Digeneans, Monogeneans, Platyhelminthes,

Platyhelminthes, broken into Platy + helminthes = ___

flat worm

all Platyhelminthes are ___

dorso-ventrally flattened acoelomates, triploblastic, and bilaterally symmetrical

Why don’t Platyhelminthes have a fossil record? Because __

they have soft bodies

Acoelomate - space between digestive system and integument is ____

filled with mesodermally derived tissue = parenchyma

Pseudocoloemate -

inside surface of integument is bounded by mesoderm

Coelomate -

Entire cavity is bounded by mesoderm

Triploblastic refers to ___

derivation of all adult organs and tissues from 3 embryonic layers

What does A point to?

pharynx

What does B point to?

gut

What does C point to?

parenchyma

What does G point to? (white portion)

Gut

What does M point to? (light gray portion)

mesoderm

What does fc point to? (small dots)

flame cells

What does N point to? (black dots under gut)

Nerve cords

What does T point to?

testes

What does O point to?

oviduct

What does V point to?

Vitellaria

What does Sd point to?

Sperm duct

What are the groups of Platyhelminthes? (older classification)

Turbellaria, Cestoda, Monogenea, Trematoda, Aspidogastrea

What group of platyhelminthes is described as free-living?

Turbellaria

We humans are ___ (body cavities)

Coelomates

Nematodes are ___ (body cavities)

Pseudocoelomates

Platyhelminthes are ___ (body cavities)

Acoelomates

The parenchyma is a “packing-material” which has various cell types for various functions, like ___

secretory, waste/food storage, energy production

The parenchyma of platyhelminthes is __

regenerative

What muscle type(s) do platyhelminthes have?

longitudinal, circular

The tegument is the ___

outer surface

What does it mean if the tegument is syncytial? It means that ___

the outer covering is one continuous layer of cytoplasm with many nuclei and no separate cell membranes

The tegument is ___ in adults

syncytial

What type of nervous system do platyhelminthes have?

Orthogon type (ladder type)

In platyhelminthes, the commissures __

connect the longitudinal nerve cords, forming a ladder-like nervous system.

In the platyhelminthes nervous system, longitudinal nerve trunks ___

run posteriorly (the length of the body)

In the Platyhelminthes nervous system, where do nerves run in relation to sensory or holdfast organs?

Nerves run anterior (in front) of the sensory or holdfast organs

The digestive system of platyhelminthes is a __

blind sac (mouth and anus = same hole)

Which group does NOT have a digestive system?

Cestodes

Platyhelminthes have a ___, from simple to highly branched

great variety in digestive systems

Platyhelminths are endowed with ___ for excretion of metabolic wastes

protonephridia

Platyhelminths excretory system is mainly to regulate ___

osmotic pressure (if too much water they can get rid of it)

Platyhelminths excretory system is composed of ___

flame cells

Excretory system; what’s PNT?

protonephridial tubule

Which Platyhelminths system is primarily osmoregulatory?

excretory system

The vast majority of flatworm species are ___

simultaneous hermaphrodites

simultaneous hermaphrodites means

male and female in the same body

Self-fertilization is rare in flatworms, but does occur among __

cestodes (tapeworms)

Reproductive System: what’s the tiny red/female sacs

yolk (vitelline) glands

Reproductive System: what’s the hole on the genital chamber?

genital pore

Reproductive System: what’s the big gray sac below the penis

genital chamber

Reproductive System: what’s the big gray sac hanging off the genital chamber

copulatory sac

____ contains subclass Aspidobothrea and subclass Digenea (new classification)

class Trematoda

____ contains subclass Eucestoda (new classification)

class Cestoidea

A sample platyhelminth is called ___, it’s a free-living flatworm – “turbellarian”

Dugesia spp.

“Turbellarians”

mostly free-living predators but some symbionts

“Turbellarians” are ALL __

hermaphroditic

Bdelloura candida is a ___

commensal living in the gills of horseshoe crabs

Of phylum platyhelminthes, ___ are primarily external parasites of fish

class monogenea

class monogenea has 1 form in mammals:

Oculotrema hippopotami

Oculotrema hippopotami lives in ___

hippo eyes

class monogenea has high ___

host and site specificity

body plan of class monogenea includes these main body parts:

cephalic region, trunk, penduncle (in some, not all), and haptor

defining characteristic of clsas monogene is __

haptor (or opisthaptor)

Class monogenea: Prohaptor =

anterior attachment organ

in class monogenea, there are 2 types of prohaptor

glandular (secretes adhesives) or oral sucker

Class monogenea: Haptor/opisthaptor =

posterior attachment organ

What does the haptor do?

Allows parasite to attach to host

what does the peduncle do?

separates haptor from the body

Class monogenea: Haptor morphology: anchors (hammuli)

large hooks

Class monogenea: Haptor morphology: hooklets

small hooks

Class monogenea: Haptor morphology: clamps

muscular pinching organ

Platyhelminthes: Class monogenea: feeding

pharynx secretes protease

Platyhelminthes: Class monogenea: intestine ___

divides into 2 crura

Platyhelminthes: Class monogenea: has a ___

direct life cycle

Platyhelminthes: Class monogenea: life cycle

egg-> onchomiracidium -> adult

Dactylogyrus  spp will interfere with __

fish respiration (bc it infects gills)

What is the small fish monogene that infects fish gills

Dactylogyrus spp

What is the small fish monogene that infects fish skin

Gyrodactylus spp.

Gyrodactylus spp. will spread by

contact

Gyrodactylus reproduction

viviparous and sequential polyembryony

sequential polyembryony generates __ from 1 zygote

up to 4 offspring

viviparous

produces live offspring, rather than eggs

[…] is a monogene parasite that infects frogs

Polystoma intergerrimum

Polystoma intergerrimum is ___, which is rare for monogeneans

Endoparasitic

When the Polystoma intergerrimum oncomiracidium attaches external gills, it’s called ___

neotenic larva

[…] is a monogene parasite that infects European freshwater cyprinid fish gills

Diplozoon paradoxum

When a Diplozoon paradoxum adds 2 more clamps, ventral sucker & dorsal papillae, it is called a ___

diporpa

Which parasite has no development unless 2 diporpa larvae meet

Diplozoon paradoxum

Which parasites are also called flukes?

Digenean Trematodes

Digenean Trematodes have a ___

minimum of 2 hosts, first is always a mollusc

Digenean Trematodes are all parasitic, and infect __

all vertebrate classes (esp fish)

Digenean Trematodes will alternate __,which is why they’re called digenetic

asexual and sexual reproductive phases

Digenean Trematodes bodies are highly variable, but they’re always __

dorsal ventrally flattened

Digenean suckers: monostome

oral sucker only

Digenean suckers: distome

oral and ventral suckers

Digenean suckers: gasterostome

single ventral sucker

Digenean suckers: amphistome

oral and posterior ventral suckers

Digenean suckers: echinostome

oral sucker with collar of spines and ventral sucker

Digenean suckers: schistostome

oral & ventral sucker, male has split body

Digenean suckers: strigeid

2 suckers; split into fore & hind body (with gonads)

The Digenean tegument is a complex structure containing ___

distal cytoplasm, cytons, and spines

What are internuncial processes

connect cyton and cytoplasm in the Digenean tegument

The excretory system of digeneans is mainly for __

osmoregulation