The biological process through which an individual organism is produced from its parents is termed as reproduction. Animals can reproduce both sexually and asexually with sexual reproduction being more common. Parthenogenesis and ZW sex-determination system are some common asexual techniques observed in animal phyla. Sexual reproduction involves the production of haploid gametes. Smaller, motile gametes are called spermatozoa. While the larger non-motile gametes are called ova. These gametes fuse to form zygote which then develops into a new organism. This book includes some of the vital pieces of work being conducted across the world, on various topics related to animal reproduction. The various studies that are constantly contributing towards advancing technologies and evolution of this field are examined in detail. This book is a vital tool for all researching or studying animal reproduction as it gives incredible insights into emerging trends and concepts.