Echinus Esculenta: Sea Urchin
The Sea Urchin belongs in the domain eukarya because of the similarities of the Sea Urchin's characteristics and the characteristics for what an organism in this domain should have. The similar characteristics are the following: being a multicellular organism, heterophoric, reproduces sexually, do not have cell walls, reacts to stimuli, and more [17].
Echinus Esculenta is a multicellular organism that lives in the ocean. Since it lives in the ocean, this organism has a water vascular system. The Sea Urchin is spherically shaped and is 3cm-10cm in diameter. This organism also has a spiky shell protecting it on the outside because in the shell there is a skeleton. This skeleton is packed with fitted plates that are made to protect them from any damages. In order for the Sea Urchin to not get attacked by predators, they have a spine that allows it to change it's color so that the sea urchin cannot be seen. This organism gets food by its sharp teeth and it's tube feet. The teeth collect any food for the Sea Urchin to consume. The tube feet are located on the exterior of the body, which allow them to roam across the ocean floor and stick to rocks. These tube feet collect food by trapping the food. They also help with the respiration for the organism. The sea urchin is important to the environment because if they die out, the animals that eat them may also die out [18].
Figure 8:What the Sea Urchin looks like
Hydra Viridissima: Green Hydra
Hydra Viridissima belongs in the domain eukarya because it has the correct characteristics that an organism should have if they are in this domaun. For Example, being multicellular, using ingestion as a mode of nutrition, being motile, and having a nervous system.
The Hydra Viridissima is a bright green Hydra that is about 0.4 inches longs and lives in fresh water. This organism is made up of two sheets of tissue, the ectoderm and the endoderm, which are separated by a type of gelatinous partition called, Mesoglea. The ectoderm layer of tissue covers the only opening of the hydra, the gastrovascular cavity. This opening is how the hydra catches food. The Green Hydra has tentacles that are used as the mouth. These tentacles. So, when the organism needs food, they use the tentacles to sting their food, which makes it paralyzed, thus making it possible to eat [19].
Figure 9:Labelled Picture of Green Hydra
Figure 10:Hydra Viridissima 237x magnification
E.G. and J.R.