Investigation of Earth’s Biodiversity

Following species are selected for this assignment:

  • Mammals:
    • Balaenoptera musculus or Blue Whales are the largest mammals on Earth. Average length of an adult male is 25 m and average females are about 27 m long. Their estimated lifespan is about 80 to 90 years. Typically, Blue Whales spend the winters near the equator and migrate towards the poles during summers (Dewey & Fox, 2002). Blue Whale belongs to the Order Cetacea. Order Cetacea includes all mammals which are adapted to aquatic life. Hence, Blue Whales belong to this order. Other species of this order include Tursiops truncates or bottlenosed dolphins and Phocoena phocoena or harbor porpoise
    • Panthera tigris or tigers are carnivorous mammals found mostly in Asia. Tigers are usually solitary animals and the main long term relationship is between the mothers and their cubs (Dacres & Lundrigan, 2007). The tiger belongs to the Order Carnivora. Members of this order descended from a late Paleocene mammal whose food habit was carnivorous. Other species of this order include Canis lupus familiaris or dog and Ailurus fulgens or Red Panda.
  • Insects:
    • Periplaneta americana or American Cockroach is found all over the world in many different habitats. The species is considered a pest and is harmful to humans as it is transmits diseases (Stetson 2001). The American Cockroach belongs to the Order Blattaria, which includes all kinds of cockroaches. Two other species of this order are Blatta orientalis or oriental cockroach and Gromphadorhina portentosa or Madagascar giant hissing cockroach.
    • Apis mellifera or honey bee live in hives made of wax secreted from their bodies. A hive has a single queen, female workers and male drone bees (Hammond, Blankenship and Francl, 2009). Honey bees belong to the Order Hymenoptera, a word which means membranous wings. Most hymenoptera help in pollination and a complete metamorphosis takes place when the young develop into adults. Other species of order include Atta sexdens or leaf cutting ants and Caliroa cerasi or pear sawfly.
  • Birds:
    • Aquilua heliaca or the imperial eagles are found in Europe and Asia. It is the second largest eagle in Europe and lives in forest in huge nests build in isolated trees. It is a carnivorous bird of prey which feeds on small mammals and reptiles (Gour, 2001). Eagles belong to the Order Falconiformes. Most diurnal birds of prey belong to this order. Other species of the order include Accipiter cooperii or Cooper’s hawk and Aegypius monachus or cinereous vulture.
    • Columba livia or common pigeon, found all over the world, are usually active during day time and feed on seeds. The pigeons along with all doves belong to order Columbiformes. Other species in this order include Chalcophaps indica or emerald dove and Claravis pretiosa or blue ground dove.
  • Echinoderms:
    • Asterias amurensis or Northern Pacific Seastar is a carnivore found in coastal areas near Japan and Australia. It has a small central disc and five arms and can reach 40-50 cms in diameter. The echinoderm is considered a pest since it feeds shellfish which forms an important part of marine food chain (NIMPIS, 2002) The Seastar belongs to the Order Forcipulatida. All starfish fall under this order. Other species of the order include Pisaster ochraceus and Pycnopodia helianthoides or sunflower stars.
    • Strongylocentrotus purpuratus or purple sea urchins are found on the pacific coastline in the low intertidal zone. The organism neither lives on its own nor in colonies but tends to group together near a food source. Its main food is algae (Worley, 2001). They belong to the order Echinoida. Sea urchins fall under this order. Other species of the order include Anthocidaris crassispina and Sterechinus neumayeri.

Common Characteristics

According to Myers (2001), all species of the animal kingdom are multi-cellular and are dependent on all other organisms, directly or indirectly, for nourishment. Besides these two characteristics which are common to all animals, the eight species selected also display other characteristics which are common to most animals. For example, each of these species “ingest food and digest it in an internal cavity (para 1)”. Also they are diploid and reproduce sexually.

Compare and Contrast

Both Blue Whale and Tigers give birth to their young and are primarily carnivore. However, blue whales are adapted to life in water while tigers are land animals. Also blue whales are migrators while tigers are territorial.

The common characteristics between cockroach and honey bee is that in both species the females produce pheromones to attract male. Also, once fertilized, both the insects lay eggs. However, despite belonging to the same class, they are vastly different. While honey bees look after their young once, the young of cockroaches do not get any parental care. Also honey bees have complete metamorphosis as they grow into adults while cockroaches do not.

Both imperial eagles and common pigeons are monogamous and form life long partnerships. Also both the birds build nest for laying eggs. But the eagles are carnivores while pigeons usually feed on seeds. Also the common pigeons are usually found near human settlements while eagles live in forests.

Both Asterias amurensis and Strongylocentrotus purpuratus are found in coastal regions. Also, in both cases fertilization is external. While Asterias amurensis is a carnivore, Strongylocentrotus purpuratus feeds on algae. Besides, while the seastar is considered a pest, the sea urchin is actually an ingredient in many sea food recipes.


Dacres, K. and B. Lundrigan. (2007). Panthera tigris (On-line), Animal Diversity Web. Web.

Dewey, T. and D. Fox. (2002). Balaenoptera musculus (On-line), Animal Diversity Web. Web.

Gour, J. (2001). Aquila heliaca (On-line), Animal Diversity Web. Web.

Hammond, G., Blankenship, M. and Francl, K. (2009). Apis mellifera (On-line), Animal Diversity Web. Web.

Myers, P. (2001). Animalia (On-line), Animal Diversity Web. Web.

NIMPIS (2002). Asterias amurensis species summary. National Introduced Marine Pest Information System (Eds: Hewitt C.L., Martin R.B., Sliwa C., McEnnulty, F.R., Murphy, N.E., Jones T. & Cooper, S.). Web.

Stetson, B. (2001). Periplaneta americana (On-line), Animal Diversity Web. Web.

Worley, A. (2001). Strongylocentrotus purpuratus (On-line), Animal Diversity Web. Web.