Leishmania donovani

This is a protist that can cause serious disease and is in a genus often transmitted by sandflies. This protist feeds

by absorbing food across its membrane.

Trichomonas vaginalis

This is a protist that can cause sexually-transmitted disease and is in a genus often transmitted by sandflies. This protist

feeds by absorbing food across its membrane.

Amoeba proteus

This protist is surrounding a small food particle with its pseudopods in order to ingest it.

Actinosphaerium eichornii

What look like “spikes” on this protist are actually pseudopods, which the protist uses to trap smaller protists

to feed on them.

Plasmodium falciparum

This protist is one of the main causes of Malaria. This protist cannot produce its own food and it also doesn’t

move on its own. Therefore, it is a parasite which lives off its host.

Monocystis agilis

This protist cannot produce its own food or move on its own. Therefore, it is a parasite which lives off its host.

This protist is often found in earthworms.

Paramecium aurelia

This protist is found in many freshwater environments. Notice how its cilia are organized into evenly-spaced rows and bundles. These beat in a regular pattern to allow the

Paramecium to feed and move.

Stentor oken

This protist is common in freshwater lakes and streams. Notice the row of cilia organized around the end and along the sides. The Stentor beat these cilia and create a vortex-

like movement, drawing in single-celled bacteria to feed on. They also use their cilia to swim.

Euglena acus

These freshwater single-celled organisms can either obtain energy from sunlight, via photosynthesis, or by

absorbing chemicals from their surroundings. A sensory organ, known as the eye spot (red in the picture) is able to

perceive the intensity of light.

Dinobryonsertularia

This colony of unicellular protists.are known for their gold-colored chloroplasts

which they use to carry out

photosynthesis.

Bacillariophyta

These protists are single-celled photosynthetic organisms. Their cell walls are composed of two interlocking silica

halves. They cause algal blooms. When they die, they sink to the ocean floor, becoming part of the sediment. The preserved remains provide a valuable record of past

oceanic environments.

Bacillariophyta

These protists are single-celled

photosynthetic organisms that are an important part of the aquatic food chain. Their cell walls are composed of two interlocking silica

halves.

Karenia brevis

Although it is difficult to see in this photo, this protist actually moves with a spinning motion produced by its two

flagella. It creates huge algal blooms. This is very common in the gulf of Mexico and is responsible for “red

tides” and die-offs of marine life and coastal birds.

Ceratium hirundinella

This unicellular protist has a thick cell wall and two flagella, which it uses to move. It also contains chloroplasts which

it uses to carry out photosynthesis.

Porphyra nereocystis

This multicellular protist is often mistaken for a plant because it obtains nutrients through photosynthesis. It

can live up to 260 meters deep in the ocean because its reddish pigments are so efficient at gathering light.

Sargassum

This multicellular protist is a common sight on beaches and in coastal waters. The brown accessory pigment

called fucoxanthin that the protist uses to carry out photosynthesis gives it its brown coloring. Sargassum is

used for food.

Fucus vesiculosus

This multicellular protist is a more common along the rocky shores on the east coast of the United States. The brown accessory pigment called fucoxanthin that the protist uses to carry out photosynthesis gives it its brown coloring. It is

used for food and as a homeopathic remedy.

Volvox

This species of protists lives in multicellular colonies. The colonies can contain as many as 50,000 cells arranged in

hollow spheres.

Spirogyra

This species of protists lives in multicellular colonies. These filiments contain the same pigments found in plants and are surrounded by a cell wall – just like in plants. This protist is

very commonly found in freshwater environments.

Physarum polycephalum

This species of protist plays a key role in recycling organic material since it is a decomposer. It is shown here growing on

the forest floor.

Saprolegnia parasitica

This type of protist is usually found on or near the water, growing on dead or decaying material. Notice the spores

contained within the oogonium shown on the right, which the fungus uses for sexual reproduction.