cnidarian dissection. moon jellyfish 1 minute video of moon jellyfish “in motion” moon jellyfish...
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Cnidarian Dissection
Moon Jellyfish
• 1 minute video of moon jellyfish “in motion”• Moon Jellyfish – YouTube
Oral arms vs. marginal tentacles
• A jellyfish has many tentacles. Some hang around the bell of the jellyfish. These hold the stinging cells. Other tentacles hang around the mouth. These are called oral arms. They may or may not have stinging cells. The oral arms pass the food into the jellyfish’s mouth. The food then goes into the animal’s stomach.
Rhopalium
• Rhopalia (singular rhopalium) are the most obvious sensory structures of scyphozoan jellyfish. They include specialized structures for sensing light (eyespots) and movement or direction with respect to gravity (statoliths).
Moon Jelly
Moon Jelly
Structures to identify
• Bell• epidermis• Oral arms• Tentacles• Mouth• Gastrovascular cavity• Rhopalium• Mesoglea• gonads
Dissection video
• http://www.youtube.com/watch?v=IdhBRz2Yq1Q
Tentacle observation
• Use a dissecting microscope
Sea anemone
Metridium information
• http://www.boydski.com/diving/photos/metridium.htm
Metridium video
• http://www.youtube.com/watch?v=AlNGccPENGw
• 1. Metridium fields • http://www.montereyscubaboard.com/metridiumfields.php
Sea anemone
• Feeding:• http://www.youtube.com/watch?v=nI8A61uq
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Sea anemone: Metridium
Sea anemone dissection
• External: basal (pedal)disk, tentacles, mouth• Internal: siphonoglyph, pharynx, septa
(incomplete and complete), coelenteron, acontia, rector muscle, gonads
Lab procedure
• You will have step by step details for dissection• Questions/sketches will be completed in your
journal and collected for a grade• Dissection quiz– Anatomical directions– Species information– Anatomy as seen in dissection