Flatworms and Related Worms

Study Notes

Flatworms (Platyhelminthes)

Characterized by a flat body shape and lack of circulatory or respiratory systems.
Exhibit a blind gut, meaning they have a single opening for ingestion and excretion.
Major classes include Turbellaria (free-living), Cestoda (tapeworms), and Trematoda (flukes).

Turbellaria

Comprises free-living flatworms commonly found in aquatic environments.

Cestoda

Known as tapeworms; they are not segmented and primarily parasitic.

Trematoda

Commonly known as flukes; members are predominantly parasitic.

Ribbon Worms (Nemertea)

Distinctive for their enclosed circulatory system and complete digestive tract.
They lack a respiratory system but possess a proboscis for feeding.

Round Worms (Nematoda)

Recognized for their round shape and presence of a complete gut.
They are pseudocoelomates, meaning they have a body cavity not completely lined by mesoderm.
Lack both circulatory and respiratory systems; movement is facilitated by longitudinal muscles.

Segmented Worms (Annelida)

Feature a segmented body plan and undergo trochophore larval development.
Have a closed circulatory system and a complete gut, yet no respiratory system.
Possess setae (bristles) and both longitudinal and circumferential muscles for movement.

Spoon Worms (Echiura)

Also known as innkeeper or weenie worms; belong to the Annelida phylum.

Polychaetes (Polychaeta)

Characterized by numerous bristles and often segmented bodies.

Errant Polychaetes

Free-living polychaetes that do not reside in tubes, showcasing mobile lifestyles.

Serpulid Worms

Tube-dwelling polychaetes constructing white, hard tubes made of calcium carbonate.
Known for the operculum on their tubes, exemplified by Christmas tree worms.

Sabellid Worms

Distinct tube worms that create soft, dark tubes not composed of calcium carbonate and lack operculum.
Commonly referred to as feather duster worms.

Spionid Worms

Tube-dwelling worms featuring two long, prominent tentacles.

Terebellid Worms

Known as spaghetti worms; these deposit feeders inhabit burrows.

Pogonophorans

Tube worms that harbor chemosynthetic prokaryotic endosymbionts, contributing to unique ecological functions.

Osedax

Known as bone-eating snot worms; a type of tube worm in the polychaeta class.

Peanut Worms (Spinuncula)

Non-segmented worms lacking a circulatory system but possessing a complete gut and an introvert for probing the substrate.

Aero Worms (Chetognatha)

Transparent and predatory plankton, contributing to marine food webs.

Description

Explore the fascinating world of flatworms and other worm types like ribbon worms and round worms. This quiz covers their biological characteristics, classifications, and habitats. Test your knowledge on the differences among Turbellaria, Cestoda, and Trematoda, along with Nemertea and Nematoda.

Flatworms and Related Worms

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Questions and Answers

What are Platyhelminthes commonly known as?

What is a characteristic of Turbellaria?

What type of worms are Cestoda?

What are Trematoda commonly known as?

What is a defining feature of Nemertea?

What defines Nematoda?

What type of larvae do Annelida produce?

What are Echiura commonly known as?

What are Polychaeta?

What defines Errant Polychaetes?

What are Serpulid worms known for?

What is a characteristic of Sabellid worms?

What are Spionid worms known for?

What do Terebellid worms refer to?

What are Pogonophorans?

What are Osedax commonly known as?

What are Spinuncula commonly referred to as?

What are Chetognatha known as?