Moon Jellyfish
Moon Jellyfish are one of the many boneless, brainless, and heartless creatures of the sea. They are very interesting and beautiful organisms. Moon jellyfish are transparent with a slight bluish pink color with four bright horseshoes shaped gonads under their stomach. What is surprising to see is that they have an incomplete digestive system. With no intestines, liver or pancreas the digestion process is near impossible. The food that does need to be digested though goes through the mouth of a moon jellyfish and is captured by its gastrovascular cavity (source of digestion that has one opening and is surrounded by tenacles). The nutrients from the food is absorbed through the gastrodermis or the inner cells of the gastrovascular cavity. Due to not having the necessary organs these jellyfish can only use the same jaw for food intake and waste discharge
Fire Coral
Fire coral are marine organisms, who just like jellyfish can really sting. They live in multiple reefs on the sea's floor as they wait to catch their pray who are usually plankton or small fish. Fire coral only have one opening surrounded by tentacles being similar to the moon jellyfish. The prey captured by the tentacles, or nematocysts, is then moved to its mouth and down to the stomach cavity. Inside the stomach cavity there is mucus that breaks down the food. All waste is also excreted through the mouth.
Rose Bubble Anemone
The Rose Bubble Anemone is another marine organism that attacks its prey with its powerful sting. Also feeding on plankton and small fish this anemone's homes include rocks and other underwater sturctures where it can wait for a good meal. The digestive system of the Rose Bubble Anemone is almost identical to that of the Fire coral and Moon Jellyfish. The Rose Bubble Anemone mouth is slit-shaped and cilitated for swift movement of the food. Food enters such a mouth when its nematocysts kill off prey for consumption. The food travels through the anemone into its gastrovascular cavity, which functions as the anemone's stomach. The stomach is lined tissue that creates digestive enzymes. When the food is broken down it is absorbed as nutrients. Waste or any other undigested material is released through the mouth from which it came.