Platyhelminthes and Rotifers

Platyhelminthes:
Overview L43
platyhelminth turbellarians:
Planaria plain & digestive tract L44 Figs 6.2(a) & 6.4; T155 Fig 8.9(b); T156 Fig 8.10(a); T157 Fig 8.12(a-c); R57 – eyespot, auricle, pharynx, gastrovascular cavity (=digestive cavity)

platyhelminth monogeneans:

Gyrodactylus – opisthaptor

Polystoma (D) T160 Fig 8.16(b)

platyhelminth trematodes:
Fasciola hepatica adult w.m. L45 Fig 6.8 & 6.9; R59 Fig 59e – oral and ventral suckers, intestine, uterus; yolk glands (=vitellaria)

Fasciola hepatica ova L46 Fig 6.10 ; T166 Fig 8.20(b)

Fasciola hepatica miracidia L46 Fig 6.10; T166 Fig 8.20(b)); R59

Fasciola hepatica cercaria L46 Fig 6.10; T166 Fig 8.20(b)); R59
Clonorchis sinensis (= Opisthorchis sinensis) w.m. L47 Figs 6.11 and 6.12; T162 Fig 8.17(b & c); R59 – mouth, pharynx, intestine, genital pore, ventral sucker, testis, uterus, ovary, yolk glands (=vitellaria)

platyhelminth cestodes:

Taenia spp. ova (= egg)

Taenia pisiformis cysticercus R60

Taenia pisiformis scolex L48 Fig 6.17; T158 Fig 8.13(b); R60
Taenia pisiformis composite L49 Figs 6.18-6.21; R60 – immature proglottid, mature proglottid, ripe (=gravid) proglottid

Dipylidium caninum w.m. (FYI) The dog tapeworm

rotifers:

Rotifers L74 Fig. 9.12 & 9.13; T179 Fig 19.3, T180Fig 10.4; R63

Questions for your lab notebook:

Evolution is often portrayed as producing greater complexity and increased size. What is an example of evolution resulting in reduced complexity?

Compare the nervous systems of planaria and Hydra.

Why is it important for an adult trematode or cestode to produce thousands (or even hundreds of thousands) of eggs?

Why is the scolex of a tapeworm not considered a "head" like other animals have?

What is the value of parthenogenensis in unstable habitats such as a temperate lake?