Adapted from “Phylum Lab” produced by the National Aquarium in Baltimore
The diversity of animal life on Earth is astounding. Each animal has a unique body plan which allows it to survive and adapt to its given surroundings. With such an abundance of species, classifying animals into different categories is necessary. At first the diversity of animals can be overwhelming, but after further research and observation, many likenesses appear. These similarities become the basis for taxonomists, the biologists who specialize in classifying animals, to organize and bring order to the animal kingdom.
Animals are classified into categories called taxa and are sorted according to their phylogeny (evolutionary history), body plan and similarity of characteristics. There are seven principle levels that organisms can be placed into: Kingdom, Phylum, Class, Order, Family, Genus, Species. All animals are in the Kingdom Animalia. As you move from species to kingdom, the animals that are grouped together share fewer and fewer characteristics at each succeeding level.
The next level after Kingdom is Phyla, which is the main focus of the lab today. Even though there are approximately thirty-five phyla within the animal kingdom, 98 percent of all animals are classified into eight of them. To get even more specific, seven of the eight phyla are invertebrates. Invertebrates comprise most of the animal kingdom, with almost 75 percent of all animals on earth being insects. They out number humans by a million to one!
From Phylum, animals are then broken down into more specific categories: class, order, family, genus, species. For example, a shark, a bird, and a human are all in the Phylum Chordata. So, what similarities do these animals have? Taxonomists would agree that all these animals have similar internal skeletons. However, these animals would not be grouped in the same Class. This process would continue until the animal is classified all the way to species type. Keep in mind that sub-phyla, do exist and even though most animals are place into these eight phyla, not only are there visible difference amongst the eight phyla, but also within each phyla. The following description of each phylum are from the “Shape of Life” guide (Sea studios Foundation, 2002).
Students will use the descriptions of the phyla (provided) to create a phylum key. By organizing characteristics into eight phyla, they will have a guide to assist them in determining which phylum is represented by preserved specimen presented to them.
Teacher’s transparency (answer key)
Preserved specimen from each of the eight phyla
1. Review the phyla descriptions provided, or use your notes/test to review the key characteristics from each phylum. 2. Each card contains a main characteristic of one of the eight main phyla. Each group/student will cut apart the cards and try to arrange them appropriately on their answer sheet. The end product is a comparison of the main characteristics of each phyla. 3. Once the answer sheet has been completed, ask your teacher to check your work. 4. When you have correctly assembled your answer sheet you may glue the characteristic cards down onto the answer sheet.
The Phylum Porifera consists only of sponges, which is unique since these animals are entirely aquatic; with 98% found only in marine environments and a small percentage found in freshwater lakes and streams. Sponges are considered the oldest and of the animal phyla. Translated from Latin, Porifera means “pore bearer.” Sponges play an important role in aquatic ecosystems, acting to filter particles out of the water especially bacteria. Sponges can be found living with coral reefs. The surface of a sponge is covered with a skin which is one cell thick. This skin is penetrated by numerous small pores and a few larger openings. These...