THE STEINHART AQUARIUM - Gulf of Guinea Science ...

Panama live nearly half a world apart from
one another, they share 13 identical poisonous
compounds. This, Fisher notes, is a beautiful
example of convergent evolution—similar
evolutionary pressures in two different parts
of the world have led unrelated frogs to find
and sequester the same poisonous alkaloids
in the same way (from Headline Science –
CAS)
Green Mantella
Mantella viridis (Mantellidae)
Distribution: Endemic to Madagascar.
Habitat: Inhabits deciduous forests. Usually
found around temporary streams. Also lives
in degraded mango plantations.
Appearance: Mantella viridis is one of the
biggest of the Madagascar mantella frogs; max
length: 3.5 cm. The back and sides are yellowgreen;
ventral parts are black with blue spots.
The toes are not webbed. A light stripe runs
along the upper lip.
Diet: Diurnal predators, eating mainly insects,
ants, and termites. May also eat fruit that has
fallen to the ground.
Reproduction and Development: Adults mate on
land and the eggs are laid in depressions in moss
or damp vegetation. Eggs hatch into tadpoles
during heavy rainfall, which washes them into
small pools of water. The tadpoles grow to a
size of about 2.5 cm. In 45–65 days they undergo
metamorphosis and take the adult form.
Mortality/Longevity: No specific information
found. Snakes, small carnivorous mammals,
and birds prey upon the frogs. Coloring and
toxins may protect against predators.
Conservation Status: IUCN Red list:
Endangered.
Remarks: Many species of tropical frogs
sequester toxins in their skins. In most cases
these toxins come from eating toxic arthropods
such as ants. During the past 30 years, over 400
alkaloids of over 20 structural classes have been
detected. The skin of Mantella viridis has been
shown to contain such toxins.
It has been suggested that South American
toxic frogs and Malagasy toxic frogs arose in
Gondwanaland before continental separation
began, from a common stock. This hypothesis
still needs to be confirmed by DNA analysis.
California Academy of Sciences
203
Madagascar Reed Frog
Heterixalus madagascariensis (Hyperoliidae)
African Tree Frogs
Distribution: Endemic to Madagascar. Found
along the northeast coast.
Habitat: Common near rainforest edges, in
dry forested areas, and coastal forests as well
as deforested areas, croplands, and even urban
areas.
Appearance: Though color can change
depending on environmental conditions,
the back is usually uniformly white, gray, or
sometimes yellow. Thighs and the undersides
of legs and feet are orange. A dark band
extends between the nostril and eye. Males to
3.5 cm snout to vent; females to 4 cm.
Diet: A nocturnal and semi-arboreal hunter
of insects, it readily eats insects as big as its
own head.
Reproduction and Development: Breed in
temporary or permanent still water year
round. Like most members of the family,
males compete over sites by calling during the
evenings. Our Steinhart reed frogs bred during
the late summer (2010); the minute tadpoles
grew out in the leaf-nosed snake (MA14) and
tiny frogs can be seen in the Klemmer’s yellowheaded
day gecko tank (MA12).
Mortality/Longevity: Life span: c. 5 years.
Conservation Status: IUCN: Species of Least
Concern; H. madagascariensis seems a survivor,
able to live and breed in a wide variety of
human-impacted habitats, including heavily
degraded forest areas and seasonably flooded
agricultural land.
Remarks: All of the 11 known species of the
genus Heterixalus are endemic to Madagascar.
Reed frogs spend days resting or sleeping
in the sun, frequently perched on emergent
vegetation of swamps and ponds, thus the
common name “reed frogs.”
Borneo File-eared Frog
Polypedates otilophus (Rhacophoridae)
Distribution: Endemic to islands of Borneo
and Sumatra.
Habitat: Secondary forest growth, edges of
primary growth; also villages, plantations, and
other disturbed habitats. Lowland: sea level to
500 m. Generally arboreal on vegetation near
pools of standing water.