Wednesday, December 10, 2008

Poisonous Animals

When biologists refer to "poisonous" animals, we are referring to animals that pass their poison through touch or being eaten. Basically, animals that have the toxin spread through tissues, and do not possess a method of delivery (such as a stinger, fangs, or spines). Let's a take a look at 2 groups of poisonous vertebrates.

Pitohuis - The World's only poisonous birds

Hooded Pitohui (Pitohui dichrous), all 6 spp.
of Pitohui are endemic (found only there) to
New Guinea

Pitohuis get their toxin from
dietary sources, in this case a
species of beetle

Pitohuis have Batrachotoxins in their
feathers and skin, sinilar to the
toxins in Dart Frog skin

Rusty Pitohui (Pitohui cristatus)

* It turns out there is one other species of poisonous bird, also from New Guinea. Both this bird and the Piohuis may cause numbness and tingling in the skin, if handled!

Blue Capped Ifrita (Ifrita kowaldi)

Poison Dart Frogs - family DENDROBATIDAE

Dendrobatids are frogs that live in the Neotropics (the tropical regions of the Americas) in Central and South America. They have varying degrees of toxicity. The gain their toxins from the ants they eat, and lose their poison in captivity.

Phylobates terribilis, perhaps the most
poisonous terrestrial vertebrate, lives in Western

Epipidobates tricolor giving its larvae a ride to
the nearest water source, perhaps a Bromeliad

Dendrobates azureus, Suriname

Dendrobates galactonotus, Brazil

D. granuliferus, Panama and Costa Rica

Dying Poison Dart Frog (D. tinctorius),
Northern South America, the natives people
use the skin secretions on young parrots to
make them grow different colored feathers

A few other poisonous vertebrates...

Common Toad (Bufo bufo) Unlike the Dart
Frogs, toads are born with their toxins.

Rough Skinned Newt (Taricha granulosa)
toxic enough to kill up to 100 people, one of the
most poisonous animals in the world

Puffer Fish may have toxic skin and internal
organs, but some humans still eat their non-
toxic flesh.

Cowfish, like this Longhorn Cowfish (Lactoria
), have toxic skin secretions that may be
released into the surrounding water.

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