Jellyfish can lay an underdeveloped fertilized egg in the form of a zygote or an embryo into the open water. The egg equipped with the zygote or embryo will start its external development out of the body of the female jellyfish, which is in the open water. For example, in a few Box Jellyfish species like Copula sivickisi fertilization can occur internally by mating. In another example, of the Aurelia Jellyfish, the male sperms swimming about in the water will reach the ova and fertilize them in the stomach of the female jellyfish.
Thus leading to internal fertilization. However, in the majority of the species, the Jellyfish can neither lay eggs nor give birth to the young ones.
That is, many jellyfish reproduce using external fertilization. Giving birth means to take care of the fertilized eggs inside or outside the body of the female until it develops into young individuals. The process of giving birth means to produce a well-developed young from the body of the female.
Or, it also means sitting or keeping the eggs so as to hatch them by the warmth of the body of the mother. In some species, it has been seen that some females carry fertilized eggs for a short time inside their stomach before releasing the developed embryo or planulae into the water. At that point, when they keep the fertilized eggs inside, the adult jellyfish do provide a bit of care and nourishment for the development.
But, as soon as the eggs are released no further care for their young is seen. They simply release the eggs and move on. In fact, most species appear to die soon after fertilization occurs.
Giving birth to young ones also demands better nourishment and care from the parental side until the eggs develop into young ones.
But, in the case of jellyfish, no such characteristics are seen. As already mentioned above in the post, there are only a few Jellyfish species that receive sperm through their mouths to fertilize the unfertilized eggs inside their body cavity. Then they do only lay the underdeveloped eggs. The water in which they live can give jellyfish coloring, as can their own unique type of farming.
Some jellyfish like the upside-down jellyfish, Cassiopeia xamachana are vegetarians that grow their own food and carry it with them. These jellyfish raise algae inside their belly, giving them a food source that they take along as they float through the oceans.
The algae can range in color, giving the jellyfish a variety of shades. Others still are influenced in color by their diet. For instance, moon jellies, when feeding on a lot of larval crustaceans that are high in certain pigments, are usually pink to purple in color.
And here at the Aquarium of the Americas, we often use brine shrimp as jellyfish food. After the jellyfish eat, the orange-colored brine shrimp can be clearly seen inside the jellyfishes' four stomachs. Newsletter Get smart. Sign up for our email newsletter. Already a subscriber? Fried Egg Jellyfish, sometimes also called Egg-Yolk Jellies, are jellyfish that sport a smooth translucent bell that has an elevated yolk-yellow bell at the center. This distinctive bell is what gives this jellyfish their name, as it looks like a cracked egg floating through the water.
This jellyfish spends a lot of time motionless, slowly pulsing its bell while drifting. The numerous short, club-like appendages extending from it contain mouth-arm openings through which the jellyfish traps prey and feeds. These appendages are usually colored a deep purple and while stingers are present, the sting has very little effect on humans. Feeding Times. Conservation Work. Web design and content by Flow Communications. Search Two Oceans Aquarium Toggle navigation.
Home Blog The life cycle of a jellyfish: Spawning, cloning and immortality. Some species are a bit more careful with their gametes. These box jellies are mating - the male pulls the female close with his tentacles, ready to pass his sperm package to her. Image courtesy of Alvaro E. This microscopic mass of cells is a planula, the larval stage of a moon jelly that is free-swimming and trying to find the perfect habitat on the seafloor. In the polyp phase, the jelly closely resembles its cousins, the sea anemones.
As the polyp grows, it begins to segment and create clones of itself. The polyp on the left is at the beginning of this stage of its life, but has not yet lost its tentacles. The scyphistoma of a moon jelly - this polyp has essentially become a stack of tiny juvenile jellyfish clones, ready to be released into the ocean. Another view of a moon jelly scyphistoma. This polyp is in the final stages of its transition into a scyphistoma - note how its feeling tentacles are being resorbed.
An ephyra of an upside-down jellyfish bred at the Aquarium. The ephyra of a moon jelly under the microscope. It may look fragile, but this organism is equipped with everything it needs to grow into a mature adult. As it grows, the ephyra begins to more closely resemble its adult stage. The adult, medusa stage of the jelly's life is what most people would recognise as a "jellyfish". However, this is only a very small part of the animal's life.
Deep-sea jelly species, like the Deepstaria, are not abundant enough to be able to rely on huge blooms to find a mate. It is these species that must rely on long adult lifespans, immortality and other unusual jelly tactics in order to reproduce. Moon jelly medusae at the Two Oceans Aquarium.
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