African Dwarf Frogs in the Aquarium

[Ollie Mengedoht]

African Dwarf Frogs in the Aquarium
More and more frequently to be found in invertebrate tanks

Text: Monika Rademacher
Photos: Oliver Mengedoht
Translation: Ulrike Bauer

African dwarf frog (Hymenochirus boettgeri)[/b]
• Family: Pipidae (tongueless frogs)
• Genus: Hymenochirus
• Species: Hymenochirus boettgeri

African dwarf frogs (ADF) are purely aquatic frogs that can reach a maximum size of 3.5 cm (m) to 4.5 cm (f) when adult. The size is measured exclusively on the trunk.



In contrast to large claw frogs, African dwarf frogs have webs between the fingers of their front feet also, which is the most obvious distinguishing feature between these two species.

However, time and again aquatic frogs are sold under the name of albino African dwarf frog in fish stores – this is a wrong, misleading name, though. Up to now, there is no known albinotic form of the genus Hymenochirus. The animals under this trade name are albinotic forms of Xenopus laevis (great claw frog). African dwarf frogs have black claws on the three toes pointing to the body on their hind feet.



Most ADF found in the trade either come from private breeders or are imported from Western Africa where they had been caught from the wild. Even though these animals look very cute and unproblematic at first glance, you shouldn't disregard some important aspects about their keeping requirements.

Keeping African dwarf frogs

TANK SET-UP:
The water level should be about 5 to 7 cm lower than the upper tank rim, as the animals have to come to the surface for breathing. With this minimum distance to the rim you can avoid that the frogs get too close to the cover and thus to the light, and furtherly you can minimize the risk that the frogs escape from the tank. They can climb short distances on plain glass due to adhesive forces.

As these frogs have a pretty delicate skin prone to fungal infections you should make absolutely sure that there are no sharp edges within the tank. You should also abstain from using sharp gravel for the animals' sake, sand is far better for them.

If you want to put aquarium dekor into your tank this has to be stood on the tank floor and it should be tip-proof. ADF like to undermine everything, and you shouldn't run the risk of something falling on the frogs during these digs (please be especially careful with stone constructions – not only can the frogs be just killed by a falling stone, but collapsing stone constructions can actually destroy the entire tank). Futhermore you should make sure that there are no places in the tank where the frogs could get stuck. They like to squeeze into the tiniest of cracks and always have to be able to get out there by themselves. They would suffocate if they couldn't reach the surface due to such an awkward position.

Just so you'll get a rough idea about what kind of crevices they can fit in: An ADF can wriggle into a crack only 2 mm wide, which unfortunately doesn't mean that it can get out as easily. Thus it is important to secure these critical spots (e.g. by wedging some filter sponge in there).



African dwarf frogs prefer tanks with a rather slight water flow, if there's too much current they have a hard time when surfacing. The tank temperature should be between 24 to 25 °C (75 to 77 °F), this makes a heater almost indispensable at least during the autumn and winter months.

STOCKING:
Due to their small size African Dwarf frogs need comparatively small tanks; the follwoing data only applies to dedicated tanks. When densely planted and providing enough shelter even a 25 l tank (6.5 g) could hold three to four frogs. However, not only the volume of the tank is decisive; more important is that the ground area meets the animals' high urge to move.

Thus a 25 l tank with the dimensions 40x25x25 cm is totally apt, whereas e.g. a tank providing the volume rather through its height that through its width would be clearly unsuitable (e.g. a hexagonal tank holding 25 l).
• 25L: up to 4 frogs
• 45L: up to a maximum of 7 frogs
• 54L: 8 to 10 frogs

When stocking an African dwarf frog tank you should pay futher attention to having at least an equal number of males and females; even more preferrable is having a minimum of two females to one male. Even a group of many females in relation to the numbers of males poses no problems – however, the reverse relation is not recommendable. The males should not be in the majority, as these little frogs are sexually very active. If there are more males than females the females will be totally stressed out.

PLANTING:
It can be quite dense, but should always leave a certain room for swimming. Plants with leaves reaching close to the surface are highly recommendable, as the ADF like to rest on such leaves, sticking their noses out of the water. I have had good results with Brazilian pennywort (Hydrocotyle leucocephala); I don't let it float, however, but plant it in the ground. Please make sure you don't provide the frogs with jumps out of the tank. ;0)



You should also consider putting plants into your tank that will provide the frogs with shelter (e.g. dwarf hairgrass (Eleocharis aciculata) planted in a bundle, purslane (Ludwigia), which grows pretty bushy, or water wisteria (Hygrophila difformis), also with a rather bushy growth).

FEEDING:
African dwarf frogs are carnivores – no exceptions. This doesn't mean that they don't eat other food as well, but it is no adequate staple for them and would lead to deficiency syndroms in the long run. Feeding a variety of live and frozen foods is very important in order to prevent illness resulting from deficiency syndroms like e.g. Hydrops, the balloon disease.

Very appropriate live foods are: Artemia, Gammarus, earthworms (cut in pieces) as well as glass worms and blackworms – I have to advise against Tubifex and bloodworms, their use is rather controversial due to their possible contaminant loads. You should not feed grubs very often as they contain a lot of fat. Newborn fish fry is also a good live food (e.g. guppies; thorny Ancistrus and the like should not be fed, however).

Glass worms and blackworms are also a good frozen food (bloodworms aren't – if you can avoid them; or feed those about every ten days or so), frozen Artemia, Cyclops (for very young frogs) and Gammarus (as far as they're eaten).
The food supply has to be controlled since ADF eat as long as they find food. This can lead to critical overeating. Semiadult and adult frogs only have to be fed once a day, and if they've eaten really much a fast day without any food at all makes a lot of sense.

SOCIALIZATION:
In general I'd recommend keeping these interesting frogs in a dedicated tank as they will display the entire range of their typical behaviour only there. A part of this is the - very low and rather uncommon – quack of the males, mating and reproduction and their behaviour in general.

You'll be able to watch them without problems in a dedicated tank, they swim there fearlessly, rest on plants and interact. As a rule, a lot of this behaviour is lost in community tanks.



However, socializing them with dwarf shrimp and snails is totally unproblematic if you take into consideration that some of the possible shrimp offspring will become live food for the frogs.

When keeping ADF in community tanks you should be aware that they usually hide and can only be seen when they're fed or rapidly swim to the surface to breathe.
Here feeding takes a lot more diligence than in a dedicated tank, as the frogs' eating speed and hunting behaviour are totally different from those of fish; thus the frogs are usually at risk of not getting enough food. Whereas fish generally eat their food right away ADF are lurking predators, which first watch their prey and attack only after that.

Please don't ever try to socialize African dwarf frogs with crayfish or crabs! Even if your crustas seem to be very peaceful, a totally unagressive test pinch would lead to very severe injuries of the delicate frog skin.

FURTHER HINTS AND TIPS:


• Molt: Like most amphibians these frogs also molt – so please don't be alarmed when the little froggie suddenly looks opaque or if there are skin shreds hanging from it that it tries to strip off. It might also happen that the frog itself or other frogs try to eat the partially shed skin. Very often the frogs molt in one piece, though.
• Social behaviour: Time and again you may read that ADF can also be kept solitarily, however, their behaviour shows that they feel a lot better in groups. They often seek the proximity of con-specifics – that's why I think that a group of three to five individuals is the minimum stock. Another fact that underlines this is that frogs feeling at home and safe in their tank and with their keeper like to swim to his (or her) hand in order to get petted.
• Clutching (Amplexus): Don't be alarmed if one of the animals clutches the others' loins from behind for hours on end. This is not a fight but a part of the mating process.
More about this, about distinguishing the sexes and the breeding of African dwarf frogs in one of the next issues!