Lamprey

Lampreys (sometimes also called lamprey eels) are any jawless fish of the order Petromyzontiformes, placed in the superclass Cyclostomata. The adult lamprey may be characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin lampetra, which may mean "stone licker" (lambere "to lick" + petra "stone"), though the etymology is uncertain.

Currently there are about 38 known extant species of lampreys. Although they are well known for boring into the flesh of other fish to suck their blood, in fact only a minority do so; only 18 species of lampreys are actually parasitic. The lampreys are a very ancient lineage of vertebrates, though their exact relationship to hagfishes and jawed vertebrates is still a matter of dispute.

Characteristics

Basic external anatomy of a lamprey

Basic external anatomy of a lamprey

Adults physically resemble eels, in that they have no scales, and can range from 13 to 100 cm (5 to 40 inches) long. Lacking paired fins, adult lampreys have large eyes, one nostril on the top of the head, and seven gill pores on each side of the head. The unique morphological characteristics of lampreys, such as their cartilaginous skeleton, suggest they are the sister taxon (see cladistics) of all living jawed vertebrates (gnathostomes), and are usually considered the most basal group of the Vertebrata. Instead of true vertebrae, they have a series of cartilaginous structures called arcualia arranged above the notochord. Parasitic lampreys feed on prey as adults by attaching their mouthparts to the target animal's body, then using their teeth to cut through surface tissues until they reach blood and body fluid. Although attacks on humans do occur, they will generally not attack humans unless starved. Non-parasitic lampreys, which are usually freshwater species, do not feed as adults; they live off reserves acquired as ammocoetes (larvae), which they obtain through filter feeding.

River Monsters

River Monsters is a British and American wildlife documentary television programme produced for Animal Planet by Icon Films of Bristol, United Kingdom. Hosted by extreme angler and biologist Jeremy Wade who travels around the globe in search of the most fearsome freshwater killers. Looking for clues, eyewitnesses and stories about people who were dragged underwater by these vicious predators, he tries to catch the biggest specimens and then release them back to the wild. His aim is to save these rare creatures from extinction and to help people understand the truth behind the horrific attacks on humans.

River Monsters became one of the most watched, most successful programmes in Animal Planet's history, and one of the most viewed series on Discovery Channel too. In the US, only the shortened version is shown and some animals Jeremy shows are just cut off. These missing scenes are shown only when it premieres on ITV (originally on on Sundays ITV1) in the UK.

Series preview

River Monsters travels worldwide with Suffolk-born British host, biologist, adventurer and extreme angler Jeremy Wade to explore rivers and lakes to uncover the creatures behind local folklore and harrowing tales of monster fish. The show has taken viewers to Germany, Spain, Italy, Scotland, Iceland, Norway, Argentina, Australia, New Zealand, Papua New Guinea, India, Japan, Russia, Suriname, Brazil, Ethiopia, Uganda, South Africa, the Republic of Congo, Mongolia, Guyana, and the American states of Alaska, Florida, Missouri, Oklahoma, Texas and Vermont.

Sea lamprey

The sea lamprey (Petromyzon marinus) is a parasitic lamprey found in the northern Atlantic Ocean along shores of Europe and North America, in the western Mediterranean Sea, and in the shores of the Great Lakes. It is brown, gray, or black on its back and white or gray on the underside and can grow up to 90 cm (35.5 in) long. After several years in freshwater habitats, the larvae undergo a metamorphosis that allows young postmetamorphic lampreys to migrate to the sea or lakes and start the hematophagous feeding. Some individuals can start the hematophagous feeding in the river before migrating to the sea, where sea lampreys prey on a wide variety of fish. The lamprey uses its suction cup-like mouth to attach itself to the skin of a fish and rasps away tissue with its sharp, probing tongue and keratinized teeth. Secretions in the lamprey's mouth prevent the victim's blood from clotting. Victims typically die from excessive blood loss or infection. After 1 year of hematophagous feeding, lampreys return to the river to spawn and die, one year and a half after the completion of metamorphosis. Lampreys are considered a delicacy in some parts of Europe, including South-Western France, but are not commonly eaten in the Americas.