African dwarf frog

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: fine.

Behavior

Plant interaction: plant safe.

Feeding

Hand-feeding is essentially the rule in any mixed tank. The frogs locate food by smell rather than sight and are easily outpaced by even slow fish at feeding time. Frozen bloodworm is the standard staple: thaw a small cube and use forceps or a baster to drop pieces near the frog. Sinking pellets formulated for amphibians work too, but they need to land within sniffing distance. Live blackworms, daphnia, and brine shrimp are useful for variety. Feeding mechanically is unusual: the animals have no tongue and engulf prey by suction. Every other day is enough; overfeeding causes bloating quickly.

Nocturnal feeder; drop food after lights out.

Compatibility

• Routinely sold next to and confused with African clawed frogs (Xenopus laevis), which reach about 12 cm and will eat anything they can fit in their mouth. Check the front feet at the store: webbed across all four toes is the dwarf frog, separated finger-like toes with small claws is the clawed frog
• Poor vision and slow feeding mean fast tankmates outcompete them at every meal. Tetras, barbs, danios, and anything that darts at food will starve the frogs out. Either hand-feed or keep them on their own
• They breathe air, so they need clear access to the surface every few minutes. A very deep tank makes that tiring
• Anything small enough to be considered food is at risk: cherry shrimp and other tiny shrimp are not safe with them. Snails are fine because the frogs cannot open shells
• Social, and do best in groups of at least three; a lone frog tends to hide and refuse food. If mixing with fish, slow and peaceful species that share the bottom or surface work best, for example otocinclus or corydoras in a larger tank, and sometimes a calm betta. A lid is a sensible precaution

Origin and habitat

A fully aquatic pipid frog native to Central and West Africa. Hymenochirus boettgeri is one of four similar species in the genus (the others are H. boulengeri, H. curtipes, and H. feae), and its known range covers Nigeria, Cameroon, Equatorial Guinea, and Gabon eastward to the Central African Republic and eastern DRC. The frog lives in shaded, still water across lowland rainforest pools and the margins of slow rivers. The species was described by Tornier in 1896 and named after the German herpetologist Oskar Boettger. A 2024 study using cytogenetic and molecular data found that wild frogs from northern Republic of the Congo are tetraploid, while the diploid frogs of the long-established aquarium line are possibly of hybrid origin (H. boettgeri x H. curtipes); the implication is that what the aquarium trade calls 'African dwarf frog' may not be true wild H. boettgeri, and the boundary of the actual species needs to be revisited. Even though it lives in water, the animal has lungs and has to surface to breathe. IUCN Least Concern.

Breeding

Breeding is straightforward in captivity, and a cool water change is usually enough to trigger it. The male produces a quiet humming call to attract a female; females are essentially silent. Amplexus is the typical frog clasp from behind, held for hours, with the female releasing batches of eggs at the surface and the male fertilizing them as she does. The eggs are mildly sticky, float, and lodge on plants or whatever surface they drift into. Adults will eat them given the chance, so move the eggs out. Hatching usually takes 1 to 2 days. Tadpoles are tiny, fully aquatic, and unusually predatory for an anuran larva; start them on infusoria, green water, or powdered fry food, and move them onto microworms or finely crushed pellets as they grow. Metamorphosis runs about 6 to 8 weeks (hind legs first, then front legs, with the tail reabsorbing as the lungs become functional). Adult sexing: males are smaller and show a white or pinkish gland under the skin just behind the foreleg, plus a noticeably larger tympanum than the female has.

Common problems

The first risk is buying the wrong species. Juvenile African clawed frogs (Xenopus laevis) look much like dwarf frogs but grow to roughly 12 cm and eat tankmates. The reliable difference is the front feet: dwarf frogs have all four toes joined by webbing, while clawed frogs have separated, finger-like front toes with small black claws. Once the right species is home, the next risk is starvation, which is by some margin the leading cause of death in community setups. The frogs see poorly and are slow, clumsy feeders that will simply not get a share of the food before faster fish hoover it all up. Hand-feeding with forceps or a turkey baster solves it, as does keeping them in a species-only tank. On the other side of the same coin, they overeat readily and get bloated, so feeding every other day rather than daily is safer. Chytrid (Batrachochytrium dendrobatidis) is always a consideration with amphibians; captive-bred dwarf frogs are lower-risk than wild-caught stock, but quarantine new arrivals and keep water clean. Watch also for bacterial skin infections (red patches or fluffy white growths) and bloating from overfeeding or internal disease. The frogs have permeable skin and absorb whatever is in the water, which means copper-based fish medications are lethal: remove frogs before treating a tank, and always dechlorinate.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size