What is another name for spirulina?

November 18, 2025 •

4 min read

While commonly sold and marketed as a 'blue-green algae,' spirulina is technically a type of cyanobacterium and was reclassified into the genus Arthrospira in the mid-20th century. This taxonomic reclassification, which also includes the newer genus Limnospira for modern cultivated strains, means that another name for spirulina is, scientifically speaking, Arthrospira. However, in commercial and popular contexts, the original, familiar name has persisted.

Quick Summary

The most accurate alternative name for spirulina is Arthrospira, a genus of cyanobacteria to which most commercial strains belong. Other common names include 'blue-green algae' or specific species like A. platensis and A. maxima. This article delves into the different names, their origins, and the scientific distinctions.

Key Points

Scientific Name is Arthrospira: While commonly called spirulina, the organism sold as a supplement belongs to the genus Arthrospira.
Newer Classification is Limnospira: Some cultivated commercial species have been further reclassified into the genus Limnospira.
Blue-Green Algae is a Misnomer: Spirulina is actually a cyanobacterium (a photosynthetic bacterium), not a true alga, which is a eukaryote.
Historically Called Tecuitlatl: The Aztecs consumed spirulina and referred to it by the name tecuitlatl.
Ensure Safe Sourcing: Some cyanobacteria produce toxins, so it is vital to purchase spirulina from controlled, reputable manufacturers to avoid contamination.

Spirulina's True Identity: From Algae to Cyanobacteria

The Scientific Name: Arthrospira

The most precise answer to the question, "What is another name for spirulina?" is the scientific name, Arthrospira. For decades, the filamentous, helical organism was mistakenly categorized in the genus Spirulina. A taxonomic revision later confirmed that most species widely consumed as a supplement are actually part of the Arthrospira genus. The distinction is based on morphological features, such as the size and presence of visible cross-walls in the filaments. While the scientific community has adopted the new name, the commercial and public use of "spirulina" has remained due to its historical familiarity.

The Rise of Limnospira

Further genetic analysis has even led to another reclassification for some commercially cultivated strains. In 2019, a study proposed moving economically important species, including what was formerly known as Arthrospira platensis and A. maxima, into the new genus Limnospira. This means that for those who buy and consume spirulina today, the most up-to-date scientific name is often Limnospira platensis, although it is almost never labeled as such.

The Common Misnomer: Blue-Green Algae

Outside of technical taxonomy, one of the most widely used alternative names for spirulina is "blue-green algae". However, this is a misnomer, as spirulina is not a true alga. True algae are eukaryotes, which means their cells have a nucleus. Spirulina and other cyanobacteria are prokaryotes, lacking a nucleus. The name stuck because of their similar aquatic, photosynthetic nature and blue-green pigmentation, which comes from chlorophyll and the blue-hued protein phycocyanin.

Photosynthetic Organism: Like plants, it converts sunlight into energy.
High-Nutrient Profile: Contains high levels of protein, vitamins, and minerals.
Diverse Habitats: Thrives in both fresh and saltwater environments, particularly highly alkaline lakes.
Ancient Food Source: Historically consumed by the Aztecs and in areas around Lake Chad.
Superfood Status: Often called a superfood for its dense nutrient content.

The Aztec Name: Tecuitlatl

Spirulina has been part of human diets for centuries. The ancient Aztecs, who harvested it from Lake Texcoco in Mexico, called it tecuitlatl. They dried the spirulina into cakes and sold it as a primary source of protein. The rediscovery of its nutritional value led to its modern resurgence as a health food.

Comparison of Spirulina's Names

To help clarify the various names associated with spirulina, the table below provides a comparison of their usage and context.


Name	Context of Use	Level of Accuracy	Description
Spirulina	Common commercial and dietary supplement name.	Low (taxonomically outdated).	Popular and widely recognized name for the superfood.
Arthrospira	Correct scientific genus for most edible spirulina strains.	High (modern taxonomy).	Used in scientific literature to accurately classify the organism.
Limnospira	Newest scientific genus for commercially manufactured strains.	High (most modern taxonomy).	Represents the most recent classification of cultivated species like L. platensis.
Blue-Green Algae	Common, informal name.	Low (biologically incorrect).	General term referring to its appearance and water-dwelling nature, but it is a bacterium, not an alga.
Tecuitlatl	Historical and cultural name.	N/A (culturally specific).	Ancient name used by the Aztecs for their harvested spirulina.
Cyanobacteria	Broader biological classification.	High (accurate classification).	The phylum to which spirulina belongs, indicating it is a type of bacterium.

Potential Confusion and Considerations

Why the Taxonomic Confusion Exists

The ongoing reclassification from Spirulina to Arthrospira and then to Limnospira highlights the dynamic nature of biological classification. Early taxonomic methods relied heavily on morphology, but advances in gene sequencing have allowed scientists to identify more precise genetic differences. This led to the realization that the organisms grown for commercial use, originally called Spirulina, were genetically distinct and belonged to a different genus.

The Importance of Safe Sourcing

Regardless of its name, it is important to remember that not all cyanobacteria are safe for human consumption. Some species produce toxins, and spirulina grown in uncontrolled, open ponds can be susceptible to contamination from these other organisms. Therefore, when purchasing spirulina supplements, it is crucial to choose products from reputable sources that adhere to strict quality control standards and test for contaminants like microcystins.

Conclusion

In conclusion, while the market and popular media continue to use the term "spirulina," its correct scientific classification is more complex. The primary alternative name, and most taxonomically accurate, is Arthrospira. Some commercially cultivated strains are even more precisely classified as Limnospira. Understanding these names, along with the common misnomer "blue-green algae," provides a clearer picture of this fascinating superfood. Ultimately, for the average consumer, the most important takeaway is to be aware of its bacterial origin and to ensure the product is sourced from a safe, reputable provider. This knowledge empowers consumers to make informed decisions about their dietary supplements.

The distinction between algae and cyanobacteria is crucial for understanding its biology, as algae are eukaryotes and cyanobacteria are prokaryotes.

Frequently Asked Questions

Spirulina is a cyanobacterium, which is a type of photosynthetic bacterium. While often called 'blue-green algae' due to its appearance and habitat, it is technically a prokaryote, unlike true algae which are eukaryotes.

The most accurate scientific name for most commercially available spirulina is Arthrospira, or more recently, Limnospira for many cultivated strains. The name "spirulina" has persisted in consumer markets for historical and popular reasons.

The scientific name was changed due to advances in biological classification, particularly gene sequencing. Newer research revealed that the commercially grown organism, based on its genetic and morphological characteristics, was distinct from the Spirulina genus and better fit into Arthrospira.

The ancient Aztecs referred to the spirulina they harvested and consumed from Lake Texcoco as tecuitlatl. It was a significant food source for them.

In 2019, taxonomic studies indicated that the commercially manufactured strains previously classified under Arthrospira were genetically distinct enough to be moved into a new genus, Limnospira. For most consumers, the difference is negligible, but it reflects modern biological understanding.

The distinction is important because while spirulina is safe and edible, certain other types of cyanobacteria can produce toxins that are harmful to humans and animals. Understanding the classification helps recognize potential safety risks with contaminated products from unregulated sources.

No, the name change is a matter of scientific classification and does not affect the nutritional composition or health benefits of the organism. The same vitamins, minerals, and proteins are present regardless of whether it is called spirulina, Arthrospira, or Limnospira.