Live Attenuated Bacterial Vaccines in Aquaculture

259 Pages·2011·6.21 MB·English

by  Reviewer 3

BETTER SCIENCE, BETTER FISH, BETTER
LIFE
PROCEEDINGS OF THE NINTH
INTERNATIONAL SYMPOSIUM ON
TILAPIA IN AQUACULTURE

Editors
Liu Liping and Kevin Fitzsimmons

Shanghai Ocean University, Shanghai, China
22-24 April 2011

Published by the AquaFish Collaborative Research Support Program

AquaFish CRSP is funded in part by United States Agency for International Development
(USAID)
Cooperative Agreement No. EPP-A-00-06-00012-00 and by US and Host Country partners.

ISBN 978-1-888807-19-6
1
Dedication:

These proceedings are dedicated in honor
Of our dear friend

Yang Yi

It was Dr. Yang Yi who first suggested having this ISTA
at Shanghai Ocean University to celebrate SHOU’s move
to the new Lingang Campus. It was through his hard work and
constant attention with his many friends and colleagues that
the entire 9AFAF and ISTA9 came together, despite the terrible
illness that eventually took his life at such a young age.

Acknowledgements:

The editors wish to thank the many people who contributed to
the collection and review and editing of these proceedings, especially
Mary Riina, Pamila Ramotar, Sidrotun Naim and Zhou TingTing
2
Table of Contents Page

KEYNOTE ADDRESS

WHY TILAPIA IS BECOMING THE MOST IMPORTANT FOOD FISH ON THE PLANET
Kevin Fitzsimmons, Rafael Martinez-Garcia and Pablo Gonzalez-Alanis 8

SECTION I. HEALTH and DISEASE

LIVE ATTENUATED BACTERIAL VACCINES IN AQUACULTURE 18
Phillip Klesius and Julia Pridgeon

ISOLATION AND CHARACTERIZATION OF Streptococcus agalactiae FROM RED TILAPIA 27
CULTURED IN THE MEKONG DELTA OF VIETNAM
Dang Thi Hoang Oanh and Nguyen Thanh Phuong

ECO-PHYSIOLOGICAL IMPACT OF COMMERCIAL PETROLEUM FUELS ON NILE TILAPIA, 28
Oreochromis niloticus (L.)
Safaa M. Sharaf and Mohsen Abdel-Tawwab

ACUTE TOXICITY OF WATER-BORN ZINC IN NILE TILAPIA, Oreochromis niloticus (L.) 39
FINGERLINGS
Mohsen Abdel-Tawwab*, Gamal O. El-Sayed, and Sherien H.H.H. Shady

FIVE STAR CERTIFICATION PROGRAM AGAINST OFF-FLAVOR IN TILAPIA FILLETS 45
Tomi HONG

ACUTE TOXICITY OF AQUEOUS Morinda lucida LEAF EXTRACTS TO NILE TILAPIA, 46
Oreochromis niloticus (LINNAEUS 1857)
Oyedapo FAGBENRO and Iyabo AKINDUYITE

HAEMATOLOGICAL RESPONSE OF NILE TILAPIA (Oreochromis niloticus) JUVENILES 52
EXPOSED TO TOBACCO (Nicotiana tobaccum) LEAF DUST
M.O. OLUFAYO AND I.A. JATTO

COMPARATIVE ASSESSMENT OF PARASITE INFESTATION OF TILAPIA IN NATURAL AND 56
CULTURED ENVIRONMENTS
ABIDEMI-IROMINI A.O and R.N EZE

OXYTETRACYCLINE MARKING STUDIES OF TILAPIA Oreochromis niloticus 60
Yasser Mohammed ABDEL-HADI

SECTION II. ACCELERATING AQUACULTURE DEVELOPMENT IN POORER COUNTRIES

INTENSITY OF FRESHWATER USE FOR AQUACULTURE IN DIFFERENT COUNTRIES 68
Claude E. BOYD* and LI Li

IMPACTS OF THE INTRODUCTION OF ALIEN TILAPIAS (Oreochromis spp.) ON 75
THE FISHERIES AND BIODIVERSITY OF INDIGENOUS SPECIES IN TRI AN RESERVOIR,
VIETNAM
Le Thanh Hung, Vu Cam Luong, Nguyen Phu Hoa, James Diana

DURATION OF APPETITE INHIBITION PREDICTS SOCIAL DOMINANCE IN NILE TILAPIA, 86
Oreochromis niloticus L.
Emmanuel M. Vera Cruz, Madelin B. Valdez, Remedios B. Bolivar, and Russell J. Borski

3
FISHMEAL-FREE DIETS IMPROVE THE COST EFFECTIVENESS OF CULTURING NILE 95
TILAPIA (Oreochromis niloticus L.) IN PONDS UNDER AN ALTERNATE DAY FEEDING
STRATEGY
Russell J. Borski, Remedios B. Bolivar, Eddie Boy T. Jimenez, Roberto Miguel V. Sayco,
Reginor Lyzza B. Arueza, Charles R. Stark, and Peter R. Ferket

HEAT-INDUCED GERM CELL LOSS IN SUB-ADULT NILE TILAPIA Oreochromis niloticus 102
Narayan P. Pandit, Madhav K. Shrestha and Masaru Nakamura

EFFECTS OF STOCKING DENSITY ON THE GROWTH, SURVIVAL AND YIELD 103
PERFORMANCE OF NILE TILAPIA (Oreochromis niloticus, Linn. 1858) IN AN
INTEGRATED CAGE-CUM-POND CULTURE SYSTEM
C. C. Ngugi, G. Kuria, K. Quagrainie, and S. Macharia

FOOD SAFETY STUDY OF LEAFY GREENS IRRIGATED WITH TILAPIA FARM 104
EFFLUENTS IN TAMAULIPAS
P. González-Alanis* J. I. Gutierrez-Olguín, H. Ezqueda-Palacios, H. H. Gojon-Báez,
G. Aguirre-Guzmán, F. M. Guzmán-Saénz, K. M. Fitzsimmons.

MASCULINIZATION OF NILE TILAPIA (Oreochromis niloticus L.) USING LYOPHILIZED 105
TESTES FROM CARABAO (Bubalus bubalis carabanesis L.), BULL (Bos indicus L.) AND
BOAR (Sus domesticus L.)
Ramjie Y. Odin and Remedios B. Bolivar

POTENTIAL USE OF BACTERIAL DEGRADATION TO ELIMINATE 121
METHYLTESTOSTERONE FROM INTESIVE TILAPIA MASCULINIZATION SYSTEMS
Rosa M. Padrón-López, Lucero Vázquez-Cruz, Ulises Hernández-Vidal,
W. M. Contreras-Sánchez* and K. Fitzsimmons

HOW TO PRODUCE BILLIONS OF HIGH QUALITY TILAPIA FRY 123
Ram C. Bhujel

IMPROVING THE SUPPLY CHAIN OF TILAPIA INDUSTRY IN THE PHILIPPINES 132
Wilfred E. Jamandre, Upton Hatch, Remedios B. Bolivar, Russell Borski

DEVELOPMENT OF SUSTAINABLE AQUACULTURE PRACTICES IN TABASCO, 157
MEXICO USING NOVEL IAA TECHNOLOGY
R. Martínez- García*, M. F. Cifuentes-Alonso, M. A. Estrada Botello,
A. S. Lopez Torres, M. de Jesús Contreras-García, A. Macdonal-Vera,
E. González-Arévalo, W. M. Contreras-Sánchez, K. Fitzsimmons

CONSTRAINTS AND OPPORTUNITIES IN CAGE AQUACULTURE IN GHANA 158
Gifty Anane-Taabeah, Emmanuel A. Frimpong, Stephen Amisah, and Nelson Agbo

GEOSPATIAL MODELING OF SITE SUITABILITY FOR POND BASED TILAPIA AND 166
CLARIAS FARMING IN UGANDA
Herbert Ssegane, E.W.Tollner, and Karen Veverica

WHAT INFLUENCES THE SUCCESS OF AQUACULTURAL RESEARCH PROJECTS? 167
Steven Buccola, Lin Qin and Rolf Fare

METHODS FOR ASSESSING ECONOMIC, ENVIRONMENTAL AND SOCIAL IMPACTS 174
OF AQUACULTURE TECHNOLOGIES: ADOPTION OF INTEGRATED
AGRICULTURE-AQUACULTURE IN MALAWI
John Antle and Roberto Valdivia

VALUE CHAIN OF CULTURED SNAKEHEAD FISH IN THE MEKONG DELTA 184
Le Xuan Sinh*, Robert S. Pomeroy & Do Minh Chung
4
USE OF GONADOTROPIN RELEASING HORMONE ANALOGS ON THE INDUCED 187
REPRODUCTION OF CHAME Dormitator latifrons
Gustavo A. Rodriguez M. de O.*, Eva A. Medina H., Jeniffer Velazquez S.,
V. Lopez L., C. Roman R., K. Dabrowski, E. Gaxiola Camacho, and M.C. Haws

SECTION III. GENETICS and REPRODUCTION

IMPROVING SALINITY TOLERANCE IN TILAPIAS: PAST EXPERIENCE AND FUTURE 193
PROSPECTS
Avner CNAANI, Ariel VELAN, Gideon HULATA*

COMPARISON BETWEEN GREEN WATER AND CLEAR WATER SYSTEMS DURING THE 202
MASCULINIZATION PROCESS OF SILVER TILAPIA, Oreochromis niloticus
Ryan S. Mohammed and Indar W. Ramnarine

OSMOREGULATORY CAPACITY OF THE NILE TILAPIA (Oreochromis niloticus (L. )) 203
DURING EARLY LIFE STAGES.
Fridman, S., Bron, J.E. and Rana, K.J.

TILAPIA GERMPLASM IN CHINA: CHANCE AND CHALLENGE 217
Zhao Jinliang

EFFECTS OF Aloe vera (Liliaceae) ON THE GONAD DEVELOPMENT IN NILE TILAPIA, 222
Oreochromis niloticus (Linnaeus 1758)
Temitope JEGEDE

MORPHOMETRIC AND MERISTIC CHARACTERISTICS AND THEIR VARIATIONS 228
BETWEEN TWO DIFFERENT STRAINS (GIFT & GIFU) OF NILE TILAPIA,
Oreochromis niloticus (Linnaeus, 1758)
A.-Al Mamun, K. M. Shahriar Nazrul*, B. S. Sarker, Md. Mofizur Rahman and U. S. Tonny

GENETIC STOCK IMPROVEMENT OF THE GIFT STRAIN IN BANGLADESH 236
M.G. Hussain, A.H.M. Kohinoor, N.H. Nguyen and R.W. Ponzoni

PRODUCTIVE PERFORMANCE AND MUSCLE GROWTH OF THREE DIFFERENT 243
STRAINS OF NILE TILAPIA, Oreochromis niloticus, DURING THE INITIAL DEVELOPMENT
T. M. de Freitas, J. T. Kojima, N. de J. Leitão, C. Nebo, F. Carani, M. D. Pai-Silva and M. Célia
Portella*

SECTION IV. NUTRITION and FEEDS

EFFECTS OF SAPONIN FRACTIONS FROM Trigonella foenum-graecum AND 245
Balanites aegyptiaca ON GENE EXPRESSION OF GH, IGF-1 AND THEIR RESPECTIVE
RECEPTORS, GROWTH, NUTRIENT UTILIZATION, BODY COMPOSITION OXYGEN
CONSUMPTION AND PLASMA IGF-1 IN NILE TILAPIA (Oreochromis niloticus, L.).
T. Stadtlander, W. K. B. Khalil,, B. Levavi-Sivan, H. Dweik5, M. Qutob,
S. Abu-Lafi, Z. Kerem, U. Focken, and K. Becker

BROODSTOCK DIETS WITH ADDED CRUDE PALM OIL RESULTED IN IMPROVED 260
REPRODUCTIVE PERFORMANCE, EGG HATCHABILITY AND LARVAL QUALITY OF
NILE TILAPIA Oreochromis niloticus
Wing-Keong Ng and Yan Wang

DISTILLERS DRIED GRAINS WITH SOLUBLES AS ALTERNATIVE PROTEIN SOURCES IN 261
DIETS OF TILAPIA, Oreochromis niloticus
LIM, Chhorn, Erchao LI and Phillip H. KLESIUS

ECONOMICALLY FEASIBLE FISH FEED FOR GIFT TILAPIA (Oreochromis niloticus) FOOD 262
FISH CULTURE IN SRI LANKA
M.H.S. Ariyaratne
5
SUPPLEMENTAL FEEDING OF NILE TILAPIA (Oreochromis niloticus L.) IN FERTILIZED 268
PONDS USING COMBINED FEED REDUCTION STRATEGIES
R. B. Bolivar, E. Boy T. Jimenez, R. Miguel V. Sayco, and R. J. Borski

THE USE OF ROASTED COFFEE PULP AS A FEED SUPPLEMENT IN PRACTICAL DIETS 275
FOR NILE TILAPIA, Oreochromis niloticus (L.)
Mohsen ABDEL-TAWWAB

PARTIAL AND TOTAL REPLACEMENT OF FISHMEAL WITH CHEESE PROCESSING 283
BY-PRODUCT MEAL IN PRACTICAL DIETS FOR NILE TILAPIA,
Oreochromis niloticus (L.): A PRELIMINARY STUDY
Mohsen ABDEL-TAWWAB*, Fayza E. ABBASS, and Medhat E.A. SEDEN

SECTION V. ECONOMICS and COUNTRY - REGIONAL REPORTS

TILAPIA CULTURE IN TRINIDAD AND TOBAGO: YET ANOTHER UPDATE 294
Indar W. Ramnarine and Capildeo Barrath

TECHNOLOGY TRAINING AND SHARING ON TILAPIA FARMING: AN EXPERIENCE 299
FROM THE ICDF WORKSHOP ON TILAPIA CULTURE IN HONDURAS
Fu-Sung Frank Chiang, Kelvin Chen, Tien-Tsai Tsai, and Cathy Chen

60 YEARS OF TILAPIA AQUACULTURE IN NIGERIA 300
O. A. FAGBENRO, O. S. FASASI, T. JEGEDE and O. O. OLAWUSI-PETERS

BEST AQUACULTURE PRACTICES STANDARDS FOR THE TILAPIA INDUSTRY 310
Darryl JORY

A HANDS-ON TRAINING HELPED PROLIFERATION OF TILAPIA CULTURE 311
IN BANGLADESH
BAQUI*, M. A. AND BHUJEL, R. C.

STATUS AND SUSTAINABILITY ANALYSIS OF THE TILAPIA AQUACULTURE IN CHINA 323
LIU Liping*, ZHANG Wenbo, Francis MURRAY, David LITTLE

TILAPIA: THE SEARCH FOR A SUSTAINABLE MODEL TO BALANCE BETWEEN 324
ENVIRONMENT, PEOPLE AND ECONOMY.
SNIR, Israel and SNIR, Yedod

TILAPIA - THE HISTORICAL PROMISE FOR TODAY, SOCIAL JUSTICE AND SECURITY 326
SNIR, Israel and SNIR, Yedod

SECTION VI. GROWOUT SYSTEMS

THE INTERNATIONAL TILAPIA AND AQUAPONICS COURSE AT THE UNIVERSITY 329
OF THE VIRGIN ISLANDS
James E. Rakocy, Donald S. Bailey, R. Charlie Shultz and Jason J. Danaher

A COMMERCIAL-SCALE AQUAPONIC SYSTEM DEVELOPED AT THE UNIVERSITY 336
OF THE VIRGIN ISLANDS
James E. Rakocy, Donald S Bailey, R. Charlie Shultz, and Jason J. Danaher

DEVELOPMENT OF A BIOFLOC SYSTEM FOR THE PRODUCTION OF TILAPIA 344
James E. Rakocy, Jason J. Danaher, Donald S. Bailey and R. Charlie Shultz

BIO-FLOC TECHNOLOGY (BFT):A BRIEF SUMMARY 359
Yoram AVNIMELECH

TILAPIA PRODUCTION USING BIO-FLOC TECHNOLOGY (BFT) 362
Yoram Avnimelech
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LENGTH-WEIGHT RELATIONSHIP OF Oreochromis niloticus IN CONCRETE 367
POND OF HABIB ADM, HUB, BALOCHISTAN
M. Y. Laghari, B. A. Dars, and N. T. Narejo, *Baoping Xin

SCALING UP OF CAGE-CUM-POND CULTURE SYSTEM OF CATFISH AND TILAPIA 372
IN CAGES IN CARP POLYCULTURE PONDS
Ram B. MANDAL, Madhav K. SHRESTHA, Dilip K. JHA and Narayan P. PANDIT

BRACKISHWATER POLYCULTURE OF TILAPIA WITH MILKFISH IN ACEH, 381
INDONESIA
Hasan Hasanuddin and Michael Rimmer

POLYCULTURE OF TILAPIA AND SEAWEEDS IN SOFT-SHELL CRAB PONDS IN 382
INDONESIA AND THAILAND
May Myat Noe LWIN

STOCKING TILAPIA IN SHRIMP CULTURE RESERVOIR: FIELD TRIAL IN ACEH, 383
INDONESIA
Sidrotun NAIM

POSTERS

THE DEVELOPMENT OF CORRELATIVE MICROSCOPY TECHNIQUES TO DEFINE 387
MORPHOLOGY AND ULTRASTRUCTURE IN CHLORIDE CELLS OF NILE TILAPIA
(Oreochromis niloticus (L.)) YOLK-SAC LARVAE.
FRIDMAN, S., Bron, J.E. and Rana, K.J.

ADDRESSING THE GOALS AND OBJECTIVES OF THE FEED THE FUTURE INITIATIVE: 388
ENHANCING THE PROFITABILITY OF SMALL AQUACULTURE OPERATIONS IN GHANA,
KENYA, AND TANZANIA
Stephanie ICHIEN* and Hillary EGNA

AQUAFISH CRSP: MITIGATING THE NEGATIVE ENVIRONMENTAL IMPACTS OF 389
AQUACULTURE PRACTICES THROUGH DEVELOPING SUSTAINABLE FEED
TECHNOLOGIES
Stephanie ICHIEN*, Ford EVANS, and Hillary EGNA

PROMOTING SUSTAINABLE AQUACULTURE AND FISHERIES DEVELOPMENT THROUGH 390
CAPACITY BUILDING: A SYNOPSIS OF SHORT- AND LONG-TERM TRAINING
CONDUCTED BY THE AQUAFISH CRSP
Ford EVANS*, James BOWMAN, Lisa REIFKE, and Hillary EGNA

PROMOTING SUSTAINABLE RICE-FISH AQUACULTURE IN IRRIGATED SYSTEMS 391
IN MALI
Coulibaly, H., L. Liping, D. Yuan, A.S. Toure, J.R. Bowman, and H.S. Egna*

TILAPIA: SILENT BOOMING IN BANGLADESH 393
Sk. AHMAD-AL-NAHID*, M. Mahfujul HAQUE, Md. Abdul WAHAB,
David C. LITTLE and Francis MURRAY

PRELIMINARY STUDY ON MICROBIAL ACTIVITY ASSOCIATED WITH TILAPIA 394
CULTURE AGAINST Vibrio harveyi
Sidrotun NAIM

THE EFFECTS OF PLANKTON ON TILAPIA GROWTH USING ORGANIC AND 395
INORGANIC FERTILIZERS AND WHAT CAUSES PHYTOPLANKTON BLOOM TO "CRASH"
Pamila RAMOTAR
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WHY TILAPIA IS BECOMING THE MOST IMPORTANT FOOD FISH
ON THE PLANET
Kevin Fitzsimmons, Rafael Martinez-Garcia, Pablo Gonzalez-Alanis
University of Arizona
Tucson, AZ, USA
locally available materials with minimal investment and placed in small ponds or in public
waters. Many countries will provide access to reservoirs, irrigation systems and public
waters to farmers and fishers with limited resources or who partner with government
sanctioned processors.
Tilapia aquaculture has also attracted multi-national firms who grow fish in multiple
countries vertically integrating feedmills, hatcheries, production, processing, packaging,
transportation, and marketing. These firms employ thousands of farmers, feeedmillers,
processing plant staff, drivers, office staff and sales forces. In many cases these employees
are the prime recipients of the foreign exchange generated by these operations (Fitzsimmons
and Watanabe, 2010).
Finally, as mentioned above, much of the global tilapia aquaculture has been
integrated into irrigation systems. By rearing fish in reservoirs, canals and farm ponds, the
effluents from tilapia farming are contributing to the fertilizer value in the water delivered to
irrigated crops. This contributes to tilapias ―green‖ reputation with the environmental
community while saving on chemical fertilizer costs for resource poor farmers. So tilapia truly
are a key contributor to global food security on several levels.

GENETICS
One of the key reasons for tilapia‘s continued expansion of production in future years
is based on the genetic diversity available from which to build. The farmed tilapias are
derived from several species in the genus Oreochromis. The fact that several of the species
easily hybridize and produce large numbers of fecund young has allowed fish breeders to
cross several species and develop strains that incorporate various traits from each of the
parent species. This further supports the contention that the tilapia have been selectively
bred and domesticated to an even greater extent than the edible carps. In fact they may be
even more domesticated and differentiated than koi are from wild carps.

Size and body shape – Some of the primary morphological characteristics that
breeders wanted to improve were the average size of the tilapia and the body shape,
especially reducing the proportion of head to fillet. In both cases the ultimate goal is to have
more edible fillet product. Most of the intensive breeding programs have focused on O.
niloticus (Nile tilapia).

The Nile tilapia strains that have been developed in recent years include:
1. The Genetically Improved Farmed Tilapia (GIFT), originally developed in the Philippines
from eight farmed and wild strains collected from around the world. The breeding
program continues under the auspices of the WorldFish Centre at Jitra, Malaysia.
2. The Genomar strain was developed by a partnership of biologists from Brazil and
Norway. It also included a large hatchery project in China, the Trapia project in
Malaysia www.trapia.com.my/ and a hatchery in the Philippines. www.genomar.com
3. The Chitralada strain was developed in Thailand, and actually was started from the
stocks of tilapia given to the King of Thailand who kept them in ponds at the Chitralada
Palace. Breeders in Thailand continued to work with this strain and eventually
developed the line that still bears the Chitralada name. It has also been used as an
important line in some of the other breeding programs.
4. The TabTim line was developed in Thailand by the CP Group as their branded tilapia
strain. The line is derived from several salt tolerant red tilapia lines, including some from
Thailand, the Bahamas and the University of Arizona. Tab Tim has been successfully
branded as a premium tilapia which receives an increased price and now is produced
and marketed in Indonesia and Malaysia as well as Thailand.
5. The GIFT Excell line is derived from some of the GIFT tilapia that were left behind in the
Philippines, when the GIFT program proper was moved to Malaysia. Some of the
original GIFT biologists have worked in the original location and have partnered with
various hatcheries to improve the strain.
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6. The GIFT Bangladesh strain is another derivation from the GIFT tilapia. In this case,
Bangladeshi scientists continued a selective breeding program with the GIFT fish sent to
Bangladesh. These fish have been bred to thrive under the climatic and cultural
conditions found at the local farms.
YY Supermale – This novel program was envisioned by biologists at University of Wales
Swansea and then put into practical operation at the Central Luzon State University in the
Philippines (Mair et al, 1997). The commercial entity arising from the project is called
FishGen. http://www.fishgen.com The technique produces all male progeny for stocking
on farm by manipulating the reproductive morphology of the grandparent fish. By treating
the juvenile grandparent fish with estrogen, breeders can produce fish with a genetically
female ―father‖. This results in 25% YY fish in the F1 which can be crossed to normal
females to produce virtually all XY (normal) male progeny in the F2 generation. In 2008
and 2009 groups in Egypt and Indonesia, respectively have reported that they have
developed their own YY stocks.

Color morphs – There have been several strains of red tilapia developed. These include
populations from Florida, Hawaii, Taiwan and Israel. Several have arisen from random
mutations in O. mossambicus and another one in O. niloticus. Diligent breeding managed to
―fix‖ these traits and develop marketable strains. In certain Asian communities the fish fetch
a premium as it is the color of ―good luck‖. In other communities, red tilapia resemblance to
red snapper or red sea bream gains a premium price.

Salinity resistance – There are several populations of O. mossambicus that are recognized for
their tolerance for extreme levels of salinity. These populations, especially from Lakes
Bardawil and Manzala in Egypt, have been used as broodlines with Red strains and other
species crosses to impart the salinity tolerance. This is another major advantage that the
tilapias have over several other farmed species including the carps. Salinity tolerance opens
up so many more options for farming opportunities in marine and brackish coastal water,
inland brackish waters, agricultural and industrial waste water, and even hydroponic solutions
used for lettuce and other vegetable production (Watanabe et al. 2006).

Genome project – An international group of geneticists is rapidly working through the O.
niloticus genome (Kocher et al., 1998; Lee et al., 2005).
http://www.broadinstitute.org/ftp/pub/assemblies/fish/tilapia/Orenil1/ The project has benefited from
several allied groups sequencing parts of the genetic make-up. Recently large parts have
been cataloged and are now being compared to previously described portions from other
cichlids and the zebrafish (Danio rerio). A grass carp genome project in 2010 provided the
first linkage map, many years behind the work done with tilapia (Xia et al., 2010). Again this
further definition and available information will likely benefit the genetic knowledge for the
tilapia sooner, and to a more full extent that that available for the various carps.

NUTRITION
Omnivores – Herbivores – One of the qualities that continues to make tilapia popular with the
―green movement‖ is the fact that they feed primarily on a very low trophic level. In nature,
the tilapias feed upon algae, fresh and decaying plant material and periphyton. In
domesticated settings the various tilapias still are fed a formulated diet that consists of grains
and agricultural by-products that serve to keep tilapia diets below the average for most other
farmed fishes. While many of the carps have similar feeding and nutritional patterns, the fact
that tilapia in general are smaller and have smaller teeth and mouths, they tend to be even
more efficient at scraping off the finest biofilms and periphyton colonies.

BioFlocs - The ability of tilapia to thrive in biofloc systems is yet another benefit that tilapia
have over many of the other common aquaculture species. Avnimelech (2009; and this
volume) describes how tilapia are uniquely adapted to thrive under biofloc conditions that
would stress most other fish. This relatively low cost system for producing healthy fish and
reducing formulated feed costs could be an additional benefit that should keep tilapia prices
competitive with other wild and farmed species.
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