Comparison of Organisms from the Class Oligochaeta and Class Chilopoda
Animal phylogeny is an interesting and rapidly changing field of study. To date, there are about 1.5 to 1.8 million species of animals that have been named and described by biologist with 15,000 to 20,000 new species named each year. However, millions more species are yet to be discovered and classified. Taxonomists have divided the animal kingdom into about 35 phyla (Solomon et al., 2011). Out of these, phylum Annelidia composed of about 15,000 species which is further divided into 3 main classes – the Polychaeta (marine worms), the Oligochaeta (earthworms and freshwater worms) and the Hirudinida (leeches). On the other hand, phylum Arthropoda is the largest animal phylum which is composed of millions of species with more than a million being described (Solomon et al., 2011). This phylum is further divided into five major subgroups – subphylum Myriapoida, subphylum Hexapoda, subphylum Chelicerata and subphylum Crustacea. In particular, the subphylum Myriapoida is further divided into two classes – the Chilopoda (centipedes) and the Diplopoda (millipedes). Lumbricus terrestris belongs to class Oligochaeta and is known as the common earthworm as it is commonly found in garden and agricultural soils of temperate regions. Similarly, Scutigera coleoptrata, also known as the house centipede from class Chilopoda, also prefers temperate climates and are often found in buildings, beneath stones or wood and in the soil. Although both species are classified under different phylum due to their phenotypic differences, biologists have assigned them into groups as the share certain ancestral characteristics with each another and also with other taxa. This essay will compare and contrast these organisms from the Class Oligochaeta (L. terrestris) and Class Chilopoda (S. coleoptrata). Although both species are easily distinguishable with an unaided eye, there are certain