Phlyum Platyhelminthes

Phlyum Platyhelminthes

The flat worms; Made up of three different classes; Cl. Turbellaria, Cl. Trematoda, Cl. Cestoda

Features of Ph. Platyhelminthes

Tripbloblastic; 2 ventral solid nerve chords; Bilateral; Protonephridia; Flat; Simultaneous hermaphrodites or monecious; mostly paracitic

General features of Class Turbellaria

Only free living Class; Marine, freshwater, and terrestrial; cephalized; EX:planaria; Mostly carnivorous; eat sessile invertebrates; they eat by external digestion; Mate with penis fecing

Why is Ph. Platyhemnthese flat

Need to be flat for better gas exhange in marine environments

Structures of Turbellaria

Latter like nervous system with Ceribrial Ganglia; 2 ventral nerve chords; Have Auricles for chemial taste and tactile; Ocelli for detecting light; Crawl using cilia

Protonephridia

remove metabolic wastes from an animal's body; Functions simular to kidneys

Anatomical features of turbellaria

Dorsal ventral flat; Gut is diverticulated/branched to reach all parts of the body; Filled with parenchyma cells; Mucular pharynx located centrally; Circular mucles and longitudinal muscles run along the body; mouth in in the middle

Cl Trematoda

The Flukes; Flat; Have a complex lifecycle with two or more intermediate hosts and one definative host; Water or wet phase is common; Serval larval phases; two rounds of asexual reproduction

Chinese liver fluke

Humans are difiniative host; passed into fresh water snails and fish though human feces; exretory pore is for reproduction

Cl. Cestoda

The Tapeworms; Very long, but not actually segmented, they are Protglottid; Strobilated; Simple lifecycle; Monecious

Strobilated

Parts fall off that are full of eggs

Gravid

Full of eggs; Think pregnat

Beef tape worms

Humans are the difinative host

Pork tape worm

Humans are the intermediate host

Parasitism

One creature benefits to one creatures detrament

mutualism

Both benefit

Commensalism

one creature benefits and one creature doesnt care

Ectoparasite

parasite on the outside of the body; EX: fleas, ticks leech

Endoparasite

On the inside parasites; Flukes or tapeworms