Phylum Platyhelminthes: General + Cotyloda (Cram)

What class do tapeworms belong to?

Class Cestoda

What are the two sub–classes of Cestoda, what are their common names?

1. Sub–Class Cotyloda – Pseudotapeworms

2. Sub–Class Eucestoda – True tapeworms

What organ do tapeworms parasitize in the definitive host?

Small intestine

True or false: The tapeworm lifecycle is always indirect

True

Head of a tapeworm

Scolex

Progressively maturing body segments of a tapeworm

Proglottids

What two organs of attachment do Sub–Class Eucestoda (true tapeworms) have on their scolex?

1. Four acetabula (suckers)

2. Rostellum (hooks)

What organ of attachment do Sub–Class Cotyloda (pseudotapeworms) have on their scolex?

Bothria (2 slits)

How do Sub–Class Eucestoda (true tapeworms) release their proglottids?

As segments

How do Sub–Class Cotyloda (pseudotapeworms) release their proglottids?

Strobila (chain)

Are the proglottids of Sub–Class Cotyloda or Sub–Class Eucestoda gravid (full of eggs)?

Sub–Class Eucestoda (true tapeworms) proglottids are gravid

What is the name for the larval form of Sub–Class Eucestoda (true tapeworms) found in the intermediate host?

Metacestodes

How do adult tapeworms absorb nutrients?

Through its skin

Where is the uterine pore in Sub–Class Eucestoda and Sub–Class Cotyloda respectively?

Sub–Class Eucestoda: Uterine pore on side

Sub–Class Cotyloda: Uterine pore in middle

What food chain (aquatic or terrestrial) do Sub–Class Eucestoda and Sub–Class Cotyloda parasitize respectively?

Sub–Class Eucestoda: Terrestrial food chain

Sub–Class Cotyloda: Aquatic food chain

Which Sub–Class requires more intermediate hosts to complete it's lifecycle?

Sub–Class Cotyloda requires at least 2 IH, Sub–Class Eucestoda usually require just 1 IH

The larval stage of which Sub–Class produces more pathology?

Sub–Class Eucestoda larvae are more pathogenic

What are the two Sub–Class Cotyloda genera?

1. Diphyllobothrium

2. Spirometra

What genus species of tapeworm is commonly called the broad fish tapeworm?

Diphyllobothrium latum

What are the two intermediate hosts of Diphyllobothrium latum?

1. Aquatic crustaceans

2. Pike, perch, trout, and other large fish

What are the definitive hosts of Diphyllobothrium latum?

Fish eating mammals (man, cats, dogs, birds, polar bears, etc.)

True or false: Diphyllobothrium latum is known for being the smallest tapeworm of man

False. It is known for being the longest, up to 12 meters in length

What does a freshwater lake have to be contaminated with in order for Diphyllobothrium to be found there?

Human sewage

What do Diphyllobothrium latum and Spirometra eggs resemble, why?

Fluke eggs, because they are both operculated

What genus of tapeworm is commonly called the zipper tapeworm?

Spirometra

What are the two intermediate hosts of Spirometra?

1. Aquatic crustaceans

2. Frogs, snakes, rodents

What are the definitive hosts for Spirometra?

Dogs and cats

What do you not treat Diphyllobothrium latum and Spirometra with?

Ivermectin