Invertebrate Biology and Behavior Introduction

Flashcards covering the introductory materials of invertebrate biology, including cellular structures of protists, taxonomy procedures, and the anatomy and behavior of major invertebrate phyla such as sponges, cnidarians, and various worm groups.

Placozoans

The most simple animals, described as sheets of cells that sit on rocks and absorb nutrients or grab bacteria from their environment.

Paramecium

A predatory ciliated protist that possesses complex cellular structures including an oral groove and a cytoproct.

Oral Groove

A mouth-like indentation in a paramecium cell that uses cilia to sweep food into vacuoles.

Cytoproct

The cell structure in a paramecium that functions as an anus to expel digestive waste.

Syncytium

A 'together cell' formed when individual cell membranes dissolve and fuse, resulting in a large mass with multiple nuclei.

Cellular Slime Mold

A type of slime mold that forms a mass or 'slug' stage while maintaining distinct individual cell membranes.

Altruism (in Slime Molds)

A biological phenomenon where certain cells give up their reproductive potential to form a stalk, allowing other cells to become spores.

Choanocytes

Specialized cells in sponges that use flagella to pump water through the porous body for feeding.

Osculum

The large opening at the top of a sponge's body where water is expelled after being filtered.

Cnidaria

A phylum of jelly-like animals, such as jellyfish and anemones, characterized by possessing specialized stinging cells.

Mesoglea

The jelly-like material that makes up the bulk of a cnidarian's body, consisting of approximately $95\%$ water.

Medusa

The free-swimming, bell-shaped life stage of a cnidarian, such as an adult jellyfish.

Polyp

The sessile, stalk-like life stage of a cnidarian that is attached to a surface.

Cnidocytes

Harpoon-like stinging cells, also called mitocytes, used by cnidarians for prey capture and defense.

Bioluminescence

The emission of light by living organisms, used by comb jellies for attracting prey or warning potential predators.

Aposematism

A defensive strategy where an animal uses signals, such as bioluminescence, to warn predators of its toxicity or venom.

Pharynx

A muscular tube extended from the underside of a flatworm's body used for scavenging or sucking down prey.

Protostome

An animal group where the original developmental opening (the blastopore) becomes the mouth.

Deuterostome

An animal group where the original developmental opening becomes the anus, and the mouth forms secondarily.

Nematodes

Also known as roundworms, these animals can be parasitic or free-living and occur in densities of up to $9 \times 10^{6}$ per cubic meter of soil.

Annelids

A phylum of segmented worms, including earthworms and various marine polychaetes.

Polychaete

A class of marine annelid worms characterized by paddle-like feet called parapodia and bristles called chaetae.

Parapodia

Multi-purpose paddle-like appendages found on the segments of polychaete worms used for swimming, crawling, or defense.