Remora Fish (Echineis Naucrates) saltwater aquarium fish portrait

Echeneis naucrates is the largest and most familiar of the remoras, immediately recognizable by the modified dorsal fin that forms an oval suction disc across the top of the head, built from roughly 18 to 28 laminae. The body is slender and elongate, dark gray to brown, and marked with a broad dark lateral stripe edged in white; the dark dorsal, anal, and caudal fins carry narrow white margins or corners. A projecting lower jaw completes the profile. The species occurs circumtropically in tropical and warm-temperate seas, ranging both inshore and offshore, over coral reefs and through open water.

Housing is the central obstacle. Published maximum lengths run from about 39 to 43 inches, and specialist references place this fish in exceptionally large, purpose-built systems, with several treating it as practical only at public-aquarium scale. Suggested minimums differ dramatically across sources, from a few hundred gallons to figures exceeding thirteen thousand gallons, so the listed minimum should be read as an absolute floor rather than a long-term target. Prioritize expansive, unobstructed swimming lanes free of sharp obstacles, fine sand, and secure rockwork with caves or crevices where the fish can rest. Moderate, broadly distributed flow suits it well.

Filtration and skimming must be heavily oversized to keep pace with an enormous appetite and the waste that follows, and strong oxygenation is important in a system of this volume. Water chemistry should remain stable at all times. Jumping is a documented risk, so fit a heavy, tightly secured lid and seal any plumbing gaps where a determined fish could force its way out.

In the wild this remora feeds on scraps left by its host, ectoparasitic crustaceans picked from that host, and free-living prey including crustaceans, crabs, squid, and small fishes. Captivity translates directly to a meaty marine menu: chopped marine fish flesh, clam, shrimp, squid, and krill are all documented as accepted foods. Portion sizes should be generous but managed carefully, since uneaten pieces decay quickly and degrade water quality in a system already carrying a heavy bioload.

Feeding recommendations vary, with references suggesting once or twice daily or several smaller meals spread through the day; at minimum, plan on daily feeding, and increase frequency for fast-growing juveniles. This is typically a willing, voracious eater that transitions to prepared meaty items without much coaxing, which makes portion discipline more of a concern than acclimation. Rotate among several food types to keep the diet varied.

Marine Fish Flesh Clam Shrimp Squid Krill
Echeneis naucrates alternates between free swimming and attaching itself with the head disc to sharks, rays, sea turtles, large bony fishes, marine mammals, boat hulls, aquarium structures, and occasionally divers. Wild individuals sometimes gather in groups, and juveniles have been observed operating cleaning stations on the reef, removing parasites from other fishes. Sources disagree on whether a living host is necessary in captivity: one specialist supplier considers a large host such as a shark, ray, turtle, or sizable fish essential, while another reference reports that the fish does well without one provided it is fed adequately and given a large artificial structure to attach to.

Compatibility is where this species becomes genuinely difficult. Repeated attachment can stress large tankmates and produce abrasions or lesions over time, so any potential host should be evaluated with that in mind. Small fishes and invertebrates that fit the mouth may simply be eaten, and this remora should never be paired with small or delicate animals. Although it is not documented grazing on corals, and clam appears in the diet only as prepared food rather than as live prey, its adult size, constant movement, and demand for vast open water make a conventional reef display an impractical home. Ornamental shrimp, snails, and diminutive reef fishes are poor choices as companions.

FAQ

Frequently Asked Questions

About the Remora Fish

  • Is this remora suitable for a typical home saltwater aquarium?
    No. It can approach 43 inches, generates a very heavy bioload, and requires vast open swimming space, which limits it to enormous specialized systems or public displays. Published minimum volumes vary widely, so the listed figure is not a long-term standard.
  • Does it need a shark, ray, or other living host?
    Sources disagree. One reference considers a large host such as a shark, ray, turtle, or big fish necessary, while another reports the fish thrives without one if well fed and given a large artificial attachment structure.
  • Can it be kept with small fishes or invertebrates?
    No. Small fishes and invertebrates that fit its mouth may be eaten, and repeated disc attachment can stress or injure larger tankmates through abrasion.