Common Remora

About

The common remora (Remora remora) is one of the more fascinating oddities in the ocean, built from the fins up for a life of freeloading. The dorsal fin has been modified over millions of years into a flat, ribbed suction disc on top of the head, which the fish uses to clamp onto sharks, rays, large billfish, sea turtles, and even whales. In the wild this arrangement works beautifully. The remora hitches free transport, picks up scraps from its host's meals, and keeps itself clean of parasites along the way. In an aquarium, however, everything that makes this fish extraordinary in the ocean becomes a logistical headache. Without a suitable host animal, remoras become disoriented and difficult to feed consistently. They are genuinely pelagic creatures that spend their lives in open water alongside large predators, so replicating anything close to their natural situation requires a massive system and ideally a compatible elasmobranch tankmate. This is firmly a species for public aquaria or exceptionally well-resourced private setups. Not because remoras are aggressive or chemically demanding, but because their behavioral and spatial needs are nearly impossible to meet at a hobby scale. A remarkable animal to observe if you ever get the chance, but best admired in a large professional exhibit.