Definition

Noun: 1. A small, needle-like, or pointed skeletal structure: A spicule is a tiny, sharp, and often mineralized structural element that forms part of the supportive framework (skeleton) in many simple aquatic animals, such as sponges and some corals.

Usage

• Spicules are microscopic or barely visible to the naked eye and are a defining anatomical feature of certain invertebrate groups.
• They are composed of materials like silica or calcium carbonate.
• The term is used primarily in biological and zoological contexts to describe these structural components.

Examples

• The scientist examined the sponge's spicules under the microscope to identify its species.
• The rigidity of the coral's structure is provided by countless calcareous spicules.
• These glass spicules give the sponge a rough texture.

Advanced Usage

• Spicular (adjective): Of or relating to spicules.
  • The spicular arrangement is unique to this family of sponges.

Variants and Related Words

• Spicula: A less common plural form of .
• Spiculum: An alternative singular form, also meaning a small, pointed structure.

Synonyms

• Spine (in a very broad, analogous sense for a small, pointed projection)
• Needle (in a descriptive, non-technical sense)
• Sclerite (a broader zoological term for a hard body part; some sclerites are spicules)

Different Meanings

The word spicule is highly specialized in modern English and almost exclusively carries the biological meaning defined above. In very rare or historical astronomical contexts, it might refer to a small, jet-like projection from the sun's surface, but this usage is now largely obsolete.

Noun

1. small pointed structure serving as a skeletal element in various marine and freshwater invertebrates e.g. sponges and corals