Lab 9: Animals: Lophotrochozoans

Vocabulary flashcards related to the lophotrochozoans, their anatomy, classification, and key characteristics.

Lophotrochozoans

A clade of triploblastic animals with bilateral symmetry, including mollusks and annelids.

Triploblastic

Animals having three germ layers: ectoderm, mesoderm, and endoderm.

Protostomes

One of the two major groups of animals, defined by their embryonic development, characterized by the mouth developing first.

Ecdysozoans

The other group of protostomes characterized by molting their exoskeleton.

Bilateral symmetry

A body plan in which the left and right sides are mirror images.

Trocophore

A planktonic larval stage found in some lophotrochozoans.

Lophophore

A tuft-like structure that surrounds the mouth and helps with filter feeding.

Acoelomate

Animals that lack a body cavity, such as flatworms.

Pseudocoelomate

Animals that possess a body cavity but lack a mesoderm lining.

Coelomate

Animals with a body cavity lined by mesoderm-derived tissues.

Schizocoely

Formation of the coelom by splitting of the mesoderm in protostomes.

Enterocoely

Formation of the coelom by budding from the archenteron in deuterostomes.

Open circulatory system

A system where blood and lymph are not separated, found in arthropods and most mollusks.

Closed circulatory system

A system where blood circulates through vessels, found in vertebrates and some invertebrates.

Hemolymph

The fluid that circulates in an open circulatory system, composed of blood and lymph.

Rotifera

A phylum of triploblastic pseudocoelomates known as 'wheel animals'.

Mastax

A jaw-like structure in rotifers used for grinding food.

Planaria

Common name for the free-living organisms in class Turbellaria of phylum Platyhelminthes.

Trematoda

Class of flatworms commonly known as flukes, often parasitic.

Cestoda

Class of flatworms known as tapeworms, which are internal parasites.

Metamerism

The segmentation of an animal's body, significant in annelids.

Clitellum

A thickened, glandular section of a segmented worm that secretes a cocoon for eggs.

Visceral mass

The central section of a mollusk that contains most of its internal organs.

Mantle

The dorsal body wall of mollusks that may function in respiration and locomotion.

Cephalopoda

Class of mollusks that includes octopuses, squids, and cuttlefishes.

Circulatory system of cephalopods

Closed circulatory system with a highly efficient gas exchange mechanism.

Branchial hearts

Hearts that direct blood from the gills to the rest of the body in cephalopods.

Siphon

A structure in cephalopods used for locomotion and expelling water.

Gills

Respiratory organs in aquatic animals used for gas exchange.

Annelida

Phylum of segmented worms, which includes earthworms and leeches.

Oligochaeta

Class of annelids that includes earthworms, characterized by a clitellum and hermaphroditism.

Pseudocoelomate organisms

Organisms such as nematodes and rotifers, having a body cavity not fully lined by mesoderm.

Aquatic or terrestrial

Referring to species that live in water or on land.

Free-living

Organisms that do not parasitize hosts and can live independently.

Parasitic

Organisms that live in or on another organism (the host) to obtain nutrients.

Scolex

The head of a tapeworm, equipped with hooks and suckers for attachment.

Proglottids

Body segments of a tapeworm, each containing a mature reproductive system.

Hydrostatic movement

Movement that is facilitated by the fluid-filled coelom in annelids.

Tentacles

Flexible appendages in cephalopods used for capturing prey.

Chromatophores

Pigment cells in cephalopods that allow them to change color.

Feeding mechanism of rotifers

Utilizes a corona of cilia to create water currents and capture food.

Lateral mantle artery

An artery in cephalopods that plays a role in the circulatory system.

Strobila

The body of a tapeworm composed of a series of proglottids.

Visceral organs in mollusks

Organs concentrated in the visceral mass for digestion and reproduction.

Loligo

A genus of squids that are the subject of dissection in labs.

Funnel retractor muscle

Muscles in cephalopods that control the movement of the siphon.