Phylum Platyhelminthes and Class Trematoda Overview

Flashcards covering the classification, morphology, and life cycle stages of flatworms (Platyhelminthes), specifically focusing on flukes (Trematoda).

Phylum Platyhelminthes

A phylum of the kingdom Animalia consisting of flatworms that are dorso-ventrally flat, obligate parasites, oviparous, and monoecious with an indirect life cycle (except for $R.\text{ nana}$).

Class Trematoda

Commonly known as flukes, these are flat, leaf-shaped parasites that require a snail as an intermediate host and are usually found in moist environments close to water.

Order Digenea

The order of Trematoda that contains flukes of veterinary importance.

Class Cestoda

Commonly known as tapeworms, this class is more prevalent than flukes and includes the subclass Eucestoda (true tapeworms).

Eucestoda

The subclass of Cestoda referred to as the "true tapeworms."

Monoecious

An organism that possesses both male and female functional reproductive organs and only requires one individual for reproduction.

Oviparous

A term describing organisms that lay eggs, meaning their ova will be found in samples.

Oral Sucker

A muscular structure at the anterior end of a fluke that surrounds the mouth.

Cecum

The structure into which a fluke's esophagus bifurcates; because flukes possess no anus, they must regurgitate food through this system.

"Fluke Puke"

A colloquial term for the food regurgitated by flukes due to their lack of an anus.

Acetabulum

A muscular organ on the ventral sucker of a fluke used for attachment.

Single Operculated

A characteristic of fluke ova, described as oval with one indentation or protrusion.

Indirect Life Cycle

A life cycle that requires at least one intermediate host; for flukes, this host is always a snail.

L1 (Miracidium)

The first larval stage in the development of a fluke.

L2 (Sporocyst)

The second larval stage in the development of a fluke.

L3 (Radiae)

The third larval stage in the development of a fluke.

L4 (Cercariae)

The fourth larval stage in the development of a fluke.

L5 (Metacercariae)

The fifth larval stage of a fluke, identified as the infective stage.