Platyhelminthes

Protostomia and Deuterostomia

What are the 2 superphyla of triploblastic metazoans?

Ecdysozoa and Lophotrochozoa

What are the 2 large clades of protostomes

Ecdysozoa

possess a cuticle that is molted as their bodies grow

trochophore larvae

\-Minute, translucent, and roughly top-shaped. \n -Have a prominent circlet of cilia and sometimes one or two accessory circlets.

clade platyzoa

unique group of lophotrochozoan protostomes that \n contain Platyhelminthes, Gastrotricha, and Gnathifera

phylum platyhelminites

Commonly called flatworms; vary in size from a millimeter to many meters in length like tapeworms

parasitic

some flatworms are free-living; others _______

class turbellaria

• Mostly free-living with some symbiotic and parasitic forms.

• Bottom dwellers in marine areas or freshwater streams, pools, and hot springs.

• Terrestrial flatworms limited to moist places.

monogenea

class of mostly ectoparasites

trematoda and cestoda

classes of mostly endoparasites

no, marine freshwater moist, bilateral, triploblastic, acoelomate, incomplete, asexual

Platyhelminth Characteristics


1. ______ clear defining feature
2. ________ environments
3. _______ symmetry, body flattened dorsoventrally.
4. Adult body ________ in layers
5. Body plan _________.
6. Gut _______, absent in cestodes.
7. ________ reproduction by segmentation, and other methods in parasitic life cycles.

syncytial tegument

parasitic species have an external body covering called a _______ that has many nuclei enclosed within a cell membrane

proglottid

segment of a tapeworm that contains its own reproductive system

cellular cilliated epidermis

outer coating in tubellarians

dual gland adhesive organs

Most turbellarians have ________ in the epidermis.

Neodermata

clade for 3 parasitic classes of platyhelminths

Syncytial

Endoparasite tegument has a ______ nature that allows more resistance due to lack of penetrable junctions between cells.

Viscid gland cells

fasten microvilli of anchor cells to substrate in tubellarian epidermis

reduce host digestive system, nutrients from host gut cavity

Endoparasite tegument can be absorptive and secretory where secreted enzymes can _________and absorb__ __________

mouth, digestive tract

Most tapeworms have no ____ and lack complete ________.

anterior

in parasites, mouth opens at ______ end

cestodes

have no digestive system, generally rely on the host’s digestive tract and absorb digested nutrients as small molecules.

vertebrates

The end host must be a ______, but intermediate hosts can be other species

snails, sheep

What are the hosts in sheep liver fluke?

eggs, snails, fish, mammals

What are the hosts of human liver fluke?

snails, produce cercaria that penetrate human skin

What are the hosts of blood flukes (schisosoma)?

Clonorchis

most important human liver fluke that also infects cats, \n dogs, and pigs

snails, crabs, humans

what are the hosts of lung flukes?

scolex

top part of tapeworm, bearing suckers and hooks, allows attachment to the host

germinative zone

where are new proglottids generated?

beef

most common tapeworm, common for human infection and lives in the alimentary canal

3

how many branched in tubellarian intestine?

fission

involves constricting behind the pharynx and separating then each half regenerates the missing parts for rapid population growth

cirrus

Tubellarian papilla-like penis or extensible copulatory organ

5mm to 50cm long

how big are species in class turbellaria?

polyclads

have a gut with many branches

presence or absence and branching of gut, type of pharynx

how are tubellarians distinguished?

tricladida

have a three-branched intestine

ciliary movements, gliding or crawling

how do tubellarians move?

opisthaptor

class trematoda lacks ________ of monogean flukes

endoparasites, vertebrates

class trematoda consists of parasitic flukes and most adults are ______ of _________.

mollusk and vertbrate

first and last hosts of subclass digenea

miracidium

free-swimming ciliated digenean larva

sporocyst, rediae, cercariae

dignean life cycle…

\-Miracidium penetrates tissues of a snail and is transformed into a _______ \n -Sporocyst reproduces asexually to form ______ \n -Rediae reproduce ____ to form _____ which emerge from snail to penetrate final host.

metacercariae

cercaria develop into juvenile flukes called _______

oral and ventral

what suckers does the human liver fluke have?

gynecophoric canal

large ventral groove in male blood flukes that is posterior to the ventral sucker and wraps around female in mating season

Schistosome dermatitis

known as swimmers itch

microtriches

small projections similar to microvilli that cover the surface of cestodes, increase the surface area for \n food absorption

pork tapeworm

Adults live in small intestines of humans, most common mode of infection occurs when pigs consume infected human fecal material containing fertilized eggs.

cysticerci

pork tapeworm larvae can migrate to organs and form ______