Arthropods, Echinoderms, and Invertebrate Anatomy Review

Vocabulary terms covering the anatomy and classification of porifera, cnidarians, worms, mollusks, arthropods, and echinoderms based on lecture notes.

Telson

The posterior-most part of the abdomen in the external anatomy of a crustacean.

Green Gland

An internal organ in crustaceans, located near the brain and stomachs, used for excretion.

Cheliped

The large claw or first pair of walking legs in a crustacean.

Setae

Bristle-like structures on the ventral surface of an earthworm segment used for movement.

Clitellum

A thickened glandular and non-segmented section of the body wall in an earthworm that secretes a viscid sac.

Chitin

The tough, flexible carbohydrate material that makes up the arthropod exoskeleton.

Malpighian tubules

Excretory organs in some arthropods that filter waste from the blood.

Chelicerae

A pair of appendages near the mouth of chelicerates, such as spiders and scorpions.

Water Vascular System

A network of hydraulic canals unique to echinoderms used for locomotion and feeding.

Madreporite

The sieve-like opening that connects the water vascular system of an echinoderm to the exterior.

Umbo

The highest part of each shell valve in a clam, located near the hinge ligament.

Osculum

The large opening at the top of a sponge through which water is expelled from the central cavity.

Spicules

Small, needle-like structural elements within the wall of a sponge.

Cnidocytes

Specialized stinging cells found in the epidermis of cnidarians.

Radula

A tongue-shaped structure used for feeding by many mollusks.

Trochophore

A free-swimming ciliated larval stage typical of many mollusks and annelids.

Flame cells

Specialized excretory cells found in flatworms (Phylum Platyhelminthes) that remove excess water.

Scolex

The head-like anterior end of a tapeworm, equipped with hooks and suckers for attachment.

Proglottid

One of the segments that make up the body of a tapeworm, containing both male and female reproductive organs.

Choanocyte

Also known as a collar cell; a cell in sponges that uses a flagellum to move water and capture food.