ZOOLOGY—STUDY OF ANIMALS Life began over 600 million years ago The evolution of animals includes the appearance of: multicellularity coelom notocord vertebrae homeothermy

An Introduction to Animals Characteristics of Kingdom Animalia

Characteristics of Animals Multicellular with specialized cells: the bodies of animals contain more than one cell. The cells are specialized. These cells do not lead independent lives, but have specialized structures and functions

Characteristics of Animals Multicellular with specialized cells Eukaryotes: cells contain membrane-enclosed nuclei (except mature human red blood cells) and have membrane-enclosed organelles.

Characteristics of Animals Multicellular with specialized cells Eukaryotes Heterotrophs: Not capable of manufacturing their own food and must rely on external food sources

Characteristics of Animals Multicellular with specialized cells Eukaryotes Heterotrophs Cells lack cell walls and photosynthetic organelles: Have no rigid structure surrounding the cell membrane and no chloroplasts to convert CO2 and water into carbohydrates.

Characteristics of Animals Multicellular Eukaryotes Heterotrophs Cells lack cell walls and photosynthetic organelles And most can 5. Reproduce sexually: Have male and female gonads that produce gametes which fuse to produce offspring. Some species have separate sexes, some do not.

Characteristics of Animals Multicellular Eukaryotes Heterotrophs Cells lack cell walls and photosynthetic organelles And most can 5. Reproduce sexually 6. Move: Some species have the ability to move their entire body; some have only cells with motile structures (cilia and flagella). Some species are motile (move) in the larval stage and sessile (do not move) in the adult stage.

What kingdom characteristics separates animals from plants?

What kingdom characteristics separates animals from plants? Members of the plant kingdom are autotrophic while all animals are heterotrophic. Members of the plant kingdom have cell walls and photosynthetic organelles  

Extremes in the animal world This species is called a 'fangtooth' and it is one of the deepest-dwelling fish in the sea.

Extremes in the animal world

The Goliath beetle Invertebrate

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry - the way body parts are arranged around a point or central axis.

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry Directions on the body - used to describe areas on the body of an animal.

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry Directions on the body Body cavities – fluid-filled space that forms between the digestive tract and the outer wall of the body.

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry Directions on the body Body cavities Formation of germ layers - layers of specialized cells in the early development.

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry Directions on the body Body cavities Formation of germ layers Pattern of body development - a sequence of developmental steps.

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry Directions on the body Body cavities Formation of germ layers Pattern of body development Body structure and relatedness – using similarities in body plans and patterns of development to classify and determine the evolutionary history of animals

When studying and describing animals, some basic body characteristics are important. These include: Body symmetry Directions on the body Body cavities Formation of germ layers Pattern of body development Body structure and relatedness These are all important parts of Animal Body Plans!

Animal Body Plans Animals are made up of a complex system of cells. Cells make up different tissues of animal’s bodies. Tissues make up different organs in animal’s bodies. And organs make up different organ systems.

Types of symmetry: Spherical-sphere-shaped, the body can be divided into two identical parts by any plane passing through the center.

Types of symmetry: Radial-the body can be divided into two identical halves by any plane that passes through the longitudinal axis.

Types of symmetry: Bilateral-the body can be divided into two identical halves by only one specific plane passing through the longitudinal axis.

Types of symmetry: Asymmetry-the body has no definite shape and cannot be divided into two identical halves.

Anatomical Orientation When studying the anatomy of animals, it is necessary to use terminology to describe directions, planes, and points of reference. Anterior/Posterior: A direction on an animals body referring to towards the head and/or tail. Dorsal/Ventral: A direction on an animals body referring to towards the spine and/or belly. Medial/Lateral: A direction referring to towards or away from the midline or mid-sagittal plane of the body. Distal/Proximal: A direction referring to farther away from and closer to another point of reference.

Anatomical Orientation

Anatomical Orientation Sagittal plane: An imaginary line or axis that goes through the body separating left and right halves. Frontal plane: An imaginary line or axis that goes through the body separating dorsal and ventral halves or sections. Transverse plane: An imaginary line or axis that goes through the body separating anterior and posterior halves or sections. Oral/Aboral: Animals with radial symmetry, oral refers to the mouth side, aboral is opposite of oral.

Anatomical Orientation

Body Planes Ways in which the body of a bilaterally symmetrical animal can be divided: Sagittal Plane – divides the body into left and right halves Frontal Plane – divides the body into dorsal and ventral halves Transverse Plane – divides the body into anterior and posterior halves

The three planes are perpendicular to each other

Cephalization: the concentration of sensory and brain structures in the anterior end of the animal.

Cephalization Nervous tissue, composed of nerve cells called neurons, is found only in animals. Along with muscle tissue, nervous tissue allows animals to sense and respond their environment. By concentrating these sense receptors at the "head" of an animal, the animal is able to respond to its environment more quickly.

Cephalization Animals can be: Highly cephalized Slightly cephalized Not cepahlized

Segmentation Metamerism: a serial (in a series) repetition (repeating) of similar body segments along the longitudinal axis of the body.

Sexual Reproduction: involves the joining of sperm and egg cells.

Insects are invertebrates

Insects are invertebrates END OF SECTION

Pattern of body development:

Pattern of body development: Zygote- the fertilized egg.

Pattern of body development: Zygote- the fertilized egg. Embryo - As the fertilized egg begins to divide, the cells in the resulting mass are identical. At some point (about 32 cells), this packed mass of cells quickly spreads into a hollow sphere of cells. This point is called blastulation and is the beginning of cell divergence.

Embryo Blastula-a hollow sphere of cells. Blastopore - the point where folding begins. Gastrula-as the blastula enlarges,it cups inward on one side.

Vertebrate embryos look very much alike in their early development.

Fetus - the embryo developed to the point that it begins to resemble the mature organism.

Germ layers: Specialization of body tissues is common in animals. During gastrulation, two or three "germ layers" form. These layers of cells become specific structures and organs in the animal.

Germ layers: Ectoderm - cells on the outside of the gastrula that become the body covering. Mesoderm - a middle layer of cells that forms the muscles and interior organs. Endoderm - cells on the inside of the gastrula that become the lining of the gut.

Embryonic Development: The development of an organism involves an increase in mass and structure. Both these changes come from an increase in cell number (due to mitosis), enlargement of cells and specialization of cells.

All division starts from a single, fertilized egg cell, the zygote.

Early Embryonic Development After fertilization of an egg occurs, the egg becomes a zygote. Then, a zygote’s cells begin dividing in a process called cleavage. Some animals (like echinoderms and chordates) exhibit radial cleavage, in which the cleavage planes are symmetrical. Other animals (like molluscs and annelids) exhibit spiral cleavage, in which the cells divide in a spiral or asymmetrical pattern.

Radial vs. Spiral Cleavage

Body Plan Development Cleavage continues to occur in the zygote until the dividing cells begin to form a fluid-filled ball of cells which is called a blastula. Inside the blastula is a fluid-filled cavity called a blastocoel. In most animals, the blastula develops into a two-layered organism called a gastrula. The gastrula is made up of two layers called the endoderm and ectoderm. Later on these will form the outer and inner tissues and organs of the body.

Early Embryonic Development in Animals

Body Cavities The gastrocoel (cavity inside the gastrula) develops into a digestive cavity in most adult animals. Some animals such as the sea anemone never advance beyond the gastrula stage. In the sea anemone, the opening or blastopore becomes the opening to the gastrovascular cavity. In most animals a third germ layer develops after the gastrula stage called the mesoderm.

Body Cavities In some animals, the mesoderm lies along the outer edge of the ectoderm, but not along the endoderm. These types of organisms are referred to as pseudocoelomate, meaning “false coelom”. In other animals, mesoderm completely fills the internal body cavity. This type of body cavity is without a coelom. These organisms are referred to as acoelomate.

Body Cavities

Body Cavities And lastly the body cavity of most animals are eucoelomate or “true coelomate”. Usually the cavity is just referred to as simply a coelomate body cavity. In this body plan, the mesoderm completely lines the endoderm and ectoderm. A true coelom or body cavity allows much more flexibility and space for internal organs. Larger and more complex organisms have a coelomate body cavity.

Body Cavities

Development of animals and their body cavities In coelomate animals if the coelom forms from mesoderm spreading out in the blastopore region, this pattern of coelom development is called schizocoelous development. In coelomate animals if the coelom forms from pouches that pinch off from a region of the endoderm and enlarge to form the coelom, this pattern of coelom development is called enterocoelous development.

Animal Development

Animal Development Another main difference in the way animals develop is the development of the blastopore, or the opening that forms the mouth or anus. In protostomes, which means “mouth first”, the blastopore develops into the mouth. (found in annelids, mulluscs, and arthropods). In deuterostomes, which means “mouth second”, the blastopore develops into the anus. (found in echinoderms and chordates).

Protostomes vs. Deuterostomes

The Development of Tissues Eventually the germ layers (ectoderm, endoderm, and mesoderm) begin to specialize to form tissues. All of the body tissues of animals are comprised of one of the four basic tissue types. Epithelial tissue Connective tissue Muscular tissue Nervous tissue

Body Tissues

Vertebrate or Invertebrate?

Vertebrate or Invertebrate?

Vertebrate or Invertebrate?

Rattlesnakes Crotalus viridis

Freaky Calves

Couch's Spadefoot Toad, Crazy Eyes Cricket Killer Couch's Spadefoot Toad, Crazy Eyes Cricket Killer. One vertical pupil and one horizontal pupil. He is blind in the horizontal one.

When the Woodchuck's incisors don't meet, and cannot be properly worn down, they continue to grow and often kill the animal by piercing it's skull or by preventing it from eating.

These are pictures of a common parakeet which has a genetic mutation called "feather duster."

 A renegade New Zealand sheep that evaded shearers for six years has finally been caught.

Brown Recluse Spider Bite Pictures                                                                       Day 3                                                                          Day 4                                                                                            Day 5                                                                          Day 6                                                   Day 9                                                                                         

                                                                        The first day of the bite.                                        Day 3. Skin begins to die.                                                                        Day 9                                                                                                Day 11                                                                          March, 2003.

http://madbeats.com/spider/healing/

The liger hybrid is more common than the tigon because the mating process is easier. The liger has both stripes and spots. The stripes are inherited from its tiger parent and the spots from the lion parent

                                                                                         These pictures were taken in 2004 by Terri Jenkins, an officer of the U.S. Fish and Wildlife service over the Harris Neck National Wildlife Refuge about 40 miles South of Savannah, Georgia. According to a news release, she was aboard a helicopter that was igniting prescribed fires in the refuge when the 12 to 13-foot alligator was spotted swimming with the full-grown deer in its mouth.

Bull Terrier vs. Porcupine

Tiger vs. Python