Chapter 33: An Introduction To Invertebrates Flashcards
Filter Feeders
An animal that feeds by using a filtration mechanism to strain small organisms or food particles from its surroundings
Spongocoel
The central cavity of a sponge
Osculum
A large opening in a sponge that connects the spongocoel to the environment
Choanocytes
A flagellated feeding cell found in sponges. Also called a collar cell, it has a collar like ring that traps food particles around the base of its flagellum
Mesohyl
A gelatinous region between the two layers of cells in a sponge
Amoebocyte
An amoeba-like cell that moves by pseudopodia and is found in most animals. Depending on the species, it may digest and distribute food, dispose of wastes, form skeletal fibers, fight infections, or change into other cell types.
Hermaphrodites
An individual that functions as both male and female in sexual reproduction by producing both sperm and eggs
gastrovascular cavity
A central cavity with a single opening in the body of certain animals, including cnidarians and flatworms, that function in both the digestion and distribution of nutrients
Polyp
The sessile variant of the cnidarian body plan.
Alternate form is the Medusa
Medusa
The floating, mouth-down form of the cnidarian body plan
The alternate form is the polyp
Cnidocyte
A specialized cell unique to Cnidaria; contains a capsule-like organelle housing a coiled thread that, when discharged, explodes outwards and functions in prey capture or defense.
nematocysts
In a cnidocyte of a cnidarian, a capsule-like organelle containing a coiled thread that when discharged can penetrate the body wall of the prey.
Exoskeleton
A hard encasement on the surface of an animal, such as the shell of a mollusk or the cuticle of an arthropod, that provides protection and points of attachment for muscles
Protonephridum
An excretory system, such as the flame bulb system of flatworms, consisting of a network of tubules lacking internal openings
Planarian
A free-living flatworm found in ponds and streams
Alimentary canal
A complete digestive tract, consisting of a tube between a mouth and an anus. Found in rotifers
Parthogenesis
A form of asexual reproduction in which females produce offspring from unfertilized eggs
Ectoproct
A sessile, colonial lophotrochozoan
Brachiopod
A marine lophotrochozoan with a shell divided into coral and ventral halves; also called lamp shells
Visceral Mass
One of the three main parts of a mollusk; the part containing most of the internal organs
Mollusk Foot
One of the three main parts of a mollusk; A muscular structure usually used for movement
Mantle
One of the three main parts of a mollusk; a fold of tissue that drapes over the visceral mass and may secrete a shell.
Mantle cavity
An water-filled chamber that houses the gills, anus, and excretory pores of a mollusk
Radula
A strap like scraping organ used by many mollusks during feeding
Ammonite
A member of a group of shelled cephalopods that were important marine predators for hundreds of millions of years until their extinction at the end of the Cretaceous period
Cuticle
Any of a variety of tough but flexible, non-mineral outer covering of an organism, or parts of an organism, which provide protection
Molting
A process in ecdysozoans in which the exoskeleton sheds at intervals, allowing growth by the production of a larger exoskeleton.
Arthropods
A segmented ecdysozoan with a hard exoskeleton and jointed appendages. Familiar examples include insects, spiders, milipedes, and crabs
Open circulatory system
A circulatory system in which fluid called hemolymph bathes the tissues and organs directly and there is no distinction between circulating fluid and interstitial fluid
Chelicerate
An arthropod that has chelicerae and a body divided into a cephalothorax and an abdomen.
Includes sea spiders Horshoe crabs, scorpions, ticks, and spiders.
Myriapods
A terrestrial arthropod with many body segments and one or two pairs of legs per segment. Millipedes and centipedes are the two major groups of living myriapods.
Pancrustacean
A member of a diverse arthropod clade that include lobsters, crabs and other crustaceans, as well as insects and their six-legged terrestrial relatives
Chelicera
One of a pair of clade like feeding appendages characteristic of chelicerates
Eurypterid
An extinct carnivorous chelicerate; also called a water scorpion
Arachnid
A member of a subgroup of the major arthropod clade chelicerata. Arachnids have six pairs of appendages, including four pairs of walking legs, and include spiders, scorpions. Ticks, and mites.
Book lung
An organ of gas exchange in spiders, consisting of stacked plates contained in an internal chamber
Incomplete metamorphosis
A type of development in certain insects, such as grasshoppers in which the young resemble adults but are smaller and have different body proportions. The nymph goes through a series of molts, each time looking more like an adult, until it reaches full size
Complete metamorphosis
The transformation of a larva into an adult that looks very different, and often functions very differently in its environment, than the larva
Echinoderm
A slow-moving or sessile marine deuterostome with a water vascular system and, in larvae, bilateral symmetry. Includes sea stars, sea urchins, and sea cucumbers
Water Vascular System
A network of hydraulic canals unique to echinoderms that branches into extensions called tube feet, which function in locomotion and feeding
tube foot
One of numerous extensions of an echinoderm’s water vascular system.
They function in feeding and locomotion.
