Introduction

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 * Introduction **

**The phylum Ctenophora is a small phylum containing about 90 species of generally small and delicate animals known as Comb Jellies. Many species are almost transparent, as well as a few species having the ability to produce green and blue coloured light. There are between 100 and 150 species of Ctenophora.**

**Characteristics of Ctenophora:**
1)Radially or biradial Symmetrical. 2)Body multicellular, few tissues, some organs and organelles. 3)Body contains an internal cavity and a mouth and anal pores. 4)Swims by means of plates of cilia (the combs) 5)Reproduction mostly sexual as hermaphrodites, occasionally asexual. 6)Has a well developed subepidermal nerve net. 7)Has a distinct larval stage which is planktonic. 8)Lives in marine environments. 9)All are carnivorous.