Definition

Noun: A type of single-celled organism, specifically a dinoflagellate, characterized by having two flagella for movement and a protective outer covering (theca or test) made of cellulose plates.

Usage

This is a scientific term used primarily in biology, marine biology, and paleontology to classify a specific group of planktonic microorganisms. * The water sample was rich in various peridinians, indicating a healthy plankton bloom. * Under the microscope, the peridinian's distinctive armored plates were clearly visible.

Advanced Usage

• Ecological Role: Peridinians are a major component of marine plankton and can be both photosynthetic and heterotrophic. Some species are known for causing bioluminescence or harmful algal blooms (red tides).
  • The bioluminescence in the bay is caused by a bloom of peridinians.

Variants and Related Words

• Dinoflagellate (n): The broader biological class to which peridinians belong. All peridinians are dinoflagellates, but not all dinoflagellates are peridinians.
• Theca (n): The scientific term for the armored shell or test composed of plates that is characteristic of peridinians.

Synonyms

• Armored dinoflagellate
• Thecate dinoflagellate

Different Meanings

This word has a single, specific scientific meaning. It does not have common idiomatic or figurative uses.

Noun

1. flagellate with a thick test composed of plates