Algae & Zooplankton

Algae form the base of the global marine and aquatic food web. We curate a selection of algae cultures that grow well, are non-toxic, and non invasive. 

Zooplankton are small animal grazers that predate microalgal plankton. We curate a selection of zooplankton that will do well in your classroom or home. 

The Algae

Algae are photosynthetic protists and bacteria that can be thought of as simple plants. In most cases, commonly described algae are unicellular phytoplankton, which means they are photosynthetic, single-celled organisms that live freely and suspended in the water they inhabit. The casual observer can view them as large (macro) or small (micro). Microalgae are unicellular and contain all necessary metabolic processes within one membrane, whereas macroalgae more closely approximate land plants as they are composed of vascular and root systems. ARS provides microalgal cultures as they are the quintessential algal morphotype and possess high growth rates, simple life cycles and are the simplest species to culture. They are organized by kingdom and division according to genetic and morphological characteristics, which are described below. 

Chlorophytes, the Green Algae

The green algae, or Chlorophyta, occur mainly in freshwater but can be found in brackish and marine ecosystems. Green algae are usually single-celled and microscopic, although some form colonies that are considered macroscopic. The colonies have very interesting and diverse morphology, forming spherical (round) colonies composed of many cells or occurring as straight or branched filaments (long, thin series of cells). Green algae are thought to be in the evolutionary line that gave rise to the first land plants and are often called grass-green algae because of the similarities in pigments to terrestrial plants. Recent genetic analyses have suggested that certain green algae are evolutionarily closer to land plants than they are to red or brown aquatic algae!


Chlamydomonas reinhardtii

About the Algae: Chlamydomonas reinhardtii is a species of unicellular flagellated green algae in the phylum Chlorophyta. Originally isolated in 1945, this species is a model organism for a variety of questions in cell and molecular biology, including the mechanics of flagellar-based motility and phototaxis. In addition to being freshwater, this species is also present in soil, though only in its vegetative stage. This stage is often the immediate product of reproduction in which the cell can split through meiosis multiple times before bursting from the mother cell wall, resulting in 4 to 8 daughter cells. Because of its long history as a model organism C. reinhardtii has also been explored as a source of biofuels and biopharmaceuticals. The cells have been used to produce complex vaccines and therapeutics, explored as a source of pure hydrogen, and even had their channelrhodopsin photopigments used in optogenetics (a method in neurobiology used to explore differential gene expression). 

C. reinhardtii Starter Culture: coming soon!

C. reinhardtii Culture Kit: coming soon! 

Freshwater Media Kit



Chlorella vulgaris

About the Algae: Chlorella vulgaris is a eukaryotic, unicellular green algae that inhabits freshwater environments. They are from the genus Chlorella, a long-studied chlorophyte algae with an incredibly inventive name derived from the Greek “chlor” (green) and the Latin “ella” (small). Chlorella cells in general have a spherical cell body with a diameter of 2-10 micrometers and contain a single, cup-shaped chloroplast. Inside the cell body, numerous starch grains can be seen, which are used to store and sequester the energetic byproducts of photosynthesis for later use. These grains surround the pyrenoid, an organelle within an organelle that assists the chloroplast with the concentration of carbon dioxide used to create sugars during photosynthesis. They can be found in colonies up to 64 cells or on their own. Learn more about Chlorella

C. vulgaris Starter Culture

C. vulgaris Culture Kit

Freshwater Media Kit


Chlorella pyrenoidosa

About the Algae: Chlorella pyrenoidosa is a eukaryotic, unicellular green algae that inhabits freshwater environments. They are from the genus Chlorella, a long-studied chlorophyte algae with an incredibly inventive name derived from the Greek “chlor” (green) and the Latin “ella” (small). Chlorella cells in general have a spherical cell body with a diameter of 2-10 micrometers and contain a single, cup-shaped chloroplast. Inside the cell body, numerous starch grains can be seen, which are used to store and sequester the energetic byproducts of photosynthesis for later use. These grains surround the pyrenoid, an organelle within an organelle that assists the chloroplast with the concentration of carbon dioxide used to create sugars during photosynthesis. They can be found in colonies up to 64 cells or on their own. Learn more about Chlorella

C. pyrenoidosa Starter Culture: coming soon! 

C. pyrenoidosa Culture Kit: coming soon!

Freshwater Media Kit


Euglena gracilis

About the Algae: Eulgena are a genus of freshwater unicellular flagellated green algae in the class Euglenoidea. The genus is extremely diverse and composes up to 1000 individual species, but there are some unifying features. All species are elongated and contain one nucleus, multiple chlorophyll-containing chloroplasts, and a contractile vacuole. This organelle helps expel freshwater from the cytoplasm and regulate the concentration of dissolved solutes in the cell. Unlike some other algal cells, Euglena lacks a cell wall and instead has a "pellicle," or flexible covering that allows the cell to change shape. In the presence of high levels of nitrogen Euglena can form toxic blooms in freshwater lakes or ponds that can harm the surrounding wildlife.  

Euglena Starter Culture: coming soon!

Euglena Culture Kit: coming soon!

Freshwater Media Salts


Scenedesmus quadratica

About the Algae: Scenedesmus is a colonial, non-motile, freshwater genus of the class Chlorophyceae. There are currently 74 accepted species within the genus, although the degree of sub-generic diveristy suggests that a reclassification of the genus may be coming soon. Unlike most other algae mentioned in this list Scenedesmus is exclusively colonial, comprising multiple linked cells that terminate in spiked bristles. The purpose of these bristles is thought to be related to predator defense. The reproductive life history of Scenedesmus is also interesting, comprised of a single cell that forms multi-nucleate bodies within a single cell wall. Once these bodies are formed, they are cleaved into uni-nucleate single cells that then burst and begin life as individual organisms. 

Scenedesumus Starter Culture: coming soon!

Scenedesumus Culture Kit: coming soon! 

Freshwater Media Kit


Nannochloropsis oculata

About the Algae: Nannochloropsis is a genus of alga within the heterokont line of eukaryotes. While they can be found in fresh and brackish waters, Nannochloropsis widely occurs in saltwater world-wide. Some Nannochloropsis species have been shown to be suitable for algal biofuel production and is popular for use in aquaculture feed and dietary supplements. Nannochloropsis is a bulldog of an algae strain, It is great for science projects as it stays in suspension and is difficult to kill.

Nannochloropsis Starter Culture

Nannochloropsis Culture Kit

Saltwater Media Kit  


Tetraselmis chuii

About the Algae: Tetraselmis is a green alga genus of eukaryotic marine and freshwater phytoplankton. Named for its four flagella arranged in two opposite pairs (“tetra” = four, “selmis” = an angler’s noose made of hair), this motile algae is cordiform (heart-shaped) with an invagination located where flagella emerge from the cell. It is covered in a thick wall composed of a series of fused plates made of carbohydrates, termed a “theca.” Tetraselmis usually possesses a single cup-shaped chloroplast enclosing a pyrenoid, or special sub-organelle used in the carbon concentration mechanism (CCM). The pyrenoid is surrounded by a wall of starch granules and mostly made up of the enzyme RuBisCO, which accepts carbon dioxide sourced from the atmosphere and transforms it into the first chemical step in the pathway used by algae to create the complex sugars they need for respiration. Thylakoids, or the structures inside chloroplasts that perform photosynthesis, weave between the pyrenoids of Tetraselmis to facilitate the transport of intermediate molecules. The position and shape of the pyrenoid within the chloroplast is thought to be taxonomically significant in Tetraselmis. Learn more about Tetraselmis.

Tetraselmis Starter Culture

Tetraselmis Culture Kit: coming soon! 

Saltwater Media Kit 

Bacillariophytes, the Diatoms

Bacillariophytes, or diatoms, are single-celled algae that have silica shells (frustules) with very intricate patterns and symmetrical shapes. In nutrient-saturated environments, diatoms are generally the most abundant phytoplankton and serve as an important food source for aquatic life in both fresh and saltwater environments. Diatomaceous earth is a deposit of fossilized diatoms; diatoms frustules give these deposits a wide range of commercial like “natural” pest control, cosmetic abrasives, and water filtration. Diatoms can either live as individual cells or linked in chains up to hundreds of cells long. Certain diatoms can also form harmful or noxious algal blooms: Albert Hitchcock's The Birds is based on the days-long harassment of a central California town by a flock of seabirds poisoned by domoic acid synthesized by the chain-forming diatom genus Pseudo-nitszchia. 


Cyclotella sp

Cyclotella meneghiniana

About the Algae: Cyclotella are a genus of widely distributed and diverse diatom species. They primarily inhabit freshwater environments, but have been found in brackish and marine regions as well. Though the genus is primarily thought of as inhabiting nutrient poor regions, recent surveys have discovered in nutrient-rich ones, which suggests that Cyclotella are cosmopolitan species, able to inhabit a broad range of environments. Cyclotella produces a large amount of triacylglycerols, which has led to investigation into its potential for biofuel production. 

Cyclotella Starter Culture: coming soon!

Cyclotella Culture Kit: coming soon! 

Freshwater Media Kit 



Thalassiosira pseudonana 

About the Algae: Thalassiosira are a genus of centric diatom and primarily grow in marine waters. Most species are cosmopolitan, or able to exist in a variety of marine environments around the world. This genera comprise the largest of the centric diatoms with more than 100 species described. They can be identified by their characteristic shape: box shaped, cylindrical, drum shaped, discoid, and coin shaped. To a trained microscopist, other readily recognized features such as strutted, occluded, and labiate processes can further distinguish specific Thalassiosira species. Cells can be found as individual bodies or in chain colonies connected by organic threads.

Thalassiosira Starter Culture: coming soon! 

Thalassiosira Culture Kit: coming soon!

Saltwater Media Kit 






Rhodophyta: The Red Algae

The red algae, or Rhodophyta, are marine algae that are most often found in shallow waters and deep tropical seas. A few also occur in freshwater. Their morphology ranges from single celled microalgae to macroalgae.  The larger species have filaments that are massed together and resemble the leaves and stems of plants. They have no flagella and typically grow attached to a hard substrate or on other algae as an epiphyte. Some species contain a red pigment phycoerythrine; others range in color from green to red, purple, and greenish-black. The cell walls of coralline red algae become heavily encrusted with calcium carbonate. 

  • Pigments include Chlorophylls -a and -d and the red pigment phycoerytherin
  • They store energy as starch
  • Cell walls are composed of cellulose or pectin, many strains can produce calcium carbonate structures similar to corals 



Porphyridium cruentum

About the Algae: The microalga Porphyridium sp. (Rhodophyta) is a potential source for several products like fatty acids, lipids, cell-wall polysaccharides and pigments. The polysaccharides of this species are sulphated and their structure gives rise to some unique properties that could lead to a broad range of industrial and pharmaceutical applications. This is one of the ONLY red microalgae strains. It is used by researchers to study the red protein based pigment phycoerytherin. Often used by the aquaculture community to bring RED color into filter feeders.

Porphyridium Starter Culture

Porphyridium Culture Kit 

Saltwater Media Kit


Cyanobacteria, The Blue-Green Algae

Blue-green algae make up the division Cyanophyta in the kingdom Eubacteria.  They are prokaryotic and have no membrane-bound organelles.  Cyanobacteria gets its common name from the blue-green pigment, phycocyanin, which along with chlorophyll a gives cyanobacteria a blue-green appearance. Phycocyanin is a protein that functions as the photosynthetic pigment in photosystem II, whereas in plants chlorophyll b is the pigment in photosystem II.

Cyanobacteria have a wide variety of habitats that range from frozen lakes, to acidic bogs, to deserts and volcanoes. They are most commonly found in alkaline aquatic environments (but also in aquatic environments ranging in salinity and acidity), they can also be found in soil, on rocks, and even in the atmosphere.


Anabaena variabilis


Arthrospira plantensis (Spirulina)

About the Algae: Spirulina is the common name of the cyanobacteria Arthrospira plantensis. It is commonly found all around the world making it one of the rare endemic strains of the Earth. It is also an extremophile for pH, it does very well at pH ranges up to 10.5. Spirulina is commonly used as a food or nutraceutical for humans and animals, where it is valued for its protein content and the antioxidant properties of its photopigments. It contains the pigment phycocyanin, which is a water soluble photosynthetic protein. Individual Spriulina cells form beautiful spiral morphologies called "tricomes."   

Spirulina Starter Culture 

Spirulina Culture Kit

Spirulina Harvesting Kit  

Spirulina Media Kits 


Oscillatoria tenuis 

, the Dinoflagellates

Dinoflagellates, have two flagella used for locomotion, one around their thallus like a belt, and the other at their bottom.  Most of these microscopic species live in saltwater, with few occurring in freshwater. Some species of dinoflagellates, including Pyrocystis fusiformis, emit bright flashes of light called bioluminescence when disturbed.  This is believed to 'blind' a predator, or if the predator eats the cell, the bioluminescence will light up the predator exposing it predation by a larger organism.


Amphidinium carterae




Pyrocystis fusiformis

About the Algae: Pyrocystis is a genus of dinoflagellate that possesses the remarkable ability to make its own light. Its name derives from the Latin pyro, meaning fire, and cystis, meaning a hollow sac or cavity.  Just like a firefly, P. fusiformis is bioluminescent, although for very different reasons. In fact, these dinoflagellates glow using the same mechanism as a firefly despite their evolutionary distance. Both utilize a pigment called luciferin and an enzyme called luciferase. When the luciferase enzyme oxidizes the pigment, the energy from the reaction is released in a tiny flash of light. When P. fusiformis bloom in nature, they’re bright enough to bedazzle the entire surf break with pinpricks of eerie blue-green light.  In fact, tourists flock to bioluminescent dinoflagellate hotspots, like Mosquito Bay, Puerto Rico, where you can swim and kayak in the luminous glow. It's hypothesized that the reason dinoflagellates evolved the ability to glow at all was to avoid being eaten (much to the contrary of fireflies, which flash in intricate patterns to attract a mate). In the dark ocean, it is advantageous to avoid being seen. When a zooplankton predator takes a mouthful of glowing dinos, it is likely to spit them right back out rather than risk glowing itself.  Otherwise, it might be seen by a bigger (more opaque) predator and become fish food. This is called the “burglar alarm” hypothesis and was caught on video in a study dating back to 1992. 


Haptophytes are another clade of photosynthetic unicellular algae, containing fucoxanthin and diadinoxanthin to give them a golden-brown color. They can be responsible for large, biologically harmful algal blooms- although they don't produce a toxin, large quantities of these alage can clog the gills of fish. Under normal circumstances, however, they are a great source of food for marine life. Unlike bacillariophytes, the shells of haptophytes are either unmineralized carbohydrates or calcium carbonate. The most common representative are coccolithophores which look like spheres of calcified pineapple rings. When coccolithophores die, they sink to the bottom of the ocean where their plates form carbonate oozes, contribute to sediment, and create limestone and chalk.




Isochrysis galbana

About the Algae: Isochrysis galbana is a great feeder algae. We know when it is happy and healthy because when you smell it, it smells like low tide! The high lipid and DHA content make it popular as an aquaculture feed for animals such as bivalves, crustaceans, and zooplankton. Saltwater reef aquarium hobbyists love this strain as it brings great pigmentation to the corals.

Isochrysis Starter Culture

Isochrysis Culture Kit 

Saltwater Media Kit 



Zooplankton are the primary way energy is transfered from plant to animal in aquatic environments.  The increased size of zooplankton compared to phytoplankton makes them eatable by larger organisms such as sardines. 


Brine Shrimp

Artemia is a genus of aquatic crustaceans also known as brine shrimp.  Artemia are able to avoid most types of predators, such as fish, by their ability to live in waters of very high salinity 250grams per liter. Artemia produce dormant eggs, known as cysts. The cysts may be stored indefinitely and hatched on demand to provide a convenient form of live feed for larval fish and crustaceans.



Artemia franciscana




Copepods are small aquatic crustaceans that are one of the most abundant multicellular animals on Earth. Copepods may even outnumber insects, although insects are more diverse. The word “copepod” originates from the Greek words “kope”, an oar, and “podos”, a foot. The etymology of its name refers to the flat swimming legs of the copepod (Mauchline 1998).

Copepods have long been recognized as a suitable food for marine fishes, especially for those in first-feeding larval stages. A number of copepod species also have short generation times and the ability to withstand variable conditions (Fleeger 2007). Consequently, copepods have become a favorable source of feed in aquaculture (Marcus 2007). Copepods are cultured for at-home use, as well as mass-cultured for various kinds of fish hatcheries.



Tigriopus californicus