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

Small, shrimp-like marine crustaceans known as krill have long featured prominently in the diets of aquarium fishes.  I’d like to relate here some personal experiences that point to their value as food for turtles, tadpoles, newts and salamanders.

Krill as Turtle Food

Some years ago a herpetologist of my acquaintance, noting that krill were quite high protein and calcium, decided to use this food as a major part of the diet of a group of Blanding’s turtles (Emydoidea blandingii) that had hatched in his collection.  The diet he used, simple by current standards, was comprised of 50% freeze-dried krill and 50% Reptomin Food Sticks.  The turtles matured into beautiful, healthy adults with hard, well-formed shells…not always an easy task in captivity.  I later successfully repeated the experiment with a clutch of Eastern painted turtles (Chrysemys picta).

Amphibians

The diet fed to tadpoles greatly influences their survival rate during the stressful period when they transform into frogs.  I have found that species typically considered to be herbivorous, such as bullfrog and spring peeper tadpoles, actually fare much better when protein such as krill is included in their diets.  Newts, amphiumas, axolotls and African clawed frogs relish krill as well.

Useful Products

We carry a wide variety of freeze dried and frozen krill of various sizes at ThatFishPlace/ThatPetPlace.  You will also find krill and shrimp in Reptomin Select-A-Food, Suprema Food Sticks and Gammarus Shrimp Supplement and in Zoo Med Can O’ Shrimp.

The World’s Most Abundant Animal?

The Antarctic krill, Euphausia superba, may be the planet’s most numerous species…550 million tons of them are swimming in the southern Pacific Ocean at any one time (our own biomass tops out at a mere 110 million tons).  Krill form nearly 100% of the diet of certain seals, whales, birds, shrimp, squid and fishes.

Further Reading

To learn more about using freshwater shrimps, please see my article Zoo Med Canned Freshwater Shrimp.

Krill image referenced from Wikipedia and originally posted by Saperaud

Blandings Turtle image referenced from Wikipedia and originally posted by Raphael Carter.

Pet turtles, especially hatchlings and young specimens, are very commonly afflicted with Vitamin A deficiencies and eye infections, both of which usually render the eyes swollen and/or difficult to open. Eventually, the turtle will become listless, cease feeding and decline rapidly in condition.

Addressing Eye Problems

While turtle eye drops are available and can be effective in certain situations, a veterinary visit should be your first step when your turtle exhibits any type of eye ailment. It is important to determine the nature of the problem before attempting treatment, as an infection will need be addressed differently than a Vitamin A deficiency. Only a veterinarian can make this determination. You can apply eye drops as a safeguard, but do not attempt treatment without a professional diagnosis.

Good Husbandry as a Disease Preventative

Be sure to provide your turtle with ample UVB radiation (the Zoo Med 10.0 bulb positioned within 12 inches of the basking site, is ideal), a balanced diet, and an appropriately warm basking site, so that its immune system will be functioning at full capacity.

As is true for all reptiles, proper husbandry is the most effective medicine at our disposal – please write in if you need specific information concerning the turtles in your collection.

Further Reading

You can read more about addressing turtle eye problems on the website of the Arizona Exotic Animal Hospital.

Image referenced from Wikipedia commons and was first posted by Jmalik

Please see Part I of this article for information on other aspects of breeding the White’s treefrog (Litoria infrafrenata): distinguishing the sexes, preparation for breeding and egg-laying.

The Tadpoles
At 80-85 F, White’s treefrog eggs will begin to hatch in 24-40 hours. The tadpoles remain largely inactive for the first 1-3 days, during which time they should not be fed. Once they begin moving about, food should always be available.

While some have raised White’s treefrog tadpoles on simpler diets, I have been most successful when using a variety of food items. In some cases, tadpoles raised on 1-2 foods develop normally, but the froglets expire within a month or two of transforming. I feed White’s treefrog tadpoles tropical fish flakes, algae wafers, and kale, romaine, dandelion and other greens that have soaked in hot water for 10 minutes or so.

Transformation
Well-fed tadpoles will transform within a month or so of hatching. Some will invariably lag behind, and may remain within the tadpole stage for an additional 4-6 weeks.

The tadpole rearing tank should be well-stocked with live floating plants such as water lettuce, water hyacinth and pothos, and lit by a Reptisun 2.0 bulb (please see Part I of this article). The plants, and a gently sloping reptile basking platform will provide the metamorphs with easy egress from the water.

The Young Frogs (Metamorphs)
Rearing a large number of froglets can be quite a challenge. Overcrowding, especially in situations of limited air flow, rapidly leads to highly contagious fungal infections of the skin. Screen cages  provided with numerous perching sites make ideal rearing enclosures.

Diet
Young White’s treefrogs usually feed vigorously, taking ¼ inch crickets, small waxworms, roach nymphs and similarly sized insects. If you are raising a large number of frogs, consider culturing flightless houseflies (available via biological supply houses). These insects are ideally sized, readily digestible and reproduce rapidly. The Zoo Med Bug Napper Insect Trap  can be employed to help provide the frogs with important dietary variety in the form of wild-caught insects.

All insects offered the frogs should be powdered with vitamin/mineral supplements  for the first few months following transformation.

The White Lipped or Indonesian Giant Green Treefrog (Litoria infrafrenata)
Native to extreme northeastern Australia, New Guinea, Timor and the Solomon Islands, this striking relative of the White’s treefrog inhabits swamps, rainforests, farms and suburban yards. It is the world’s largest treefrog, reaching a snout-vent length of nearly 6 inches.

White-lipped treefrogs tend to be high strung, and do not take well to handling. They should be housed in a large, well-planted terrarium provisioned with numerous perches and arboreal hideaways. This frog is less cold-tolerant than its plucky relative; ambient temperatures of 78-82 F by day and 74-76 F by night suit it well.

White lipped treefrogs may be bred as has been described for White’s treefrogs, but during the cooling-off period temperatures should be kept at 70 F during the night, and 74 F during the day.

Dietary variety for both adult white-lipped treefrogs and their tadpoles seems to be of even greater importance than is the case for other frogs. The metamorphs invariably develop skin problems if crowded or kept without adequate air circulation.

Further Reading
You can read more about the natural history and captive care of the white-lipped treefrog on the web site of the World Association of Zoos and Aquariums.

Image referenced from Wikipedia and originally posted by PicTrans.

In Part I of this article, I discussed how we can use simple pitfall traps to capture nutritious foods for pet reptiles, amphibians and invertebrates.  While writing, it occurred to me that one of North America’s largest and most interesting beetles, the caterpillar hunter (Calosoma scrutator), often turns up in such traps.

Interesting but Ignored

Caterpillar hunters exhibit many qualities that render them ideal terrarium subjects.  They are large, bold, diurnal, brightly-colored, voracious predators, temperature-hardy and breed well.  Despite this, like most US natives, they receive virtually no attention from hobbyists.  Caterpillar hunters are, however, much in demand elsewhere – on my last visit to Japan, entomologists at the Tama Zoo (which hosts a huge building and an outdoor exhibit for insects) assured me they would accept all that came their way.

Natural History

Our native caterpillar hunters are mostly large and brightly-colored, and spend the day searching for insects and their pupae.  Over 2,000 species (Family Carabidae) roam our forests, fields and parks, with 40,000+ having been described worldwide.  One, the forest caterpillar hunter, was imported to the USA from Europe in 1905 to battle gypsy moths.  The grub-like larvae of most are also predacious, constructing burrows from which they ambush passing insects.

Caterpillar hunters are the most numerous predators within many habitats.  Calleida decora, for example, achieves densities of over 5,000 individuals per acre on US soybean farms.  Much favored by farmers battling the velvet bean caterpillar, a single beetle may consume 7-10 caterpillars each day, and each female produces 800-1,000 eggs.

Captive Husbandry

Caterpillar hunters make fascinating terrarium subjects.  Clad in beautiful iridescent colors, most are not at all shy about revealing a range of interesting behaviors.  They do well at normal room temperatures and can be housed in planted terrariums or simple plastic enclosures.  Adults hibernate during the winter, with some species reaching at least 3 years of age.

I have bred two species in captivity, and it seems likely that many others would be equally cooperative.  Caterpillar hunters can be fed crickets, newly molted (white) mealworms and their pupae, waxworms (which, being caterpillars, are a favorite!) and wild-caught insects.

As certain species defend themselves with irritating secretions, caterpillar hunters are best handled with gloves of tongs.

Further Reading

An interesting account of caterpillar hunter behavior is posted at

http://books.google.com/books?id=Qv0SAAAAYAAJ&pg=RA3-PA103&lpg=RA3-PA103&dq=Calosoma+scrutator+appetite&source=bl&ots=Hblglvy188&sig=z1NFPCmeytF-oh_OGWMvdmNZsak&hl=en&ei=WhNlSozhN4HaNpOD0Z8M&sa=X&oi=book_result&ct=result&resnum=9.

Caterpillar hunter image referenced from Wikipedia and originally posted by Fritz Geller-Grimm

Caterpillar hunter larva image referenced from Wikipedia and originally posted by Gyorgy Csoka, Hungary Forest Research Institute, Bugwood.org

In direct contrast to popularly-held theories, researchers at Australia’s University of Melbourne believe that the need to rapidly signal other chameleons, and not the need to hide from predators, has driven the evolution of the amazing color-changing abilities possessed by these lizards.  In a sense, the primary function of color change is to render the animals more conspicuous – the opposite of being well-camouflaged!

Camouflage

However, the need to camouflage still exerts an influence.  By being able to affect color changes in a mere fraction of a second, the lizards lessen the chance that predators will notice them.

Earlier research at the University of Melbourne has also revealed that at least 1 species does endeavor to “match” the background upon which in rests.  In fact, Smith’s dwarf chameleon actually alters the degree of color change it exhibits in response to the type of predator it faces (please see article below).

Other Possibilities: My Experience

I have noticed that, unlike most animals that display (male birds, for example, often sing for hours on end, even if when other birds are not visible), chameleons only flash messages when in the presence of possible rivals or mates.  This would also seem to limit their exposure to predators.

Chameleons also display an incredible range of subtle color variations, most not visible to the human eye which, I believe, also assists in “getting their message across” as quickly as possible.

Further Reading

To learn more about new research regarding color change and predator avoidance, please see my article Chameleons and Camouflage.