches to close.

Timing and Indications of Sexual Maturity

Depending upon dietary and other factors, male green iguanas may reach sexually maturity as early as 18 months of age or as late as 7 years or more.  Unfortunately, the onset of aggression may be quite sudden, may not occur every year, and can last from 2 weeks to several months.  As you can see from the preceding story, animals may be even-tempered for many years before suddenly changing their behavior.

Males in breeding condition may exhibit a deepening of coloration in the orange-tinted areas of the head and body, and may head-bob and erect their crests.  Waxy secretions are usually present along the femoral pores, and dried semen is often found in their cages.  However, these changes do not always precede aggressive behaviors, so caution is always a necessity around large males.

Dealing With an Aggressive Iguana

A number of strategies for dealing with aggressive male iguanas have been proposed, with results varying widely.  I suggest that a plastic garbage can lid be held as a ready shield when working around aggressive males…a broom works well if the animal is at large in a room.  Fighting back with these tools may convince the animal to seek an easier target.  Avoiding close contact with the animal until the “mania” has passed, and keeping a shield at hand, are the safest options.  An alcohol-soaked rag (please see below) and, if possible, a helper, are very useful as well.

Some pet owners deflect aggression by providing their iguana with a towel to attack (or mate with!), while others keep the animal in a darkened room for 3-4 days to lessen the production of testosterone and other hormones.  Surgically neutering the animal is also an option, but the results of such have been mixed – in a significant number of cases the aggressive behavior remains largely unchanged.

If You Are Bitten

If you are bitten, do not pull your hand away.  Stabilize the animal so that it cannot thrash about and apply an alcohol-soaked rag to the lizard’s nostrils (avoid the eyes).  Liquor is fine to use (for the rag, not for drinking while working with your pet!) and should always be within reach during the breeding season.  Once the iguana releases its grip, secure it in its enclosure and call your doctor for instructions as to wound care.  Please do not neglect this step, as a tetanus shot or other care may be required, even for relatively minor wounds.

The Tail as a Weapon

The iguana that I am holding in the accompanying photo caused the cuts visible on my arm with a mere flick of his tail…the jaws are capable of doing much worse.  I came across him and the larger male (who, at 5’11” long, was the largest I encountered in the field) while working on anaconda research in Venezuela’s central llanos country.

Gravid Female Iguanas

Mature female iguanas often develop eggs as spring arrives.  Such will occur with or without the presence of a male, so be sure to watch even those animals which are housed alone.  Ideally, unmated females will resorb the eggs into their bodies, and have no need for nesting sites.  However, sometimes the eggs develop fully and, consequently, must be deposited.

Gravid (egg-bearing) female iguanas will usually cease feeding, or feed less vigorously, and will become very restless.  They often injure themselves by rubbing along cage walls and screening at this time, and they may attempt to dig through the cage floor.

Providing a Nest Site and Avoiding Egg Retention

Females without access to an appropriate nest site may retain their eggs, which will lead to potentially fatal health problems.  Provide gravid females with a large plastic container filled to a depth of 18-24 inches with moist top soil and moss.  Covering the container and warming the earth’s surface with a lamp may induce her to accept it as a nest site.  There are a number of other tricks you can try…please write in it you need further information.

Veterinary intervention may be required if the female refuses to lay her eggs.  In many cases, an injection of oxytosin is effective in causing the eggs to be expelled.

Further Reading

I’ve written about my experiences with wild green iguanas in another article on this blog.  Please see The Green Iguana on the Venezuelan Llanos.

An interesting article on iguana farming and conservation efforts in Belize is posted at http://www.thewildones.org/Belize/iguana.html.

 

Those of us who keep the smaller varieties of insect-eating reptiles, amphibians and invertebrates (dwarf leaf chameleons, bark scorpions), or who raise the young of others (many newly-transformed frogs and baby lizards), are faced with great challenges when it comes to providing a balanced diet.  Many of these animals consume dozens if not hundreds of different types of invertebrates in the wild.  Yet in captivity they must get by on very limited number of commercially bred insects – pinhead crickets, fruit flies and springtails.  Although vitamin/mineral supplements help, the situation is far from ideal, especially where little-studied species are concerned.

Special Concerns

The problem is particularly acute because nutritional deficiencies suffered early in life are difficult or impossible to reverse later on…reptiles and amphibians that remain small never outgrow this dilemma.  Those of you with an interest in invertebrates may face similar concerns when you breed mantids and certain spiders and scorpions.

An Ideal Food Source for Smaller Pets

A very simple (and free!) solution to this problem lies as close as the nearest pile of decaying leaves – leaf litter invertebrates.  A vast army of tiny decomposers and scavengers – ants, slugs, millipedes, sow bugs, beetles, mites, springtails, bristletails and termites – inhabit accumulated leaves in city gardens and pristine forests alike.

Even excluding earthworms, the weight of the invertebrates in a single acre of New England forest leaf litter can top 3 tons – greatly exceeding that of all resident mammals and other vertebrates!  So how do we get at them? More on that next week.

Other Sources of Tiny Insects

The Zoo Med Bug Napper, a very effective insect trap that I rely upon throughout the warmer months, will attract tiny gnats, moths, beetles and flies along with larger insects.  These too make fine foods for your smaller pets.

For information on a simple method of gathering termites, please see my article Building a Termite Trap.

Next time I’ll explain how to harvest and use this bonanza of free food, and my unexpected find when visiting reptile collections overseas.

Further Reading

Several tiny invertebrate species can be cultivated as food.  Please see my articles on Breeding Flour Beetles  and Sow Bugs for further information.

 

Click: Surinam Toads (Pipa pipa) as Pets: Acclimating New Animals and Special Considerations – Part 1, to read the first part of this article.

Arranging Shelters and Hiding Spots
Give the frog as much cover as possible – plastic plants with weighted bases and others secured around rock ornaments or otherwise held at the bottom of the aquarium are best. The frogs will push beneath the plants and hide. They seem to prefer this to caves, and in fact rarely enter enclosed shelters in the manner of African clawed frogs.

However, Surinam toads will shelter under driftwood if the wood is arranged to provide an overhanging ledge as opposed to a discrete cave. Piling a few pieces atop one another usually does the trick, and adds a nice touch to the aquarium’s décor as well.

Light
When you first acquire your frog, do not use an aquarium light, and never turn the room light on when the room is very dark…the shock of the sudden glare would be very stressful. A group of frogs I received recently for a public exhibit were so shy that I needed to cover the aquarium with dark material for 2 weeks…if you do likewise, be sure to remove the covers slowly so as not to startle the frog.

Once your pet has acclimated to captivity you can use a light…just be sure to utilize real or artificial floating plants  and the shelters described above to cut down on light levels. Surinam toads are nocturnal – even by day the turbid waters in which they dwell filter out a good deal of sunlight.

Filtration and Water Quality
You’ll need an effective filter, but take care to adjust the water flow so that it does not move the frog about. Although they are powerful swimmers, Surinam toads do not take well to strong currents.

Partial water changes (20-50% every 1-4 weeks, depending upon filtration) are vital to maintaining good water quality. Use a test kit to check your ammonia levels frequently. In common with other aquatic amphibians, Surinam toads excrete wastes in a highly toxic state. High levels of ammonia will cause them to cease feeding, and eventually to expire. Bear in mind that the waste products are largely comprised of liquids and will not be visible. Be sure to de-chlorinate all water used in the aquarium.

Fungus, Injuries and Parasites
Check the skin for grey or white areas, either of which might indicate fungus, and also for injuries…these frogs do not ship well, and often arrive in poor condition. Please write in for suggested treatments if you observe any unusual marks, scratches or discolored skin.

I sometimes treat wild caught Surinam toads for parasites following a fecal test or cloacal swab, but am hesitant to suggest this as a necessary precaution – amphibian medicine is not, to say the least, an “exact science”. However, it’s something to consider if your frog refuses to feed or experiences other difficulties…please write in if you would like to explore this option further.

Further Reading
Please see Breeding a Skin-Brooding Amphibian: the Surinam Toad (Pipa pipa)  to read about my first experience in breeding this fascinating animal.

You can watch a captive Surinam toad feeding below:

(Note the frog’s backward “shoveling” motions with the rear legs. This is how they push their way below plants and bottom debris).

Feeding Surinam toads can be a bit tricky as well, but is a very interesting endeavor (please see video above). I’ll provide some suggestions that have worked for me (or, rather, my frogs!) next time.