Chapter 33: Protostomes Flashcards

Comprehensive vocabulary flashcards covering the clades and phyla of Protostomes, including Lophotrochozoa, Ecdysozoa, and their specific biological characteristics as presented in Chapter 33.

Protostomes

A group of animals that includes the clades Lophotrochozoa and Ecdysozoa.

Lophotrochozoa

A clade of protostomes whose embryos develop using spiral cleavage, most live in water, and move using cilia or body musculature contractions.

Trochophore

A defining characteristic of Lophotrochozoa described as a free-living larva.

Lophophore

A horseshoe-shaped crown of ciliated tentacles surrounding the mouth, used for filter-feeding in certain Lophotrochozoans.

Ecdysozoa

A clade of protostomes containing animals that molt a hard external skeleton (exoskeleton), primarily comprising Arthropods and Nematodes.

Platyhelminthes

A phylum of flatworms characterized by simple bodies with no circulatory or respiratory systems but complex reproductive systems.

Flame cells

Cells located on the side branches of the flatworm's excretory system that use flagella to move water and substances into tubules.

Neodermata

A subphylum of flatworms that includes all parasitic species, subdivided into Trematoda and Cercomeromorpha.

Trematoda

A subgroup of flatworms known as flukes that attach to hosts using suckers, anchors, or hooks and have complex life cycles with multiple hosts.

Cercomeromorpha

A subgroup of flatworms known as tapeworms that hang onto the host's intestinal wall using a scolex.

Proglottids

The repeated units forming most of a tapeworm's body, each acting as a complete hermaphroditic unit.

Rotifera

A phylum of bilaterally symmetrical, unsegmented pseudocoelomates known as "wheel animals."

Corona

A conspicuous ring of cilia at the anterior end of rotifers used for locomotion and sweeping food into the mouth.

Mantle

A thick epidermal sheet in mollusks that bounds the mantle cavity and secretes the shell.

Ctenidia

Gills found in aquatic mollusks that also function to filter food in most bivalves.

Radula

A rasping, tonguelike structure used in feeding that is characteristic of most mollusks except bivalves.

Nephridia

Excretory organs in mollusks and annelids used for nitrogenous waste removal; in mollusks, they consist of cilia-lined openings called nephrostomes.

Veliger

The second free-swimming larval stage in mollusks, occurring only in bivalves and most marine snails.

Torsion

A unique process in Gastropoda where the mantle cavity and anus are moved from the posterior to the front.

Chromatophores

Specialized cells in cephalopod skin that allow for changing color for camouflage or communication.

Annelida

A phylum of segmented worms whose body is built of repeated units separated internally by septa.

Chaetae

Bristles of chitin found in most groups of annelids that aid in locomotion.

Clitellum

A structure found in the clade Clitellata (earthworms and leeches) that secretes a mucus cocoon for reproduction.

Nemertea

A phylum of ribbon worms, including the species $Lineus\,longissimus$ which can reach lengths of $60\,m$.

Rhynchocoel

A fluid-filled coelomic cavity found in Nemerteans.

Bryozoa

A phylum of colonial animals called "moss animals" where individuals secrete a chitinous chamber called a zoecium.

Brachiopoda

A phylum known as lamp shells that possess two calcified shells (dorsal and ventral) and a lophophore.

Nematoda

A phylum of roundworms characterized by a flexible, thick cuticle that is molted (ecdysis) and the use of piercing organs called stylets.

Tagmata

Specialized body regions in arthropods, typically identified as the head, thorax, and abdomen.

Ommatidia

Independent visual units that compose the compound eyes of many arthropods.

Malpighian tubules

Excretory structures in terrestrial insects that eliminate nitrogenous wastes as concentrated uric acid or guanine to conserve water.

Chelicerae

The most anterior appendages in the class Chelicerata, which may function as fangs or pincers.

Biramous

A term describing the "two-branched" appendages characteristic of the class Crustacea.

Nauplius

The characteristic larval stage of crustaceans, providing evidence of a common ancestor for the group.

Metamorphosis

The developmental process in insects which can be simple (immature stages similar to adults) or complete (including wormlike larvae and a pupa/chrysalis stage).