African Dwarf Frog Tank Setup

Setting up a tank for Hymenochirus: easy access to air, gentle filtration, warm water, sinking foods, shed skin, chytrid and Salmonella awareness, tankmates and how they differ from Xenopus.

Overview

African dwarf frogs belong to the genus Hymenochirus (family Pipidae), which contains four species. A 2023 study notes that Hymenochirus boettgeri and Hymenochirus curtipes are the two sold as "African dwarf frogs" in the aquarium trade, and that H. curtipes is rarely available because it is hard to breed in captivity. In the wild they live in forested equatorial Africa, from Nigeria and Cameroon through the Congo River basin. There they occupy shallow rivers, creeks and ponds in the dry season and flooded forest in the wet season. Adults reach about 2.5–3.8 cm and weigh only a few grams. Wikipedia gives an average lifespan of five years, with some individuals living longer than 20 years. Breeding is covered in Aquairi's separate African dwarf frog breeding guide.

Dwarf frogs are not clawed frogs

Hymenochirus is often confused with the African clawed frog (Xenopus), which is larger and more aggressive. Wikipedia describes three reliable differences:

Dwarf frogs have webbing on all four feet. Clawed frogs have webbed hind feet but free, unwebbed front digits.
Clawed frogs have eyes on top of the head. Dwarf frogs have eyes on the sides.
Clawed frogs grow much larger and are voracious predators that can become invasive.

Tank layout and access to air

Dwarf frogs spend their whole lives underwater but have lungs, not gills, and must swim to the surface to breathe. An exotic animal hospital care sheet recommends at least 2 gallons (about 7.5 L) of water per frog and warns against the small vases sometimes sold as "living art". It also advises plants, a rock or a branch reaching close to the surface, so frogs can rest there and gulp air without struggling up through the water column. In a research colony, aquaria were filled so that at least 1 cm of air space remained between the water and the lid.

Resting spots near the surface: live plants or a rock or branch reaching close to the surface (veterinary care sheet).
Hiding places and dim areas: caves, submerged wood or smooth decorations, so the frogs are not under bright light all the time (veterinary care sheet).
Substrate: gravel too large to be swallowed while foraging (veterinary care sheet).
Smooth decor: the research colony checked enrichment items for rough surfaces or sharp edges that could damage skin.

Filtration, flow and water quality

The Merck Veterinary Manual notes that some aquatic amphibians need gentle filtration that keeps the water clean without creating strong currents. The veterinary care sheet suggests a sponge, undergravel or canister filter and a weekly change of 10–20% of the water with dechlorinated water. In the research colony, targets were ammonia at or below 0.25 ppm, nitrite at 0 ppm and nitrate at or below 40 ppm, with pH around 7.

Temperature recommendations agree closely. The veterinary care sheet gives 78–82 °F (about 25.5–28 °C) and says water should never go above 85 °F or below 70 °F (about 29.5 °C and 21 °C). The research colony held 25 °C ± 0.5 °C, and the Merck manual gives 24–27 °C for tropical amphibians. The same study notes that H. boettgeri can breed in water that swings daily between 19 °C and 30 °C.

Feeding: sinking foods

Dwarf frogs have no tongue or teeth. They find food with sensitive fingers, smell and the lateral line, push it into the mouth with their webbed feet and draw it in by suction using a hyobranchial pump. They are scavengers that eat living, dying or dead material. Because they feed underwater, food has to sink.

Staple: sinking pellets made for clawed frogs, or sinking pellets for carnivorous freshwater fish (veterinary care sheet).
Variety: thawed frozen bloodworms, blackworms, live white worms and brine shrimp nauplii, rinsed in fresh water. The care sheet notes that pellets alone are not a complete diet.
Amount: as much as the frogs will eat, several times a week, with leftovers removed after about 30 minutes (veterinary care sheet). The research colony fed brine shrimp and frozen bloodworms three times a week.

Shedding

Shed skin is a normal part of tank maintenance. The veterinary care sheet advises removing uneaten food, shed skin and feces with a turkey baster or dip net so they do not overload the filter. Shedding becomes a warning sign when it is excessive. The Merck Veterinary Manual lists excessive shedding, loss of appetite, weight loss and pale or greyish skin as signs of chytridiomycosis.

Chytrid and Salmonella

Chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is a severe amphibian disease that Merck says can wipe out a population in days. H. boettgeri is susceptible to Bd. In a 2023 study, 18% of a sample of frogs bought from suppliers tested positive for Bd by qPCR. All infected frogs in that study were cleared with a controlled heat treatment under laboratory testing. Wikipedia notes that Xenopus is not visibly affected by Bd and may act as a carrier. The veterinary care sheet asks owners never to release dwarf frogs, because they may carry diseases that harm native frogs.

Dwarf frogs can also carry Salmonella. The US CDC investigated 224 human Salmonella Typhimurium infections in 42 states between 2009 and 2011 that were linked to African dwarf frogs from a single breeder. The median patient age was 5 years. The CDC advises that children under 5, pregnant women and people with weakened immunity avoid contact with frogs, their water and their habitats.

Tankmates

The veterinary care sheet notes that dwarf frogs often fail to compete with aggressive tropical fish and do poorly in community aquariums. They are slow bottom foragers that find food by touch, smell and the lateral line, so aggressive or fast-feeding fish should be avoided. Watch at feeding time to make sure the frogs actually eat.