Phylum Nematoda ( Roundworms) Platyhleminthes (Planarians and Tape worms) and Annelids (Clamworm Earthworm Roundworm)

who are the nematodes?

roundworms

are roundworms free living or parasistic

can be both

the cylindrical bodies of nematodes are covered by an exoskeleton called a

cuticle

do nematodea reproduce asexually or sexuallly

sexually

what is the symmetry, tissue organization, body cavity, and digestive opening for nematodes (roundworms)

symmetry: bilateral

tissue: triploblastic

body cavity: pseudocoelomate

digestive opening: tube within a tube (inner tube is lined w endoderm)

what type of circulatory system, habitat, respiratory organs, locomotion, excretory system, support system, segmentation, appendages and nervous system do nematodes have

circulatory: none really, transport nutrients in the pseudo coelom

habitat: parasitic, moist soil, bottom of lakes

respiratory organs: none, esentially anaerobic

locomotion: live in gut, limited in movement

excretory: two lateral lines

suppport: hydrostatic skeleton; external cuticle

segmentation: none

appendages: none

nervous system: dorsal and ventral nerve

Ascaris Nematode Anatomy

Nematode (MALE)

Nematode (FEMALE)

Nematode FEMALE EGGS

Vinegar Eels

who are part of the Phylum Platyhelminthes

Planarian and Flatworms

What is the symmetry, tissue organization, type of body cavity and digestive opening for Platyhlminthes (Planarians)

symmetry: first animal organization we have studied that has bilateral

tissue organization: triploblastic

body cavity: acoelomate

digestive opening: one opening sac like

what type of circulatory system, habitat, respiratory organs, excretory system do planarians/ Playthemites have

circulatory:none

habitat: aquatic

respiratpry organs: cells directly across membranes

excretory systems: flame cells; 2 lateral excretory canals. seperate organs a uterus and testes (involved in osmoregulation)

what type of locomotion, support system, segmentation, appendages, nervous systems do planarians/ Platyhleminthes have

locomotion: crawling, creep over

support: hydrostatic

segmentation: none

appendages: none

nervous system: brain, two ventral nerve cords; ladder like nervous system

do planarians(phlyum Platyhelminthes) exhibit cephalization

yes (organisms are able to asses the enviornment they are about to enter by going head first)

three tissue layers in flatworms (planarains)

inner layer- endoderm

outer layer- ectoderm

middle layer- mesoderm

what are the two types of parasitic worms of platyheliminthes

flukes nad tapeworms

definitive host vs intermediate host (planarians)

definitive: reprduces sexually on hosts digestive system

intermediate: found on muscle tissues or internal organs of host and reproduce asexually

reproduction in flatworms is (planarians)

monoecious (one individual has both sex)

Planarian (Flatworm)

Planarian w Gut Injected

Planarain Cross Section at the level of Pharynx

Tapeworm

Tapeworm (notice hooks)

Tapeworm showing eggs in Uerus

Tapeworm cysts in meat

Life cycle of a beef tapeworm

mature progolottids are released from end of tapeworm and leave with the host’s feces.
• In one type of cycle, tapeworm eggs in contaminated food or water are ingested by
intermediary hosts, such as pigs or cattle.
• The eggs develop into larvae that encyst in the muscles of their host.
• Humans acquire the larvae by eating undercooked meat contaminated with cysts.
• The larvae develop into mature adults within the human.

posterior, ventral, dorsal, anterior

what are proglotidds in tapeworms platyhelminthes

sac of sex organs

who are part of the phylum annelida?

clamwor, earthworm, and the roundworm

what is the symmetry, tissue organization, type of body cavity, digestive opening and circulatory system for the annelidas?

symmetry: bilateral

tissue organization: triploblastic

body cavity: coelomate

digestive opening: two openings, tube within a tube

circulatory: closed circulation with blood vessels

what is the habitat, respiratory organs, excretory system, and locomotions of annelids?

habitat: clamworm is aquatic but earthworm is terrestrial

both respiratory organs are the skin and parapodia

the excretory system is the nephridia

locomotion for clamworms is swimming and parapodia, but with earthworm is setae and crawling

what type of support system, segmentation, appendages, nervous system do annelids have

support system: hydrostatic skeleton

segmentation : yes metameristem

appendages: clam worm has parapodia but earthworm has none

Nervous system: dorsal brain, ventral nerve cord

the first segmented worms to evolve were which ones?

annelid

what is parapodia?

paired of lateral appendages that some annelids have

how do earthworms crawl?

crawl by perstistalsis

what are the three clases for the phylum Annelids

1) oligochaeta earth worms (terrestrial)

2) polychaeta (many setae/chaeta) mainly marine

3) hirudinea (leeches)

why are earthworms part of class oligocaeta

have brsitles made of chitin present in each segment (chaetae), lack a head, monoecious, but can still exchange for fertilization

A- typhlosole

B- longitudinal muscle

C- circular muscle

D- nerve cord

E- ventral vessel

F- nephridium

G- intestine

H- dorsal vessel

Earthworm cross section with ventral nerve and bloood vessel (label the ganglia and ventral vessel)

what is an example of class polychaeta

clamworm

most polychaetas are ____________. many crawl, or burrow on seafloor, while a few drift. They each have a lot of _______________ setae. They do have a ________ region.

marine

chitinous

head

Clamworm Dorsal view

A- Mouth

B- Jaw

C- Pharaynx

D- Eyes

E- Tentacles

F_ Chaetae

G- Parapodia

H- Bristles

I- Palp

Clamworm cross section

Clamworm

Paddlelike Parapodia “almost feet”

function in locomotion

Nematodes such as roundworms reproduce

sexually and are dioceious

Are nematodes segmented?

NO

A- Bristles

B- Parapodia

C- Tentacles

D-Eyes

In planarians which organ system is the pharynx a part of?

digestive system, the pharynx is used to swallow prey

earthworms and nematodes both have cuticles what is the purpose of a cuticle?

the purpose of the cuticle is to be a protective layer. In nematodes the cuticle is part of their exoskeleton. The cuticle allows for gas exchange and helps these worms retain water, and prevents moisture loss

even tho clamworms and earthworms are both part of the annelid phlyum, why do clamworms not have a cuticle?

clamworms do not have a cuticle because they are commonly found in habitats that are aquatic therefore they do not need a cuticle to prevent moisture loss.

what is the difference between acoleomates and pseduocoloemtes ?

aceolomates lack a body cavity and they have no coelom such as flatworms. While pseudocoelomates have a body cavity, and their coloem is only partially lined with mesoderm, for example roundworms

why is the erathworm locomotion so unqiue

crawl by perstalsis, which means they contract their muscles. The longitudunal muscles thickens and shortens, but contractions of the circular muscles constricts and elongates the worms