2Nd Parasitology Exam Cestodes Morphology & Life Cycle

Front 1

Taenia pisiformis

Back 1

Scolex with armed rostellum, 4 suckers; rectangular proglottids, Ova: spherical, striated shell

Hint 1

General Taeniidae pattern: Gravid proglottids passed in feces > ova disseminated in environment by motile proglottid > intermediate, Cysticercus in liver/mesenteries of intermediate host (6-8w) > ingested by definitive > SI

Front 2

Taenia taeniaformis

Back 2

Scolex with armed rostellum, 4 suckers; rectangular proglottids, Ova: spherical, striated shell

Hint 2

Strobilocercus in liver of intermediate host > ingested by definitive host > SI

Front 3

Taenia ovis, hydatigena, multiceps

Back 3

Scolex with armed rostellum, 4 suckers; rectangular proglottids, Ova: spherical, striated shell

Hint 3

Larval tapeworms (Cysticercus): Ovis = striated /cardiac mm, Hydatigena = liver (also swine), Multiceps = brain (also cattle, cats; asexual repro larval stage)

Front 4

Taenia saginata

Back 4

Scolex w/ 4 suckers, lacks hooks; rectangular proglottids

Hint 4

Larval tapeworm (Cysticercus bovis): in striataed/cardiac mm, ingested by definitive host > SI

Front 5

Taenia solium

Back 5

Scolex has 4 suckers, hooks; rectangular proglottids

Hint 5

Larval tapeworm (Cysticercus cellulosae): in striated/cardiac mm, Humans directly ingest ova (self-infection) > aberrant migration of cysticerci > ocular, neuro, muscle dz

Front 6

Echinococcus granulosus

Back 6

"3 segment tapeworm" V. small. Scolex with armed rostellum, 4 suckers, strobila 3-4 proglottids w/ unilateral pores, Egg spherical, radiations in shell, hexacanth

Hint 6

Larvae: Unilocular hydatid cyst; one big cyst with multiple dots, each dot = tapeworm

Front 7

Echinococcus multilocularis

Back 7

V. small. Scolex with armed rostellum, 4 suckers, strobila 3-4 proglottids w/ unilateral pores, Egg spherical, radiations in shell, hexacanth

Hint 7

Multilocular (alveolar) hydatid cyst, various organs; like tumor

Front 8

Dipylidium caninum

Back 8

Most common tapeworm of dogs and cats, Scolex w/ rostellum and 4 suckers, Oval proglottids, not overlapping

Hint 8

Cysticercoid stage in hemocoel of arthropod, Flea feeds on detritus/debris containing eggs > dog ingests flea

Front 9

Anoplocephala perfoliata

Back 9

Scolex with unarmed rostellum, 4 suckers, Short, wide proglottid, Ovum = letter D

Hint 9

Gravid proglottids released but EGGS passed in feces; Cysticercoid larval stage

Front 10

Anoplocephala magna

Back 10

Scolex with unarmed rostellum, 4 suckers, Short, wide proglottid, Ovum = letter D

Front 11

Moniezia spp

Back 11

Scolex w/ 4 suckers; short, wide proglottid, Ovum = diamond

Hint 11

Cysticercoid larva stage

Front 12

Thysanosoma actinoides

Back 12

Proglottids with fringe on posterior

Hint 12

Adults in duodenum, bile duct

Front 13

Mesocestoides corti

Back 13

Scolex with 4 suckers, Strobila: small oval sesame-seed proglottids with single ventral genital pore, parauterine organ

Hint 13

Tetrathyridium, young & adult can go through asexual repro (longitudinal fission)

Front 14

Raillietina

Front 15

Davainea

Front 16

Pseudophyllidean tapeworms

Back 16

Indentions in scolex (BOTHRIA) for attachment

Hint 16

Segments not passed in feces; pass eggs in uterine pore, proglottids dissolved

Front 17

Spirometra spp

Back 17

Scolex w/ 2 bothria, Square proglottids, single ventral pore, Eggs operculated: no rim

Hint 17

Ova in feces à ova in water, develop, hatch à free-swimimng coracidium ingested by 1st IH à PROCERECOID à ingested by 2nd IH à PLEUROCERCOID (spargana) à ingested by paratenic or definitive host

Front 18

Diphyllobothrium latum

Back 18

“Broad fish tapeworm”

Hint 18

Definitive host ingests undercooked fish