A Survey of the Animal Kingdom: Coelomates

Comprehensive vocabulary flashcards covering coelomate phyla, including Mollusca, Annelida, Arthropoda, Echinodermata, and Chordata, along with their diagnostic anatomical features, subdivisions, and representative classes.

Coelom

A fluid-filled body cavity completely lined by tissue derived from the mesoderm, which allows for the development and suspension of internal organs and supports complex organ systems.

Coelomate Body Structure

A body plan featuring outer skin (ectoderm), muscle and peritoneum derived from mesoderm, a gut lined by endoderm, and internal organs suspended within a true coelom.

Radula

A rasping, tongue-like organ used for feeding in molluscs.

Ctenidia

Gills located in the mantle cavity of molluscs that function in respiration or filter-feeding.

Trochophore

A small, free-swimming, ciliated larval stage found in molluscs and marine polychaete annelids.

Class Gastropoda

A class of molluscs possessing $1$ shell; examples include snails, limpets, and abalones.

Class Pelecypoda

A class of molluscs (also called Bivalvia) characterized by having $2$ shells; examples include clams, mussels, oysters, and scallops.

Class Cephalopoda

A class of molluscs characterized by a well-developed head and tentacles; examples include squids, cuttlefish, octopuses, and nautilus.

Class Scaphopoda

A class of burrowing molluscs possessing a tubular shell; commonly known as tusk shells.

Class Polyplacophora

A class of molluscs characterized by a flattened body covered with overlapping dorsal plates; represented by chitons.

Class Aplacophora

A class of burrowing, worm-like molluscs that lack shells; examples include Chaetoderma and Solenogastres.

Metamerism

The condition of having repeating body segments (metameres or somites), characteristic of annelids and arthropods.

Septa

Sheet-like internal partitions that separate individual repeating segments from each other in annelids.

Chaetae

Bristle-like structures borne on the body segments of most annelids.

Nephridia

Specialized organs in annelids responsible for excretion and osmoregulation (water and ion balance).

Class Polychaeta

A class of marine annelids with bristle-bearing segments and trochophore larvae; examples include rugworms and tubeworms.

Class Oligochaeta

A class of burrowing terrestrial and freshwater annelids; examples include earthworms, pot worms, and ice worms.

Class Hirudinea

A class of aquatic, terrestrial, or parasitic annelids possessing flattened bodies and suckers; represented by leeches.

Haemocoel

The much-reduced, blood-filled primary body cavity found in arthropods.

Cuticle

An exoskeleton made of chitin to which muscles attach in arthropods.

Class Trilobita

An extinct class of marine arthropods that formed part of marine ecosystems approximately $300\text{ M}$ years ago.

Class Crustacea

A class of arthropods inhabiting oceans, freshwater, and land; examples include crabs, shrimps, and lobsters.

Class Chelicerata

A class of arthropods that includes spiders, horseshoe crabs, ticks, mites, and scorpions.

Class Insecta

The most abundant class of arthropods, most possessing compound eyes for vision; examples include beetles and weevils.

Class Myriapoda

A class of arthropods characterized by elongated bodies and many pairs of legs; examples include centipedes and millipedes.

Calcareous Ossicles

Calcium-based skeletal plates embedded within the skin of echinoderms.

Tube Feet

Small fluid-filled structures whose concerted action allows echinoderms to move slowly.

Class Asteriacea

A class of echinoderms possessing $5$ short arms with rows of tube feet on the lower side; example includes the common starfish.

Class Echinoidea

A class of echinoderms possessing $5$ rows of tube feet and a rasping jaw apparatus; represented by sea urchins.

Class Ophioroidea

A class of echinoderms characterized by slender arms that move horizontally; represented by brittle stars.

Class Crinoidea

A class of echinoderms found at the bottom of the sea, possessing tentacles and a stalk for anchorage; examples include sea lilies and feather stars.

Class Holothuroidea

A class of sediment-feeding echinoderms residing on ocean floors; represented by sea cucumbers.

Stichopus horrens

The scientific name for the warty sea cucumber.

Bêche-de-mer

Sea cucumbers that have been processed and dried for human consumption as food.

Phylum Chordata

A phylum of coelomate animals characterized by a notochord, a hollow dorsal nerve cord, pharyngeal clefts, segmented muscle blocks, a post-anal tail, and blood circulation.

Subphylum Urochordata

A chordate subphylum (also called Tunicata) of potato-shaped, sessile or attached invertebrate marine filter-feeders; represented by sea squirts.

Subphylum Cephalochordata

A chordate subphylum (also called Acraniata) of small, eel-like invertebrates; represented by lancelets (Amphioxus).

Subphylum Vertebrata

A chordate subphylum (Craniata) comprising around $5\%$ of all animals on Earth, possessing an endoskeleton of bone or cartilage divided into a braincase, vertebrae, bones, and gill arches.

Class Agnatha

A class of jawless vertebrate animals considered living fossils; represented by lampreys.

Class Chondrichthyes

A class of vertebrates comprising cartilaginous fishes; examples include sharks and rays.

Class Osteichthyes

A class of vertebrates comprising bony fishes; examples include carp, grouper (Lapulapu), and red snapper.

Class Amphibia

A class of vertebrates adapted to both land and water; examples include frogs, toads, and salamanders.

Class Reptilia

A class of vertebrates adapted to terrestrial life by possessing thick, leathery skin; examples include crocodiles, snakes, turtles, and lizards.

Class Aves

A class of vertebrates characterized by the presence of feathers; represented by birds such as chickens and turkeys.

Class Mammalia

A class of vertebrates characterized by having hair and mammary glands; examples include cows, goats, dolphins, whales, bats, chimpanzees, rodents, and humans.