Chapter 33: Noncoelomate Invertebrates Flashcards
Sponges
Phylum: Parazoa
Loose body organisation
Multicellular
No body sym.
Asexual/sexual reproduction
Parazoa: defining features
Animals that lack specialised tissue
Asymmetric
Multicellular - 3 cell layers
Pseudocoelomates
Cavity between tissues derived from mesoderm & endoderm
No clade
Examples of pseudocoelomates
Rotifers
Round worms
Bilaterian acoelomates
Have bilateral symmetry
E.g. flatworms, flukes, tapeworms
Eumetazoa:
Animals with TRUE tissues
Cnidarians
Cnidarians
Polyps
Medusa
Tissues & no organs. No circulatory/respiratory systems
Distinguished by capsules
Nerve cells
Nematocysts
Defining feature of Cnidarians
Used to capture prey
Examples of Cnidarians
Hydra
Jellyfish
Sea anemones
Class Anthozoa
Largest class of Cnidarians ~ 6200 species e.g. sea anemones, corals, sea fans
Can be hard/soft corals
Cubozoa
Box jellyfish - ~50 species
Predators
Fatal stings to humans
Flatworms:
Phylum: Platyhelminthes I
Bilateral symmetry Triploblasty Incomplete gut Lacks circulatory system Thin bodies allow for gas diffusion between body + air
Platyhelminthes II
Asexual reproduction
fission, budding
Tubellaria
Free living flatworms
Marine, freshwater, terrestrial
Paraphyletic
Neodermata
Parasitic flatworms
Live as ectoparasites or endoparasites
Or live on bodies of other animals
Lack features of free living flatworms e.g. eyespots
Platyhelminthes III
Soft cephalized body
Cilia and muscle contraction
Digestive tract with single opening
No respiratory/circ or skeletal system
Platyhelminthes Reproduction
Hermaphrodite - each individual containing both male & female sexual structures
Platyhelminthes: flatworms
Have regenerative ability
Able to regrow parts of their body that they are missing
Trematoda - Flukes
Attach to host’s bodies by means of suckers, anchors or hooks.
Takes in food (cells/fluids) of host
First intermediate host - always a snail
Final - always a vertebrate
Flukes (cause disease in humans)
Clonorchis sinensis
Flatworm paratizes humans
Lives in bile duct of liver (also cats, dogs and pigs)
Cercomeromorpha
Tapeworms & hydatids
Hang on inner wall of host’s intestines through terminal attachment structure
Cercomeromorpha
Lacks digestive cavity + digestive enzymes
Most tapeworms - occur in intestine of vertebrates. Regularly occur in humans
Tapeworm structure
Long, flat body
Divided into three zones: scolex, the neck, and repetitive sections, the proglottids.
The scolex
in flatworms
It is not a head
Has neither concentrated nervous tissue/mouth
Proglottid (features)
Is a complete hermaphroditic unit
Contains both female and male reproductive organs
A sponge’s structural materials (spicules, spongin) are manufactured by:
Amoebocytes
Cnidarians capture food with:
Nematocysts - stinging capsules
Coral animals’ exoskeleton compose of ______
Calcium carbonate.
Sponges are most accurately described as:
filter feeders
Characteristic of cnidarians:
gastrovascular cavity
Scyphozoa
Jellyfish
Anthozoa
Sea anemones, corals, sea fans
Cubozoa
box jellies
Hydrozoa
hydroids, Hydra, Portugese man-of-war
Diploblasty
Two primary germ layers:
ectoderm and endoderm
Characteristic of Platyhelminthes
Dorsoventrally flattened
The _______ are small openings (pores) which allow water to enter a sponge
ostia
Flatworms lack a fluid filled cavity in which the gut is suspended therefore are termed _______
Acoelomates
In sponges what is the function of the Ostia?
They allow water carrying oxygen and food to enter the body.
Choanocytes in sponges are for:
collecting food.
Found lining the internal cavity of the sponge
