Invertebrate Phylum: CNIDARIANS (Coelenterates)
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Transcript of Invertebrate Phylum: CNIDARIANS (Coelenterates)
Invertebrate Phylum:CNIDARIANS
(Coelenterates)
Vocabulary"Cnidarian” = nettle
"Coelenterata" = hollow gut
polyp = "vase" shaped body form
medusa = "bell" shaped body form
Cnidocyte = stinging cell
Vocabularynematocysts = capsule with coiled,
threadlike tube; inside cnidocytes
endoderm= inner layer of skin
ectoderm= outer layer of skin
mesoglea= jelly-like layer between ectoderm and endoderm
Types
anemones, jellyfish, hydras, coral, Portuguese-man-o-war
Characteristics* Polyp - sedentary, nonmotile, cylindrical body with mouth and tentacles
* Medusa - upside down bowl, mouth and tentacles facing down; modified for swimming
Characteristics* Food digestion
- Paralyze prey with cnidocytes - Tentacles push food to mouth - Cells in gastrovascular cavity release enzymes over prey - Waste ejected through mouth
"Nerve Net" = simple nervous system around mouth
Habitat
Fresh and salt waterWorldwide
Mostly South Pacific and Caribbean
ReproductionAsexual
Buds grow tentacles and separate (warm)Sexual
Eggs and sperm made in testes and ovaries
Sperm fertilize egg; zygote with protective cover shed in spring (fall,
cool)