Cnidaria Phylum
Cnidaria is a phylum that contains 10,000 species of animals that are mostly aquatic. These diverse animals all have stinging cells known as nematocysts. Cnidarian animal species are believe to be related because of these stinging cells that they may have obtained from a common ancestor. The name of the Phylum comes from a greek word called cnidos this meant a stinging net.
Urticina Lofotensis
Female Uriticina Lofotensis become fertile in December as sea temperature drops significantly. large eggs are produced at large quantities. Males then release sperm into the sea shortly afterwards. The sex cells are released from the mouth/anus of the both the male and female Uriticina Lofotensis. The eggs and sperm externally fertilize. the fertilized eggs develop into planula larvae which drift with the waves and settle and grow wherever they land.
Montastraea Annularia
This species of coral reproduce by budding off. This is when an offspring breaks off of its parents and lives on its own. They also externally reproduce which is when sperm and eggs are released into the sea and fertilize each other.
Box Jellyfish(Chironex Fleckeri)
Mating occurs annually. During mating the male and female entangle their tentacles together. While entangled the male brings his manubrium which is like a mouth/anus closer to the female's manubrium and releases ball of sperm that appears red. The female ingests the sperm from the water and the eggs develop internally inside the female box jellyfish.