Lecture 14: Invertibrates I Flashcards
What is phylum cnidaria?
jellyfish
What is a two way gut?
one opening for food and excretion
What is the gastrovascular cavity(GVC)?
Place of digestion ,excretion, respiration, etc.
What is a polyp?
sessile, fixed in place
What is a medusa?
nekton that moves thru water
What are cnidocytes?
Stinging cells that have a nematocyst that have organelles packed with stinging string. Also, cnidocil which is the trigger and operculum which is the cover
What is the nerve net?
Where there is no brain and no nervous system
What are the classes in phylum cnidaria?
- Hydrozoa
- anthozoa
- cubozoa
What is class hydrozoa in phylum cnidaria?
It is a water animal.
What are hydroid jellies?(part of hydrozoa)
Where there is both polyp and medusa forms
What is polyp colony? (part of hydrozoa)
It is asexual reproduction where the hydranth feeds and gonangium is reproduction.
What is medusa?(part of hydrozoa)
It is sexual reproduction. It is dioecious and has craspedote which is a velum. It also has a valum which is the veil membrane and bordering cavity. It also has a manubrium which is the center stalk.
What is the planula(part of hydrozoa)?
The ciliated larva and also the zygote and forms to polyp
What is class scyphozoa?
true jellies
What is a hydra?(part of hydrozoa)
Where there is not a lot of medusas
What is the dominant life stage in scyphozoa?
The medusa
What is the medusa form in scyphozoa?
It is is dioecious and has a acraspedote of no velum. Also has none or reduced manubrium.
What are the features of a hydrozoa?
- hydroid jellies
- polyp colony
- medusa
- planula
What is a scyphistoma?(scyphozoa part)
A polyp form for asexual reproduction
What is a strobila (part of scyphozoa)?
Where sexual reproduction begins. Also where the ephyra breaks off to young medusa.
What are the features of scyphozoa?
- Medusa is the dominant life stage
- medusa form that dioecious
- planula
- scyphistoma
- strobila
What is class anthozoa?
The flower animal
What are features of anthozoa?
- polyp form only
- has many orders
What are the orders for class anthozoa?
- Actiniaria
- Scleractinia
- Alcyonacea
- Pennatulacea
What is order actiniaria?
sea anemone
What is order scleractinia?
stony corals or hard corals
What is order alcyonacea?
gorgonian soft corals and sea fans
What is pennatulacea?
sea pens and pansies
What is class cubozoa?
Box jellies
What are the features of cubozoa?
- sting is toxic
- have box shaped medusas
- have velarium which is a veil like structure
What is phylum ctenophora?
Comb jellies
What are the features of ctenophora?
- two way gut
-GVC - Radial symmetry
- diploblastic
-ectoderm
-endoderm- collenchyme: gelatinous layer in between
- Colloblast: stinging cells
- Nerve net
- Eight comb rows(ctenes=combs and swimming plate)
- 2 long tentacles
What are the classes for ctenophora?
- Tentaculata
What are the orders for ctenophora?
- Cydippida
2.Lobata - Cestida
What is order cydippida?
Egg shaped and spherical comb jellies
What is order lobata?
They are flattened lobes extending from body
What is order cestida?
A long ribbon shaped comb jellies
What are the features of phylum platyhelminthes?
- two way gut or no gut
- bilateral symmetry of
cephalization - triploblastic of ectoderm(epidermis), endoderm(gastrodermis), mesoderm(mesenchyme)
- acoelomate
- cerebral ganglia-concentration of nerve fibers in head
- ladder- nervous system like with more nerve net structure
- gas exchange and excretion occurs through epidermis
- can be hermaphroditic (both male and female organs)
What is phylum platyhelminthes?
flat worms
What are the classes of platyhelminthes?
- turbellaria(free living flatworms)
- trematoda(parasitic flukes)
- cestoda(parasitic tapeworms)
What are the features of class turbellaria?
- are planarians(genus: planaria, dugesia)
- have ocelli or eyespots/pigmented pit for sensing light
- Do asexual reproduction through fracturing and can regenerate through missing pieces
- sexual reproduction is either cooperative where both cross fertilize and inseminate(pair up) OR it is competitive where they fight to see who gets inseminated
What are the features of class trematoda?
- an example is clonorchis which is the human liver fluke
- In a human host it lives in bile duct and eggs are expelled through feces. Contaminates water then affects snail.
- In the snail host, they eat the eggs or are infected by miracidia.
-Eggs hatch into miracidia
-Miracidia have cilia for swimming
-miracidia develop into sporocyst
-sporocyst produces a lot of redia
-redia reproduce asexually into cercaria
-cercaria swim away
-exponential multiplication - in a fish host the cercaria encyst in flesh
- in human host, the human eats the contaminated fish
- Another example is schistosoma which is human blood fluke where cercaria can penetrate human skin. Can attach in water.
What are the features of cestoda?
- have scolex which is the suckers and hooks to attach to intestinal lining
- have proglottids which are segments for reproduction
-Immature proglottids
-mature proglottids which are mature sex organs
-gravid proglottids which are filled with fertilized eggs. They also break off and are released with feces - have no mouth or GVC and just absorb nutrients from intestine
- can infect intermediate hosts pig and cattle
What are features for phylum cnidaria?
- two way gut
- radial symmtry
- diploblasctic(ectoderm, endoderm, mesoglea)
- polyp(stuck to floor)
5.medusa
