THE STEINHART AQUARIUM - Gulf of Guinea Science ...

202 A Docent Field Guide to the Species of the Steinhart Aquarium
Appearance: Green with prominent white
stripes. Hind legs are relatively short. Length:
5–7.5 cm.
Diet: Small insects such as flies and ants.
Reproduction and Development: Breeding
takes place during the rainy months, and
the frogs do not return to the ground. They
deposit eggs in leaf nests attached to branches
overhanging water. The leaves are rolled up
and secured by a waxy substance, and upon
hatching, tadpoles fall into the water where
they mature.
Remarks: The waxy monkey tree frog is
adapted to a warm, dry environment by
diurnal torpor, uric acid excretion, and the
ability to secrete a waxy substance on the skin
that limits water loss. The lipid secretions are
distributed over the skin by the legs in a wiping
movement.
Though visitors rarely see this nocturnal
species move about; the frog, rather than
hopping, grabs branches and moves like tiny
monkeys swinging through the trees.
Golden Mantella
Mantella aurantiaca (Mantellidae)
Distribution: Very limited in west central
Madagascar.
Habitat: Sunny patches in the high montane
rainforest. Entirely terrestrial. Diurnally active.
Appearance: Length to 3 cm. Adult body
color may be yellow, orange or gold. Black
eye, horizontal pupils. Juveniles are black and
green.
Diet: Very young tadpoles rasp algae and plant
matter. 6-8 week old froglets begin to hunt
for flea-sized food. ~10 weeks begin to hunt
fruitflies and other insects.
Reproduction and Development: Males
call to females from their territories on the
ground. Females roam among competing male
territories. Fertilization internal (unusual for a
frog). Lays eggs on leaf litter during the rainy
season. Egg mass requires high humidity,
warmth and no direct sunlight, but not
immersion. At ~ 10 days larvae have absorbed
much of their yolksac, the jelly surrounding
the eggs liquifies and forms a communal pool
for the clutch. A few days later tadpoles are
washed into small pools by rain. Rear legs start
developing at 3-4 weeks, front legs a week later.
At this point the larval gills regress and the
larvae can drown without access to air. They
reach adult breeding size in 9–12 months.
Conservation Status: Listed as endangered
(IUCN) due to destruction of their habitat
and introduced predators. Pet trade also
decimating this species.
Remarks: The animal’s bright color advertises
the toxicity of skin secretions that protect it
from most predators.
Painted Mantella
Mantella baroni (Mantellidae)
Distribution: Endemic to the forests of eastcentral
Madagascar.
Habitat: Includes swamp forests, semi-arid
streambeds, bamboo groves, and streamside
forests, including rainforests. Also lives in
degraded and second-growth forests.
Appearance: Females generally larger than
males. Length from snout to vent: 3 cm.
Diet: Diurnal; feed on insects, especially ants.
Reproduction and Development: Like all
mantellas, lack amplexus (the nuptial embrace
of most frog species). Instead, females lay
eggs on land, but always close to water. When
tadpoles develop, they are washed by rain into
nearby stream or pool. Are successfully bred in
captivity, though captive bred individuals are
not widely available.
Conservation Status: IUCN: Least concern.
A fairly common frog within its area of
distribution, parts of which are within borders
of protected areas, though its increasing
popularity in the pet trade may be reducing
its numbers.
Remarks: Research over the past several
decades has shown that the poison dart frogs
(Dendrobates spp.) acquire their alkaloids
by eating ants, but the poison source for
Madagascar frogs remained unknown until
recently. Now, Academy entomologist Brian
Fisher and Cornell chemist Valerie Clark,
together with colleagues from the United
States and Madagascar, have found that
Madagascar’s Mantella frogs also acquire
their toxins from ants. Both groups have
evolved ways to ingest the poisonous ants
without harming themselves. Their bright
colors are aposematic signals of toxicity.
Even though the frogs in Madagascar and