B.N. Pandey, Ph.D., is a Professor and Head of the Department of Zoology at Purnea University, Purnia, Bihar. During his Ph.D., Dr. Pandey worked in collaboration with Professor L.I. Kurochkin, Institute of Cytology and Genetics, Novosibirsk, Moscow (USSR). Also, he has worked on “Population Health” in collaboration with Professor Susan Dawson of Utah State University, USA. With his extensive teaching and research experience, Dr. Pandey has published 111 research papers in national and international journals of repute, and has organised several national seminars and symposia including the reputed All India Zoological Congress. Under his learned supervision, eighteen research scholars have successfully completed Ph.D. He has been awarded a Certificate of Merit for Excellence in Teaching by the Vice Chancellor, B.N. Mandal University, Madhepura, Bihar. Teacher of Outstanding Merit by the Ministry of Youth Affairs, Govt. of India; and a Gold Medal by the Zoological Society of India for his contribution to research. He is a member of Editorial Board/Advisory Board and Reviewer of many national and international journals. Major research projects sanctioned by the Ministry of Environment and Forests and Indian Council of Medical Research have benefited from his knowledge and contributions. He is also a fellow of the Zoological Society of India and the Society of Environmental Sciences. He has edited two books and has authored B.Sc. Zoology Series (Vols. I–V), published by Tata McGraw Hill, New Delhi and Biology of Chordates, published by the Prentice Hall of India, New Delhi. His areas of research interest include Aquatic Biology, Population Genetics, and Population Health. Dr. Sanjeeva Kumar is working as the Principal, Purnea College, Purnia (Bihar). Dr. Kumar got first position in first class in M.Sc. (Zoology). Despite of his busy schedule, he has a keen interest in teaching and research. Two students have successfully completed their Ph.D. dissertation work under his supervision. He has also published a considerable number of research papers in the journals of national and international repute. He has participated in different seminars/symposia and has presented research papers. His areas of research interest include Environmental Biology and Fish Biology.