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

Uploaded to Wikipedia Commons by Miroslav Deml

Keepers of Poison Frogs, Mantellas, newly-transformed frogs, and other tiny amphibians face difficulties in providing their charges with a varied diet.  Wild frogs consume dozens to hundreds of invertebrate species, but captives are usually limited to fruit flies, flour beetles, pinhead crickets and springtails.  Vitamin/mineral supplements help, but dietary variety remains critical.

Throughout my career at the Bronx and Staten Island Zoos, I have relied heavily upon wild-caught invertebrates.  I recently “re-discovered” an old favorite – the various Sap or Picnic Beetles (Family Nitidulidae).  I first used Sap beetles when rearing Wood Frog metamorphs decades ago, and later fed them to Spring Peepers, Red-Eyed Treefrogs, Poison Frogs and others in zoo collections.  Many small amphibians will eagerly gobble up Sap Beetles, but Poison Frog and Mantella keepers will find them especially useful.  Sap Beetles never fail to bring an enthusiastic feeding response, and can save us some time and money while providing nutrients missing from standard foods.

Natural History

Sap Beetles are classified in the Family Nitidulidae, which contains nearly 3,000 members.  Most top out at 1/8 inch, with the largest barely reaching ¼ inch in length.  Several species, commonly known as “Picnic Beetles”, show up when sweet foods are served outdoors.  Some feed upon over-ripe fruits, corn and other crops, while others take nectar, sap, fungi and carrion. Read More »

Poison Frogs (also known as Dart or Arrow Poison Frogs) exhibit an amazing array of colors and patterns – some so spectacular as to appear unreal. What’s more, they are active by day, exhibit complex social behaviors, and care for their tadpoles in “mammal-like” fashion…and are not at all shy about doing so. Small wonder they are among the most desirable of all amphibian pets! Once considered delicate captives, Poison Frogs are now regularly bred in captivity and may live to age 15 or beyond.

The following information can be applied to most available species, including Blue, Green and Black, Strawberry, Golden, and Phantasmal Poison Frogs. However, details vary; please write in for information concerning individual species.

Natural History

These 0.75 – 2 inch-long beauties are native to Central and South America. Identification by physical appearance alone is difficult, as some species exhibit a great many color variations. Their taxonomy is in flux, with various authorities recognizing between 180 and 300+ species. Read More »

I’ve always favored the boldly-marked Green and Black Poison (or “Dart”) Frog, Dendrobates auratus, over most of its relatives.  This was a turn of good fortune for me, as this gorgeous creature is one of the largest and easiest of the poison frogs to maintain.  It is also not at all shy – while working in Costa Rica, I was surprised at how easy wild ones were to observe – and makes a wonderful exhibit animal.  Green and Black Poison Frogs have become almost common in the trade, yet many remain unaware of some surprising aspects of their lives in the wild.

Little-Known Facts

First a few notes that have surprised me over the years.

Hobbyists accustomed to seeing these frogs in terrariums may be surprised to learn that wild specimens sometimes venture into forest canopies over 100 feet above ground…quite a climb for a minute frog!  Read More »

Central and South American frogs of the family Dendrobatidae secrete virulent skin toxins (histrionicotoxins, batrachotoxins and others) when disturbed.  Many people believe that the toxins of many species of Poison Frogs, known also as “Poison Arrow Frogs” and “Dart Poison Frogs”, were once used to coat darts and arrows used in hunting and warfare.  Actually, this is not the case – but the actual facts are no less interesting.

Origin of Frog Toxins

Poison Frog toxins are derived from the diet, being concentrated and synthesized from chemicals within the ants and millipedes (and possibly other invertebrates) upon which the frogs feed.  Wild-caught frogs gradually lose their protective toxins after a time in captivity… captive-born Poison Frogs do not develop toxic skin secretions unless they are fed the appropriate types of invertebrates.

Some years ago, I was fortunate enough to be at the National Aquarium in Boston when the origin of Poison Frog toxins was being investigated.  In one experiment, Green and Black Poison Frogs (Dendrobates auratus) that had lost their skin toxicity were liberated in the aquarium’s huge rainforest exhibit.  When recaptured some time later, the frogs had regained their potent skin toxins.  Studies showed that the source of these toxins were invertebrates that had been transported to the exhibit in soil and on tropical plants.

Toxin Use in Hunting

The use of frog toxins on hunting darts was first reported in the literature in 1823, by British naval captain C. Cochrane.  He reported that certain forest-dwelling people collected Golden Poison Frogs (Phyllobates terribilis) and confined and fed the frogs until toxins were needed.  The frogs were pierced with a stick in order to induce the secretion of the toxins, which appeared as white froth on the skin.

Up to 50 darts could be treated with the secretions from a single frog, and the darts were reported to retain their potency for at least 1 year.  A jaguar shot with a poison-coated dart was said to die within 4-5 minutes, and monkeys and smaller animals were killed instantly.

Darts, and not arrows, were utilized for hunting…toxin use on arrows shot from bows has never been observed.

Toxins were used in this manner by the Mucushi, Chaco and, possibly, other groups of people.

Toxins and Warfare

It comes as a surprise to many folks that frog toxins have never been documented as being used in wars or against human enemies.

Frog Species Utilized

The skin secretions of only 3 species of frog have been identified as being used as dart coatings.  These frogs are not, as often believed, the familiar Dendrobates species, but rather belong to the related genus Phyllobates.  Frogs belonging to this genus are less commonly seen in the pet trade than Dendrobates, although one, the Golden Poison Frog (P. terribilis), is fairly well-established in captivity.

Medicines from Frog Skin

The skin toxins of a great many frogs, related and unrelated to the Dendrobatids, are highly complex and are being studied with a view towards developing medications that may be useful in oncology and infectious disease research.  A compound derived from the secretions of the Phantasmal Poison Frog (Epipedobates tricolor) shows great promise as a pain medication…it is more effective than morphine, non-addictive and non-sedating.

Further Reading

You can read more about studies on the medicinal value of frog toxins here.

Golden Poison Frog image referenced from wikipedia and originally posted by Wilfried Berns