DEEP–SEA EELS (TELEOSTEI: ANGUILLIFORMES) OF THE INDIAN EEZ: SYSTEMATICS, DISTRIBUTION AND BIOLOGY Thesis submitted to COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY in partial fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY in MARINE BIOLOGY Under the FACULTY OF MARINE SCIENCES SUMOD K. S. Centre for Marine Living Resources & Ecology Ministry of Earth Sciences Kochi- 682037 DECEMBER 2018 Deep–sea Eels (Teleostei: Anguilliformes) of the Indian EEZ: Systematics, Distribution and Biology Ph. D. Thesis in Marine Biology Author Sumod K. S. Centre for Marine Living Resources & Ecology Ministry of Earth Sciences, Government of India Block C, 6th Floor, Kendriya Bhavan, Kakkanad Kochi682037, Kerala, India Email: [email protected] Supervising Guide Dr. V. N. Sanjeevan Former Director Centre for Marine Living Resources & Ecology Ministry of Earth Sciences, Government of India Block C, 6th Floor, Kendriya Bhavan, Kakkanad Kochi682037, Kerala, India Email: [email protected] December 2018 This is to certify that the thesis entitled “Deep–sea Eels (Teleostei: Anguilliformes) of the Indian EEZ: Systematics, Distribution and Biology” is an authentic record of the research work carried out by Mr. Sumod K. S. (Reg. No.: 4326), under my scientific supervision and guidance at the Centre for Marine Living Resources & Ecology (CMLRE), Kochi, in partial fulfilment of the requirements for award of the degree of Doctor of Philosophy of the Cochin University of Science & Technology and that no part thereof has been presented before for the award of any other degree, diploma or associateship in any University. Further certified that all relevant corrections and modifications suggested during the pre- synopsis seminar and recommended by the Doctoral Committee have been incorporated in the thesis. Dr. V. N. Sanjeevan Former Director Centre for Marine Living Resources & Ecology Ministry of Earth Sciences Kochi Kendriya Bhavan, Kakkanad December 2018 Kochi 682037, Kerala, India I hereby declare that the thesis entitled “Deep–sea Eels (Teleostei: Anguilliformes) of the Indian EEZ: Systematics, Distribution and Biology” is an authentic record of research work conducted by me under the supervision of Dr. V. N. Sanjeevan, Former Director, Centre for Marine Living Resources & Ecology (CMLRE), Kochi and no part of it has been presented for any other degree or diploma in any University. Kochi-16 Sumod K. S. December, 2018 Dedicated to my son Akshath Krishna I would like to express my deep sense of gratitude and indebtedness to my supervising guide Dr. V. N. Sanjeevan (Former Director, CMLRE) for providing inspiration, for his timely guidance and constant support. The freedom of work accorded by him and his patient, timely, measured criticism has been invaluable to me in my research career. I also express my deepest gratitude to Dr. M. Sudhakar (Director, CMLRE) and Dr. P. Madeswaran (Former Director, CMLRE) for providing facilities and for their encouragement. This work was carried out as part of the project “Deep-Sea and Distant Water Fishery Resources of the Indian EEZ‟ under Marine Living Resources (MLR) Programme of the Ministry of Earth Sciences, Government of India, implemented by the Centre for Marine Living Resources & Ecology, Kochi. I express my gratitude to Project Coordinator Mr. N. Saravanane (Scientist E), Dr. Sherine Sonia Cubelio (Scientist D), Dr. Hashim Manjebrayakath (Scientist D), for their encouragement and support. This thesis would not have come to fruition without the support extended to me by Dr. Smitha B. R. (Scientist D). I also thank Dr. G. V. M. Gupta (Scientist F & Member-RC, Dr. A. Shivaji (Scientist E), Dr. Anil Kumar Vijayan (Scientist D), Mrs. Ashadevi C. R. (Scientist D), Dr. Rasheed (Scientist D), Mr. M. Subramanian (Scientist C), Mr. Telson Noronha (Scientist C), Mr. C. Vasu (Scientist C), Mr. Abdul Basheer (Former PA to Director) and Mr. B. Kishore Kumar (STA) of CMLRE for all their co-operation during the period of work. The support and cooperation from the FORV Sagar Sampada Vessel Management team at CMLRE led by Dr. A. Shivaji (Scientist E) as well as the Captain, Crew, Chief Scientists and scientific team of FORVSS Cruises are gratefully acknowledged, as is the cooperation extended by the Fishing Master Mr. Thomas Paul, Fishing Hands Mr. Tapan Kumar Malo, Mr. S. B. Prakash, Mr. Pradeep, Mr. Binoy V., Mr. Rathinavel and Mr. Sunil Kumar and service engineers of M/s. Norinco Pvt. Ltd. I sincerely acknowledge the constant and tireless support of teammates Dr. Vinu Jacob, Mr. Rajeesh Kumar M. P., Dr. Aneesh Kumar, Dr. Vishnu K.V., Ms. Chippy Khader, Mr. Thomy R, Mrs. Meera K.M., Ms. Deepa K.P., Mr. Shileesh., Mr. Shaheer, Dr. Vineesh N., Mr. Rajeev R., Mr. Ruffus Thella, Dr. Usha V. Parameswaran, Dr. Aiswarya Gopal, Mrs. Sree Renjima G., Mr. Karthikey Muniraj, Mr. Jijith S. S., Mr. Midhun Shah Hussein, Siby T. Baby, Mr. Muhammed Rafeeq. I sincerely thank Mr. Arun C.N., Mr. Jijomon, Ms. Mariyakutty P. J., Mrs. Bijimol, Mrs. Mini M. K., Ms. Sajitha for their timely help in the laboratory. I would also like to extend my deep sense of gratitude to Dr. D. G. Smith, Smithsonian Institution, Museum Support Center, Suitland, MD, U.S.A., Dr. John E. McCosker, California Academy of Sciences, San Francisco, CA, U.S.A., Dr. Husan- Ching Ho, National Museum of Marine Biology & Aquarium, Pingtung, Taiwan., Dr. Yusuke Hibino, Kitakyushu Museum of Natural History and Human History, Fukuoka, Japan., Dr. Ronald Fricke, State Museum of Natural History Stuttgart., Dr. Anil Mohapatra, Estuarine Biology Regional Centre, Zoological Survey of India., Dr. Bineesh, Zoological Survey of India, Andaman and Nicobar Regional Centre., S. S. Mishra, Zoological Survey of India, Kolkata for their valuble support during the course of this work. I express my sincere gratitude to my family – my daddy, mummy, Achan, Amma, brother Sunod, Sister Ahalya, Saju uncle, vallyamummy, my wife Sukanya, son Akshath Krishna and other family members for their patience and support while I undertook the task of completing my thesis. Above all I bow my head before the Almighty for all the blessings showered upon me throughout my life and in the journey of my Ph. D work. Sumod K. S. Chapter 1 GENERAL INTRODUCTION ................................................................ 01-26 1.1 Introduction ................................................................................. 01 1.2 Order Anguilliformes ................................................................. 03 1.2.1 General characteristics & classification of Anguilliformes ........ 04 1.2.2 Systematic classification ........................................................... 06 1.2.3 Phylogenetic relationships .......................................................... 11 1.2.4 Fossil Anguilliformes ................................................................. 13 1.2.5 Diversity & distribution ............................................................ 14 1.2.6 Reproduction and early life history ............................................ 15 1.2.7 Food and feeding ........................................................................ 20 1.2.8 Commercial importance ............................................................. 22 1.3 Deep-sea Anguilliformes of India: Relevance of the study ........ 24 1.4 Objectives ................................................................................... 25 1.5 Outline of thesis .......................................................................... 25 Chapter 2 STUDY AREA, METHODOLOGY & DATA ANALYSIS ................... 27-47 2.1 Study Area ................................................................................. 27 2.2 Sampling ..................................................................................... 28 2.3 Taxonomic analysis .................................................................... 34 2.4 Otolith morphology ..................................................................... 35 2.5 Molecular taxonomy .................................................................. 36 2.6 Numerical abundance .................................................................. 37 2.7 Length weight relationship ......................................................... 39 2.8 Sex ratio ...................................................................................... 40 2.9 Fecundity ..................................................................................... 40 2.10 Food and feeding ......................................................................... 41 2.11 Biomass estimation ...................................................................... 41 2.12 Data analysis ................................................................................ 42 Chapter 3 DEEP-SEA ANGUILLIFORMES OF INDIAN EEZ: TAXONOMY & SYSTEMATICS .......................................................... 49-296 3.1 Introduction ................................................................................. 49 3.2 Methodology ............................................................................... 60 3.3 Results ........................................................................................ 62 3.3.1 Sampling sufficiency .................................................................. 62 3.3.2 Taxonomy of deep-sea Anguiliiformes in Indian EEZ. ............. 65 3.4 Otolith morphology of selected species of deep-sea Anguilliformes .........................................................................