Biology Week 16 - Day 2

Invertebrates:
animals with no vertebral column.

How does an animal with a hard exoskeleton grow larger?

There are about 10 invertabrate phyla containing more than 95% of all animal species. Invertebrates have a wide range of characteristics, the lack of a backbone being the major common trait.

Some invertebrate phyla:

Porifera
Sponges are aquatic animals that represent a transition from unicellular to multicellular life. Of the 10,000 species of sponges, only about 150 species live in fresh water. Adult sponges are sessile, meaning that they attach themselves to a surface and do not move. Because they are sessile, sponges are filter feeders, screening food out of the water that flows through their body.

Cnidaria

Freshwater hydra, jellyfish, and corals go through a transition in body forms. The medusa stage (bell-shaped) is specialized for swimming and the polyp stage (vase-shaped) is specialized for a sessile life. All members of the phylum have these two stages at one time in their life, even though the medusa stage may be found only as an embryo. All cnidarians have tentacles containing cnidocysts and nematocysts, specialized stinging cells for defense and capturing food.

Nematoda

Roundworms have a long, slender body that tapers at both ends. They range in length from 1 millimeter to 4 feet in length. This phylum is the first to have a digestive tract with two openings, which is a major advancement over the phyla up to this point. The vast majority of these animals are free-living, but there are about 150 species that are plant and animal parasites. It has been said that if all things except roundworms were erased from the earth, one could recognize where plants, animals, and even cities were by looking at the roundworms.

Mollusca

Snails, clams, and octopi are the first animals with a true coelom, a hollow, fluid-filled cavity completely surrounded by the mesoderm. The phylum is divided into three diverse classes.
• Gastropoda: most members of this class have a one-piece, external shell. Gastropods include snails and slugs.
• Bivalvia: members have an external shell divided into two halves that are connected by a hinge. Bivalves include clams, oysters, and scallops.
• Cephalopoda:these marine mollusks are the most advanced group in the phylum. Their nervous and circulatory systems are highly advanced and they have an internal shell supporting the body. Octopus and squids are cephalopods, including the giant squid - the world's largest known invertebrate.

Annelida

Segmented worms are more advanced than roundworms and have several visible characteristics that distinguish them. They are named for the many body segments that make an annelid look like it is composed of a series of "rings". Unlike roundworms, the segmented worms have an obvious head and tail. All segmented worms have one of two types of structures extending from their bodies that are used for locomotion. Most annelids have hair-like bristles known as setae and some have fleshy protrusions called parapodia.

The body extensions are used to divide annelids into three classes:

• Oligochaeta: members of this class have few setae on each segment. The earthworm belongs to this class and has two pair of setae on each segment.
• Polychaeta: two-thirds of all annelids are polychaetes. These marine animals have many setae projecting from parapodia. Polychaetes also differ from other annelids in that they have antennae and specialized mouth parts.
• Hirudinea: the smallest class of annelids contains the leeches, which have no setae or parapodia. Most leeches live in calm, fresh water and some live in moist vegetation on land, but none live in salt water. Many leeches are carnivores that feed on small invertebrates, but some species are parasites that suck blood from other animals.

Arthropoda

Three-fourths of all animal species, including spiders, crayfish, and insects, are arthropods. This phylum is composed of a very diverse group of animals that are bilaterally symmetrical. The following characteristics have allowed arthropods to adapt to almost every environment on Earth:
• Jointed appendages: the phylum name means "jointed foot". All the appendages (body extensions) of arthropods are jointed, giving them a wide range of controlled motions.
• Exoskeleton: the exoskeleton provides support and protection. It is composed of three layers that are secreted by the epidermis.
• Segmented body: the segments in the arthropod body make movement possible, even with the hard exoskeleton.

Echinodermata

Starfish, sand dollars, and sea urchins are found in marine environments ranging in depth from shallow tide pools to 10,000 meters. Most of the 7,000 species of echinoderms have a type of radial symmetry called pentaradial symmerty, in which the body parts extend from the center along five spokes.

In addition to their radial symmetry, echinoderms have three other major characteristics that are not shared by any other invertebrate phylum:

• They have an endoskeleton composed of calcium carbonate plates known as ossicles. These may be attached to spines that protrude through the skin. The phylum name echinoderm means "spiny skin".
• They have a water-vascular system - a network of water-filled canals inside their body.
• They have many small, movable extensions of the water-vascular system called tube feet, which aid in movement, feeding, respiration, and excretion.

Day 2 Assignment - Intro to Animals (Test Your Concept Understanding) Right click on this(Invertebrates) and "save target as" to you desktop. After video has downloaded watch video and complete the questions below. What are Invertebrates? What is special about the tentacles on a jelly fish, how do they work? Describe how the larvae of the jellyfish develop into the adult form? How large can a Giant Squid become? To what class of marine mollusks do Giant Squids belong? What does the name mean? What helps the Giant Squid devour its prey? Which taxonomic class do the spiders belong too? How do the body parts differ between spiders and insects? Do spiders have antennae? Do all spiders develop silk? True or false: All spiders kill or paralyze their prey with fangs and poison? Without spiders what environmental problems would we face? What color blood and how many hearts does an Octopus have? What taxonomic class are the octopi placed in? The skin on each octopi sucker contains 3 types of cell that feel _________ and _________ but most detect ________ acting like taste buds. True or False: Octopi are capable of complex behaviors. Do you think octopi are intelligent? Explain your answer. When you use a bath sponge, what part of the animal's body are you using? What is the only Arizona representative of the Phylum Cnidaria? Describe two problems caused by parasitic roundworms. What native Arizona animals are in the Phylum Mollusca? In which of the phyla are leeches placed? How can a leech be safely removed from skin? Explain how this leech is used: Hirudo medicinalis ? Many invertebrates have an open circulatory system. What is an open circulatory system? What are the major differences between the phyla Nematoda and Annelida? What does the name "Arthropoda" mean? Search and find an illustration or picture of a representative animal from each of the phyla listed above. Cut and paste the picture along with the common and scientific name onto your assignment (use pictures from outside of our site). You may also draw your pictures. Only complete the following questions if you are instructed to do so. Current Event Biology questions: Use your prior knowledge and research skill to answer the following questions. "SARS" what does this stand for? What is thought to cause this illness? What are the symptoms of this illness? How does it spread? Is there an incubation period? How many people has it infected world wide so far. Any cases found in the U.S.? How many deaths so far? What if any treatments or cures have been found so far?

Day 3-4 Computer Assignment - Intro to animals
This assignment must be completed by the beginning of class on the next class after tomorrow to receive credit.
PowerPoint Scoring Rubric Word doc. rubric

PowerPoint is a "presentation graphics" program. It is used to visually provide information to a group of people - not just one person sitting in front of a computer. Color combinations and font size must make the slides easily read from a distance.

1. All living arthropods are placed in one of the three subphyla. Choose one particular arthropod and make a PowerPoint presentation including the following:
   1. A title slide with a picture of your animal and its common and scientific name (include student name, date, class period and assignment number).
   2. A slide describing the physical characteristics of your animal.
   3. A slide describing the behaviors of your animal.
   4. A slide describing the environment where your animal usually lives.
   5. A slide describing the interactions of your animal with humans.
   6. A final work cited slide (cite correctly).
   7. Include one other picture of your animal on a slide other then the first one.

• Make sure to put information in your own words and summarize (pictures always help).
• Always save the file in two places.
• Print a copy of your power point in the handout form (six slides to one page) and turn in.

Research Links:

• Search - Invert. circulatory system
• Search - open/closed circulatory system
• Search - The Animal Diversity Web
• Search - BIODIDAC, digital biology resources
• Sponges - Glasgow University
• About Octopi - Mote Marine Laboratory
• Invertebrate Anatomy & Dissection Guides - Lander University
• Marine Reef Organisms - Gray's Reef National Marine Sanctuary
• The World of Parasites - By J. M. Smith
• Parasitism and Symbiosis - By J. M. Smith
• Tapeworms & Parasites - Ohio State Univeristy
• Pheromones - Lund University, Sweden
• Snails - Frescargot Farms
• Insect Orders - California Academy of Sciences
• Other Invertebrate Links - Desert Vista High School

Animals with a hard exoskeleton must shed the exoskeleton through a process of "molting" before they can grow in size.

While there may be more than one way to describe animal success, insects are the most numerous and diverse animals on earth today.