This ClipArt gallery offers 113 images of algae. Algae are eukaryotic organisms that lack many organs found in land plants. The most known and largest examples are seaweeds.

An illustration of the aboral side view of the Noctiluca scintillans. Noctiluca scintillans, also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate that exhibits bioluminescence. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelles, or "microsources", located throughout the cytoplasm of this single-celled protist. Nonluminescent populations within the genus Noctiluca lack these microsources.

Aboral Side View of the Noctiluca Scintillans

An illustration of the aboral side view of the Noctiluca scintillans. Noctiluca scintillans, also published…

An illustration of the lateral view of the Noctiluca scintillans. Noctiluca scintillans, also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate that exhibits bioluminescence. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelles, or "microsources", located throughout the cytoplasm of this single-celled protist. Nonluminescent populations within the genus Noctiluca lack these microsources.

Lateral View of Noctiluca Scintillans

An illustration of the lateral view of the Noctiluca scintillans. Noctiluca scintillans, also published…

An illustration of the first stage of fission in the Noctiluca scintillans. Noctiluca scintillans, also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate that exhibits bioluminescence. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelles, or "microsources", located throughout the cytoplasm of this single-celled protist. Nonluminescent populations within the genus Noctiluca lack these microsources.

Stage One in the Fission of Noctiluca Scintillans

An illustration of the first stage of fission in the Noctiluca scintillans. Noctiluca scintillans, also…

An illustration of the second stage of fission in the Noctiluca scintillans. Noctiluca scintillans, also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate that exhibits bioluminescence. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelles, or "microsources", located throughout the cytoplasm of this single-celled protist. Nonluminescent populations within the genus Noctiluca lack these microsources.

Stage Two in the Fission of Noctiluca Scintillans

An illustration of the second stage of fission in the Noctiluca scintillans. Noctiluca scintillans,…

An illustration of the young stages of Noctiluca scintillans. Noctiluca scintillans, also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate that exhibits bioluminescence. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelles, or "microsources", located throughout the cytoplasm of this single-celled protist. Nonluminescent populations within the genus Noctiluca lack these microsources.

Young Stage of Noctiluca Scintillans

An illustration of the young stages of Noctiluca scintillans. Noctiluca scintillans, also published…

An illustration of the young stages of Noctiluca scintillans. Noctiluca scintillans, also published as Noctiluca miliaris, is a free-living non-parasitic marine-dwelling species of dinoflagellate that exhibits bioluminescence. The bioluminescent characteristic of N. scintillans is produced by a luciferin-luciferase system located in thousands of spherically shaped organelles, or "microsources", located throughout the cytoplasm of this single-celled protist. Nonluminescent populations within the genus Noctiluca lack these microsources.

Young Stage of Noctiluca Scintillans

An illustration of the young stages of Noctiluca scintillans. Noctiluca scintillans, also published…

An illustration of Noticulales with buds. The Noctilucales are a peculiar order of marine dinoflagellates. They differ from most others in that the mature cell is diploid and its nucleus does not show a dinokaryotic organization. These cells are very large, from 1 to 2 millimetres in diameter, and are filled with large buoyant vacuoles. Some may contain symbiotic green algae, but there are no chloroplasts. Instead, they feed on other plankton, and there is usually a special tentacle involved in ingestion.

Noctilucales

An illustration of Noticulales with buds. The Noctilucales are a peculiar order of marine dinoflagellates.…

An illustration of Noticulales in section: an, anus; d, denticle; f, flagellum; t, tentacle. The Noctilucales are a peculiar order of marine dinoflagellates. They differ from most others in that the mature cell is diploid and its nucleus does not show a dinokaryotic organization. These cells are very large, from 1 to 2 millimetres in diameter, and are filled with large buoyant vacuoles. Some may contain symbiotic green algae, but there are no chloroplasts. Instead, they feed on other plankton, and there is usually a special tentacle involved in ingestion.

Noctilucales

An illustration of Noticulales in section: an, anus; d, denticle; f, flagellum; t, tentacle. The Noctilucales…

The Noctilucales are a peculiar order of marine dinoflagellates. They differ from most others in that the mature cell is diploid and its nucleus does not show a dinokaryotic organization. These cells are very large, from 1 to 2 millimetres in diameter, and are filled with large buoyant vacuoles. Some may contain symbiotic green algae, but there are no chloroplasts. Instead, they feed on other plankton, and there is usually a special tentacle involved in ingestion.

Noctilucales

The Noctilucales are a peculiar order of marine dinoflagellates. They differ from most others in that…

These protozoans form colonies. Pandorina colony colony seen from above.

Pandorina

These protozoans form colonies. Pandorina colony colony seen from above.

These protozoans form colonies. Pandorina cells just fused.

Pandorina

These protozoans form colonies. Pandorina cells just fused.

These protozoans form colonies. Pandorina cells completely fused.

Pandorina

These protozoans form colonies. Pandorina cells completely fused.

This illustration shows the features in the life history of Pandorina: A, a colony of plants. B, each plant of the colony dividing to form a new colony. C, the plants of a colony escaping as gametes. D, the conjugation of two gametes of unequal size. E, later stage in the conjugation. F, gametospore or resting spore. G, Large zoospore formed from the gametospore. H, a colony formed by the division of the zoospore, G.

Pandorina

This illustration shows the features in the life history of Pandorina: A, a colony of plants. B, each…

Pandorina, a one-celled, fresh water form, is a genus of green algae composed of 8, 16, or sometimes 32 cells, held together at their bases to form a globular colony surrounded by mucilage. The cells are ovoid or slightly narrowed at one end to appear keystone- or pear-shaped.

Pandorina

Pandorina, a one-celled, fresh water form, is a genus of green algae composed of 8, 16, or sometimes…

The paramecium is a one-celled ciliate in the Kingdom Protista. This one is dividing.

Paramecium

The paramecium is a one-celled ciliate in the Kingdom Protista. This one is dividing.

The paramecium is a one-celled ciliate in the Kingdom Protista. These two are separating after conjugation.

Paramecium

The paramecium is a one-celled ciliate in the Kingdom Protista. These two are separating after conjugation.

Paramecium are one-celled organisms. They are elliptical in shape and active swimmers.

Paramecium

Paramecium are one-celled organisms. They are elliptical in shape and active swimmers.

Paramecium are one-celled organisms. They are elliptical in shape and active swimmers.

Paramecium

Paramecium are one-celled organisms. They are elliptical in shape and active swimmers.

Paramecium are one-celled organisms in the Protista kingdom. They are slipper-shaped, nearly transparent and move by way of cilia. nucleus (n); vesicles (v);

Paramecium

Paramecium are one-celled organisms in the Protista kingdom. They are slipper-shaped, nearly transparent…

Paramecium are one-celled organisms in the Protista kingdom. They are slipper-shaped, nearly transparent and move by way of cilia. nucleus (n); vesicles (v);

Paramecium

Paramecium are one-celled organisms in the Protista kingdom. They are slipper-shaped, nearly transparent…

Paramecium are one-celled organisms in the Protista kingdom. They are slipper-shaped, nearly transparent and move by way of cilia.

Paramecium

Paramecium are one-celled organisms in the Protista kingdom. They are slipper-shaped, nearly transparent…

Polycystina are microscopic in size and possess a structureless sarcode-body, enclosed in a perforated shell. They are exquisitely beautiful (Nicholson, 1871)

Polycystina

Polycystina are microscopic in size and possess a structureless sarcode-body, enclosed in a perforated…

Polycystina are microscopic in size and possess a structureless sarcode-body, enclosed in a perforated shell. They are exquisitely beautiful (Nicholson, 1871)

Polycystina

Polycystina are microscopic in size and possess a structureless sarcode-body, enclosed in a perforated…

"Hydra viridis, the freshwater polyp. The animal is attached to the stem of a plant, and is represented with the base of attachment uppermost; the mouth, not actually seen in the drawing, is at the lower extremity of the body, surrounded by the circle tentacles." — Encyclopaedia Britannica Company, 1910

Freshwater Polyp

"Hydra viridis, the freshwater polyp. The animal is attached to the stem of a plant, and is represented…

Polystomella are grouped in the Bryozoan Phylum.

Polystomella

Polystomella are grouped in the Bryozoan Phylum.

Radiolarians exhibit a wide variey of shapes. They have a glassy skeleton.

Radiolaria

Radiolarians exhibit a wide variey of shapes. They have a glassy skeleton.

"Grinnellia Americana. a, structure of the leaf; b, vertical section of a conceptacle, showing the chains of spores." -Whitney, 1911

Marine Red Algae

"Grinnellia Americana. a, structure of the leaf; b, vertical section of a conceptacle, showing the chains…

Upper end of a Rockweed, Fucus vesiculosus.

Rockweed

Upper end of a Rockweed, Fucus vesiculosus.

"Part of thallus of a rockweed (Fucus platycarpus)." -Bergen, 1896

Rockweed

"Part of thallus of a rockweed (Fucus platycarpus)." -Bergen, 1896

Known as rockweed or bladder wrack, this species of seaweed is in the Fucaceae family of brown algae. "Fructifying Tip of a Frond of Rockweed (Fucus vesiculosus). a, a, air-bladders; b, b, conceptacles." -Whitney, 1911

Fructifying Tip of a Frond of Rockweed

Known as rockweed or bladder wrack, this species of seaweed is in the Fucaceae family of brown algae.…

"Transverse section of conceptacle of a rockweed (Fucus platycarpus). h, hairs; a, antheridia; o, oogonia." -Bergen, 1896

Rockweed Section

"Transverse section of conceptacle of a rockweed (Fucus platycarpus). h, hairs; a, antheridia; o, oogonia."…

33. Saw-edge wrack, 34. Bladder wrack, 35. Sugar-tangle.

Seaweeds

33. Saw-edge wrack, 34. Bladder wrack, 35. Sugar-tangle.

Sertularia are members of the Protista kingdom. It is an example of another group of the hyroid zoophytes, almost all the members of which are marine.

Sertularia

Sertularia are members of the Protista kingdom. It is an example of another group of the hyroid zoophytes,…

Sertularia are members of the Protista kingdom. It is an example of another group of the hyroid zoophytes, almost all the members of which are marine.

Sertularia

Sertularia are members of the Protista kingdom. It is an example of another group of the hyroid zoophytes,…

Sertularia are members of the Protista kingdom. This is an example of the egg-producing gonophore.

Sertularia

Sertularia are members of the Protista kingdom. This is an example of the egg-producing gonophore.

This illustration shows the sexual reproduction of Spirogyra: A, in lower portion of figure formation of the tubes between the opposite cells of the filaments is shown. Above the contents of two cells have united with two cells of another filament, forming two gametospores. B, germination of a gametospore.

Spirogyra

This illustration shows the sexual reproduction of Spirogyra: A, in lower portion of figure formation…

"One sporophyll with empty sporangia."—Finley, 1917

Sporophyll

"One sporophyll with empty sporangia."—Finley, 1917

"1. Chara vulgaris; 2. a portion of a branch with a nucule and globule; 3. the globule more magnified; 4. the spiral tubes of the latter; 5. a nucule cut open; 6. a nucule in germination." -Lindley, 1853

Common Stonewort

"1. Chara vulgaris; 2. a portion of a branch with a nucule and globule; 3. the globule more magnified;…

Tubularia are members of the Protista kingdom. The pipe-coralline (Tubularia) is an example of another group of the hyroid zoophytes, almost all the members of which are marine.

Tubularia

Tubularia are members of the Protista kingdom. The pipe-coralline (Tubularia) is an example of another…

A Vaucheria; single cell grown on into a much-branched thread; the end of some branches enlarging, and the green contents in one (a) there condensed into a spore.

Vaucheria

A Vaucheria; single cell grown on into a much-branched thread; the end of some branches enlarging, and…

A Vaucheria; spore and the mature spore escaping.

Vaucheria

A Vaucheria; spore and the mature spore escaping.

These protozoans form colonies. The large spherical colonies of Volvox globator are composed of several thousand cells around a hollow center.

Volvox

These protozoans form colonies. The large spherical colonies of Volvox globator are composed of several…

These protozoans form colonies. The large spherical colonies of Volvox globator are composed of several thousand cells around a hollow center. This is a type of reproductive cell.

Volvox

These protozoans form colonies. The large spherical colonies of Volvox globator are composed of several…

Volvox is one of the best-known chlorophytes, a division of green algae, and is the most developed in a series of genera that form spherical colonies. This mature Volvox colony is composed of numerous flagellate cells.

Volvox

Volvox is one of the best-known chlorophytes, a division of green algae, and is the most developed in…

Volvox is one of the best-known chlorophytes, a division of green algae, and is the most developed in a series of genera that form spherical colonies. A reproductive cell of Volvox globator.

Volvox

Volvox is one of the best-known chlorophytes, a division of green algae, and is the most developed in…

Under certain circumstances some cells may store up food matters beome eggs, while others, known as sperm-cells, develop a flagellum. These reproductive cells separating from the colony they swim actively uniting with an egg. This union of two individuals in Vorticella results inthe power of division. The cells produced remain together, form a spere, and finally develop a Volvox colony.

Volvox

Under certain circumstances some cells may store up food matters beome eggs, while others, known as…

A reproductive cell of Volvox globator.

Volvox

A reproductive cell of Volvox globator.

Vorticella is a protozoan. Except for when young, it is usually found attached to dead leaves or sticks throughout its life. This shows free-swimming individuals conjugating with a large, stalked individual.

Vorticella

Vorticella is a protozoan. Except for when young, it is usually found attached to dead leaves or sticks…

The vorticella is an interesting protozoan. It is found on submerged stems and leaves in stagnant water, sometimes appearing like a delicate white fringe.

Vorticella

The vorticella is an interesting protozoan. It is found on submerged stems and leaves in stagnant water,…

Vorticella are members of the Protista kingdom. They are often found in stagnant pools, attached to the stems of aquatic plants.

Vorticella

Vorticella are members of the Protista kingdom. They are often found in stagnant pools, attached to…

Vorticella are members of the Protista kingdom. They are often found in stagnant pools, attached to the stems of aquatic plants.

Vorticella

Vorticella are members of the Protista kingdom. They are often found in stagnant pools, attached to…

Vorticella are members of the Protista kingdom. They are often found in stagnant pools, attached to the stems of aquatic plants.

Vorticella

Vorticella are members of the Protista kingdom. They are often found in stagnant pools, attached to…

This illustration shows two common forms of the Zygnematales: A, Spirogyra- n, nucleus; p, pyrenoid. B, Zygnema.

Zygnematales

This illustration shows two common forms of the Zygnematales: A, Spirogyra- n, nucleus; p, pyrenoid.…