Lampreys of the world. An annotated and illustrated catalogue of lamprey species known to date.

Abstract

Lampreys are aquatic, jawless vertebrates belonging to the Order Petromyzontiformes. The order comprises 39 species widely distributed in the Northern and Southern hemispheres, but virtually absent in the intervening tropical zone. There is one family in the Northern Hemisphere (Petromyzontidae) comprising 35 species and two families in the Southern Hemisphere (Geotriidae and Mordaciidae) comprising, respectively, one and three species. Lampreys undergo a radical metamorphosis from the l arval to the adult form. While lamprey larvae (ammocoetes) of all species are very similar in their habits (filter–feeding on microorganisms in a freshwater habitat), the adults vary considerably in their mode of life. Some are parasitic and anadromous, others parasitic but restricted to fresh water, while still others are nonparasitic (non–feeding) and restricted to fresh water. The taxonomic characters used to describe ammocoetes and adults are fully explained and illustrated. A key to adults and a partial key to larvae are presented. This catalogue provides an account for each of the 39 species. Each species account gives information on the taxonomy including synonyms, common names, diagnostic features of ammocoetes and adults (with drawings of the adult body and oral disc), habitat and biology, geographic distribution (with map), interest to fisheries and references.