The representatives of the phylum Annelida are known as segmented worms or ringed worms. Annelida is derived from Latin word ‘anellus’ meaning little ring. It is a large phylum with over 22,000 living species. Among them, Polychaetes constitute about 12,000 species while Clitellates contains about 10,000 species. The major groups include earthworms, ragworms and leeches. … Read more
Leuckart (1847) first coined the name Cnidaria. The term ‘Cnidaria’ is derived from two words; Gr. Knide=nettle and L. aria=like or connected with. Cnideraia are also known as Coelenterata. They have diverse colorful, radially symmetrical bodies which are known as the flower of the sea. The phylum Cnidaria contains more than 10,000 living species, among … Read more
Scottish Anatomist and Zoologist Robert Edmond Grant proposed the name Porifera (L. Porus, pore and ferre, to bear). The representatives of Phylum Porifera are also known as Sponges. They are simple types of aquatic invertebrates. This phylum contains about 10000 species; among them, most of the species are Marine and some are freshwater (about 100 species). … Read more
There are approximately 8.7 million species on earth and their variety is simply astonishing. Besides, no two individuals of any animal-form are exactly alike. Hence, there must be some arrangement to group them in orderly categories to study the animal world. The diversity or differences also signify that organisms are really not so different from … Read more