Difflugia is a freshwater amoeba with an external, egg-shaped shell that is composed of sand and other organic particles. The amoeba ingests the particles and imbeds them in a secreted matrix. An opening in the shell or tests allows the amoeba to extend its pseudopodia out of the shell to capture food. The shelled amoeba are among the most beautiful animals on earth.

This slide shows a variety of shelled amoeba called foraminiferans; only the shells (or tests) are present here. Foraminiferans are mostly marine and contribute to much of the ocean's floor. They are important in oil formations. Most foraminiferans are multichambered. Their close relatives, radiolarians, also produce tests.

Most common flagellate in the human digestive tract (internal parasite).

Causes sleeping sickness. Trypanosoma are the purple ribbon-like shapes around the bloodcells.

This slide shows Paramecium caudatum in conjugation. Note the two paramecia are adhered together. Conjugation is a special type of sexual reproduction in which the micronucleus is exchanged. At the end of the process, eight paramecia will result from the original two. This process might remind one of gametogenesis in higher animals.

Undergoing fission, fission is an asexual method of reproduction.

This slide shows the cessile cilliate Stentor. Around the oral surface are fused rows of cillia called membranelles. Unlike Vorticella, the macronucleus of Stentor resembles a string of beads.

Vorticella is a common freshwater cilitate whos body is somewhat vase-shaped and is attached by a long contractile stalk. Around the anterior edge of the organism are rows of fused cillia called membranelles. The edge membranelles beat in a counterclockwise direction. The deeply stained structure within the body is the macronucleus.

Picture from http://www.edu-center.pref.tokushima.jp/kyozai/

This slide shows the "ring stage" of Plasmodium - the causative agent of malaria. Plasmodium is so small that it occupies about 1/4 of a human red blood cell. There are three important kinds of human malaria, each caused by a different species of Plasmodium. In the life cycle of Plasmodium, the sexual cycle occurs in the mosquito, whereas the asexual cycle occurs in man. All members of the Phylum Apicomplexa are parasitic; Plasmodium is a blood parasite.

Ctenophores are commonly called sea gooseberries, sea walnuts, and comb jellies. All are marine. Ctenophores are closely related to the Cnidarians. One major difference is the presence of a comb-like locomotor structures arranged in rows, usually eight.

mushroom coral, only one big polyp. Single coral, not colonial.

This is a preserved sea anemone called Metridium. The class Anthozoa contains the anemones and corals. They represent the most complex forms of coelenterates. All are polyps. No medusa is present.

Two general types of corals exist: hard and soft. This is a collection of hard corals. What you see here are the skeletons of many once living coral polyps. Each polyp looks like a small sea anemone; its epidermal layer secretes the calcareous exoskeleton.

From left to right, top to bottom: Fungia (Mushroom Coral), Aeropora palmata (Moosehorn Coral), Millarina impiatia(Lace Coral), Siderastra radians (Starlet Coral), Aeropora cirvicornis, Porites (Finger Coral).

common name: white coral

organ-pipe coral

sea fan

Spicules are a major component of the skeletons of most sponges. Spicules may be either calcareous or silica. Calcium carbonate sponges have calcareous spicules; whereas glass sponges, bath sponges, and freshwater sponges have silica-type spicules.

These are dried specimens of Scypha. If you closely examine the specimens, you will see the calcium carbonate spicules. Note the basic body shape. The large opening into the body is called the osculum. It serves as an exit for water.

This bath sponge is actually dried skeletons composed of the protein material spongin. The living remains of the sponge is gone. Common names for bath sponges include: Yellow Sponge, Hardhead Sponge, Sheep's Wool Sponge and Grass Sponge.

Fresh water sponge

This specimin represents the skeletal remains of Venus Flower Basket (Euplectella). The skeleton of this glass sponge is composed of fused 6-rayed silica spicules. An interesting commensal relationship exists between Venus Flower Basket and certain species of shrimp. A young male and female shrimp enter the spongocoel; after growth, the shrimp are unable to escape through the sieve plate covering the osculum. In Japan, the sponge with its imprisoned shrimp was formerly given as a wedding present, symbolizing the idea "till death do us part".

The medusa or jellyfish is an important stage in the life cycle of many coelenteratas. Two types of medusae can be distinguished: those with a velum and those without the velum. The velum is a shelf-like membrane located around the margin of the medusa. All hydrozoa medusae have the velum, whereas all scyphozoa medusae lack the velum. The velum on the medusae of Obelia however, is much reduced and difficult to observe.

Gonionemus is a marine jellyfish where the medusa is the dominant stage. Gonionemus has a velum. Gonionemus is one of the larger hydrozoan medusae.

Physalia is actually a colony of polyps greatly specialized for performing some functions. Some of the polyps are for reproduction, some for defense, and others for food gathering. The gas filled sac is the pneumatophore. The gaseous material within the pneumatophore varies from species to species; often carbon monoxide and nitrogen are present.

This slide shows the stage in the life cycle of Aurelia known as the strobila. The strobila resembles a stack of saucers. Each disk will seperate itself from those below and will swim away as a small medusa known as an ephyrae. It should be noted that the scyphistoma becomes divided into disk forming the strobila by transverse fission.

This slide shows the stage in the life cycle of Aurelia known as ephyra. The ephyra is a small, immature medusa that came from the strobila. The ephyra will grow into the adult medusa or jellyfish. Note the 8 pairs of lappets. A club-shaped structure called a rhopalium is located between two lappets. Aurelia has 8 rhopalia. The rhopalium functions in balancing the medusa.

Aurelia belongs to the class Scyphozoa. These jellyfish can easily be distinguished from the hydrozoan jellyfish by the notches in the margin of the medusa and by the lack of a velum. Note the four C-shaped gonads. Aurelia grows to 12-15 inches in diameter.

This slide shows the polyp stage, called a scyphistoma, found in the life cycle of Aurelia. The scyphistoma is formed from the planula larva. The scyphistoma becomes divided into disks, resembling a pile of saucers; at this stage it is known as a strobila. A scyphistoma may live for several years, and it produces additional scyphistomae by external budding.

Stages of development: Planula larva, Scyphistoma, Strobila, Ephyra, Medusa (dominant)

This slide shows the planula larva of Aurelia. The planula larva is the typical larval form of members of the Phylum Cnidaria. It is a free-swimming, ciliated, non-feeding larva. In the jellyfish Aurelia, the planula becomes attached to some object and there it will develop into a polyp called the scyphistoma. Unlike most cnidarians, Hydra does not produce a planula.