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ZOO 115 Invertebrate Zoology. Platyhelminthes Parasites. SUCKERS AND HOOKS - Cestoidea. home.earthlink.net/~xylaria/em/tapeworm.jpg. www.icr.org/research/ma/images/ma-r01-f12.jpg. Parasitism - Adaptations. Method of attachment SUCKERS - Trematoda and Monogea.
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ZOO 115 Invertebrate Zoology Platyhelminthes Parasites
SUCKERS AND HOOKS - Cestoidea home.earthlink.net/~xylaria/em/tapeworm.jpg www.icr.org/research/ma/images/ma-r01-f12.jpg Parasitism - Adaptations • Method of attachment • SUCKERS - Trematoda and Monogea
static.howstuffworks.com/gif/mosquito6a.jpg a.abcnews.com/images/2020/pd_eating_070521_ms.jpg Parasitism - Adaptations • Getting into host • Penetration – special glands to digest skin • Getting into host • Passive – eaten by host • Need outer resistant covering • Living tegument • Permeable to H20, amino acids, sugars • Tolerate great changes in pH.
Parasitism - Adaptations • Osmotic Pressure • Must be lower than surroundings – why? • Facultative anaerobic respiration • 4X more efficient than in vertebrates • Reduced structures • Sensory (except chemo) • Muscles • Nervous system • Digestive tract
Parasitism - Adaptations • Increased reproduction • Produce many many eggs • e.g. Fish tapeworm 2 million eggs/day and can live for 15 yrs (100 trillion eggs in lifetime) • Polyembryony – many young from one egg. • Asexual stages amplify numbers • e.g. Fasciola hepatica produces 500,000 eggs in a lifetime that produce 42 trillion offspring.
www.semioticon.com/seo/M/images/mimicry_2.jpg Parasitism - Adaptations • Host reactions to parasites • Susceptibility varies with life cycle and health of host • Single host – parasite usually becomes more commensal • Castration • Multiple hosts – parasite can kill the host • Snails • Ants • Internal parasites – develop ways of hiding from immune system
Parasitism - Adaptations • Host specificity varies • Some are completely specific to their hosts • Problems with non-specificity • Swimmer’s itch • Nematode and encephalitis
Class - Trematoda • Common Name - Flukes • Common parasites of all major vertebrate taxa. • >11,000 species
web.bio.utk.edu/guffey/BiaB Class Trematoda - General Anatomy of Adult • Suckers for feeding and attachment • Non-cliated tegument • Protection against enyzmes, • Gas exchange • Eliminate nitrogenous waste • Absorb glucose and amino acids
www.cat.cc.md.us/courses/bio141/labmanua/lab22/images www.cat.cc.md.us/courses/bio141/labmanua/lab22/images Class Trematoda - General Anatomy of Adult
Class Trematoda – Life Cycles • Chinese Liver Fluke (Opisthorchis or Clonorchis) • Infests 20 million E. Asians • Adult ~ 2.5 cm in length • Live 8 yrs • Produce 4000 eggs per day for 6 mo • Symptoms: Jaundice, gallstones, debilitation and liver cancer
Amplification Adult Redia Miracidium Sporocyst Cercaria Metacercaria ucdnema.ucdavis.edu/imagemap/nemmap/ent156html/slides www.biology.ualberta.ca/courses.hp/zool250/Labs/Lab05/ /www.spelman.edu/~biology/bio112/lab/images bio.winona.msus.edu/bates/Parasitology/Images/ Cercaria biodidac.bio.uottawa.ca/ftp/BIODIDAC/Zoo/Platyhel/DIAGBW www.cdc.gov/ncidod/eid/vol5no5/images ucdnema.ucdavis.edu/imagemap/nemmap/ent156html/slides Class Trematoda - Life Cycle
Male Female /www.biology.ualberta.ca/courses.hp/zool250/Labs Class Trematoda – Life Cycles • Blood Fluke (Schistosoma sp) • Dioecious: Male 6-10 mm, Female much smaller (fits into groove in male) • Develop cercaria directly from sporocyst (no redia)
Class Trematoda - Reproduction • Why is amplification important? • What impact might the multiple host strategy of the parasite have on the hosts?
www.pubs.royalsoc.ac.uk/proc_bio_content/images/ bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab-4a/Class_Monogenea http://www.paru.cas.cz/helminti/Monogenea.html Class Monogenea • Ectoparasites – only one host • Mostly infest fishes • Adults have suckers and hooks • Larvae – hooked free-swimming (oncomiradium)
www.chilternkoi.nildram.co.uk/ Class Monogenea – life cycles • Dactylogyrus sp. • More eggs with increasing temperature • Eggs released – sit on bottom • Hatch into swimming larvae • On contact with fish metamorphose into adult form
www.biology.ualberta.ca/courses.hp/zool250 Class Monogenea – life cycles • Polystoma sp. • Eggs stay in frog until frog gets in water • Hatch into swimming larvae • Larvae attach to gills of tadpoles • Tadpoles metamorphose and larvae crawls over belly and goes into bladder
faculty.clintoncc.suny.edu/faculty/Michael.Gregory/files Class Cestoda • Common name: Tapeworms • ~3400 species • Gut is absent – specialized neodermis for nutrient uptake. • Live about 15-20 yrs • Can copulate
Scolex news.bbc.co.uk/media/images/ Hooks Suckers Neck www.personal.psu.edu/users/t/r/trp2 www.microscopyu.com/galleries/smz1500/images www.scoop.co.nz/stories/images www.ibiblio.org/herbmed/eclectic/thomas/pics Class Cestoda - Anatomy • Can reach 15 m in length! • Head region • Attach to prey’s intestinal tract
biodidac.bio.uottawa.ca/ftp/BIODIDAC/ZOO/PLATYHEL/PHOTO/ www.personal.psu.edu/users/t/r/trp2 www.ibiblio.org/herbmed/eclectic/thomas/pics Class Cestoda - Anatomy • Proglottids • Each is a complete hermaphroditic reproductive system • Both Cross and Self-Fertilization
http://wdfw.wa.gov/wlm/regions/reg5/graphics/tapeworm.jpg biodidac.bio.uottawa.ca/ftp/BIODIDAC/ZOO/PLATYHEL/PHOTO/ www.path.cam.ac.uk/~schisto/Pictures/Eggs/Other_helminth_eggs bioweb.uwlax.edu/zoolab/Table_of_Contents/Lab-4b/ Class Cestoda – Life Cycles
users.rcn.com/jkimball.ma.ultranet/BiologyPages/ Class Cestoda – Life Cycles • If eggs go in water • swimming larvae (onchosphere) hatches within 10 days • Eaten by copepods • Copepods eaten by fish • Penetrates gut, migrates to muscle and transformed into dormant miniaturized adult • Eaten by warm-blooded host
Class Cestoda – Life Cycles • If eggs go on land • Eggs eaten by cattle • Onchosphere larvae hatch, bore into intestinal wall and transported through circulatory system to muscle tissue • Develops into bladderworm larvae (Cysticercus). • Eaten by warm-blooded host. http://sps.k12.ar.us/massengale/tapeworm.gif
Class Cestoda • Causes Diarrhea, Weight loss and inflammation • Biggest problem is accidental infestations • Bladder worm will develop into tissue other than muscle. • Cyst can contain liters of fluid which could cause severe infection if released