Remora Fish (Echineis Naucrates) saltwater aquarium fish

Overview:

Remora fish are highly specialized pelagic hitchhikers that live by attaching to larger marine animals, including sharks, rays, and sea turtles. They are not ideal “display” pets and are very rarely suitable for standard home aquariums. Their care needs are complex because they require exceptional water quality, high oxygenation, strong swimming space, and access to appropriate host species or a comparable large, active marine environment. The best habitat is a very large, mature saltwater system with powerful circulation, excellent filtration, stable salinity, and plenty of open water. Fine gravel, cramped quarters, and sharp décor should be avoided. Remoras are best kept only by advanced marine facilities or experienced aquarists with large-species systems and a clear long-term plan.

Diet and Feeding:

In the wild, remoras feed on scraps, small prey items, and host-associated leftovers, but they should not be assumed to survive on “leftover food” alone in captivity. A healthy remora requires a varied marine diet of chopped seafood, small marine fish pieces, shrimp, squid, krill, and other nutrient-rich frozen marine foods. Offer frequent feedings, especially for juveniles, because remoras have a high metabolic need and can lose condition quickly if underfed. Use vitamin-soaked foods when possible to reduce deficiency risk. Observe feeding closely: a remora that is not actively eating is a concern. They should never be fed mammalian meats or low-quality feeder fish, as these can cause nutritional problems and contamination risk.

Compatibility:

Compatibility is one of the biggest challenges. Remoras are generally peaceful, but they are not casual community fish. They may stress tankmates by constant attachment attempts, especially with slow, shy, or delicate fish. They are best housed only with very large, robust marine animals in systems designed for them, and even then only if the host species can tolerate their presence. Avoid pairing them with small reef fish, ornamental species, or animals that could be harmed by suction attachment. They are also poor candidates for mixed-aggression tanks because they can be injured by territorial species and may become difficult to manage as they grow. In many home setups, the most appropriate choice is not compatibility management but avoiding ownership altogether.

Health and Quarantine:

Remoras are sensitive to stress, poor water quality, and handling injury. Common health concerns include abrasions from attachment, weight loss from inadequate feeding, and parasitic infections acquired from wild collection. Quarantine is essential for any new specimen, ideally in a large, stable marine isolation system with strong aeration and close monitoring. Watch for rapid breathing, skin lesions, refusal to feed, or abnormal swimming. Preventive care should focus on pristine water, low stress, secure acclimation, and consistent nutrition. Because remoras are difficult to treat safely once ill, early detection is critical.

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Remora fish are highly active, pelagic hitchhikers that spend most of their time swimming in open water or attaching to larger hosts, so they require a spacious aquarium with strong flow and ample unobstructed swimming room rather than dense cover or bottom structure. Temperament is generally peaceful but highly dependent on their host association and size class, and they are usually not territorial; conspecifics may tolerate one another in very large systems, but crowding can lead to stress and competition for attachment sites. A minimum tank size of 300 gallons is recommended, with layout focused on open lanes, minimal sharp decor, and sturdy visual barriers only where needed to reduce line-of-sight stress without impeding movement. They coexist best with robust, reef-safe species and large, non-aggressive tank mates, but small or delicate fish may be harassed by their persistent following behavior or outcompeted for space. Remoras are opportunistic carnivores that feed primarily on scraps, small crustaceans, parasites, and meaty leftovers, using their grazing and scavenging behavior rather than active hunting. In captivity, they do best on frequent offerings of high-quality frozen and prepared marine foods, with careful attention to water quality and consistent feeding to reduce dependence on host-derived food.

FAQ

Frequently Asked Questions

About the Remora Fish

  • Can a remora fish be kept in a home aquarium, and what size tank would it need?
    In practical terms, no—remoras are not appropriate for typical home aquariums. They are pelagic, high-oxygen, open-water fish that grow large, swim constantly, and naturally attach to much larger hosts. Even juvenile remoras outgrow most hobby systems quickly and do poorly without immense swimming space, strong filtration, and specialized husbandry. A truly suitable setup would be public-aquarium scale, not a normal hobby tank.
  • If I buy a juvenile remora, can I train it to eat prepared foods in captivity?
    Sometimes juveniles will accept chopped seafood, frozen marine foods, or specially offered pieces of fish, squid, and shrimp, but feeding alone is not the main issue. The bigger problem is that remoras are highly adapted to life alongside larger animals, and many refuse to thrive long-term even when they eat. They often need frequent, varied feedings and excellent water quality, and stress from captivity can make feeding inconsistent.
  • Does a remora need a host fish or shark to survive in an aquarium?
    It does not biologically require a host to stay alive, but it is strongly adapted to associating with one. In captivity, the lack of a proper host can lead to abnormal behavior, reduced activity, and poor long-term welfare. They may try to attach to tankmates, equipment, or the glass, which is not a substitute for natural host interactions and can create stress or injury.
  • Why does my remora keep trying to stick to the glass, powerheads, or other fish?
    That is normal remora behavior. The modified dorsal fin on top of its head acts like a suction pad, letting it attach to moving animals or surfaces for transport and feeding opportunities. In aquariums, they often latch onto glass, overflow boxes, pumps, heaters, or tankmates because those are the closest available “platforms.” This behavior can be a problem if they injure themselves or harass other fish.
  • Are remoras compatible with reef tanks or predator tanks?
    Usually not in the way hobbyists expect. In a reef tank, a remora may attach to corals, rockwork, or equipment and can become a nuisance due to its size and constant movement. In a predator tank, it may try to attach to large fish or sharks, but compatibility depends entirely on the species, tank scale, and the predator’s temperament. Most home aquariums are too small and too artificial to meet the needs of a remora safely or humanely.