amphibian defense notes

Before we start today’s lesson, there is one fact I want to put out there before the SLO test.

The tympanic membrane is the ear drum of a frog/toad.

On some species, such as Bullfrogs,the size of the tympanic membrane issexually dimorphic.

Larger than the eye in males. Smaller than the eye in females.

Amphibian DefenseAmphibian Defense

ToxinsToxins

ToxinsToxins – most amphibians are distasteful to – most amphibians are distasteful to their predators.their predators.


Many species have very poisonous Many species have very poisonous chemicals that can be released from their chemicals that can be released from their skin glands.skin glands.



Amphibians are poisonous, not venomous.Amphibians are poisonous, not venomous.



Amphibians are poisonous, not venomous.Amphibians are poisonous, not venomous.

You must know the following 3 examples of You must know the following 3 examples of toxins produced by amphibians.toxins produced by amphibians.

BatrachotoxinBatrachotoxin – a chemical compound – a chemical compound produced by posion arrow frogs.produced by posion arrow frogs.

BatrachotoxinBatrachotoxin – a chemical compound – a chemical compound produced by posion arrow frogs.produced by posion arrow frogs.

These frogs exhibit bright “warning colors” to These frogs exhibit bright “warning colors” to prevent predators from attacking them.prevent predators from attacking them.

Toads produce a chemical called Toads produce a chemical called bufoteninbufotenin. This . This chemical causes increased heart rate and potentially chemical causes increased heart rate and potentially heart failure.heart failure.

Toads produce a chemical called Toads produce a chemical called bufoteninbufotenin. This . This chemical causes increased heart rate and potentially chemical causes increased heart rate and potentially heart failure.heart failure.

Bufotenin is released from bean-shaped glands called Bufotenin is released from bean-shaped glands called parotoid glands parotoid glands located behind toads’ eyes.located behind toads’ eyes.

A family of salamanders called newts produce a very A family of salamanders called newts produce a very toxic chemical called toxic chemical called salamandrinsalamandrin in their skin glands. in their skin glands.

A family of salamanders called newts produce a very A family of salamanders called newts produce a very toxic chemical called toxic chemical called salamandrinsalamandrin in their skin glands. in their skin glands.

SalamandrinSalamandrin is lethal in very small doses. is lethal in very small doses.

Red-spotted Newt (eft). Efts Red-spotted Newt (adult). Thisare subadult newts. is an Ohio native.

MimicryMimicry is a means of defense utilized by is a means of defense utilized by amphibians as well as many other animals.amphibians as well as many other animals.


Mimicry is a strategy in which a nonpoisonous Mimicry is a strategy in which a nonpoisonous animal that has evolved to look like a similar animal that has evolved to look like a similar poisonous species.poisonous species.


Mimicry is a strategy in which a nonpoisonous Mimicry is a strategy in which a nonpoisonous animal that has evolved to look like a similar animal that has evolved to look like a similar poisonous species.poisonous species.

This mud salamander mimics the toxic red eft. It is native to This mud salamander mimics the toxic red eft. It is native to eastern Ohio.eastern Ohio.

Aposomatic colorsAposomatic colors

Aposomatic colorsAposomatic colors are the “warning colors” that toxic are the “warning colors” that toxic animals exhibit to inform predators that they are animals exhibit to inform predators that they are dangerous.dangerous.

Aposomatic colorsAposomatic colors are the “warning colors” that toxic are the “warning colors” that toxic animals exhibit to inform predators that they are animals exhibit to inform predators that they are dangerous.dangerous.

Aposomatic colors are Aposomatic colors are generally bright shades generally bright shades that stand out against that stand out against the background.the background.

Aposomatic colors are the “warning colors” that toxic Aposomatic colors are the “warning colors” that toxic animals exhibit to inform predators that they are animals exhibit to inform predators that they are dangerous.dangerous.


Examples:Examples: redred



Examples:Examples: yellowyellow



Examples:Examples: blueblue



Examples:Examples: yellow on yellow on

blackblack

Cryptic colorationCryptic coloration

Cryptic colorationCryptic coloration allows animals to hide in their habitat. allows animals to hide in their habitat.

Counter shadingCounter shading

Counter shadingCounter shading is a type of cryptic coloration. Frogs that is a type of cryptic coloration. Frogs that set at the surface on algae mats are often green dorsally.set at the surface on algae mats are often green dorsally.


The same frog’s body is white on the underside. The same frog’s body is white on the underside.


The same frog’s body is white on the underside. When The same frog’s body is white on the underside. When it swims into open water, predators looking up at its belly it swims into open water, predators looking up at its belly from below will not be able to see it against the bright from below will not be able to see it against the bright light of the sky.light of the sky.

A few amphibians A few amphibians have sufficiently have sufficiently sharp teeth that sharp teeth that they will they will bitebite as a as a means of defense.means of defense.

Other means of defense……Other means of defense……


1.1. HidingHiding – –


1.1. HidingHiding – most small salamanders simply stay – most small salamanders simply stay hidden beneath logs or rocks.hidden beneath logs or rocks.


1.1. Hiding – most small salamanders simply stay Hiding – most small salamanders simply stay hidden beneath logs or rocks.hidden beneath logs or rocks.

2.2. EscapeEscape – –



2.2. EscapeEscape – many amphibians, especially frogs simply – many amphibians, especially frogs simply leap away from danger.leap away from danger.



2.2. Escape – many amphibians, especially frogs simply Escape – many amphibians, especially frogs simply leap away from danger.leap away from danger.

3.3. UrinationUrination




3.3. UrinationUrination – some amphibians, most notably toads, – some amphibians, most notably toads, empty their bladder when they are in the empty their bladder when they are in the

graspgrasp of a predator. of a predator.




3.3. Urination – some amphibians, most notably toads, Urination – some amphibians, most notably toads, empty their bladder when they are in the empty their bladder when they are in the


4.4. Distress call Distress call




3.3. UrinationUrination – some amphibians, most notably toads, – some amphibians, most notably toads, empty their bladder when they are in the empty their bladder when they are in the


4.4. Distress call Distress call – when captured by or escaping from a – when captured by or escaping from a predator, most frogs/toads emit a distict call that is predator, most frogs/toads emit a distict call that is recognized by their own species as a warning.recognized by their own species as a warning.

amphibian defense notes

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