My Inner Fish

In Your Inner Fish, they talked about how fish related to humans. This relates to what we are learning this unit, which is about evolution. The video talked about how fish evolved, and how they have similar traits to humans. We learned about how there was a gene called "Sonic Hedgehog". Sometimes, when the gene is stronger, people grow extra digits, and if the gene is too weak, people end up having less than normal. Some people have six or even four digits. Humans and fish both have gill arches. They look almost identical. Gill arches in humans are jaws and in fish, they are used for gills. This shows how gill arches are analogous structures. In the video, they found a Tiktaalik. It was the first fish to come onto land. They used their neck to watch for predators and hunt smaller prey.



some people have six fingers instead of five
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Tiktaalik coming onto land

Purple-striped Jellyfish

The purple striped jellyfish is from the class Scyphozoa. It is from the phylum Cnidaria. It is in the kingdom Animalia. They are known as the "true jellyfish". Scyphozoa display a four type symmetry. They can consist as much as 98% of water. This jellyfish swims by alternating contracting and relaxing a ring of muscle fibers in the mesoglea around the rim of the dome.The purple-striped jellyfish (Chrysaora colorata) is from the order Semaeostomeae. It is from the family Pelagiidae and the genus Chrysoara. The sting of this jellyfish is extremely painful to humans. When the prey touches a marginal tentacle of the purple-striped jellyfish, stingers are immediately discharged to paralyze the prey and the marginal tentacle bends to the nearest oral arm. The oral arm is used to catch motionless prey and to move prey to the gastrovascular cavity. 


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