Donkey Fish

About

The jackknife fish (Equetus lanceolatus) is one of those species that stops you in your tracks the moment you see it. The body is cream to white with a dramatic black stripe that runs from the tip of the tall, elongated dorsal fin down through the eye and continues along the body to the tail. The overall silhouette really does resemble a folding blade. Juveniles are especially theatrical, with that oversized dorsal fin looking almost comically large relative to the body. In the wild, this species ranges across a huge stretch of the Western Atlantic, from Bermuda and the Carolinas all the way south to Brazil, where it turns up in bays, sounds, and along coral reefs at varying depths. It tends to be a calm, approachable fish in its natural habitat, which carries over into aquarium life. Juveniles are sometimes found closer to shore, while adults tend to favor deeper reef environments. Diet in the wild leans heavily on small crustaceans like shrimp and crabs, supplemented by worms and mollusks, so replicating that protein-rich menu in captivity is important. Despite the care level listed as beginner, this is a marine species that needs a well-established reef or fish-only setup with plenty of hiding spots and calm tankmates to really thrive.