The Biology and Culture of Tilapias

429 Pages·2004·8.73 MB·English

The Biology and Culture of Tilapias
Ian R. Smith Memorial Library
& Documentation Center
DATE DUE
3 0 MAR 20041
l%is volume is dedicated to
Dr. Ethelwynn Trewams
in racognition of her outskurding contributions
to Zfsheria science and to mark the occcrsion
of her eightieth birthday,
6"JVove&er- 1 980 ;
logy and Culture of Tilapias
Proceedings of the International Conference on the
Biology and Culture of Tilapias, 2-5 September 1980
at the Study and Conference Center of the
Rockefeller Foundation, Bellagio, Italy, sponsored by the
International Center for Living Aquatic Resources Management
Manila
Edited by
&d R.H. Lowe-McConnell
INTERNATIONAL CENTER FOR LIVING AQUATIC RESOURCES MANAGEMENT
iii
The Biology and Culture of Tilapias
7
Proceedings of the International Conference on the "3
Biology and Culture of Tilapias, 2-5 September 1980
at the Study and Conference Center of the
Rockefeller Foundation, Bellagio, Italy
sponsored by the International Center for Living
Aquatic Resources Management, Manila
1982
Printed in Maniia, Philippines
Published by ICLARIM, MCC P.O. Box 1601, Makati, Metro Manila,
Philippines
Pullin, R.S.V. and R.H. Lowe-McComell, Editors. 1982. The biology and
culture of tilapias. ICLARM Conference Proceedings 7,432 p. Inter-
national Center for Living Aquatic Resources Nanagsment, Manila,
Philippines.
ISBN 01154389 ISBN 971-04-0003-7 ~10th
ISBN 971-04-0004-5p aper
Cover: styZ&ad tibiaa rtifact porn Indonesia.
iv
Preface
Tilapias are a major protein source in many of the developing countries.
Although endemic to Africa, their distribution has been widened by artificial
introductions, mainly since the 19508, to include much of the tropics and
subtropics. Tilapias have many attributes that recommend them for culture.
They show excellent growth rates on low protein diets, whether cropping
natural aquatic production or receiving supplementary food. They tolerate
wide ranges of environmental conditions, show little susceptibility to disease
and are amenable to handling and captivity. They have a short generation
time and breed in captivity. Most important of all, they enjoy wide accep-
tance as food fish because of their high palatability and history of use from
inland fisheries. With all these advantages, tilapias could become prime
domesticated species for fish culture.
The culture of tilapias however, is still beset with problems of rearing and
general husbandry. These result from an inadequate research base on their
biology, particularly behavior and physiology, and insufficient cooperation
between fish biologists and culturists. The former have often pursued limited,
essentially academic studies within their specialist fields and the latter have
paid inadequate attention to published information. In particular, there is a
great deal of information gathered by field biologists which is relevant to
the behavior, growth and reproduction of tilapias in culture systems.
This conference was convened to bring biologists and culturists together
to present reviews of existing information in their specialist fields; to discuss
current research areas and culture methods; to define future research require-
ments and to comment on any other measures which would help the future
development of tilapia culture.
It was seen as a unique opportunity to address some of the unresolved
problems for researchers and culturists alike ranging from standardization of
nomenclature and techniques for the development of known genetic strains
and hybrids to optimization of growth and feeding and control of repro-
duction.
When editing this volume we decided to accept the division of the tilapias
into the genera Sarotherodon (mouthbrooders) and TYlapia (substrate
spawners). However, as explained in the addendum to Dr. Trewavas' paper,
the subgenus Oreochromis has been raised to generic status. The maternal
mouthbrooding tilapias so far used in fish culture should now be referred to
as Oreochromis (e.g., Oreochrornis mossam bicus, 0. niloticus, 0. aureus).
The generic name Sarotherodon is now restricted to a West African group
(which includes S. melanotheron) and to S. galilaeus.
ICLARM wishes to thank the Rockefeller Foundation, not only for pro-
viding the superb facilities of the Bellagio Study and Conference Center,
but also for their generous sponsorship of the conference participants. The
administrator and staff of the Bellagio Center also deserve special thanks for
their hard work and help in ensuring the success of this conference. Finally,
we wish to thank Dr. Roy Harden Jones for preparing the excellent indexes
and Linda Temprosa for assembling the reference list.
Contents
Session 1: Biology
..................
Chairman's Overview. R. H. LOWE-MCCONNELL 1
................
Tilapias: Taxonomy and Speciation. E. TREWAVAS 3
Ecology and Distribution of Tilapias. J-CL. PHILIPPART
.....................................
J-CL.RUWET 15
AND
Life Histories of Tilapias: An Evolutionary Perspective. D.L.G. NOAKES
.......................................
E.K.BALoN 61
AND
.............
Tilapias in Fish Communities. R.H. LOWE-MCC~NNELL 83
Session 2: Physiology
.......................
Chairman's Overview. D.J.W. MORIARTY 115
..............
Environmental Physiology of Tilapias. 6. CHERVINSKI. 119
Reproductive Physiology in Cichlid Fishes, with Reference
......
to Tilapia and Samthemdon. B. JALABEARNDT Y. ZOHAB 129
'/~eedinD~i,g estion and Growth-Qualitative Conside
L ...............................&.**......
S.H.BOWEN 141
Feeding, Metabolism and Growth of Tilapias: Some Quantitative
...........................
Considerations. MS. CAULTON 157
Session 3: Culture
........................
Chairman's Overview. H.F. HENDERSON 181
Tilapia Culture in Pond.s. u.n.d.e.r. C.o.n.t.r.o.ll.ed. .C.o.n.d.i.ti.o.n.s.. .B.. .H.E.PW..E.R .A.N.D. .
Y.PRUGININ.... 185
. ..........................
Cage Culture of Tilapias A.G. COCHE/' 205
. . ...........
Diseases of Tilapias R.J. ROBERTASN D C SOMMERVILLE 247
Session 4: Culture-Related Topics
. ........................
Chairman's Overview H.F. HENDERSON 265
Genetic Markers in Sadherodon and Their Use for Sex and
. .....................
Species Identification R.R. AVTALION 269
Tilapia Hybridization. L.L. LOVSHIN. ...............I .......... 279 .
. .............
Control of Tilapia Reproduction R.D. GUERRERIIOI 309
A Study of the Problems of the Mass Production of Hybrid
. . ..................................
Tilapia Fry D MIRES 317B
Introduction
This conference brought together 19 tilapia biologists and experimental
culturists from 10 countries. It was designed from the outset as a technical
conference on the basic biology of the tilapias and applications in culture
systems. The conference did not consider the commercial aspects of tilapia
culture. A further conference will be held in Israel, 8-13M ay 1983."
The conference consisted of fifteen major review papers grouped under
three main session headings:
Biology - taxonomy and speciation, ecology and distribution, tilapias
in fish communities, and life histories.
Physiology - environmental, reproductive, feeding and digestion, metabo-
lism and growth.
Culture - ponds, cages, diseases, hybridization, genetic markers, con-
trol of rbproduction and mass fry production systems.
The proceedings follow this arrangement with each session preceded by a
chairman's overview. The culture session was split into two parts: culture
systems and culture-related topics. About half the conference was devoted to
discussion sessions and a summary of these follows the papers presented. The
conference produced a consensus statement and a list of research require-
ments, which may stimulate the further development of tilapia culture.
The references cited have been combined into a single bibliography to
provide a useful information source on both cultured and wild tilapias. The
indexing is designed for easy referencing on systematics, biology and culture.
*Details from the Organizing Committee, International Symposium on Tilapia in Aqua-
culture, P.O. Box 3064, Tel Aviv, 61030, Israel.
vii i
SESSION I: BIOLOGY
Chairman's Overview
At the start of this first session of the Conference it is very important to
stress the aims of the meeting, as set out in Roger Pullin's letter of invitation,
namely, "the urgent need to bring tilapia biologists and culturists together to
exchange views and information and to define approaches and priorities for '
future work". We need to keep this firmly in mind and aim to produce the
most constructive guidelines for future research.
The two groups of people mentioned, the tilapia biologists who have
been working mainly under field conditions or in laboratories (or both)
and those with practical experience of aquaculture, have much to give
one another of very different experiences that can help to solve one another's
problems. This is a two-way process. As a field worker myself, I know only
too well the complexity of working conditions in natural waters in the
tropics, where so many species interact and where, for example, it is often so
difficult to determine fish growth rates. We have to look to those who grow
tilapias in ponds to solve many problems posed in the field, in particular,
those concerning the switch from growth to reproduction (nanism, dwarfing)
which is such a special feature of tilapia biology. I regard this as possibly the
key problem for our attention. If we could really understand the mechanism
which controls the switch from growth to reproduction, this would be one
of the biggest steps towards improving tilapia culture.
This session is concerned mainly with field studies, and should provide a
good background to our subsequent consideration of the physiology of
tilapias from both field and laboratory work. For those who grow tilapia in
ponds, we must stress the vast scale of the theatre for field studies. The
equatorial Lake Victoria in East Africa is over 6.5 million ha and the Kafue
floodplain, another site for much tilapia research, around 121,000 ha.
Sampling such huge areas presents special problems, and errors arise in
extrapolation of results. Catch statistics are of very variable reliability
compared with emptying a pond and weighing all the fish. Furthermore,
what is loosely referred to as 'fish production' from these vast areas is really
the fish catch and only a very small percentage of the total biological pro-
duction (unlike ponds from which most of the total production may be
channelled into spawners).
In this session we have four papers.
Dr. Ethelwynn Trewavas first introduces the taxonomy and speciation
of tilapias, and says why it is so important to know which species we are
dealing with when making studies of any kind. We all owe a great debt of
gratitude to Dr. Trewavas who has toiled away for very many years putting