Page 17 - Amphibian

Light muddy brown
skin on back with spots
on limbs is common
frog’s normal color
and pattern

COLOR VARIETY
These three frogs may
look different but they are all
the same species of European
common frog (pp. 6–7). The frog
on the left is the usual color and
A trio of European common frogs pattern, the spotting in the middle one
is produced by a high density of brown-
black pigment cells, and the frog on the right
Polymorphism is more plainly marked. These frogs are not
polymorphic, but have a very variable color
If a species of animal has different “morphs,” or forms, the species is described pattern, not distinct color morphs.
as being “polymorphic.” The differences between morphs are quite small, such
as color, patterns (stripes vs. spots), or size variations. “Polymorphism” does
not refer to larger differences, or changes, in body shape, nor does it refer to
the tadpole and adult stages in an amphibian’s life (pp. 38–41). Sometimes
“polychromatism” describes species like poison-dart frogs (pp. 56–57) or
African reed frogs, where outstanding variations in color or pattern
are found within a single species. “Dimorphism” occurs
where there are only two varieties of color or pattern.

Multiple spots forming
paler yellow stripes

Skin has glands producing toxic
secretions as a defense mechanism

Brightly
colored
parotoid
gland to
warn off
predator

POLYMORPHIC
PATTERNS
Although these fire salamanders (pp. 6–7)
Stripe all have different patterns, they belong to the same species,
A quartet of instead which is said to be “polymorphic.” However, because each of
fire salamanders, which can be of spots these salamanders lives in a separate population in different
6–12.75 in (15–32 cm) long, including tail areas of Europe, each belongs to different subspecies.

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