Class Hydrozoa, Scyphozoa, and Anthozoa
Pneumatophore
-the gas-filled float of some colonial Physalia
Hydra (phylum Cnidaria)
. A solitary hydroid . Found in pools, quiet streams, and spring ponds, usually on the underside of leaves of aquatic vegetation, especially lily pads.
Radiates
.Are radially (or biradially) symmetrical, a form of symmetry in which body parts are arranged concentrically around an oral-aboral axis. .Both Cnodaria and Ctenophora are DIPLOBLASTIC because the epidermis and gastrodermis develop from the two embryonic germ layers (ectoderm and endoderm) .Have a tissue level of organization
Hydrotheca
a cup like piece of perisarc that protects hydranths in thecate hydroids
Obelia (phylum Cnidaria)
A colonial hydroid found in marine waters and attached to seaweeds, rocks, shells, and other objects
Gonionemus (Phylum Cnidaria)
A hydromedusa= Hydrozoan medusa Medusa fairly large and suitable for continued study of the hydroid life cycle Found in shallow protected coastal and bay areas along both coasts of U.S.
Hydranth
Nutritive polyps
Exumbrella
The convex outer (aboral) surface
Gonopore
Opening of the reproductive systems of an organism to the outside.
Subumbrella
The concave (oral) surface of gonionemus
Eumetazoans
True multicellular animals (Cnidaria and Ctenophora)
Medusa buds
one of the buds of a hydroid destined to develop into a gonophore or medusa.
Class Hydrozoa
1. Hydra 2. Obelia 3. Gonionemus All have cnidocytes, stinging cells
Two important metazoan features shared by all radiates are:
1. Two embryonic primary GERM layers (ectoderm and endoderm) that are homologous to those of more complex metazoa and 2. Internal space afor digestion, the gastrovascular cavity, which lies along the polar axis and opens to the outside by a mouth.
Dimorphism
The presence in a species of more than one morphological kink of individual--is common in Cnidarians but absent in ctenophores
Gonangium
a reproductive polyp of a colonial hydroid, giving rise asexually to medusa buds. Origin of gonangium.
Physalia (Phylum Cnidaria)
A hydrozoan
Polymorphism
a discontinuous genetic variation resulting in the occurrence of several different forms or types of individuals among the members of a single species. A discontinuous genetic variation divides the individuals of a population into two or more sharply distinct forms.
Nematocyst
a stinging cell that is used to inject a toxin into prey
Basal disc
base of a hydra, adheres to substrate or sometimes surface of water
Coenosarc
cellular body wall surrounding gastrovascular cavity
Hypostome
elevated mound of tissue that expands or contracts to regulate size of mouth opening
Cnidocyte
nematocyst-containing stinging cell on a cnidarian's tentacle
Gonotheca
parts of the obelia hydrpoid colony
Perisarc
sheath covering the stalk and branches of a hydroid