L4: Lophotrochozoa (Spiralians), phylum Platyhelminthes Flashcards
Identify features that unite Lophotrochozoans Why is the monophyly of Platyhelminthes in question? Describe how the nervous and excretory systems are more complex in turbellarians compared to those of cnidarians? Understand general anatomical features of turbellarians Describe the general life history of digenean trematodes Understand general anatomical features of tapeworms
What is a lophophore?
A feeding structure with a complete digestive system and highly ciliated tentacles
Trochophore larvae have a ___ digestive system
Complete
The phylum platyhelminthes refers to what?
What kind of animal?
Flatworms
platys = flat, helmins = worm
What triploblastic pattern do platyhelminthes have?
Acoelomate/Pseudocoelomate/Coelomate
Acoelomate
Have no coelom, no body cavity
What is parenchyma tissue?
Large, loosely filled tissues
Derived from mesoderm
Describe the presence of the platyhelminthes gut, respiratory, and circulatory systems
Incomplete gut, no respiratory or circulatory systems
One opening in gut
Describe the function of a protonephridia
Excretion, osmoregulation
Describe the nervous system of platyhelminthes
Anterior ganglia; longitudinal, ventral nerve cords
T/F platyhelminthes are monecious with self-fertilization
F - they are monoecious with internal fertilization
Monecious - male and female function in same animal
Internal fertilization - Egg and sperm fuse inside animal
Self fertilization - Egg and sperm from same animal fuse
What are the 4 classes in the platyhelminthes?
Tubellaria (planarians)
Trematoda (Flukes)
Monogenea (monogenetic flukes)
Cestoidea (Tape worms)
In the class Turbellaria,
T/F Are parasitic
F - Are free-living (non parasitic)
In the class Turbellaria,
Where do they inhabit?
Benthic, marine and freshwater environments
In the class Turbellaria,
How do they move?
Circular and longitudinal muscle fibres
Cilia on ventral surface
In the class Turbellaria,
T/F: Predatory
True
In the class Turbellaria,
T/F: Monophyletic
F: Polyphyletic
In the class Turbellaria,
T/F: Have cephalization
True!
Identify the kind of the asexual reproduction of Turbellarians
Asexually by transverse fission
Describe the sexual reproduction of Turbellarians
Where sperm goes, where fertilized eggs go, where fertilization occurs
Sperm deposited into copulatory sac of partner, moving to gential chamber into oviducts where fertilization occurs
Fertilizated eggs move down oviduct and are deposited in protective cocoon.
Most species have direct development, some have swimming larval stage
Direct development: newborn looks like mini adult
In the class Trematoda…
T/F - Are parasitic
T
In the class Trematoda..
What are the two subclasses?
Digenea and Aspidogastrea
In the class Trematoda…
Describe the Tegument Structure (syncytium)
The external epithelial
covering
What is a common fluke in the class Trematoda?
Common Liver Fluke
Describe how the Trematode Common Liver Fluke has a complex life history?
Starts in a snail, then goes to water, then to plants, then becomes an adult in a sheep or human, releasing eggs in feces that eventually returns to water
Briefly describe Monogenea
What they infect, what they are commonly called
Ectoparasites of fishes
Called Gill Flukes
