Animal Taxonomy and Systematics

Study Notes

Is the branch of zoology that focuses on identifying, describing, naming, and classifying animals.
Includes understanding the relationships between different animal types.
Origins of the term "systematics" come from the Latinized Greek word "systema," meaning "to put together."
Linnaeus used the term "systematics" in the 4th edition of his book "Systema Naturae" in 1735.
Simpson (1961) defined systematics as the scientific study of the diversity of organisms and their relationships.

Aristotle (384-322 BCE) was an early zoologist and attempted to classify animals.
His classification was based on observable characteristics like blood presence and birth method.
He categorized animals into aquatic, terrestrial, and aerial groups.

Carl Linnaeus (1705-1778) developed the classification system commonly used today.
His system employs binomial nomenclature (Genus species).
Genus categorizes animals sharing many similar characteristics.
Species categorizes animals with similar characteristics capable of interbreeding.

The classification system is hierarchical, starting with the most inclusive kingdom and progressing to less inclusive categories down to species..
The hierarchy includes Kingdom, Phylum, Class, Order, Family, Genus, and Species (sub categories are also employed)
Using Latin is essential in the naming of animal species.

Protozoa are single-celled organisms.
They are classified into Subkingdom Protozoa, with four subphyla based on locomotion: Mastigophora (flagella), Sarcodina (pseudopodia), Ciliophora (cilia), and Sporozoa (no locomotion).
Protozoa can be unicellular or acellular, with a single protoplasmic mass.

Size: Typically microscopic, ranging from 2-3 µm to 16 mm. Some are visible to the naked eye.
Structure: Single nucleus (often with endosomes), distinctive ectoplasm, and endoplasm.
Water Balance (osmoregulation): Contractile vacuoles remove excess water (common among water-dwelling protozoa).
Habitat: Solitary or colonial, some are free-living, and others are parasitic.
Reproduction is both asexual (binary fission, multiple fission, and budding) or sexual (fusion of gametes)
Some Protozoa are harmful and cause diseases (e.g., Trypanosoma) while others are helpful as they can eat harmful bacteria (e.g., Paramecium) and serve as food for other animals.
Digestion occurs intracellularly within food vacuoles.
Respiration takes place by diffusion through the body surface. Some can respire without oxygen, and others die exposed to oxygen.
Excretion occurs by the diffusion of waste products across the body surface.
Some protozoans are harmful to humans, causing diseases like Trypanosomiasis.
Others are helpful because they eat harmful bacteria.
Protozoans reproduce asexually through binary fission, multiple fission and budding.
They can also reproduce sexually through gamete fusion.

Amoeba belongs to the Subkingdom Protozoa, Phylum Protozoa, Subphylum Sarcodina, and Class Amoebozoa .
Characterized by locomotion using pseudopodia.
Amoeba exhibits different forms based on the locomotion.

Entamoeba includes the species such as Entamoeba histolytica (pathogenic) and Entamoeba coli (non-pathogenic)
The parasitic Entamoeba histolytica and the non-pathogenic Entamoeba coli are part of the Class Zoomastigophora.
Transmission through ingestion of food or water contaminated with fecal matter.
Prevention through improved hygiene is vital.