hydrozoa
/'haidrə'zouə/
Học thuậtThân thiện
A student observes a living hydrozoa under a microscope in a marine biology lab.
Definition
- Noun:
- A class of coelenterates: Hydrozoa refers to a taxonomic class within the phylum Cnidaria. These aquatic animals are characterized by a life cycle that typically involves two distinct body forms: a usually colonial, sedentary polyp stage (hydroid) and a free-swimming medusa stage (jellyfish). Examples include hydras and many types of jellyfishes.
Usage Examples
- Noun:
- The biology student studied the life cycle of the Hydrozoa under a microscope.
- Many Hydrozoa, like the Portuguese man o' war, are known for their powerful stings.
Advanced Usage
- Scientific Classification: The term is used in formal biological taxonomy. It is often capitalized when referring specifically to the class: .
- The specimen was identified as belonging to the Hydrozoa.
Variants and Related Words
Hydrozoan (noun/adjective): An individual organism belonging to the class Hydrozoa. Also used as an adjective to describe characteristics of this class.
- Noun: A hydrozoan was observed budding.
- Adjective: The hydrozoan life cycle is complex.
Hydroid (noun): Refers specifically to the polyp, often colonial, stage in the hydrozoan life cycle.
- The reef was covered with a hydroid colony.
Synonyms
- Cnidarians (broader term): Hydrozoa are a class within the phylum Cnidaria, which also includes classes like Anthozoa (corals, sea anemones) and Scyphozoa (true jellyfish).
- Zoophytes (archaic/less precise): An old term for plant-like animals, which sometimes included hydrozoans.
A student observes a living hydrozoa under a microscope in a marine biology lab.
Noun
- coelenterates typically having alternation of generations; hydroid phase is usually colonial giving rise to the medusoid phase by budding: hydras and jellyfishes