Slender suckerfish

Slender suckerfish
Drawing by Dr Tony Ayling
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Echeneidae
Genus: Phtheirichthys
Gill, 1862
Species: P. lineatus
Binomial name
Phtheirichthys lineatus
(Menzies, 1791)
Synonyms

Echeneis apicalis Poey, 1860
Echeneis lineata Menzies, 1791
Echeneis sphyraenarum Poey, 1860
Echeneis tropica Euphrasen, 1791
Phtheirichthys multiradiatus Schultz, 1943

The slender suckerfish or lousefish, Phtheirichthys lineatus, is a rare species of remora, family Echeneidae, and the only member of the genus Phtheirichthys. It is found around the world in tropical and subtropical seas.[1]

The body of the slender suckerfish is elongate, with long dorsal 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 lamellae. The caudal fin is paddle-shaped. The head and body is 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.[2] It usually measures 34 cm long but has been reported up to 76 cm.[3] The sucker disk is fully developed in 50 mm individuals.[4]

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.[1] The slender suckerfish feeds mostly on scraps of fish and plankton, as opposed to more host-dependent remoras that feed on host parasites.[5] Nothing is known of its reproduction.[2]

References

  1. ^ a b Froese, Rainer, and Daniel Pauly, eds. (2008). "Phtheirichthys lineatus" in FishBase. November 2008 version.
  2. ^ a b Lachner, E.A. (1986). "Echeneididae". In Whitehead, P.J.P, et al.. Fishes of the North-eastern Atlantic and the Mediterranean. Paris: United Nations Educational, Scientific and Cultural Organization. ISBN 9230023094. 
  3. ^ Eschmeyer, W.N. and Herald, E.S. (1983). A Field Guide to Pacific Coast Fishes of North America: From the Gulf of Alaska to Baja California. HMCo Field Guides. ISBN 9780618002122. 
  4. ^ Cressey, R.F. and Lachner, E.A. (Jun 1, 1970). "The Parasitic Copepod Diet and Life History of Diskfishes (Echeneidae)". Copeia (American Society of Ichthyologists and Herpetologists) 1970 (2): 310–318. doi:10.2307/1441652. JSTOR 1441652. 
  5. ^ Strasburg, D.W. (Oct 9, 1959). "Notes on the Diet and Correlating Structures of Some Central Pacific Echeneid Fishes". Copeia (American Society of Ichthyologists and Herpetologists) 1959 (3): 244–248. doi:10.2307/1440398. JSTOR 1440398.