Needlefish & Frogs

Needlefish and aquatic frogs do not belong in the same aquarium. Depending on the exact species of frog, the needlefish will either act as predator or prey. Additionally, some fish that go by the common name "needlefish" actually prefer salty, brackish water that does not suit aquarium frogs. Between predation and water chemistry, these organisms do not go together.

  1. Aquarium Frogs

    • Clawed frogs lack webbing on their front fingers.

      Pet shops typically sell two types of aquatic frogs, the dwarf frog and the clawed frog. Dwarf frogs (Hymenochirus spp.) typically grow to about an inch and a half and get along well with most other fish. The clawed frog (Xenopus spp.) looks almost identical to dwarf frogs as a juvenile, but will reach an adult size of about 6 inches. Clawed frogs are very predatory and will eat anything they can fit inside themselves. You can tell a young clawed frog from dwarf frogs by looking at their front limbs. Dwarf frogs have webbed fingers, while clawed frogs lack webbing on their front hands, giving them a clawed look and their common name.

    Needlefish Predation

    • Several fish sell under the name needlefish, including Xenentodon cancila, but also the livebearing halfbeaks. Despite several unrelated fish having this common name, convergence has given them much in common. These fish have a very predatory nature and will readily eat dwarf frogs. Dwarf frogs can do little to defend themselves from needlefish, which move more quickly than the defenseless amphibians.

    Clawed Frog Predation

    • Clawed frogs can turn the tables on needlefish. Needlefish specialize in quick, darting attacks, catching prey with speed and surprise. Their bodies are built for speed, and the brute-force attack of a fully grown clawed frog can easily overwhelm needlefish. Needlefish sharing aquariums with clawed frogs will face a constant threat of predation from their amphibian roommates.

    Water Parameters

    • Many species that sell by the name needlefish actually prefer saltwater or brackish water. Brackish water has more salt than freshwater, but less than full-strength sea water. While aquatic frogs can adapt to a wide variety of water conditions, this does not include brackish water or seawater. Xenentodon cancila, a common needlefish, does thrive in freshwater, but again, it will eat dwarf frogs, and clawed frogs will eat it. Aquarium frogs and needlefish do not get along in aquariums.