Definition

1. Noun:
   • A taxonomic class of marine animals: "Class Actinozoa" refers to a large class of sedentary marine coelenterates (cnidarians) that includes organisms like sea anemones and corals. In their life cycle, the medusoid (free-swimming) phase is entirely absent or suppressed.

Usage Notes

• The term "Class Actinozoa" is primarily used in formal biological and zoological classification. It is a scientific term and is not commonly used in everyday language.
• In modern taxonomic systems, this group is often referred to as "Anthozoa." "Actinozoa" can be considered a synonymous or older classification.

Examples

• Noun:
  • The study focused on the reproductive biology of various species within the class Actinozoa.
  • Sea anemones and stony corals are both members of the class Actinozoa.

Advanced Usage

• In taxonomic hierarchy: The term is used to denote a specific rank (class) within the phylum Cnidaria.
  • The phylum Cnidaria is divided into several classes, including the class Actinozoa.

Variants and Related Words

• Anthozoa (n): The modern class name often used synonymously with Actinozoa, encompassing sea anemones, corals, and sea pens.
• Actinozoan (n/adj): (Noun) An individual organism belonging to the class Actinozoa. (Adjective) Relating to or characteristic of this class.
  • The actinozoan polyp is a common body form.

Synonyms

• Anthozoa: The more commonly accepted modern synonym for this class of animals.

Related Terms

• Cnidarian (n): A member of the phylum Cnidaria, which includes jellyfish, hydras, sea anemones, and corals. Actinozoa is a class within this phylum.
• Polyp (n): The sedentary, cylindrical life stage characteristic of actinozoans, as opposed to the medusa stage.
• Sessile (adj): Describes organisms that are fixed in one place and not free-moving, a key characteristic of most actinozoans.

Noun

1. a large class of sedentary marine coelenterates that includes sea anemones and corals; the medusoid phase is entirely suppressed