Lamprey Quiz #1
Lamprey Quiz #2
Ecology Connections

Life ProcessLifeCycle.jpg
Spawning Phase: Spring -early summer
Once sea lampreys have reached sexual maturity, they stop feeding and begin to congregate off the mouths of streams and rivers in preparation for spawning.
Lampreys construct crescent-shaped nests of small stones and gravel. The female may lay 30,000 to 100,000 eggs. After spawning, the adults die.

Larval Phase:
Most fertilized eggs settle in amongst the gravel of the nest and hatch in a few weeks. The young larvae emerge from the nest and then burrow into the stream's sand and silt bottom. The larvae feed on algae, detritus, and various small organisms.

Transforming Phase: Late summer- early fall
After three or more years as harmless larvae, they undergo a change called transformation, where they develop eyes and a sucker-like mouth with sharp teeth.

Parasitic Phase:
Lampreys typically move into the sea to begin a parasitic life, attaching to a fish by their mouths and feeding on the blood and tissues of the host They can spend 12-18 months in the parasitic phase until they are sexually mature enough to reproduce.Diet/Nutrition
Larva Phase: algae, detritus and various small organisms
Parasitic Phase: feed off host (fish)
One lamprey can consume over 40 pounds of fish in its lifetime
Spawning phase: No feeding

Specialized Systems DigestiveCirculatoryNervousExcretoryReproductiveMotile? yesDigestive System
Mouth →Pharynx→ Esophagus → Intestines
Alimentary canal: runs from mouth to the anus. No stomach Intestines: The site of the emulsification, digestion and absorption of nutrients. The latter portion of the intestine digests bacteria, reabsorbs water and forms feces. The last section of the intestine narrows to form an exit called the anus. The resulting solid wastes leave the body at this point. Nervous systemLamprey's have a primitive vertebrate nervous system, meaning the brain structure is fairly simple compared to other vertebrate animalsSystem consists of the brain and a hollow spinal cordSituated above the alimentary canal. Vertebrate nerve cord and brain contain a cerebrospinal fluid which contains mineral salts and traces of protein and sugar. The fluid helps to support the nervous tissue and probably plays some part in its nutrition.The nerve fibers are not covered by the myelin sheath (a fatty insulating layer) found in all higher vertebratesTherefore nervous conduction is slow. The complex nervous connections found in higher forms are impossible in these early vertebrates.Picture_2.pngCirculatory/Respiratory Systems Blood flows through a series of vessels to supply oxygen and nutrients to the body and to remove carbon dioxide and other wastes. Arteries and arterioles carry blood away from the heartVeins and venules carry blood back towards the heartCapillaries are the smallest vessels where the gases are exchanged with the cells of the body A lamprey “breathes” by extracting the oxygen present in the water in which it livesWater: mouth →pharynx → respiratory tube Within the respiratory tube are seven gill pouches, each containing the finer feather-like gill lamellae. The gill lamellae increase the surface area of the respiratory structures and contain the small capillary beds that extract oxygen. Problem: When a lamprey is feeding and attached to a fish the mouth serves as an attachment function, it is no longer available for use in respiration. Solution: Water can be drawn directly into the respiratory tube through the external gill slits. Muscular contractions change the volume of the respiratory tube and thus control the movement of water over the gill lamellae. Excretory System Kidney: filters out waste from the bloodIons, water and other nitrogenous wastesResponsible for maintaining osmoregulation The balance between the salts in the body and the salts in the environment. Freshwater: kidneys excrete extremely dilute urine to maintain the ionic balance in the body. Salt water: kidneys excretes a highly concentrated urine. Lampreys rely on the gills to rid the body of excess salt. Reproductive System In late winter, the lamprey's sexual reproductive system grows and their intestines shrinkTherefore, they don't eat in the winter but live off stored fat Female Reproductive SystemEcological Niche- Chordata Challenge: Considered a pest Evolutionary HistoryOf the 46,000 known species of vertebrates, lampreys and hagfish are the only surviving jawless vertebrates.Lampreys are the most “primitive” of the vertebrates, meaning that they are the least altered from the first vertebrates.They lack jaws, paired pectoral and pelvic fins, and scales. “Apart from being the oldest fossil lamprey yet discovered, [these fossils] show that lampreys have been parasitic for at least 360 million years”. - Dr. Bruce Rubidge
Difference between Lamprey and Hangfish
  • Hagfish have no spinal cord, while lamprey's do
  • Lamprey can survive in both salt water and in freshwater, while hagfish cannot
  • While lampreys feed of the living, hagfish feed off of the dead
VideoDirty Jobs - Spit Take | Sea Lamprey Exterminator Bibliography: "Blood-sucking Lamprey Is 360 Million Years Old." Conservation and Environmental Science News. 25 Oct. 2006. Web. 04 May 2011. Gianaro, Catherine. "Lampreys Show Little Evolutionary Variation over 360 Million Years." University of Chicago Chronicle: June 11, 2009. Web. 04 May 2011. "Lamprey (fish) -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 04 May 2011. "Nonvertebrate Chordates, Fishes, and Amphibians." Web. 4 May 2011. <Nonvertebrate Chordates, Fishes, and Amphibians>. "Sea Lamprey Life Cycle - Marquette Biological Station." U.S. Fish and Wildlife Service Home. 14 July 2010. Web. 04 May 2011. "Sea Lampreys." - Grains of Knowledge. Web. 04 May 2011. "Vertebrate Nervous System." The Internet Encyclopedia of of Science. Web. 04 May 2011.