Phylum Cnidarians
Jellyfish, hydra, and sea anemones
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| Term | Definition |
|---|---|
| Phylum Cnidarians | Jellyfish, hydra, and sea anemones |
| Characters of Cnidarians | Sort bodies that exhibit radial symmetry, 2 germ layers |
| Cnidarians germ layers | Outer layers are epithelium with jelly like middle called mesoglea |
| Epithelium contains... | nerve cells and contractile cells |
| Nerve cells | able to sense outside stimulus and coordinate the animals response |
| Contractile cells | bend the organisms body allowing it to move through the water |
| Polyp | Cup shaped tubular body form with a mouth and tentacles at one end and a base that attaches to a hard surface on the other end, sessile |
| Medusa | Umbrella shaped body with its mouth facing downward and tentacles extending around it, motile (free swimming) |
| Cnidocytes | stinging cells on tentacles |
| Nematocytes | coiled tubes containing an attached barb that discharges a toxin when launched |
| Central digestive system (Cnidaria) | One opening, Enzymes in gut break down food, epithelial cells absorb nutrients, expel waste back out the mouth |
| Class Scyphozoa | Jellyfish (typically small, motile) |
| Reproduction (Jellyfish) | reproduce sexually and asexually |
| Life cycle of Jellyfish | Start as polyp and become more prominent medusa |
| Class Anthozoa | Sea Anemone and Coral (Only exist in polyp form) |
| Sea Anemone use... | chemical recognition system to release nematocysts and to form a symbiotic relationship |
| Coral are... | colonial creatures that produce a limestone cup that the coral polyp can retract into, create coral reefs |
| Class Hydrozoa | Hydra, Hydroid colonies, and Portuguese Man of War (mostly marine animals, very small, colonial species) |
| Stem cells | Can differentiate into other cells |
| Phylum Echinoderm | Sea stars, Sea urchins, and Sea cucumbers |
| Characteristics of echinoderms | marine animals, spiny skinned animals |
| Pentaradial symmetry | split 5 ways |
| Water vascular system | system of tubes filled with water extending through the entire body used for feeding, respiration, movement, and sensation |
| Sieve plate | filters sea water before entering the system |
| Ring Canal | where water enters, surrounding the mouth |
| Radial Canals | extend from the central part of echinoderms body down each ray |
| Lateral Canals | branch perpendicularly off the radial canals and terminate at tube feel |
| Tube feet | hollow feet-like knobs used for breathing and movement |
| Ampulla | muscle structures on the internal side of tube feet |
| Endoskeleton | an internal skeleton made up of plates called ossicles |
| Mouth is on the... | bottom side |
| Anus is on the... | upper side |
| Open circulatory system | blood flows freely through body cavity |
| Regeneration | ability to replace damaged areas |
| Class Asteroidea | Sea Star (have 2 stomachs) |
| Class Ophiuroidea | Brittle stars |
| Class Echinoidea | Sea urchins and sand dollars |
| Class Holothuroidea | Sea cucumbers |