Ch 33 An Introduction to Invertebrates Flashcards
Three major groups of bilateral animals
1) Deuterostomes
2) Lophotrocozoa
3) Ecdysozoa
Phylum Porifera
Sponges
Sponges have 1)___ ___ ___ but no 2)___ ___
1) Specialized cell types
2) True tissues
What kind of locomotion is exhibited by sponges?
None, they are sessile
What creates water currents that move through the body of the sponge?
Movement occurring in flagella-bearing collar cells
What supports the sponge body?
Spicules
Spicules
Tiny calcium or silicon structures
What structures in sponges function in digestion?
Amoebocytes
Phylum Cnidaria
1) Jellyfish
2) Anenomes
3) Corals
Cnidarians posses what kind of symmetry?
Radial
How do cnidarians feed?
By capturing food particles or prey from the water
What are the two body forms of cnidarians?
1) Polyp (sessile)
2) Medusa (free-swimming)
Many cnidarians have a life cycle that includes both 1)___ and 2)___ stages
1) Polyp
2) Medusa
Cnidarians can possess sense organs used in 1)___ and detection of 2)___
1) Balance
2) Light
Nematocysts
Held under high pressure (140 atm)
Launch a venomous spine at prey
Lophotrocozoans share traits of:
1) Lophohore
2) Trocophore
Lophophore
A horse-shoe shaped feeding structure
Trocophore
Ciliated larva
Phylum Platuhelminthes
Flatworms
Flatworms lack:
1) Circulatory system
2) Respiratory system
3) Skeletal system
4) Coelom
5) Complete gut
What indicates that flatworms may not be a good monophyletic taxon?
No shared derived trait unites all members of this group
Groups based on 1)___ form have been shown to be 2)___
1) Coelom
2) Polyphyletic
What was once the basis for major classification within the protostomes?
Coelom
Reproduction of flatworms:
Usually, sexual via hermaphroditism
Class Monogenea
All parasites
Phylum Playhelminthes
Monogeneans have what?
The unciliated synctial layer typical of flatworms (except Turberllaria)
Monogeneans are usually the parasites of what?
The skin and gills of fish
Class Trematoda
Flukes (all parasitic)
Phylum Platyhelminthes
Flukes are usually the parasites of what?
A mollusc and vertebrate host
How many people are infected with flukes?
200 million
Symptoms of fluke parasitism:
1) Pain
2) Anemia
3) Dysentery
4) Liver damage
Class Trematoda
Phylum Platyhelminthes
Dicroceolium (Class Trematoda) alters ant behavior for what purpose?
To increase the likelihood that it will be passed on to the next host (cow)
Class Cestoda
Tapeworms
Phylum Platyhelminthes
Tapeworms lack:
1) Head
2) Digestive system
3) Sense organs
Tapeworms are mostly the parasites of what?
The intestine of vertebrates
Proglottids
Comprises the body of tapeworms
Are tapeworms hermaphroditic or gonochoric?
Hermaphroditic
Scolex
Hooked structures
What attaches a tapeworm to the host’s intestine?
The scolex
Phylum Rotifera
Rotifers
Maximum size of rotifers
3mm
What kind of habitats to rotifers live in?
A wide range of aquatic and marine habitats
Are rotifers able to survive extreme environmental conditions (drying, cold)?
Yes
Three feeding types of rotifers:
1) Predators
2) Parasites
3) Filter feeders
What is the mouth of rotifers equipped with?
A hard, muscular jaw
Are rotifers hermaphroditic or gonochoristic?
Gonochoristic
Phylum Mollusca
Mollusks
Mollusca is one of the largest phylums, with over ___ species
90,000
What limits mollusk habitat?
Their need for water
What kind of climates do mollusks live in?
They are found in polar to tropical regions
What is the size range of mollusks?
Microscopic to ~1 ton
Mollusk shells are composed of ___ ___
Calcium carbonate
Radula
A scraping, tongue-like feeding structure
In what mollusks is the radula found?
All major mollusk classes, except bivalves
Mantle
Encloses a mantle cavity and a muscular foot
Most gastropods mollusks are ___
Herbivores
How do bivalves move?
1) By extending and anchoring the foot
2) Propelling water between the valves
Class Cephalopoda
Octopods and squid
Phylum Mollusca
Class Gastropoda
Snails and slugs
Phylum Mollusca
Class Bivalvia
Clams
Phylum Mollusca
