Term | Definition | Example |
Kingdom Animalia | collective classification of multicellular organisms | invertebrates and vertebrates |
Colonial Hypothesis | multicellularity may have arisen when cells produced by a dividing protist remained together | colonial protists |
Syncytial Hypothesis | multicellularity could have arisen when plasma membranes were formed within the cytoplasm of a large, multinucleate protist | multiple fission |
Phylum Porifera | cellular organization, multicellular, division of labor, asexual/sexual reproduction, symmetry, mostly marine | sponges |
Porifera | pore-bearing/pore-bearers | 9000 species of sponges |
Radial Symmetry | two or more planes that divide the organism into mirror images | sponges or jellyfish |
Asymmetry | no symmetry | amoeba |
Sessile | permanently attached to a substrate | all adult sponges |
Intracellular Digestion | within the cell | bacteria, protists, algae, detritus |
Ostia (ostium) | incurrent pores; many small pores; allows for the passage of water into the spongocoel | Grantia or Scypha |
Osculum (oscula) | excurrent pore: large pore; allows water to exit spongocoel; can have more than one | Grantia or Scypha |
Spongocoel | internal cavity; not a true body cavity; food/oxygen extracted from water in cavity | Grantia or Scypha |
Pinacocytes | flat cells forming the outer epithelium | any sponge |
Porocyte | cells that line the pore and regulates water flow | any sponge |
Choanocytes | "collar cells", flagellated cells that line the interior; creates the water current and filters for food | any sponge |
Mesoglea | gelatinous protein matrix that fills the space between the pinacocytes and choanocytes | mesohyl - another name |
Amoebocyte | cell found in the mesoglea; specialized for reproduction, secreting skeleton, transporting food, storing food, and forming contractile rings | any sponge |
Acoelomate | NOT a true coelom | any sponge |
Spicules | calcareous or siliceous; variety of shapes and sizes | see spicule handout |
Spongin Fibers | internal network of flexible protein fibers composed of collagen | bath sponge |
Ascon (asconoid) | vase-like shape; simplest and least common; ostia lead directly to spongocoel | Class Calcarea |
Sycon (syconoid) | sponge wall appears folded; water enters through dermal pores which connect to radial canals which open into the spongocoel | Class Calcarea or Hexactinellida |
Leucon (leuconoid) | extensively branched canals; incurrent canals open into choanocyte chambers and excurrent canals lead away from the chambers | Class Hexactinellida or Demospongiae |
Color | wide variety | red, yellow, orange, green, purple, blue, black |
Toxic sponges | contain toxins on the spicules | Fire Sponge |
Reproduction | asexual or sexual | regeneration/ egg and sperm |
Regeneration | asexual; replacement of injured or lost body parts | any sponge |
Gemmules | asexual; internal buds; masses of encapsulated amoeboid cells produced during unfavorable conditions | some sponges |
Sexual Reproduction | egg and sperm; fertilization in mesoglea; zygote to ciliated larvae; 2 days larvae settles | some sponges |
Monoecious | both sexes in one individual | most sponges |
Dioecious | separate sexes | some sponges |
Cross-fertilization | exchange sperm and egg | primarily used by most sponges |
Class Calcarea | a.k.a. Calcispongiae; limy sponges; calcium carbonate spicules; fringe of spicules around osculum; needle or 3-4 rayed spicules; all three body forms; all marine | Grantia (Scypha), Leucosolena |
Class Hexactinellida | a.k.a. Hyalospongiae; glassy sponges; silicon dioxide spicules; six-rayed; intricate lattice; sycon or leucon; all marine; deep water | Euplectella - Venus Flower Basket |
Class Demospongiae | people/natural sponges; silicon dioxide or spongin fibers or both; needle or 4-rayed spicules; all marine except one family; brilliantly colored | Spongilla (fresh), Haliclona (finger), Microciona (red beard), sheepswool (bath), fire sponge, loggerhead |
Sponillidae | only family of freshwater sponges | Spongilla |