Can a Fish & a Frog Mix?

Pet fish and frogs share a number of similarities: they greatly depend on water for survival, they are very sensitive to water chemistry and they're often kept in aquariums. Though it's possible to keep frogs and fish together in the same enclosure, it is not an easy undertaking and requires careful species selection.

  1. General Concerns When Mixing Species

    • Novice keepers of both frogs and fish are often encouraged to keep their pet̵7;s habitat simple. This usually means keeping only one specimen of one species in the habitat. Disease transmission, antagonistic behavior, stress and competition for resources are all factors that can cause problems when keeping multiple specimens of the same species together. When keeping different species together, predation, husbandry parameters and chemical compatibility become important considerations as well. Accordingly, only experienced keepers should attempt to keep a frog and a fish in the same habitat.

    Terrestrial Frogs

    • Frogs and toads that spend most or all of their time on land are the best option to keep with fish as the two animals utilize different spaces. American toads (Bufo americanus), eastern spadefoot frogs (Scaphiopus holbrookii) and poison dart frogs (Dendrobates sp.) are good choices for this approach. Additionally, because of the different microhabitat use, highly aggressive fish like African cichlids (Cichlidae) or oscars (Astronotus ocellatus) can be incorporated with this approach. Be aware that most terrestrial frogs will move to the water to deposit their eggs, so frogs that demonstrate breeding behaviors should be temporarily removed or provided with a fish-free water area.

    Arboreal Frogs

    • Tree frogs make excellent specimens for mixed species habitats because, like terrestrial frogs, they don̵7;t share cage space with the fish. Green (Hyla cinerea), grey (Hyla versicolor) and red-eyed (Agalychnis callidryas) tree frogs all make excellent subjects for this approach. As with terrestrial frogs, it's important to watch for breeding behavior, like male vocalizations, which may draw the frogs to the water. Additionally, it's important to ensure that the water stays clean; tree frogs hanging out over the aquatic section may defecate in the H2O.

    Aquatic and Semi-Aquatic Frogs

    • When frogs and toads share the water, two primary challenges face the keeper: water chemistry and predation. Many frogs emit poisonous secretions from their skin; in some species, the toxins can prove fatal to the fish. Some species, like African clawed frogs (Xenopus laevis), have been kept successfully with fish and likely don̵7;t pose a threat to the water chemistry. Other species, like fire-bellied toads (Bombina sp.), have stronger toxins and should not be kept with fish. Predation concerns can be reduced by keeping fish and frogs of approximately the same size together. When this can't be done, select fast fish species like guppies and tetras that will usually evade the frogs. Some fish species are primarily herbivorous -- for example, algae-eating Plecostomus species -- and these fish can be used without fear of them eating the frogs. Aggressive frogs like bullfrogs (Lithobates catesbeianus) and leopard frogs (Lithobates pipiens) may eat any frogs small enough to fit into their mouths. The aquatic fire-bellied and Suriname toads (Pipa pipa) are interesting captives, but are supremely adapted to catching small fish.