Advertisement Upgrade to remove ads


External bristles found in most annelids; aid in movement


fleshy protrusions found in polychaetes that aid in locomotion and feeding


Temporary storage area found in earthworms


The thick, muscular part of an earthworm's gut that grinds soil, releasing and breaking up organic matter


An infolding of the intestinal wall that increases the surface area available for digestion

aortic arch

A muscular blood vessel that links the blood vessels from the dorsal and ventral parts of an animal's body


Excretory tubule that eliminates cellular wastes and excess water in an earthworm


Swollen area of an earthworm's body that secretes a film a mucus and functions in reproduction

seminal receptacle

Reproductive structure that secretes sperm in an earthworm


Larval stage of development found in most aquatic mollusks and annelids

visceral mass

The central region of a molluck's body that contains some internal organs


Layer of epidermis covering the visceral mass that secretes the shell

mantle cavity

The space between the mantle and visceral mass that protects the gills of mollusks


Group of nerve cell bodies in different areas


A flexible, toungelike strip of tissue covered with tough, abrasive teeth that point backwards; main feeding adaption of mollusks


A mollusk that has a well-developed head and flattened foot, such as a snail, slug, or conch


Circulatory fluid of a gastropod's circulatory system


Body cavity of a gastropod


A mollusk with a shell that is divided into two halves (valves) connected by a hinge

incurrent siphon

Tube found in bivalves through which water enters the body

excurrent siphon

Tube through which water exits that mantel cavity of a bivalve


Marine mollusks that are specialized for a free-swimming, predatory existence


an invertebrate with a soft unsegmented body often enclosed in a hard shell containing calcium carbonate

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again


Reload the page to try again!


Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording