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Echeneis naucrates, commonly known as the Slender Suckerfish or Sharksucker, is a fascinating marine fish belonging to the family Echeneidae. It is renowned for its unique modified dorsal fin, which forms a powerful suction disc on its head, allowing it to attach to larger marine animals such as sharks, rays, turtles, and even boats. This commensal relationship provides the remora with transportation, protection from predators, and access to food scraps from its host's meals. While often perceived as parasitic, the relationship is generally considered commensal, as the remora typically does not harm its host, and may even benefit it by cleaning parasites from its skin.
Physical Characteristics
- Body shape
- elongated
- Coloration
- Typically dark grey to brownish-grey dorsally, fading to a lighter grey or whitish ventrally. A prominent dark longitudinal stripe, often bordered by thinner white stripes, runs from the snout through the eye to the caudal fin. The fins are generally dark.
- Scale type
- cycloid
- Mouth position
- superior
- Distinctive features
- Large, oval-shaped suction disc on the dorsal surface of the head, composed of 16-28 lamellae (transverse movable plates)., Elongated, slender body., Lower jaw projects beyond the upper jaw.
- Dorsal fin
- The first dorsal fin is modified into a large, oval, lamellated suction disc on the head. The second dorsal fin is long and low, originating behind the pectoral fin base and extending almost to the caudal fin.
- Tail fin
- Slightly forked or emarginate, with the upper and lower lobes often elongated.
- Pectoral fin
- Relatively large and pointed, positioned low on the body.
- Distinctive fins
- The anal fin is similar in shape and size to the second dorsal fin, positioned directly below it.
Identification Tips
Suction Disc
The most defining feature is the large, oval suction disc on the top of its head, which is clearly visible and unique among fish.
Body Shape and Stripe
Its elongated body and the prominent dark longitudinal stripe running along its flanks are key identifiers.
Jaw Structure
The projecting lower jaw is also a characteristic trait.
Habitat
- Water type
- saltwater
- Depth
- Typically found in oceanic and coastal waters from the surface down to about 100 meters (330 feet), though they can range deeper.
- Environment
- Pelagic, often associated with large marine animals (sharks, rays, turtles, cetaceans) or floating debris and boats. Also found in coastal areas, including reefs and estuaries.
- Geographic range
- Circumglobal in tropical and subtropical waters of the Atlantic, Pacific, and Indian Oceans. Its distribution largely mirrors that of its hosts.
Aquarium Information
- Care level: advanced
- Temperament: peaceful
- Diet: carnivore
- Minimum tank size: 500 gallons
- Temperature: 72-78°F (22-26°C)
- pH level: 8.1-8.4
- Hardness: 8-12 dKH
- Compatibility: Generally compatible with large, robust fish that are not easily intimidated. Not suitable for reef tanks due to potential for disturbing corals and invertebrates. Requires a host or a smooth surface to attach to.
- Special requirements: Requires a very large aquarium with strong filtration and excellent water quality. A smooth, flat surface (e.g., a large PVC pipe or acrylic sheet) should be provided if a suitable host fish is not present, as they need to attach to something. They are prone to stress if unable to attach. Feeding can be challenging; they often prefer to scavenge from other fish or be target-fed.
Wild Information
- Conservation status: least concern
- Seasonality: Present year-round in tropical and subtropical waters, with no specific seasonal migrations for breeding or feeding.
- Market price: Low
- Commercial importance: low
- Taste: Mild, somewhat oily
- Texture: Firm, flaky
- Cooking methods: Fried, Baked, Grilled
- Nutritional value: Good source of protein and omega-3 fatty acids, similar to other lean white fish.
Key Facts
The Ultimate Hitchhikerbehavior
The Slender Suckerfish is famous for its unique ability to attach to larger marine animals using a modified dorsal fin that acts as a powerful suction cup, allowing it to travel effortlessly across vast distances.
Cleaning Crewinteresting
While primarily seeking transportation and food scraps, remoras are also known to clean parasites and dead skin from their hosts, providing a beneficial service in some cases.
Ancient Fishing Techniqueinteresting
Historically, some cultures, particularly in the Indo-Pacific, used remoras tied with a line to catch large turtles or other fish. The remora would attach to the prey, and both would then be reeled in.
Not a Parasitebehavior
Despite common misconceptions, the relationship between a remora and its host is generally considered commensal (one benefits, the other is unaffected) rather than parasitic (one benefits at the expense of the other).
Suction Poweramazing
The suction disc of a remora is incredibly strong, capable of withstanding significant drag forces, allowing them to remain attached even to fast-swimming sharks or boats.
Safety Information
Safe- Safety level: safe
- Venomous: No
- Edibility: edible
- Handling notes: Slender Suckerfish are not venomous and pose no direct threat to humans. When handling, care should be taken not to damage their suction disc, as it is crucial for their survival. They can attach firmly to skin or objects, and detaching them should be done gently by sliding them forward, rather than pulling directly, to avoid injury to the fish or skin abrasion.
Similar Species
Whitefin Sharksucker
Echeneis neucratoides
Echeneis neucratoides has a similar body shape and stripe but typically possesses white margins on its dorsal, anal, and caudal fins, which are usually dark in E. naucrates. The number of lamellae in the suction disc can also differ slightly (E. neucratoides typically has 18-21, while E. naucrates has 16-28, with significant overlap).
Spearfish Remora
Remora brachyptera
Remora brachyptera has a shorter, stouter body and a relatively smaller suction disc compared to E. naucrates. Its coloration is generally more uniform dark grey or brown, lacking the distinct longitudinal stripe of the Slender Suckerfish. It also has fewer lamellae in its disc (12-17).
Common Remora
Remora remora
Remora remora is generally stouter and less elongated than E. naucrates. It has a larger, broader head and a more uniformly dark coloration, lacking the prominent stripe. The number of lamellae in its disc is typically 16-20.
Scientific Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Actinopterygii
- Order
- Carangiformes
- Family
- Echeneidae
- Genus
- Echeneis
- Species
- Echeneis naucrates
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