red algae

American  

plural noun

Biology.

1. marine algae of the phylum Rhodophyta, in which the chlorophyll is masked by a red or purplish pigment.

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red algae British  

plural noun

1. Also called: red seaweed.  the numerous algae that constitute the phylum Rhodophyta , which contain a red pigment in addition to chlorophyll. The group includes carrageen, dulse, and laver

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Other Word Forms

Derived Forms

• red-algal
  adjective

Etymology

Origin of red algae

First recorded in 1850–55

Example Sentences

Others are much larger and multicellular, such as kelp, slime molds, and red algae.

From Science Daily • May 7, 2026

Galdieria extract blue comes from a unicellular red algae, which is an organism that thrives in extreme marine and terrestrial environments, according to the National Institutes of Health.

From Los Angeles Times • May 14, 2025

Kombu hails from kelp and is thicker and more substantial, while nori is derived from red algae.

From Salon • May 14, 2024

Fish love to eat the former but tend to avoid the red algae, Edmunds says, allowing them to grow unchecked until they smother corals to death.

From Science Magazine • Nov. 6, 2023

They gobbled red algae until their bodies turned the color of blood.

From "The House of the Scorpion" by Nancy Farmer