The slender suckerfish or lousefish (''Phtheirichthys lineatus'') is a rare species of

remora The remora (), sometimes called suckerfish, is any of a family (Echeneidae) of ray-finned fish in the order Carangiformes. Depending on species, they grow to long. Their distinctive first dorsal fins take the form of a modified oval, sucker-li ...

found around the world in tropical and subtropical seas, in areas like the Atlantic, Pacific, and Indian Ocean, from depths from 1 to 100 meters deep. The body of the slender suckerfish is elongated, with long

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

and anal fins. The dorsal fin rays number 29-33, the anal fin rays 29-34, and the pectoral fin rays 18-21. The adhesive disk atop the head is small, length 18-28% of the standard length, with 9-11

lamella Lamella (plural lamellae) means a small plate or flake in Latin, and in English may refer to: Biology * Lamella (mycology), a papery rib beneath a mushroom cap * Lamella (botany) * Lamella (surface anatomy), a plate-like structure in an animal ...

e. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

is paddle-shaped. The head and body are pale, dark brown, or blackish. Larger specimens have a distinctive dark brown stripe running along the side of the body, bordered by narrower white stripes above and below. The fins are blackish, with the outer portions of the longer dorsal and anal fin rays and the margins of the outer caudal fin rays light. It usually reaches in total length (TL), but has been reported up to TL. The sucker disk is fully developed in 50-mm individuals. With the smallest adhesive disk amongst the remoras, the slender suckerfish is not strongly host-dependent and can be encountered free-swimming or attached to inanimate objects. The slender suckerfish feeds mostly on scraps of fish and

plankton Plankton are the diverse collection of organisms found in water (or air) that are unable to propel themselves against a current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucia ...

, as opposed to more host-dependent remoras that feed on host

parasite Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson has ...

s. Nothing is known of its reproduction.

References

{{Taxonbar, from=Q657932 slender suckerfish Cosmopolitan fish slender suckerfish