ISSN 0429-9345
FAO
FISHERIES
TECHNICAL
PAPER
362
FOOD
AND
AGRICULTURE
ORGANIZATION
OF THE
UNITED NATIONS
Rome, 1996
edited
by
Gertjan de Graaf and Hans Janssen
Nefisco Foundation
Amsterdam, the Netherlands
The designations employed and the presentation of material in
this publication do not imply the expression of any opinion whatsoever on the
part of the Food and Agriculture Organization of the United Nations concerning
the legal status of any country, territory, city or area or of its authorities,
or concerning the delimitation of its frontiers or boundaries. |
M-44
ISBN 92-5-103918-6
All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner. Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed to the Director, Information Division, Food and Agriculture Organization of the United Nations, Viale delle Terme di Caracalla, 00100 Rome, Italy.
© FAO 1996
2. THE AFRICAN CATFISH (Clarias gariepinus and Clarias anguillaris)
3.1. Description of the genus and species
3.2. Habitat
3.3. Natural food and feeding
3.4. Natural reproduction
3.5. Oocyte development
4.1. Gonadal development in captivity
4.2. Induced propagation without hormone treatment
4.3. Semi-artificial reproduction through hormone treatment4.3.1. Hormone induced reproduction in ponds
4.3.2. Hormone induced reproduction in a happa placed in ponds
4.3.3. Hormone induced reproduction in concrete tanks with a gravel substrate4.4.1. Introduction
4.4.2. Broodstock care and selection of ripe breeders
4.4.3. Hormone injection
4.4.4. Maturation processes and stripping of eggs
4.4.5. Incubation of fertilized eggs
5. FRY NURSING IN EARTHEN PONDS
5.1. Pond preparation, fertilization and feeding rates.
5.1.1. Cleaning
5.1.2. Liming
5.1.3. Fertilization
5.1.4. Daily supplementary feeding5.2. Impact of tadpoles
5.3. Nursing of catfish larvae in protected ponds5.3.1. Stocking density of the catfish larvae
5.3.2. Size and form of the nursing pond
5.3.3. Duration of the rearing period and cannibalism among the catfish fingerlings
5.3.4. Pond monitoring and predator control
6. MONOCULTURE OF AFRICAN CATFISH
7. POLYCULTURE OF AFRICAN CATFISH WITH NILE TILAPIA
8.1.1. Economics of fingerling production
8.1.2. Economics of polyculture and monoculture