Lecture 7 Flashcards
Common Names for Calcarea, Demospongiae, Hexactinellida
boring sponge, bath sponge, six rayed sponge
Common name for anthozoa
Sea Anemone or Corals
Characteristics for Cnidaria
Cnidocytes, Mesoglea, Gastrovascular cavity, weaker - radial symmetry, sessile or free floating
Germ layers of cnidaria
ectoderm (epidermis), endoderm (gastrodermis) - have some mesoderm derived cells likes muscle but no true mesoderm
Mesoglea
Gelatinous Material between the two layers, helps with form and bouyancy
gastrovascular cavity in cnidaria
for digestion, gas exchange, N2 waste, and hydrostatic skeleton **some corals have calcium carbonate skeleton
Cnidocytes
stinging cells, cnidocil is hair like trigger, nematocyst ejects to sting with toxins
Feeding and digestion in Cnidaria
nematocysts entangle and paralyze prey, gastrodermal glands secrete mucus and enzymes for intercellular digestion, and nutritivie cells phagocytize food particles, peristaltic motion to eject cavity of material
reproduction
many have alternate polyp and medusae. most dioecious - medusa have eggs and sperm for sexual, some polyps bud asexually. Medusa zygote- planular larva, polyp, medusa
Nervous system in cnidaria
proto neurons form nerve net, sensitive to touch
locomotion in cnidaria
polyps are usually sessile but may glide, medusae are free floating, some with limited swimming capacity
Class Anthozoa
colonial or solitary polyps, gastrodermis with septa, sea anemones
Class Scyphozoa
true jellyfish, medusa stage prominent, cnidocytes in gastro and epidermis, moon jelly/aurelia
Cubozoa
cuboidal medusa, ex sea wasp/chironex
hydrazoa
nematocysts only in epidermis, mostly marine, some freshwater, hydra/obelia
Ctenophora
sea walnuts/comb jelly, swim with oral end upward, bioluminescence, marine
Characteristics of Ctenophora
Eight rows of ciliary bands for locomotion, colloblasts (adhesive cells for capturing prey), gelatinous mesoglea, gastrovascular cavity, two classes tentaulata (with tentacles), nuda (no tentacles)
