Invertebrate Flashcards

Flashcards reviewing key vocabulary and concepts from a lecture on invertebrates, including rotifers, tardigrades, lophophorates, mollusks, and annelids.

Invertebrates

Animals without a backbone.

Rotifers

Tiny, multicellular animals (phylum Rotifera) found in moist environments, possessing a complete digestive tract and organ systems; important as food for other animals and as decomposers.

Parthenogenesis

A form of asexual reproduction where an egg develops without being fertilized.

Tardigrade (Water Bear)

A microscopic animal known for its ability to withstand extremely harsh conditions, including the vacuum of outer space and high levels of radiation.

Lophophorates

A group of marine animals characterized by the presence of a lophophore, a ring-shaped tentacle structure used for capturing food.

Lophophore

A ring-shaped tentacle structure used by lophophorates to capture food.

Ectoprocts (Bryozoa)

Lophophorates that resemble corals or plants.

Phoronids

Lophophorates that resemble tube worms but possess a lophophore.

Brachiopods

Lophophorates that resemble mollusks (bivalves) but have shells that are not mirror images of each other.

Nemertea (Ribbon Worms)

Marine worms with a unique proboscis (a mouth within a mouth) used to capture prey.

Proboscis

A mouth part in ribbon worms with a hook or harpoon that then shoots out of their mouth to then capture prey.

Mollusks

Mostly marine animals (some terrestrial) characterized by a body plan comprising a foot, visceral mass, and mantle.

Foot (Mollusks)

The part of a mollusk used for movement.

Visceral Mass

The main body of a mollusk containing most of its organs.

Mantle

A tissue in mollusks that secretes the shell.

Radula

A teeth-like structure in some mollusks (especially gastropods) used for scraping food.

Gonochoristic

Having separate male and female individuals; dioecious.

Hemolymph

The fluid in mollusks with an open circulatory system that mixes with body tissues.

Open Circulatory System

A circulatory system where hemolymph leaves blood vessels and mixes with body tissues before re-entering the vessels.

Closed Circulatory System

A circulatory system where blood remains within blood vessels.

Polypolycophora (Chitons)

Marine animals with eight dorsal plates on their back, found in intertidal zones.

Intertidal Zone

The area along the beach with rocks where the tides go in and out.

Gastropods

A class of mollusks that include snails, slugs, limpets, abalones, nudibranchs (sea slugs), and conches; most have spiral shells.

Torsion (Gastropods)

A body change in many gastropods (like snails) where the anus is rearranged to be above the head.

Bivalves

A class of mollusks with mirror-image shells (e.g., clams, oysters, mussels).

Teredo navalis (Shipworm)

A type of clam that burrows into and eats wood in the water, causing damage to wooden ships and structures.

Creosote

A toxic chemical used to treat wood to prevent shipworm damage.

Cephalopods

A class of mollusks that include octopuses, squids, cuttlefish, and nautiluses, characterized by a head and tentacles.

Chromatophores

Cells in cephalopods that allow them to camouflage and change skin texture.

Melanin

The pigment found in cephalopod ink (and human skin) that gives it a dark color.

Annelids

Segmented worms with a true coelom, a closed circulatory system, and a well-developed organ system.

Septa

Walls that separate each segment in an annelid worm.

Metamere

A segment or division of the body in certain annelids.

Annuli

Ring like groove that marks segments.

Clitellum

A structure in earthworms that produces cocoons for fertilized eggs.

Oligochaeta

A class of annelids that include earthworms; characterized by the absence of parapodia but setae (hair) are present.

Setae (Chaetae)

Hair-like structures found on annelids, used for movement and as chemosensors.

Polychaeta

A class of annelids that include mostly marine tube worms; they have parapodia with setae used for gas exchange and chemosensing.

Parapodia

Fleshy appendages found paired on each segment of polychaetes and used for gas exchange and locomotion.

Hirudinea

A class of annelids that include leeches; most are ectoparasites.

Hirudin

An anticoagulant chemical produced by leeches, used in medicine to prevent blood clotting.