Definition

Noun: * A type of bacteria: Predominantly photosynthetic prokaryotic organisms containing a blue pigment (phycocyanin) in addition to chlorophyll. They are not true algae but are often called algae due to their appearance and habitat. They can occur as single cells or in colonies and are found in diverse aquatic and terrestrial environments. They are important as phytoplankton, forming the base of many aquatic food webs.

Usage Examples

• Noun:
  • The pond turned a murky color due to a massive bloom of blue-green algae.
  • Scientists study blue-green algae for their role in early Earth's atmosphere.
  • Some species of blue-green algae can produce toxins harmful to animals and humans.

Advanced Usage

• Scientific name: The more precise, modern term for this group is cyanobacteria. In scientific contexts, "cyanobacteria" is preferred.
  • The study focused on the nitrogen-fixing capabilities of the cyanobacteria (blue-green algae) in the rice paddy.

Variants and Related Words

• Cyanobacteria (n): The scientific, taxonomic name for blue-green algae, identifying them as a phylum of bacteria.
• Phytoplankton (n): Microscopic aquatic organisms that photosynthesize; blue-green algae are a significant component of phytoplankton.
• Algal bloom (n): A rapid increase in the population of algae (including cyanobacteria) in an aquatic system, sometimes caused by blue-green algae.

Synonyms

• Cyanobacteria (This is the direct scientific synonym).
• Blue-green bacteria (A less common descriptive synonym).

Notes on Meaning

• The term "blue-green algae" is a common, historical name that is technically a misnomer, as these organisms are prokaryotic bacteria, not eukaryotic algae. The name persists due to their algal-like appearance and ecological role. The defining characteristic is the presence of the blue pigment phycocyanin, which, combined with chlorophyll, gives them their distinctive color.

Noun

1. predominantly photosynthetic prokaryotic organisms containing a blue pigment in addition to chlorophyll; occur singly or in colonies in diverse habitats; important as phytoplankton