I N D U C E D F I S H B R E E D I N G I N D U C E D F I S H B R E E D I N G A Practical Guide for Hatcheries NIHAR RANJAN CHATTOPADHYAY Professor, Department of Aquaculture, Faculty of Fishery Sciences, West Bengal University of Animal & Fishery Sciences, Kolkata, West Bengal, India AMSTERDAM • BOSTON • HEIDELBERG • LONDON • NEW YORK • OXFORD PARIS • SAN DIEGO • SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Academic Press is an imprint of Elsevier Academic Press is an imprint of Elsevier 125 London Wall, London EC2Y 5AS, United Kingdom 525 B Street, Suite 1800, San Diego, CA 92101-4495, United States 50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom Copyright © 2017 Elsevier Inc. All rights reserved. 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British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress ISBN: 978-0-12-801774-6 For Information on all Academic Press publications visit our website at https://www.elsevier.com Publisher: Nikki Levy Acquisition Editor: Patricia Osborn Editorial Project Manager: Karen R. Miller Production Project Manager: Lisa Jones Designer: Victoria Pearson Typeset by MPS Limited, Chennai, India Dedicated to our loving and living GOD LORD JAGANNATH PREFACE Since joining the Department of Aquaculture, Faculty of Fishery Sciences, West Bengal University of Animal and Fishery Sciences, Kolkata, as Reader and subsequently Professor of Aquaculture, I have thought to review the status of the hatchery sector, as this the primary input that is fish seed is produced in the hatchery sector. I started my work involving the hatcheries of district 24 pargonas (pgs) north, WB, India, as primary activities relating to seed production in captivity started in this district. Dissemination of induced breeding technology was done in the said district through the establishment of one pio- neer hatchery in the country. The initial establishment of hatcheries in freshwater sector was made with the help of a government official of the state hatchery in Naihati of the said district and state. During study I noticed that, except for one or two hatcheries, most of the hatcheries were established afterwards without any institutional or government support. Realizing the short-term profit, people from diverse sectors started venturing into the hatchery business by learning the technol- ogy from neighboring ignorant fish breeders, who are not in any way aware of the basic principles of the technology. This way mushroom hatchers came up from the late 1970s and are still appearing. When we extended our study to two neighboring states (i.e., Assam and Bihar), we were astonished to notice that in one state (Assam) the farmers had learnt the technology by visiting different hatcheries of Bengal. In Bihar, the entire breeding operation in hatcheries was conducted by hired ignorant fish breeders from Bengal, particularly from the said district where primary work relating to breeding started in the late 1960s. Though there are some basic differences in the dis- semination and establishment of hatcheries of the three leading seed- producing states in India, an overall negative approach was being developed among fish breeders of three states. Induced fish breed- ing, that is production of fish seed in captivity, was developed with the idea of production of the desired quality seed in captivity in times of need. The initial defect in the transfer of technology, without any insti- tutional support, directs such a novel technology in a direction where quality and standards, the basic principles of the technology, are a matter of great concern. To date no institutional approach for a train- ing program has been conducted to make these people apprised of the negative consequences developed in the sector due to their unsci- entific and illegal profit-making approaches. This trend attracts peo- ple from different sectors in the seed production business, mainly on the understanding of huge profits within a very short period of time. Hence the people involved in the hatchery sector, being both illit- erate and ignorant, have inadvertently used the technology since its inception only for short-term profit-making. In this endeavor they xiv Preface started indiscriminate hybridization by maintain a small number of the founder population. Rarely do they exchange broods and pedigrees, both of which stand as primary criteria for quality seed production. The potency of the gland is never considered as an important criterion for quality seed. This type of unscientific activities, by maintaining a small number of founder population, invited a great deal of negative genetic consequences such as inbreeding and depression, genetic introgres- sion, genetic drift, and ultimately homogenization of the wild gene pool. Due to the want of any certification procedure, the seed produced in the said hatchery sectors were not only qualitatively inferior but were affected with various congenital abnormalities and diseases. Thus the effective hybrid and inferior seed are transported not only to diverse geographical territories of the country but are also used to regenerate the wild stock through ranching programs. Practices like the entry of cultured fish into the wild are expected to affect the wild gene pool as fish reproductive isolation is not as strong as in other ver- tebrates. This has been elucidated through the capture of hybrids and deformed fish from different stretches of river. This practice to reju- venate the wild population, as it is understood now, has already pro- duced an overall negative impact through contamination of the native gene pool. While the wild population is declining alarmingly in the major rivers of India, this type of unscientific approach resulting in the entry of cultured fish, without any scrutiny, into the wild may pose a threat to very existence of the prized fish (i.e., rohu, catla, mrigal). Intensive study for a period of 4–5 years covering three leading seed producing states of India are comprised into thirteen chapters. Fish breeding in captivity, which started initially by using prevailing congenial environment-like undulating terrain, a vast catchment area and bundhs in some regions, known as bundh breeding. Afterwards by the hormone induction application, from the discovery of induced breeding in 1950, that were extensively in use for production of qual- ity seeds in captivity. Starting with traditional bundh breeding, and the intensive field study that was carried out to take note of the dif- ferent breeding practices, including the scientific induced breed- ing technology. Special emphasis was given for collecting data on the history, modus operandi, status of the technology, and its modi- fication from the time of its implementation as several innovative approaches on the part of fish breeders. In India, since the discovery of induced breeding technology and its subsequent dissemination to field, without maintaining any code of practice of transfer technol- ogy, has turned such an epoch making technology to the fresh water aquaculture sector. The fish farmers and a large number of illiterate people from other occupations, realizing the large short term profits, started practicing the technology for profit-making propositions, by learning the technology from neighbouring illiterate fish breeders. Preface xv This sort of unscientific transfer was not restricted to one state instead the people from different states visited the pioneer state like West Bengal and carried away the technology without any scientific back up. This resulted in gross misappropriation of technology for a period of 50–60 years, and has created a lot of negative genetic conse- quences like inbreeding, genetic drift, genetic introgression, and ulti- mately resulted in contamination in the wild gene pool. The author has, time and again, tried to elucidate such an irreparable, damag- ing, and unscientific misappropriation on the part of such a novel technology, solely for profit. Now, though such a pernicious activity on the part of fish breeders are known to scientists, policy makers, and government officials, however, nothing has been seriously initi- ated yet. Although there are no paucity of scientific publications at national and international level. It is interesting to note that fish breeders are innovative and in times of difficulty, have developed innovative technologies to over- come situations. One such example is the discovery of suitable a chemical substance to remove the glue from eggs of fish that lay adhesive eggs. Recently, a new approach in the name of conservation hatchery is in use to replenish the loss and rejuvenation of wild stock. I appreciate the scientific endeavour from different positions, regions and states to find an immediate approach to save the prized fish of India. INTRODUCTION: PREEXISTING (TRADITIONAL) AND MODERN FISH BREEDING METHODS IN PRACTICE AMONG FISH FARMERS Aquaculture in India and neighboring countries, such as Bangladesh and Pakistan, mainly constitutes Indian major carp (IMC), namely, the catla (Catla catla, Hamilton), the rohu (Labeo rohita, Hamilton), the mrigal (Cirrhinus mrigala, Hamilton), and rarely Kalbasu (Labeo calbasu, Hamilton) as this is being threatened. These carp contribute approximately 75% of the aquaculture pro- duction in India (FAO, 1997). As these carp are economically very important, research on cultivating these species of fish was initiated in India during the early 1950s to study and understand the biology of these economically important species, particularly the major carp, and to develop suitable technologies for various farming systems. India possesses nearly 11% of the world’s 20,000 known species of fish, and is one of the richest nations in the world with regard to genetic resources of fish, which are distributed over a network of perennial river systems. Considering the culture fisheries or aqua- culture, fish culture in India is almost as old as in China; the average per hectare production per year remained as low as 0.6 tonnes until the 1960s. This was due to lack of proper technology, as the fish farm- ers followed traditional or empirical methods for farming. Before the introduction of fish breeding technology following the Chinese method (Linpe method), fish seeds were collected from the wild by collectors using a traditional scoot net. As this resulted in the collec- tion of a mixture of both the economic and uneconomic species, this wild collection failed to create a significant impact on the culture sec- tor, which still remained quackery. In the backdrop of such a state, induced breeding, primarily of IMC, is a great landmark in the aquaculture development in India and also made blue revolution possible. After its development at the CIFA center of Bhubaneswar, Orissa, India, the technology was not disseminated properly to the farms following the principle of trans- fer of technology. The farmers of Bengal started using the technology xviii INTRODUCTION without having primary training on fish genetics and basic principles of the technology. The farmers of Assam and Bihar learned the tech- nology afterwards by visiting Bengali fish breeders. This indicates that the fish breeders of the three states started using the technology only for their profit and short-term gain, due to the paucity of space and money the fish breeders adopted various injudicious ways like mixed spawning, indiscriminate hybridization, and use of immature brooders with skewed sex ratio and also multiple breeding. As we know, mixed spawning leads to hybridization inadvertently as the sexual isolation of fish is not stringent. Hybrid fertility is observed in the case of intergeneric and reciprocal hybridization. Again it is well- known that inadvertent hybridization and backcrossing of F1 hybrids, which is the usual practice of the hatcheries of the three states, would cause genetic introgression resulting in contamination in the wild gene pool of these prized fish of India. Experience with hybridization of domestic common carp with its wild ancestors resulted in the con- tamination of both the stocks and in the deterioration of their eco- nomically important traits. Along with this, inbreeding is a common practice as the fish breeders maintain a small number of founder populations. It is known that one generation of inbreeding resulted in increased high deformity (37.6%) and decreased food conversion efficiency (15.6%) and fry survival (19%). Due to the basic defect in adoption of the technology, the potency of the gland was never con- sidered as a criteria for fish-breeding purposes. Due to this, the actual number of the breeding population decreased successively. Now it appears that there is a need for an objective study to develop a breed- ing strategy and selective breeding program. The genetic conse- quences of mixed spawning should be assessed under experimental conditions and by surveying the natural populations. The problems of stock contamination may be assessed with subtle tools of isozyme and DNA polymorphism. The primary goal of the seed production industry should be to produce “quality fish seed” and subsequent distribution of the same among the farmers for culture or further growing out. In scientific terms, “quality seed” may be defined as those having better food con- version efficiency, high growth rate potential, better ability for adapt- ing to changing environmental conditions, disease resistant (Padhi and Mondal, 1999), and fetching a high market price. Seed produc- tion is a complex procedure and requires extensive knowledge of fish physiology, fish endocrinology, and also knowledge of the envi- ronmental influence on maturation, spawning, and hatching. It also requires knowledge of hormone-induced breeding (Atz and Pickford, 1959), population genetic principles, hybridization, and brood stock development, the art of hatchery and nursery management along with other relevant aspects needed to produce quality seed in INTRODUCTION xix captivity. Ideal seed production technology encompasses the follow- ing criteria: 1. Brood stock collection and management along with replacement of stock from nature at certain intervals; 2. Collection of good-quality (having the right potency) pituitary gland and its preservation in ideal conditions; 3. Selection of ideal breeders; 4. Maintenance of an ideal spawning and hatching environment; 5. Artificial breeding; 6. Hatchery and nursery management. The practice of breeding is the practical aspect of a thorough understanding of the science of fish physiology, endocrinology, genetics, and the breeding environment in captivity. The fish breed- ers, being totally unaware of the scientific basis of the technology, started using the technology empirically only for profit and short- term gain for a fairly long time. Again the farm-raised spawn and fry are not only transported to diverse geographical territories but find their way into natural systems through ranching and natural phe- nomena. All these practices over the years, as mentioned, led to the development of a series of negative consequences through inbreed- ing, genetic drift, indiscriminate hybridization, mixed spawning, and genetic introgression. Again, the gene pool has been modified consciously by selective breeding of fish for some commercial gain such as increased growth rate or disease resistance ability. On the other hand, due to lack of awareness of the scientific aspects of fish breeding and fish genetics, the breeders invite such consequences in the gene pool of farm-raised fish, which in the course of time will contaminate the native gene pool. This is evident from the collection as well as availability of phenotypically different fish species of IMC (rohu, catla, and mrigal) both from farms and natural harvests. Fish breeding in captivity through hormone injection or manip- ulation of available environmental conditions dates back to 1882. Before successful standardization and dissemination of induced breeding technology, there happens to be evolutionary history start- ing from bundh breeding to portable circular hatchery through a number of intermediate models. Just before the implementation of induced breeding technology 70% of the seed requirement was met from the fish seed raised out of bundh breeding. As the fish seed raised here was mainly through natural process and environmental maneuvering, the quality was good and there were no complaints from the farming community regarding poor growth, delayed matu- rity, deformities, and the many other unwanted consequences as are faced now after introduction of induced-breeding technology. Linpe method of induced breeding: Collaborative efforts by Chinese and Canadian researchers led to the development of a