Transcript Parasites
Parasites What is a parasite? • Parasitism is a type of symbiotic relationship between two different organisms. The parasite benefits from a prolonged, close association with the host, which is harmed • Many possess special adaptations Tapeworms Tapeworms • Up to 35 feet long • Lay millions of eggs each day • Attach to the intestines and absorb nutrients from its host Hookworms Hookworms • Burning lake water? • Hookworms enter through the skin and migrate through the bloodstream to the lungs and intestines. They may also be ingested through contaminated food or water. You may have itchiness or redness where the larvae penetrate the skin (most likely your feet). • One symptom is craving to eat soil Roundworms Roundworms • Here is a staggering statistic: the World Heath Organization reported that about 25% of the world’s population is infected with roundworm. • These parasites can grow to 13 inches inside the intestine and can lay as many as 300,000 eggs in a single day • Ascaris lumbricoides • Partial cause of distented stomachs in starving children Pinworms Pinworms • Have you ever been awakened in the middle of the night by an itchy anus? If so you have these little guys. They sneak out at night to lay their eggs on the fertile skin surrounding your anus! • Get these nasty little guys from contaminated food Special parasites • While all parasites possess special adaptations to be able to survive in their host, some are more bizarre than others….. Human Bot Fly Human bot fly • http://www.youtube.com/watch?emb=0&aq=f& aq=1&v=4B7Top18qXY&eurl=http%3A%2F%2Fvide o.google.com%2Fvideosearch%3Fq%3Dbot+fly& oq • Lays egg in human host. Larvae grows and eventually falls out Candiru Candiru • Type of catfish with tiny barbs • Usually parasitizes fish gills • Has been known to follow urea trails and swim up the urethra Castrating Barnacles Castrating barnacles • Briarosaccus callosus • Find way into crab through a ‘kink’ in exoskeleton • Eventually can control crab Leucochloridium paradoxum Leucochloridium paradoxum • Leucochloridium paradoxum are a type of fluke (a.k.a., parasitic flatworm) that prey on • They take up residence in the snail’s eyestalks. As they mature, the flukes become visible through the snail’s translucent skin and look like caterpillars. • Birds eat these, and the cycle starts again Cymothoa exigua Cymothoa exigua • A parasitic crustacean • Attaches itself to a fishes tongue and feeds on the blood • Eventually the tongue atrophies, and this parasites functionally replaces the old tongue with its own body. Lamprey’s Lamprey • Type of parasitic fish • Attaches to passing fish and feeds on their blood • Very specialized mouth parts Filaria Worm Filaria worm, Wuchereria bancrofti • Elephantitis is a disease caused by the parasite Wuchereria bancrofti. This parasite is introduced into the body by a mosquito bite. The parasite will then migrate to the lymphatic system. The parasite does not cause any direct harm to the host; it is the side effects of the infestation that cause the damage. • Elephantiasis is the result of the parasites blocking the lymphatic ducts. With the lymphatic ducts blocked, the lymph fluid does not circulate well and will accumulate, causing swelling. Filaria worm, Wuchereria bancrofti • filarial worm embryos living underneath the skin can sense the onset of night, which is their cue to head upward to the skin’s surface in order to increase their chances of being picked up by a passing mosquito • But not all organism negatively affect their host: Coolest Symbiosis Example Boxer Crab, Lybia tessellata