What is an obelia?
Obelia is a genus of hydrozoans, a class of mainly marine and some freshwater animal species that have both polyp and medusa stages in their life cycle.
What is a hydrozoan?
The class Hydrozoa belongs to the phylum Cnidaria, which are aquatic (mainly marine) organisms that are relatively simple in structure.
What is a cnidaria?
Cnidaria is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter.
What is a polyp?
An obelia polyp is a two-layered tube with a central gut. A ring of tentacles around the mouth. The polyp remains is a fixed location on a hard surface under the water.
What is a medusa?
An obelia medusa is the free-floating form that resembles an umbrella with tentacles hanging down from the edges. The mouth is on the underside and is centrally located.
What is a zygote?
A zygote is an egg that has been fertilized by a sperm.
What is a blastula?
The blastula is an animal’s early stage of development that is composed of a hollow ball of cells.
What is a planula?
An obelia planula is a free-swimming or crawling larval. The planula body is cylindrical and has numerous cilia that are used for locomotion.
What is a hydrula?
An obelia hydrula is a simple polyp that attaches to a hard surface via the pedal disc. The hydrula uses the process of budding to form an entire colony.
What is metagenesis?
A type of life cycle in which sexual and asexual reproduction is alternated within a given organism. The alternation between the two diploid phases is called metagenesis.
What are the types of body symmetry?
Body symmetry describes how the structures of an organism are arranged. The major symmetry types in animals are bilateral, radial, biradial, spherical, and asymmetrical.
What is metamorphosis?
Metamorphosis is the process in which an organism changes from one form to a different, distinct form.
Some organisms reproduce sexually, while others asexually. A few use a combination of both types of reproduction to ensure the survival of the species. In this investigation, you’ll experience the metagenesis life cycle of a hydrozoan in the genus Obelia and identify structures associated with each part of the cycle. Get started now.
