Echeneidae

Echeneidae, commonly known as remoras or suckerfishes, is a family of ray-finned fishes distinguished by a broad suction disc on the head that enables them to attach to larger marine animals. They are found in tropical and temperate seas worldwide and are often seen clinging to sharks, rays, whales, sea turtles, and occasionally ships.

Morphology and adaptation: The suction disc is formed by modified dorsal fin rays and contains lamellae that create strong attachment. The body is elongated and typically streamlined for efficient movement in open water. Coloration ranges from gray to brown with pale markings, and adults vary in size across species, generally from about 20 to 75 cm.

Ecology and behavior: Remoras are primarily ectoparasites or commensals, feeding on external parasites, scraps from the host’s meals, and sometimes small planktonic prey drawn to the host. Their attachment to hosts can reduce energy expenditure for movement while providing access to food resources. Detached individuals may swim freely to relocate.

Taxonomy and conservation: Echeneidae includes several species grouped into a small number of genera. They belong to the broader percomorph fishes and are not generally considered threatened, though local populations can be affected by changes in host availability and marine ecosystem conditions. The relationship between remoras and their hosts is a notable example of commensalism in marine environments.