Definition

1. Noun:
   • A specialized cell in sponges: A "collar cell" is a type of flagellated cell found in sponges (phylum Porifera). Its defining feature is a collar-like ring of cytoplasm that surrounds a single, whip-like flagellum. These cells are crucial for creating and maintaining a constant flow of water through the sponge's body.

Usage

• Noun:
  • The beating flagella of the collar cells draw water into the sponge.
  • Collar cells are responsible for both feeding and respiration in sponges.

Advanced Usage

• "Choanocyte": This is the more precise, scientific synonym for a "collar cell." The term "choanocyte" is derived from Greek words meaning "funnel" and "cell," describing its shape and function.
  • The sponge's internal chambers are lined with choanocytes, or collar cells.

Variants and Related Words

• Choanocyte (n): The formal biological term for a collar cell.
• Flagellum (n): The long, thread-like appendage that provides motility; it is the central structure within the collar of a collar cell.

Synonyms

• Choanocyte: The direct scientific synonym.

Notes on Meaning

• The term "collar cell" refers specifically to a biological structure within simple aquatic animals. It does not have a general or metaphorical meaning outside of zoology and biology. Its function is integral to the filter-feeding lifestyle of sponges.

Noun

1. any of the flagellated cells in sponges having a collar of cytoplasm around the flagellum; they maintain a flow of water through the body