Invertebrate Animal Vocabulary Flashcards
Vertebrates
an animal of a large group distinguished by the possession of a backbone or spinal column, including mammals, birds, reptiles, amphibians, and fishes.
invertebrates
an animal lacking a backbone, such as an arthropod, mollusk, annelid, coelenterate, etc. The invertebrates constitute an artificial division of the animal kingdom, comprising 95 percent of animal species and about 30 different phyla.
Consumer
an organism that derives the organic compounds and energy it needs from the consumption of other organisms; a heterotroph.
Ganglion
a structure containing a number of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber.
Gut
the stomach or belly
Coelom
the body cavity in metazoans, located between the intestinal canal and the body wall.
Bilateral Symmetry
the property of being divisible into symmetrical halves on either side of a unique plane.
Radial Symmetry
symmetry around a central axis, as in a starfish or a tulip flower.
Asymmetry
lack of equality or equivalence between parts or aspects of something; lack of symmetry.
Sponges
a primitive sedentary aquatic invertebrate with a soft porous body that is typically supported by a framework of fibers or calcareous or glassy spicules. Sponges draw in a current of water to extract nutrients and oxygen.
Cnidarians
an aquatic invertebrate animal of the phylum Cnidaria, which comprises the coelenterates.
Flatworms
a worm of a phylum which includes the planarians together with the parasitic flukes and tapeworms. They are distinguished by having a simple flattened body which lacks blood vessels, and a digestive tract which, if present, has a single opening.
Roundworms
a nematode, especially a parasitic one found in the intestines of mammals.
Mollusks
an invertebrate of a large phylum which includes snails, slugs, mussels, and octopuses. They have a soft unsegmented body and live in aquatic or damp habitats, and most kinds have an external calcareous shell.
Open circulatory system
Open circulatory systems (evolved in insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. Blood is pumped by a heart into the body cavities, where tissues are surrounded by the blood.
Closed circulatory system
Closed circulatory systems (evolved in echinoderms and vertebrates) have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities. Blood flow is not sluggish.
Annelid worms
The annelids include earthworms, polychaeta worms, and leeches. All members of the group are to some extent segmented, in other words, made up of segments that are formed by subdivisions that partially transect the body cavity. Segmentation is also called metamerism.
Exoskeleton
a rigid external covering for the body in some invertebrate animals, especially arthropods, providing both support and protection.
Compound eye
an eye consisting of an array of numerous small visual units, as found in insects and crustaceans.
Antenna
either of a pair of long, thin sensory appendages on the heads of insects, crustaceans, and some other arthropods.
Metamorphosis
(in an insect or amphibian) the process of transformation from an immature form to an adult form in two or more distinct stages.
Endoskeleton
an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates.
Water vascular system
(in an echinoderm) a network of water vessels in the body, the tube feet being operated by hydraulic pressure within the vessels.
