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Wild Caught Invertebrates as Reptile and Amphibian Food: Pesticide Concerns – Part 1

 

I frequently recommend wild-caught invertebrates as food for captive herps, birds, invertebrates and fishes. Today I’d like to address the thoughtful comments posted by some of our blog readers regarding potential pesticide contamination.

Secondary Poisoning

Secondary poisoning, the killing of animals other than the species that is the target of a pesticide, is an important concern whenever toxins are used.

Modern Pesticides

Commercial pesticides have evolved quite a bit since the secondary poisoning effects of DDT were documented in the 1960’s. Today, a combination of species-specific products and short half-lives (the time the pesticide remains lethal once applied) greatly reduces the risk to non-target species. This is especially true where West Nile Virus control and similar programs are undertaken by local municipalities…the chemicals used are carefully evaluated, and follow-up studies are implemented.

Secondary Poisoning Facts

As regards captive animals, the concern is that they will be affected by a pesticide after consuming food animals that have themselves been exposed.

While valid, such is not quite as likely as it may appear at first glance. Even as regards the highly publicized DDT scenario, the effects of DDT were manifested largely among top consumers (eagles, ospreys and other raptors) that consumed, over many years, fishes and birds that had concentrated the toxin in the course of feeding upon insects.

The non-target species were not killed outright, but the cumulative effects of the concentrated DDT rendered bird eggshells brittle and subject to breakage. There are, of course, exceptions…but, in any event, pesticides now in use are formulated so as to exert far less radical effects on non-target species.

Zoo Practices

During my 30+ years working with major zoos, aquariums and nature centers in the USA and Japan, wild-caught invertebrates have often been used to supplement the diets of reptiles, amphibians, birds and other creatures. The use of light-based insect traps (i.e., the Zoo Med Bug Napper) has been a standard practice in zoos long before my time in the field; laboratory analysis of invertebrates so collected has supported the safety of the practice as regards most species.

All major zoos use insecticides to kill roaches and rodenticides for mice and rats. Except in very unique situations, it is simply impossible to control such pests by other means. Roaches and mice survive for varying periods after being sprayed or consuming poison. During that time, they enter enclosures housing animals that prey upon them (this is well documented by cameras installed to record nocturnal behavior). During my time in the zoo field, the only local case of secondary poisoning that occurred involved a wreath-billed hornbill that consumed poisoned mice nearly exclusively over a period of years.

My Collection

In my collection, the use of native invertebrates dates back over 40 years. In a great many cases, animals that I have kept on such diets have reproduced and even set or approached longevity records (musk turtle, still alive at age 40; marine toads, 20+ years; African clawed frog, 19 years; weather loach, 19 years). My experience is echoed by many of the prominent hobbyists and herpetologists with whom I have long worked.

That being said, there are specific species and situations that warrant caution. I’ll cover these in Part II of this article.

Further Reading

Please see my article Collecting Invertebrates: an Entomologist’s Technique and the articles referenced there for further information.

 

Conservation Update: Endangered Anderson’s Salamanders Bred by US Hobbyists

One of the world’s rarest amphibians is being bred by dedicated hobbyists and is now available in the US pet trade. Anderson’s salamander, Ambystoma andersoni, which was only formally described in 1984, is limited in range to a single high altitude (6,000+ feet above sea level) lake and stream in south-central Mexico (Laguna de Zacupa, Michoacan, Mexico).  The IUCN lists it as “Critically Endangered”.

Rare Aquatic Salamanders of Mexico’s Highlands

Anderson’s salamander is part of a complex of similar aquatic, neotenic salamanders which includes the Mexican axolotl (A. mexicanum).  Neotenic species retain larval characteristics such as external gills and an aquatic lifestyle upon maturity.

A dozen or more species of these unique, poorly-studied amphibians inhabit mountain lakes in Mexico.  Most are found only in a single lake or, in the case of the axolotl, may exist only in canals and other habitat remnants. Some, including the Dumeril’s salamander (A. dumrelii), seem to have adapted to waters that are somewhat saline in nature.

Hope for the Species’ Survival

The sole population of Anderson’s salamanders is threatened by pollution, habitat loss and collection for the (human) food trade.  Its relative, the Mexican axolotl, was saved from extinction by captive breeding efforts, and is now in the unique position of being one of the most common captive and rarest wild salamanders.

Originally surfacing in Europe, captive-bred Anderson’s salamanders are now available in the USA as well.  This represents a unique opportunity for serious hobbyists to help learn about and conserve an endangered species. As a bonus, Anderson’s salamander is large, beautifully patterned and relatively hardy as well.

Keeping Anderson’s Salamander

The captive husbandry of Anderson’s salamander is similar to that of the Mexican axolotl (please see article referenced below)…please write in if you are interested in becoming involved what may become a most worthwhile amphibian breeding effort.  At this point, noted salamander specialist Michael Shrom is likely the only person breeding Anderson’s salamanders in the USA. You can contact Michael at shrommj at ptd.net.

Further Reading

You can read more about the natural history of Anderson’s salamander and its relatives at http://www.mexico-herps.com/caudata/ambystoma/ambystoma-andersoni.

For information on the Mexican axolotl, please see my article The Natural History and Care of the Mexican Axolotl http://blogs.thatpetplace.com/thatreptileblog/2008/12/19/the-natural-history-and-captive-care-of-the-mexican-axolotl-ambystoma-mexicanum-natural-history-part-1/.

Photos courtesy of Michael Shrom.

Tailless Whipscorpions – the Weirdest of All Arachnids?

Having long worked with a variety of the world’s most unusual invertebrates, I had imagined myself ready for any and all surprises that might be offered by these fascinating creatures.  Yet the first tailless whipscorpion that I encountered in the wild – a huge specimen that met my gaze inside a hollow tree in Venezuela (where I was searching for yet another bizarre beast, the giant vampire bat) – stopped me in my tracks.

Although relatively harmless, these most unusual Arachnids certainly are formidable – some might say “nightmarish” – in appearance.  If you are looking to add an animal that borders on the unbelievable to your collection, look no further than these fascinating spider relatives.

Description

Tailless whipscorpions are members of the Arachnid order Amblypygi, related to but distinct from the spiders and scorpions.  The incredibly long front legs have evolved into sensory organs, and are slowly moved back and forth, touching this and that, as the animal senses its way about.  It really is quite a sight to behold – one simply has no frame of reference, no matter how many odd creatures have crossed one’s path.

These specialized legs may cover a span of over 1 ½ feet. Some of the larger tropical species also sport 8 inch long “regular legs” and flattened bodies exceeding 2 inches in length – very impressive beasts over-all.  Huge pinchers, kept close to the body until needed to grasp meals, add to the effect.

Tailless Whipscorpions in Captivity

The huge Tanzanian giant tailless whipscorpions (Damon variegatus and D. diadema), are becoming increasingly popular with invertebrate enthusiasts, with captive reproduction now regularly recorded.  I have housed similarly-sized individuals in groups without incident, and was even successful in breeding them in this situation (I removed the youngsters to prevent predation).

In common with all related species, Tanzanian giants are arboreal, and need wide, flat climbing surfaces.  Cork bark slabs are ideal.  They should be provided a varied diet consisting of crickets, waxworms, roaches, locusts and wild caught insects.

All species kept to date require very damp conditions and temperatures of 72-76 F.  Despite their tropical origins, tailless whipscorpions are most often found in caves, wells, hollow trees and other cool micro-habitats.  Most fail to thrive if kept warmer than 80 F.

Although lacking venom glands, tailless whipscorpions can break the skin with their formidable front claws.  For this reason, and because they move very quickly and shed legs easily, these odd creatures should not be handled.

Further Reading

You can learn more about the natural history of African tailless whipscorpions at http://www.arc.agric.za/home.asp?pid=4078.

Image referenced from Wikipedia and originally posted by Luis Fernandez Garcia

 

Krill in Turtle Diets: an Interesting Experiment and Some Useful Products

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

KrillSome 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.

Turtle Eye Ailments: Vitamin A Deficiencies and Eye Infections

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

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