Platyhelminthes Flashcards
What are the classes of flatworm?
Turbellaria, Monogenea, Trematoda and Cestoda.
Which class of flatworm is free-living?
Turbellaria.
What are some features of Turbellaria?
Free-living.
Aquatic.
Covered by a ciliated epidermis (no cuticle).
1-600mm long.
What are some features of Monogenea?
Fish + amphibian ectoparasites. Monogenetic flukes (locomotion). Covered by a tegument. Reduced/Absent oral sucker. Pro + opisthaptors present.
What are prothaptors and opisthaptors?
Prothaptors = suckers. Opisthaptors = anchors.
What are some features of Trematoda?
Digenetic, endoparasitic flukes.
Covered by a tegument.
One or more oral suckers.
Haptors absent.
What are some features of Cestoda?
Tapeworms - endoparasites.
Covered in a tegument, scolex and strobila of proglottids.
Digestive tract absent.
What are some features of the planarian body plan?
3 layers. Food sucked in by mouth or pharynx is everted. Faecal matter excreted through mouth. Branched intestines. No circulatory system.
What is the reproductive strategy of most flatworms?
They are hermaphroditic. Species engage in sexual and asexual reproduction.
Describe reproduction in Turbellaria.
Sexual + asexual. Hermaphroditic. Can be cut into pieces and regenerate into a full worm!
Describe reproduction in Monogenea.
Monogenea = one-generation. Direct life cycle. Hermaphrodites but cross-fertilise during sexual reproduction.
Describe reproduction in Trematoda.
Sexual + asexual. Often alternate sexual and asexual phases in different hosts. Most are hermaphrodites.
Describe reproduction in Cestoda.
Exclusive hermaphrodites. Cross-fertilisation is most common. Self-fertilisation occurs only in the gut.
Why are free-living flatworms important?
In marine systems they make up to 25% of meiofauna (minute invertebrates). Sometimes equal in biomass to nematodes. Also used as models for stem cell research.
Why are parasitic flatworms important?
They are of medical and veterinary importance.
