1. Zoology Class Introduction
4. Cnidaria and Worms
5. Mollusca and Anneliida
7. Phylum Chordata
8. Freshwater Fish
10. Lizards and Turtles
15. Zoology Careers
16. Cloned Food Animals
1. Zoology Class Introduction
All members of the Kingdom Animalia are multicellular, eukaryotic, heterotrophic organisms.
Zoology, the study of animals, has many subdivisions based on specific areas of interest.
Invertebrate zoolgy is the study of multicellular animals without backbones.
Vertebrate zoology is the study of animals with backbones.
- Entomology - study of insects
- Myrmecology - study of ants
- Apiology - study of honey bees
- Arachnology - study of spiders and their relatives
- Malacology - study of mollusks
- Conchology - study of mollusk shells
- Ichthyolgy - study of fish
- Herpeteology - study of amphibians and reptiles
- Ornithology - study of birds
- Mammalogy - study of mammals
- Cetology - study of marine mammals
- Primatology - study of primates
Morphology is the study of the shape, form, and structure of animals and their parts.
Comparative anatomy is the study of the similarity and differences in the anatomy of different groups of animals.
- Structures are homologous if they have arisen from the same ancestral structure, but perform either similar or different functions in modern animals. Examples are the wings of birds, the human arm, and the forelimb of whales.
- Analogous structures have developed from different ancestral structures, but perform similar functions. Examples are the wings of birds and the wings of insects.
Layers of cells that originate in the developing embryo and become specific structures in the animal are known as germ layers.
There are four body types defined by the presence or absence of a coelom, or body cavity. The body types below are arranged from least complex to most complex:
- Ectoderm - the outer layer which forms the body covering.
- Mesoderm - the middle layer which forms the organs inside the body.
- Endoderm - the inner layer which forms the lining inside the body cavity.
- Acoelomate, with only two germ layers, ectoderm and endoderm. (Hydra)
- Acoelomate, with three germ layers, ectoderm, mesoderm, and endoderm. (Flatworms)
- Pseudocoelomate, with a "cavity" forming between the mesoderm and the endoderm. (Roundworms)
- Coelomate, with a true body cavity forming within the mesoderm. (Segmented worms, Freshwater muscles, all Arthropods, and all Chordates)
Taxonomy is the science of naming and classifying organisms on the basis of their evolutionary relationships. Visible traits are most often used for this classification.
Although the binomial system requires that each species be assigned a unique, two-word (Latin) name, there must be a hierarchial system for arranging organisms in a logical and retrievable fashion. Such a system now recognizes at least seven taxonomic ranks (taxa) to which each organism must be assigned.
In addition to the basic seven categories above, many other taxonomic ranks exist (Subphyla, Superclasses, Subspecies, etc.).
For example, the Linnaean Classification of Humans is:
All organisms must be assigned at least the seven obligatory taxa.
Recent molecular studies have led systematists to the conclusion that all life shares a common ancestor and that there are three major evolutionary lineages. Accordingly, each of these lineages is called a Domain, which supercedes the Kingdom as the broadest taxonomic grouping. These Domains are:
- The Archaea - Procaryotic microbes that inhabit extreme, anerobic environments, such as high temperature rift valleys on the ocean floor and those with high salt or acid contents.
- The Eubacteria - True bacteria, which are procaryotic as well.
- The Eucarya - All eucaryotic organisms, that is, the protists, fungi, plants and animals. Eucaryotic organisms arose about 1.5 billion years ago, probably through the fusion of several specialized microbes into a larger, unspecialized one.
There are about 1.5 million named animal species.
You've heard of a gaggle of geese, a plague of locusts, and a school of fish. But how do you refer to a group of foxes, frogs, or owls? Find out with this page of animal group names.
- These are divided into approximately 34 phyla, based on the complexity of their body.
- All 34 phyla contain invertebrates, even the phylum Chordata.
- 94% of all animal species are invertebrates.
- 82% of all animal species are Arthropods.
- 3% of all animals are in the phylum Chordata.
- 0.03% of all animals are mammals.
This class will focus on these seven animal phyla.
Animal collections are stored in different ways. Mammals and birds are often stored as "study skins" in climate controlled rooms to reduce insect and weather damage.
Larger invertebrates, fish, amphibians, and reptiles are often stored in jars of preserving liquid.
Insects are usually pinned and stored in climate controlled rooms.
Making study skins