Breeding
Eggs
Thumbnail species generally lay only a few eggs at a time,
although the smaller Epipedobates may lay clutches of up to 20 eggs.
5-10 is an average clutch size for larger Dendrobates, although
up to 20 eggs may be laid on rare occasions (this is sometimes the result
of more than one female depositing eggs in the same location). Large Phyllobates such
as P. terribilis commonly lay clutches of up to 30 eggs. Mantella
aurantiaca clutches are often number 50-100 eggs.
Most young frogs lay several infertile egg clutches before
producing their first fertile clutch, so be patient!
Fungus on eggs is a common problem. Often this shows that
eggs have not been fertilized, but may spread from infertile to fertile eggs.
Eggs should be partly (not completely) submerged in clean, soft water. Antifungal
agents such as methylene blue may be effective in preventing fungal losses.
Tadpole tea (see below) is also effective against fungus.
Eggs are normally deposited in a secluded location. This may
be on a leaf, on the glass of the vivarium or under a piece of corkbark. Mantellas
are often particularly secretive about egg deposition. Frogkeepers often provide "honeymoon
huts" consisting of cleaned coconut shell halves with a notch in the rim.
A shallow dish or leaf is placed in the hut for the frogs to lay their eggs
on. This can easily be removed for artificial rearing.
Thumbnail species lay eggs and rear tadpoles in small bodies
of water such as bromeliad axils, or plastic 35mm film cannisters (positioned
at various angles depending on the species).
Also See Egg Development.
Froglets
Newly metamorphosed froglets are very delicate and should be
handled as little as possible. They are very subject to stress (provide hiding
places), extreme
temperatures and desiccation. They usually do not begin feeding for several
days after leaving the water. Suitable first foods depend on the species.
Many larger frogs can take Drosophila melanogaster on metamorphosis, but
small species
may require springtails.
Incubators/Temperature
For most species, room temperature (20-25°C) works fine.
Avoid letting eggs/tadpoles get too hot (in Summer or on light fittings) or
too cold.
Excessively
low temperatures during egg/tadpole development MAY be one source of SLS.
If temperature control is a problem, a simple incubator can be made out of
a plastic
box
or an aquarium containing several inches of water, and a thermostatic
aquarium heater.
Metamorphosis
Metamorphosis from tadpole to frog is the equivalent of your
pet hamster turning into a dog. All major body organs are remodelled, some (tails)
disappear and
new ones (legs) appear. This process is stressful and things go wrong
- SLS. Frogs do not feed during metamorphosis
due to remodelling of
mouthparts
and internal organs. Tadpoles may leave the water at any stage after
all four legs develop, sometimes with complete tails intact. Newly metamorphosed
frogs
climb well and must be kept in escape-proof containers!
Sexing
Sexing frogs depends on the species involved, but:
- Females are generally larger and more heavily built then males
- Male frogs call (females also call in some species, e.g. Phyllobates
bicolor)
- In some Dendrobates species (e.g. D. tinctorius),
the toepads on the front feet of males are 2-3 times wider than the toepads
on the back feet, whereas in females the front toepads are only 1-2 times
wider than the rear ones (this method is not always reliable!).
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Tadpoles
In nature, dartfrogs transport newly hatched tadpoles from the
egg deposition site to a small body of water in which they will develop.
This behaviour
is rarer in captive bred dartfrogs as most keepers remove eggs from
the parents for artificial rearing. Mantellas do not transport tadpoles,
but lay egg clutches where tadpoles can wriggle into water when they hatch (unless
removed
for artificial
rearing).
Tadpoles sometimes developed trapped air bubbles which affects
their swimming and possibly feeding. There may be several possible
reasons
for this:
- water supersaturated with gas (nitrogen)
- bacterial fermentation due to poor water quality
- intestinal parasites
Placing the tadpole in very shallow water (just enough to cover
it and improving the water quality may cure this problem.
Feeding:
- Algae flakes/tablets/wafers for fish
- Intrapet Liquifry
- Dried Spirulina algae (from healthfood shops or online)
- Natural algae (illuminate tadpole containers but watch the
temperatures!)
- Bloodworms (live/frozen)
- Daphnia
Don't overfeed and pollute the water!
Rearing:
Obligate eggs feeders (e.g. D. pumilio) must be allowed to
rear their own tadpoles in the vivarium. Eggs/tadpoles
of other
species are
commonly removed for
artificial rearing as parents may have lost the instinct
to rear their own young after
generations of captive breeding.
Conventional wisdom says that tadpoles of Dendrobates must be reared in individual containers. These may be
anything
from 100mL to several
litres
in size. Some
people change the water, others do not. However, many
people successfully raise tadpoles of all species communally
in
heavily planted aquaria
or large plastic
tubs (the bigger the better). Tadpoles of Phyllobates and Epipedobates can usually be reared communally without
any
problems.
Water quality is important in tadpole rearing. The water
should not stink! Live plants help to keep water clean:
Java moss
is useful, as are rooted
cuttings of plants such as pothos (Scindapsis)
and Tradescantia.
Tadpole Tea
Tadpole tea is an infusion which contains tannins, humic
acids and other compounds and has antibacterial and
antifungal properties.
To make tadpole
tea, place
organic material such as peat, dried oak leaves,
Indian Almond Leaves, etc
in water and boil or soak until
the suspension has the colour of tea.
Warning:
Do not use tea, which contains caffeine!
Commercial blackwater extract shares some of the properties of tadpole tea
but it is obviously cheaper and much more rewarding to make your own.
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