lecture 17 Flashcards
Most animals on earth belong to what clade?
Bilateria
What is a key feature of the Bilateria?
They posses bilateral systemtry
What is cephalization?
differentation of a head region
Are Bilateria cephalization?
They have varrying degrees, including anterior concentartion of neural ganglia ( brain)
What is a neural ganglia?
Brain
What type of embryos do Bilateria posses?
Triploblasic embryos.
are Acoela Bilateria?
Yes they are
What phylum do marine worms reside from?
Acoela
What us unique about Acoela?
They have no brain and they have no gut cavity.
What is a .worm?
General term for an animal with a body that lacks shell or elaborate appendages and usually longer than wide.
Where on the phylogentic tree would Acoela be in relation to the rest of the Bilateria?
Some molecular data places acoela as basal to the rest of the Bilateria
What are the four main characteristic of Lophotrochozoa?
- Some have lophophore
- Some have trochophore larva
- others have neither
- Main similarities are in DNA
How many phyla exist within Lophotrochozoa?
There are roughly 18
what Lophotrochozoa phylum contains flatworms?
Platyhelminthes.
What does the root word “platy” mean?
Flat
What does the root word “helminth” mean?
Worm
Flat worms have no fluid filled body cavity, what is this called?
Acoelomate.
Are flatworms triploblastic?
Yes they are.
How many species of Platyhelminthes are there?
roughly 20,000 spp
What are the two major classes of Platyhelminthes?
Class turbellaria
Class cestoidea
What is unique about the Turbellaria?
They are called the free-living flatworms.
- The epidermis of Turbellaria are covered in epidermal cilia.
Turbellaria have a pair of ___________ and ____________ near the front of their body.
Ventral nerve cords
and
pair of ganglia
Do turbellaria have an anal opening?
Nope
Are Turbellaria predatory?
Yes some are , mostly on other small metazoans.
What do NON-predatory Turbellaria feed on>
They feed on bacteria and protists, or decaying organic matter.
How do turbellaria reproduce?
PENIS FENCING.
They are hermaphroditic.
What class do tape worms reside from?
Cestoidea
Tapeworms are entirely ___________ in digestive systems of animals
endoparasitic
do tapeworms have a digestive system?
No, they digest their food through thin body walls.
What is the speciality organ that a tapeworm has that allows it to hold onto a hosts intestines
Scolex
What is the organ of a tapeworm that is devoted to reproduction? and where is it found?
after the SCOLEX comes a long chain of units devoted to reproduction called
- proglottids.
How are the eggs of Cestoidea implanted into Intermediate hosts?
They are eaten by the intermediate host.
How do the larvae of the Cestoidea get transported from the intermediate host into the final host?
The final host eats the intermediate host.
What is a final/definitive host?
Hosts in which a parasite engages in sexual reproduction
Can tape worms infect dogs? if so what are they?
Yes,
The Echinococcus granulosus infects herbivorous mammals as intermediate hosts to later infect dogs.
Once a Cestoidea tapeworm is in the tissue of a human, what do they do next?
Once they are in the tissues, larvae undergo asexual reproduction and split into thousands of new larvae that are located within a large -hydatid cyst.-
What dose the root word -Branch- mean?
Arm
What dose the root word -pod- mean
Foot
Phylum ___________ is one of four lophophore-bearing phylum.
brachiopoda
How do Brachiopoda feed? And what specialized oragan allows them to feed this way?
They suspension feed through the use of paired lophophores
True or false:
Brachiopda do not have complete gut and anal openings
False:
They do have complete gut and anal openings.
True or false:
Brachiopoda were far more diverse in the past having up to 30 000 spp compaired to modern counts of around 300 spp.
True
What do the root words -ecto- and -proct- mean?
Outside anus
True or false:
Ectoprocta are almost entirely colonial?
True
What is the other name for Ectoprocta?
Bryozoa
What do the root words -baryo- and -zoa- mean?
Moss - Animal
What makes Ectoprocta diff rent from corals?
many species have units that are specialized for different tasks.
What dose the root word -annulus- mean?
ring
What is the defining feature of Phylum Annelida
They are segmented worms (ringed)
What were the original three categories of Annelida?
polychatea
oligochaeta
hirudinea
What did later molecular data show about the classes of Annelida?
It showed that Oligochaeta and Hirudinea were part of the class Polychaeta
making it only one class.
What are the basic characteristics of Annelids? *(Phylum Annelida)
(3 things)
- They are segmented, with segmented being separated by septa
- They are Eucoelomate, with their body cavity being lined with mesoderaly derived tissues
- They have a closed circulatory system.
What are the defining characteristics of Polycheata?
Their body is made of segmented fleshy lobes of Parapodia that bear many chaetae
What dose the root word -parapodia- mean?
Not quite feet
What do the root words -poly- and -chaeta- mean?
Bristle
How dose the development of the head and parapodia in polychaeta differ in errant and sedentary species?
Errant species have more developed heads and parapodia than what it found in the sedentary species.
What dose -sedentary- mean?
rarely move, but can if necessary
True or false:
Errant polychaetes are usually predatory.
True
How do senentary polychates feed?
They feed primarily through 3 different methods:
- ingesting substrate
- suspension feeding by filtering food particles from the water column.
- deposit feeding by trailing sticky tentacles over substrate and licking off the adhering matter.
True or false:
PolyChaetes are free spawning
True
What dose it mean to be free spawning?
Means that eggs and sperm released into the water fertilize upon interaction outside the body of the parent animals.
Trochopore larvae are _______, with subsequent larvae leading _______ lives.
Planktonic
Benthic
What dose it mean to be benthic?
Means that you live at or near the bottom of a body of water.
What is the most commonly known Oligochaeta?
The terrestrial earthworm
Non-Leech spp. of Oligochaeta still have a few________
Chaetae
How do Oligochaeta reproduce?
They are simultaneous hermaphrodites that transfer sperm by copulation.
What happens during copulation?
A gelatinous cocoon secretion is made from the clitellum where eggs and sperm are deposited for external fertilization.
True or false:
Oligochaetes are external fertilizers?
True.
True or false:
oligochaetes undergo direct development, meaning that they have no larval stage.
True.
What is the usefulness of Oilgochates?
They are useful in maintaining soil conditions through digesting organic matter (composting) and through losing soil for root systems.
Why is there few worms native to Canada?
Because most of the worms in Canada were killed by glaciation.
What are Hiudinea?
They are leeches
What dose the root word -hirudo- mean?
Leech
Where do Hiudinea live?
Mostly in freshwater, although some live in marine and terrestrial enviorments.
Hirudinea lack________, but have __________
They lack parapodia, but have clitellum
Hirudinea enteriely lack_____
Chaetae
What do Hirudinea feed on?
They are predators that feed on soft bodied invertebrates.
True or false:
Some Hirudinea feed on the blood of vertebrates.
True……They are leeches.
What is one use of Hirudinea in human sociaty?
We use them for medical practice for releasing swelling, and attachment of severed extremities.
What is the most characterizing feature of Mollusca?
They have a calcareous shell that encoulses their soft bodies.
what dose the rot word -moll- mean?
Soft
What are the basic characteristics of molluscan?
7 things 1 movement, 1 feeding, 1 shell, 4 about internals
- Their calcareous shell is secreted by a thin layer called the mantle
- Muscular ventral foot used for movement.
- Their mouth-parts are strap-like rasping organs called radula.
- They posses gills for gas exchange
- They have an open circulatory system
- they are Not clearly segmented
- many of them are trochophores
What class makes up 75% of extant mollusc species?
Snails
What dose the root word -gastro- and -pod- mean?
Stomach
foot
Shelled species of Gastropoda undergo ______, visceral mass twists during development so that anal opening is above head.
Torsion.
True or false:
Land snails and slugs (Gastropoda) have lungs and breath through the moisture in the air.
False. They have lungs that they use for gas exchange.
________ are shell-less sea Gastropoda.
nudibranchs (sea slugs)
What protection do Nudibranchs have?
They are protected by nematocysts of cnidarians.
What is comprised of Class Bivalvia of Phlyum Gastropoda?
Clams, oysters, and Scallops.
What is the defining feature of Class Bivalvia?
They have a two hinged shell.
What do the root words -bi- and -valv- mean?
two
door
How do Class Bivalvia feed?
They feed through filtering water through their gills
True or false:
members of Class Bivalvia have no radula.
True
True or false:
Although some Class Bivalvia are sessile, most are sedentary and can move if needed.
True
What is an example of a sedentary animal?
Mussels.
What is important about Class Bivalvia?
- they are widely consumed
- They produce pearls
- they can be invasive pests (zebra mussels)
What is the defining feature of Cephalopoda?
They have long tentacles arranged around their mouths
What are some Cephalopoda?
squids, cuttlefish, octopuses
What dose the root word -cephalo- and -pod- mean?
Head
foot
True or false:
All Cephalopoda except for one are predatory, evolving their radula to become a biting beak.
True
True or false:
Most spp of Cephalopoda have NO evedance of external shells?
True.
Although the nautilus has one.
True or false:
some taxa of Cephalopoda have interal shells remnants?
True, like the cuttlebone in the cuttlefish.
Cephalopoda have a tube of mantle fused to make ______
Siphon
What is the siphon used for?
Jet-propulsion
What is unique about Cephalopoda circulatory system?
They are the only molluscs to have a closed circulatory system.
True or false:
many octopuses show maternal care.
True.
What type of development do Cephalopoda juveniles undergo?
Direct development.
What is cool about Cephalopoda eyes?
They have very advanced color vision that rivals that of vertebrates.
What is known about Cephalopoda behavior?
They convay very complex behavior with some species seeming to be at least as intelligent as dogs
