Bell Work: Name the different types of symmetry. Which type do sponges (Phyla Porifera) have?

Phylum Chordata – the Vertebrates Chordates- Vertebrates belong to this phylum. Some Chordates are very simple compared to vertebrates. They do not even have a backbone or a well developed head!

Chordates At some point in their life, all Chordates have these four special body parts: a notochord (a semi flexible cord that runs along the length of the body) a hollow nerve cord (with nerve fibers that make contact with muscles) pharyngeal pouches (openings between pharynx and the outside of the animal) tail (an extension of the notochord and dorsal nerve cord)

Ectothermic Vs Endothermic Endotherms - are also known as warmblooded. They can maintain a constant body temperature. Ectotherms - are also known as coldblooded. They are animals that have a body temperature that fluctuates (changes) with the temperature of the environment.

Fish

Fish were the first vertebrates on Earth Fossil evidence indicates that fish appeared about 500 million years ago. Fish make up more species than all other vertebrates combined. There are more than 25,000 species of fishes.

Fish Characteristics Body Temperatures - Fish are ectothermic. External Covering - Fish are covered with scales. Cartilaginous fish (sharks belong to this group) are covered with denticles. This is the same material as teeth. They give the animal the feel of sandpaper.

Fish Characteristics Method of Breathing: Fish breath through gills. Organs that remove oxygen from the water. Gills are also used to remove carbon dioxide from the blood. Type of symmetry: Bilateral

Characteristics of Fish Type of Reproduction: Sexual, most lay eggs, some have live birth Type of Fertilization: Most fish reproduce by external fertilization. However some do reproduce by internal fertilization.

Amphibians

Characteristics of Amphibia Amphibians: Amphibian means double life. Most amphibians have two parts to their lives. Embryos must develop in a very wet environment. After they emerge from an egg they live in the water. They then develop into an animal that can live on land. Body Temperature: Amphibians are ectotherms (coldblooded) External Covering: Most have thin, smooth skin, and moist skin. Many have poison glands.

Characteristics of Amphibians Method of breathing: The young breathe through gills, as it develops into an adult it develops lungs. Some develop directly into adults and skip the aquatic stage. Some amphibians breathe through their skin.

Characteristics of Amphibians Type of Symmetry: Bilateral Type of Reproduction: Sexual, most lay eggs, eggs are laid in water. Type of Fertilization: External fertilization

Reptiles

Characteristics of Reptilia Reptiles have adapted for life on land. They developed a thick, dry skin, and an egg that could be laid on land. They were the first animals to inhabit the land. Body Temperature: Reptiles are ectotherms (cold blooded). External Covering: Thick, dry skin, covered with scales.

Characteristics of Reptiles Method of breathing: Retiles have lungs. Type of Symmetry: Bilateral symmetry Type of Reproduction: Most lay eggs. The eggs are amniotic eggs. The shell keeps the egg from drying out and protect the developing embryo. The shell is porous and allows oxygen and other gases to enter the shell. Type of Fertilization: Internal fertilization

Birds

Characteristics of Aves Birds first appeared on Earth about 150 million years ago. Birds have a high metabolism and eat a large amount of food compared to their body weight. They have a beak and cannot chew their food and swallow small stones to help grind their food in an organ called the gizzard.

Characteristics of Aves (Birds) Body Temperature: Birds are endothermic (warm blooded). External covering: Birds are covered with feathers except for their legs, feet and beaks. The legs and feet are covered with scales.

Characteristics of Birds Method of Breathing: Lungs. Birds have a very efficient system to meet their needs of oxygen for flight. They have a system of weight reducing air sacs and interconnecting tubes to allow the lungs to get more oxygen. Type of Symmetry: Bilateral

Characteristics of Birds Type of Reproduction: Birds lay amniotic egg with a shell. Type of Fertilization: Internal fertilization.

Mammals

Mammalia Mammals first appeared in the fossil record about 280 million years ago. Mammals come in a wide variety of sizes from the tiniest bat that weighs only ounces to the largest of whales with a mass of over 90,000 kg! They also live in very cold places and the hottest deserts. Mammals have mammary glands that secrete milk to feed their young. Female mammals usually give birth to live young and care for their young.

Mammals Body Temperature: Mammals are endotherms (warm blooded). External Covering: Mammals are covered with fur. Most mammals have a layer of fat under the skin that acts as insulation.

Mammals Method of Breathing: Lungs. Mammals also have a large muscle underneath the lungs to help bring air into the lungs called a diaphragm. Type of Symmetry: Bilateral

Mammals Type of Reproduction: Most mammals give birth to live young. Mothers nurse their young and are protective of their young. Type of Fertilization: Internal fertilization.

Quiz Let’s take a quick quiz over the vertebrate animals.