explain the obelia sp! life cycle!
Answers
Zoology
Obelia's life cycle is sequential, i.e.
- Planula larvae
- Skifistoma
- Strobilia
- Efira
- Adult Medusa
Discussion :
Obelia sp. is one of the species of Cnidaria. Obelia belongs to the Hydrozoa class. Obelia has a life cycle starting from
1. Planula Larvae :-
Planula larvae are a type of larva that can swim freely in the ocean. Bula-shaped planula larvae (like Bacillius bacteria).
Planula larvae have two body layers, namely
Ektoderm
Endoderm
These larvae move with cilia that are in their entire body (political type). This larva at the end of the metamorphosis will harden which will then sleep on the sea floor.
Later it will turn into a skifistoma
2. Skifistoma :-
Skifistoma is a type of young polyp. Skifistoma has a slight difference with strobilia ie Strobilia already has a gonad in its reproductive polyps while the skifistoma does not yet have one and only has eating polyps Skifistoma is still small and young while Strobilia is large The planula larva is just said to be a scifistoma if it is attached and embedded in the surface of the substrate.
3. Strobilia :-
Strobilia is an adult polyp phase in the Obelia life cycle.
Strobilia has several characteristics, namely Has two polyps, namely eating polyps and reproductive polyps Hydroriza which has developed and attached to the substrate (a kind of 'root' if it is for plants) It has gonadium channels in which there is a growing medusa Has two layers lining the gastrovascular coenosark and perisark In eating polyps, it is covered by the epidermis and gastrodermis Have a gastrozoid in the eating polyp
4. Efira :-
- Efira is a young medusa that just comes out and escapes from reproductive polyps. Efira flew freely and floated in the water. Efira has tentacles which contain knoboblasts.
- Knidoblasts have nematocytes that produce nematocic poisons which are shot into prey
5. Adult polyps :-
Adult polyps are just like efira but only later they will release the ovum and sperm and fertilization will occur in the water so that the zygote is formed
6. Zygote and Blastula :-
This zygote is small in size. Zygotes have their own food reserves. Cells from the zygote will divide into almost the same stage as the human blastula.
HEY MATE HERE IS THE ANSWER
In Obelia, the most conspicuous stage is the polyp. This stage of the Obelia life cycle is actually a colony of many interconnected polyps that share a single gastrovascular cavity.
2
In the Obelia colony, the polyps take on different functions. Some have stinging tentacles that are specialized for capturing prey and feeding, while others are specialized for reproduction.
3
The reproductive polyp produces—by asexual means—tiny medusa body forms. These medusae grow and bud off from the parental tissue. The medusae nearest the tip of the polyp are the most mature and are the first to leave the parent animal. Because they can swim, the medusae help disperse the species in the sea.
4
A medusa may be male or female. Male and female medusae have gonads which produce sperm and eggs, respectively. The medusae reproduce sexually by releasing their sex cells into the water. The sperm cells meet and fertilize the eggs, which become the single-celled zygotes of the next generation.
5
A zygote begins to divide and develops into an immature larval stage, called a planula. A planula, which is covered with cilia, swims to a substrate and settles there. It grows and develops into the polyp body form. A single polyp of Obelia becomes a colony of polyps through asexual budding. Some of the polyps differentiate into the reproductive forms that, in turn, bud off medusae. The medusae will swim away and begin another round of the cnidarian life cycle.