EXPERT TOPIC 1303- SHRIMP

May | June 2013
EXPERT TOPIC - SHRIMP
The International magazine for the aquaculture feed industry
International Aquafeed is published six times a year by Perendale Publishers Ltd of the United Kingdom.
All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies,
the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of
information published.
©Copyright 2013 Perendale Publishers Ltd.All rights reserved.No part of this publication may be reproduced in any form
or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058
INCORPORATING
f ish farming technolog y

42 | InternatIonal AquAFeed | May-June 2013
EXPERT T●PIC
Welcome to Expert Topic. Each issue will take an in-depth look
at a particular species and how its feed is managed.
SHRIMP
EXPERT TOPIC

Shrimp
Farmed shrimp was a $US10.6 billion indus-
try in 2005 (WWF). The species is one of
the fastest growing in aquaculture with an
approximate rate of 10 percent annually. The
production of whiteleg shrimp (Litopenaeus
vannamei, formerly Penaeus vannamei) in
particular, generated the highest value of
major cultured species at $US11.3 billion.
L. vannamei was first cultivated in Florida in
1973 from larvae spawned and shipped from
a wild-caught mated female from Panama. In
1976, due to good pond results and adequate
nutrition, the culture of L. vannamei began
in South and Central America. By the early
1980s, through intensive breeding and rearing
techniques, L. vannamei was being developed
in the USA (including Hawaii), and much of
Central and South America (FAO).
L. vannamei is popular because of its high
yield and short grow out period. The yield
per hectare is up to three times that of the
giant tiger shrimp (Penaeus monodon). The
grow out period is also shorter for L. van-
namei, 60-90 days, compared to 90-120 days
for P. monodon. Overall, it costs about half as
much to produce a kilo of L. vannamei as it
does to produce a kilo of P. monodon.
1
China
Although, L. vannamei was introduced into
Asia in 1978-9, it was not until 1996 that the
species was cultivated on a commercial scale.
First in Mainland China and Taiwan and subse-
quently to the Philippines, Indonesia, Vietnam,
Thailand, Malaysia and India.
The largest seafood producer and export-
er in the world, China also boasts a large L.
vannamei production industry, with Mainland
China producing more than 270,000 met-
ric tonnes in 2002. Production reached an
estimated 300,000 metric tonnes (71%
of the country’s total shrimp
production) in 2003 and hit 700,000 tonnes
in 2004 (Network of Aquaculture Centres in
Asia-Pacific).
More InforMatIon:
www.enaca.org
byMarnieSnell
May-June 2013 | InternatIonal AquAFeed | 43
EXPERT T●PIC
3
1
4
5
2
6

2
India
In the 1990s, Indian shrimp aquaculture expe-
rienced rapid growth. Production increased
from 30,000 tonnes in 1990 to 102,000
tonnes in 1999 (FAO). This expansion
brought economic success for the country.
By the start of the 21st century, the shrimp
aquaculture sector accounted 1.6 percent
of Indian export earnings and employed an
estimated 200,000 people.
Yet the development of shrimp aquac-
ulture has become more controversial. The
introduction of L. vannamei in 2009 has led
to widespread illegal farming and posed the
threat of disease. However, there are organi-
sations dedicated to tackling the problem.
One example is the Coastal Aquaculture
Authority (CAA) which aims to shut down
unregistered shrimp hatcheries and farms.
The scale of the issue is rather large as out of
14,549 CAA registered farms, just 246 have
permission to cultivate whiteleg shrimp.
More InforMatIon:
www.fao.org/docrep/x8080e/x8080e08.htm
www.thehindu.com/news/cities/Vijayawada/arti-
cle2878953.ece
3
Ecuador
The 1970s set a president for the devel-
opment of Ecuador’s shrimp farming
industry. L. vannamei, captured from the
beach surf was transferred into 20-hec-
tare ponds that Ecuadorian producers
built on mud flats.
During the mid-1970s, animal
feed and pet food company, Ralston
Purina began conducting pond trials in
Ecuador to demonstrate the benefits
of feeding.
As land and labour were cheap,
disease was rare and wild seed was in
abundance, the shrimp farming business
was profitable and by 1977, approxi-
mately 3,000 hectares of extensive
shrimp farms had been developed in
Ecuador.
As a result, shrimp feed mills were
developed during the 1980s, marking
the transition of Ecuadorian farms from
extensive to semi-intensive production.
More InforMatIon:
www.shrimpnews.com/FreeReportsFolder/
HistoryFolder/HistoryWorldShrimpFarming/
ChamberlainsHistoryOfShrimpFarming.html
4
Brazil
Although shrimp farming was already
operational during the 1980s, it was
the introduction of L. vannamei in 1992 that
allowed for a swift expansion in Brazil’s shrimp
farming industry. Shrimp culture is now one
of the most organised sectors within Brazilian
aquaculture.
In 2003, the total production of L. van-
namei reached 90,190 tonnes produced from
14,824 ha of shrimp ponds. In some states,
productivity reached 8,700 kg/ha/year with
the best yields obtained in the northeast
region.
With exports reaching 60,000 tonnes in
2003, representing 60.5% of the total Brazilian
fishery export and generating US $230 million
for the Brazilian economy, shrimp culture is
now one of the most important economic
activities in the Northeast region.
Most of the shrimp farms are small scale
(75 %), followed by medium (9.6%) and large
scale (5.52%). The average yield increased
from 1 015 kg/ha/year in 1997 to 6,084 kg/
ha/year in 2003, compared to an international
average of 958 kg/ha/year (FAO).
More InforMatIon:
www.fao.org/fishery/countrysector/naso_brazil/en
5
Thailand
Shrimp farming has been practised in Thailand
for more than 30 years, with its development
expanding rapidly during the mid-1980s. This
expansion was supported by advances in
shrimp feed and the successful production of
larvae in 1986.
The most popular shrimp cultivated in
the country is the giant tiger prawn (Penaeus
monodon) which accounts for 98 percent of
shrimp production and around 40 percent of
total brackish water aquaculture production
(FAO). L. vannamei was first introduced to
Thailand in the late 1990s as an alternative to
the native P. monodon.
The production of L. vannamei in Thailand
rapidly increased from 10,000 metric tons in
2002 (Briggs et al. 2004) to approximately
300,000 metric tons in 2004, which com-
prised 80 percent of total marine shrimp
production.
More InforMatIon:
www.fao.org/fishery/countrysector/naso_thailand/en
India’s indigenous shrimp
T
he Rajiv Gandhi Centre for
Aquaculture (RGCA) in Tamil Nadu,
India has produced a specific pathogen
free variety of shrimp. The new variety is
set to help commercial shrimp farmers and
boost India’s seafood exports.
The selectively bred mother shrimps are
capable of producing quality seeds that
harness higher growth and survival rates.
Until now, Indian shrimp hatcheries
imported such brood stock from the USA,
Thailand and Singapore, resulting in high
shipping costs and big transit losses. The
average cost of brood stock was estimated
at Rs5,000.
It is estimated that 80 percent of India’s
shrimp farmers are small scale - the quality of
seeds largely affects their crop success. Due
to the high costs, some hatcheries have been
sourcing brood stock from shrimp ponds,
which ultimately results in the production of
poor quality seeds and subsequent crop loss
to farmers.
2
EXPERT T●PIC

Innovations for a better world.
Bühler AG, Feed & Biomass, CH-9240 Uzwil, Switzerland, T +41 71 955 11 11, F +41 71 955 28 96
fu.buz@buhlergroup.com, www.buhlergroup.com
Fatten up your bottom line. Bühler high-performance animal and aqua feed production
systems are used by leading companies around the world. These producers know they
can rely not just on the technology itself, but also on the support that accompanies it. A
service combining local presence with global expertise both lowers feed mill operating
costs and increases capacity utilization. To find out more, visit www.buhlergroup.com

Cause
of EMS
detected
T
he pathogen which
causes early mortality
syndrome (EMS) has
been identified by
researchers at the University
of Arizona, USA.
A research team led by
Donald Lighter found that EMS,
or more technically known as
acute hepatopancreatic necrosis
syndrome (AHPNS), is caused
by a bacterial agent, which is
transmitted orally, colonizes the
shrimp gastrointestinal tract and
produces a toxin that causes tis-
sue destruction and dysfunction
of the shrimp digestive organ
known as the hepatopancreas.
The disease was first record-
ed in China in 2009 and has
since spread to Vietnam (2011),
Thailand (2012) and Malaysia
(2012). EMS kills shrimp
between 10-40 days after the
post-larval stage with mortalities
of up to 70 percent. Shrimp
that survive suffer from stunted
growth and tale twice as long to
achieve significant grow out.
The economic impact of
EMS is perhaps yet to be
fully felt. However, the dis-
ease is one of the most sig-
nificant reasons in the fall in
Thai shrimp production. In
2010, the country produced
600,000 toms of shrimp but
by 2012, this figure has fallen
to 500,000 tons, a drop of
around 18 percent.
Lightner’s team identified the
EMS pathogen as a unique strain
of a relatively common bac-
terium, Vibrio parahaemolyticus,
that is infected by a virus known
as a phage, which causes it to
release a potent toxin. A simi-
lar phenomenon occurs in the
human disease cholera, where a
phage makes the Vibrio cholerae
bacterium capable of producing
a toxin that causes cholera’s life-
threatening diarrhea. EMS how-
ever, is not a danger to people.
Research continues on the
development of diagnostic
tests for rapid detection of the
EMS pathogen that will ena-
ble improved management of
hatcheries and ponds, and help
lead to a long-term solution for
the disease. It will also enable a
better evaluation of risks associ-
ated with importation of frozen
shrimp or other products from
countries affected by EMS.
Some countries have imple-
mented policies that restrict the
importation of frozen shrimp
or other products from EMS-
affected countries. Lightner
said frozen shrimp likely pose
a low risk for contamination
of wild shrimp or the envi-
ronment because EMS-infected
shrimp are typically very small
and do not enter international
commerce. Also, his repeated
attempts to transmit the disease
using frozen tissue were unsuc-
cessful.
In an effort to learn from past
epidemics and improve future
policy, the World Bank and
the Responsible Aquaculture
Foundation, a charitable edu-
cation and training organisa-
tion founded by the Global
Aquaculture Alliance, initiated
a case study on EMS in Vietnam
in July 2012. Its purpose was
to investigate the introduction,
transmission and impacts of
EMS, and recommend manage-
ment measures for the public
and private sectors.
6
EXPERT T●PIC

Providing proficient tools to achieve cost-
effective and sustainable aquaculture practices
Central Office and Orders
Jesús Aprendiz, 19. 1º A-B
28007 Madrid
T. +34 915 014 041
norel@norel.es www.norel.es
Aqua Range
FUNGINAT AQUA
ECOBIOL AQUA
AQUABOND
GLYMET MIX AQUA AQUANOX
GUSTOR AQU
AQUABOND
GUSTOR AQUA
AQUANOX

Application
of isotopic
techniques
to assess the
nutritional
performance of
macroalgae in
feeding regimes
for shrimp
by Julián Gamboa-Delgado
PhD, research officer, Programa
Maricultura, Universidad Autónoma
de Nuevo León, Mexico
D
ue to their nutritional prop-
erties, several species of
macroalgae have been used as
dietary supplements for shrimps
and other marine species. Since macroalgae
represent a natural source of nutrients in
the shrimp’s natural environment, attempts
have been done to co-culture macroalgae
and shrimps.
The nutritional
performance
and digestibil-
ity of macroalgae-
derived meals
have been tested
in formulated diets
for shrimp. One of
the aspects requir-
ing further research
is represented by
the loss of nutritional
properties occurring
when the macroalgal
biomass is dried out as
compared when the algal
biomass is ingested as live
biomass.
Several nutritional method-
ologies have been used to evalu-
ate the performance of different
ingredients used or proposed for
aquaculture feeds. The use of stable isotopes
as tools to assess nutritional contributions of
specific ingredients to growth is one of many
emerging nutritional techniques applied in
aquaculture.
The chemical composition of macroalgae
varies among species and environmental con-
ditions; however, most are rich in non-starch
polysaccharides, vitamins, and minerals. In
particular, green macroalgae (Chlorophyceae)
often have higher protein content than brown
seaweeds. Such nutritional properties, in con-
junction with novel macroalgae production
methods, have increased the interest in their
use as dietary ingredients for aquaculture
diets. Additionally, there are studies that have
focused on their use as additives to enhance
the immunological status of the farmed animals.
The green macroalgae Ulva (Enteromorpha)
clathrata, also known as aonori in Asian
countries, has worldwide distribution and due
to its nutritional profile, has been evaluated
as a dietary supplement for aquatic species.
U. clathrata has been mass-cultured in recent
years under a patented technology developed
by Aonori Aquafarms Inc. By applying this
methodology, macroalgae biomass is rapidly
grown in ponds without eliciting detrimental
effects to the environment.
Evaluation of macroalgae in
shrimp nutrition studies
Although it has been observed that use of
macroalgal biomass alone as feed does not
fulfil the nutritional requirements for optimal
growth in marine shrimp, co-culture of U.
clathrata and Pacific white shrimp L. vannamei
has been conducted with positive results in
terms of lower feed utilization and improve-
ment of the shrimp nutritional quality, flesh
colour and texture.
Recent nutritional studies have also shown
that when dry Ulva clathrata meal is fed
to Pacific white shrimp as an ingredient in
practical diets, it has an apparent digestibility
coefficient for dry matter of 83 percent, while
the same value for protein is 90 percent.
However, the high ash content and the rela-
tively low protein content of this macroalgae
species prevent its dietary inclusion at high
levels when attempting to replace other
ingredients such as fishmeal.
Stable isotopes to assess
the nutritional contribution
of macroalgae
Over the last few decades, different iso-
topic methodologies have been adopted from
the ecological sciences and have been applied
to animal nutrition studies. Most elements in
organic matter are present as two or more
stable isotopes and heavier isotopes have
a tendency to accumulate in animal tissue.
For example, animal predators have higher
isotopic values than their preys; therefore, a
specific isotopic signature is conferred to each
Table 1: Growth, survival rate and estimated consumption of formulated feed and live
macroalgae biomass (dry weight) by juvenile litopenaeus vannamei reared on five different
feeding regimes for 28 days (n= 8-20, mean values ±SD)
Feeding
regime
Survival (%)
Final wet
weight (mg)
Weight
increase (%)
Consumed
formulated
feed (g)
Consumed
U. clathrata
(g)
100F 95 ± 13a 995 ± 289a 429 0.94 -
75F/25U 93 ± 11a 1067 ± 364a 467 0.81 0.40
50F/50U 78 ± 11ab 768 ± 273ab 308 0.43 0.44
25F/75U 60 ± 21b 424 ± 207b 125 0.14 0.65
100U* 23 ± 4c 221 ± 49c 18 - 1.32
Initial wet weight = 188 ±28 mg
Different superscripts indicate significant differences at p<0.05
* Parameters in animals from feeding regime 100U were estimated on experimental day 21
Juvenile Pacific white shrimp
feeding on U. clathrata
macroalgal biomass. Long fecal
strands are frequently related
to fast gut transit
ImagecourtseyofAlbertoPena©
7
EXPERT T●PIC

trophic level (primary producers, herbivores,
carnivores).
In the case of plants and macroalgae, their
carbon isotope values are strongly influenced
by the type of photosynthesis they present.
On the other hand, the nitrogen stable iso-
tope values of plants and macroalgae can be
easily manipulated by means of specific fertilis-
ers, to eventually conduct nutritional studies.
By using such techniques, it can be possible
to determine the proportions of available
dietary nutrients that have been selected,
ingested and incorporated into animal tis-
sue (Figure 1). As the average sample size
required for stable isotope analysis (carbon
and nitrogen) is only 1 mg of dry tissue or
test diet, the technique has been very useful in
larval nutrition studies. It has been employed
to quantify the proportions of nutrients incor-
porated from live and formulated feeds in fish
and crustacean larvae.
Likewise, stable isotope analyses of dif-
ferent plant-derived ingredients (soy protein
isolate, corn gluten and pea meal) have been
carried out to explore the contribution of the
dietary nitrogen supplied by these sources (as
compared to fish meal) to shrimp growth. In
the context of macroalgae as source of nutri-
ents, isotopic techniques have been applied
as nutritional tools to quantify the relative
contributions of dietary carbon and nitrogen
to the growth of Pacific white shrimp co-fed
formulated feed and live macroalgal biomass
of U. clathrata.
Experimental
design
Taking advantage
of the contrast-
ing natural carbon
and nitrogen stable
isotope values meas-
ured in a commercial
formulated feed and
in live macroalgal bio-
mass of U. clathrata,
the study aimed to
quantify the relative
contribution of nutri-
ents to the growth of
Pacific white shrimp.
Animals were allocat-
ed to duplicate tanks
individually fitted with air lifts and connected
to an artificial-seawater recirculation system.
Feeding regimes consisted of a positive
isotopic control (100% formulated feed,
treatment 100F), a negative isotopic control
(100% macroalgae, treatment 100U) and
three co-feeding regimes in which 75, 50,
and 25 percent of the daily amount of con-
sumed macroalgal biomass was substituted
by formulated feed (treatments 75F/25U,
50F/50U, and 25F/75U, respectively) on a
dry weight basis.
The digestibility of both feeding sourc-
es for L. vannamei has been previously
assessed and is similarly high (>80%).
Live macroalgae was supplied to shrimp
by attaching the algal biomass to plastic
mesh units from which the algal filaments
were constantly available and easily nibbled
upon by shrimp.
Feeding rations and proportions were pro-
gressively adjusted in relation to the amount
of macroalgal biomass consumed, animal sur-
vival and sampling. Shrimp samples (whole
bodies and muscle tissue) and diet samples
were collected and pre-treated for isotopic
analysis.
Growth and survival
There was a high variability in final wet
Figure 1: Carbon and nitrogen flow in shrimps produced
under semi-intensive farming conditions. Bold arrows
indicate components that can be isotopically analyzed to
determine their origin and fate
EXPERT T●PIC
Using unique macroalgae formulas to
improve health, taste and quality of shrimp100% Marine Natural Diet
A New Dimension
in Sustainable Aquaculture
Feed Ingredients from the Sea
T: +353 (0)93 51807
E: info@oceanharvest.ie
Scientifically proven
activity against
whITe SpoT vIrAl dISeASe
& lower FCr
Need to keep up to date with news about shrimp?
Global Aquaculture News scours the web every day to bring
you all of the latest information available.
Visit: www.aquafeed.co.uk/aquaculturenews

weight of shrimps under the different dietary
treatments; however, a clear tendency for
higher growth was observed in shrimps reared
on regime 75F/25U (1,067 ±364 mg, final
mean weight), followed by shrimps fed only
on formulated feed (995 ±289 mg). Shrimps
from both feeding regimes increased their
weight more than 400 percent (Table 1).
Animals fed only on U. clathrata bio-
mass showed very low growth (221 ±49
mg) and only 23 percent of the animals in
this treatment survived by day 21. Higher
survival rates (93-95%) were observed in
shrimps reared on feeding regimes 100F and
75F/25U, while shrimps in dietary treatments
50F/50U and 25F/75U had respective mean
survival rates of 78 and 60
percent. The positive effect
of supplying both, live feeds
and formulated diets has been
recurrently observed in previ-
ous crustacean studies.
Dietary contributions
from macroalgae and
formulated feed
At the end of the experi-
ment, isotopic values of shrimp
tissue reared on co-feeding
treatments were strongly
biased towards the isotopic
values of U. clathrata biomass.
Figure 2 combines carbon
and nitrogen stable isotope
values measured in shrimps
and provides a graphic indica-
tion of the total organic matter
contributed by both, the for-
mulated feed and macroalgae.
Results from an isotopic mixing
model indicated that shrimps in
the three co-feeding regimes
incorporated significantly higher
amounts of dietary carbon and
nitrogen from U. clathrata biomass than from
the formulated feed (Table 2).
At the end of the experiment, shrimps in
treatment 75F/25U incorporated 68 percent
of carbon from the formulated feed and 32
percent from the macroalgae. Shrimps under
feeding regimes 50F/50U and 25F/75U incor-
porated significantly higher amounts of dietary
carbon from U. clathrata (49 and 80%, respec-
tively) when compared to the expected
dietary carbon proportions supplied by these
the co-feeding regimes (34 and 70%, respec-
tively). Shrimp grown in co-feeding regime
75F/25U incorporated 27 percent of nitrogen
from the formulated feed and the remaining
73 percent from the macroalgal biomass,
while animals reared on regimes 25F/75U and
50F/50U incorporated the majority of their
dietary nitrogen (98 and 96%, respectively)
from the macroalgae.
The lower growth attained by these ani-
mals indicated that a very high proportion of
the isotopic change was due to high nitrogen
metabolic turnover and not to tissue accre-
tion. Due to its lower carbon and nitrogen
contents, the macroalgal biomass had to be
consumed at higher amounts in order to sup-
ply the observed elemental contributions to
shrimp whole bodies and muscle tissue.
The availability and
incorporation of nutrients from
formulated and live feeds
The higher than expected contributions
of macroalgal carbon and nitrogen to shrimp
growth are possibly related to the high
digestibility of U. clathrata and its continuous
availability for shrimp. Chemical analyses of U.
clathrata have shown that it typically contains
low to medium protein levels (20 - 30%) and
very low lipid levels. The cell wall polysac-
charides in macroalgae might represent more
than half of dry algal matter, but a tentative
role of the latter as energy source is unlikely as
specific enzymatic activities for these polysac-
charides (ulvanase, fucoidanase) have not
been reported for Penaeid shrimps. Despite
their lower nutrient concentration, live feed
contains higher water content which contrib-
utes to higher digestibility.
In contrast, formulated feed can contribute
nutrients that are scarce or absent in live feed,
but the incorporation of such nutrients is limited
by low feed digestibility or unsuitable formulation.
Previous co-feeding experiments conducted on
postlarval shrimp and larval fish have shown
that the supplied live feed frequently contributes
higher proportions of nutrients to the growth of
the consuming animals than those supplied by
formulated feeds in co-feeding regimes.
Conclusion
Although the live macroalgae by itself was
not nutritionally complete for Pacific white
shrimp, it supplied a very significant propor-
Table 2: estimated contribution of dietary nitrogen supplied
from formulated feed and live biomass of Ulva clathrata and
incorporated in tissue of postlarval Pacific white shrimp L.
vannamei as indicated by stable isotope analysis.
Feeding regime
expected* observed
Whole
bodies
Muscle
tissue
75F/25U
Formulated feed 79.6a** 15.9 b 20.5 b
Ulva biomass 20.4 84.1 79.5
50F/50U
Formulated feed 66.1a 2.2 b 6.9 b
25F/75U
Formulated feed 30.1a 1.0 b 3.2 b
*Expected proportions are estimated from the actual
proportions of formulated feed and macroalgal biomass
offered (on a dry weight basis)
**Superscripts indicate significant differences between
expected and observed dietary contributions
Figure 2: Carbon and nitrogen dual isotope (‰) plot of whole bodies and muscle
tissue of white shrimp L. vannamei reared on feeding regimes consisting of different
proportions of formulated feed and live U. clathrata biomass. Muscle tissue values
for treatment 100U were estimated for day 28 from values in whole bodies. n= 2-4,
mean values ±SD
EXPERT T●PIC

tion of structural carbon and nitrogen when
co-fed with formulated feed.
However, the high amount of nutrients
derived from the live macroalgae biomass in
co-feeding regimes supplying more than 50
percent of macroalgae, was not reflected in a
fast growth increase. This was possibly due to
the restriction of other nutrients in this mac-
roalgae species. Interestingly, shrimp under
the co-feeding regime supplying 75 percent
of formulated feed and 25 percent of live
macroalgae biomass showed higher growth
rates than animals reared only on commercial
formulated feed, although the difference was
not statistically significant.
The low levels of energy, amino acids and
fatty acids in the macroalgae biomass avail-
able to shrimp, were compensated through
high ingestion rates, which caused a higher
incorporation of nutrients in shrimp tissue.
On the other hand, it is very likely that the
carbohydrates and lipids supplied by the
formulated feed significantly contributed to
the energy requirements of shrimp under the
three co-feeding regimes.
The importance of the natural productivity to
shrimp grown in semi-intensively managed ponds
has been widely documented. The systematic
use of macroalgae in production ponds not only
provides a significant nutritional supply to cultured
organisms, but also offers substrate for periphyton
growth and refuge for moulting shrimps. In addi-
tion, it has been demonstrated that Ulva clathrata
and other macroalgae species are efficient remov-
ers of the main dissolved inorganic nutrients,
hence maintaining good water quality levels in
aquaculture ponds and effluents.
Diverse isotopic techniques can be applied
to elucidate the transfer of nutrients at the level
of amino acids and fatty acids; therefore, future
experimental assays might reveal what specific
nutrients are contributed from the macroalgal
biomass (or any other component of the natu-
ral biota) and from the supplied formulated
feeds. The loss of some nutritional properties
that occurs in dietary ingredients that undergo
drying (or freeze drying) has not been thor-
oughly explained and future studies applying
stable isotopes might shed some light on the
differences observed when aquatic animals
consume moist or dry dietary components.
References
Burtin, P. 2003. Nutritional value of seaweeds.
Electron. J. Environ. Agric. Food Chem. 2:498–503.
Cruz-Suárez, L.E., A. León, A. Peña-Rodríguez, G.
Rodríguez-Peña, B. Moll, D. Ricque-Marie. 2010.
Shrimp/Ulva co-culture: a sustainable alternative to
diminish the need for artificial feed and improve
shrimp quality. Aquaculture 301: 64–68.
Gamboa-Delgado, J. 2013. Nutritional role of
natural productivity and formulated feed in semi-
intensive shrimp farming as indicated by natural
stable isotopes. Reviews in Aquaculture In press.
Gamboa-Delgado, J., M.G. Rojas-Casas, M.G.
Nieto-López, L.E. Cruz-Suárez 2013. Simultaneous
estimation of the nutritional contribution of
fishmeal, soy protein isolate and corn gluten to
the growth of Pacific white shrimp (Litopenaeus
vannamei) using dual stable isotope analysis.
Aquaculture 380-383: 33-40.
Gamboa-Delgado, J., A. Peña-Rodríguez, L.E. Cruz-
Suárez, D. Ricque D. 2011. Assessment of nutrient
allocation and metabolic turnover rate in Pacific
white shrimp Litopenaeus vannamei co-fed live
macroalgae Ulva clathrata and inert feed: dual
stable isotope analysis. J. Shellfish Res. 30: 1–10.
Moll, B. (Sinaloa Seafields International). 2004.
Aquatic surface barriers and methods for culturing
seaweed. International patent (PCT) no. WO
2004/093525 A2. November 4, 2004.
Villarreal-Cavazos D.A. 2011. Determinación
de la digestibilidad aparente de aminoácidos de
ingredientes utilizados en alimentos comerciales
para camarón blanco (Litopenaeus vannamei) en
México. PhD Thesis. Universidad Autónoma de
Nuevo León, Mexico. http://eprints.uanl.mx/2537
More InforMatIon:
Julián Gamboa-Delgado PhD
Tel: +52 81 8352 6380
Email: julian.gamboad@uanl.mx
EXPERT T●PIC
20th
Annual Practical Short Course on
Aquaculture Feed Extrusion,
Nutrition, & Feed Management
September 22-27, 2013
For more information, visit
http://foodprotein.tamu.edu/extrusion
or contact
Dr. Mian N. Riaz
mnriaz@tamu.edu
979-845-2774
Hands-On Experience
Texas A&M University in College Station, Texas
o various shaping dies (sinking, floating, high fat),
coating (surface vs vacuum), nutrition, feed
formulation, and MUCH MORE!
Extruding Aquaculture Feeds
o 30+ lectures over a wide
variety of aquaculture
industry topics
o one-on-one interaction with
qualified industry experts
o at the internationally
recognized Food Protein
R&D Center on the campus
of
o discussion and live equipment demonstrations
following lectures on four major types of extruders
also stimulate digestive enzyme production
(Cahu et al. 1998).
Production of microalgae
Despite the many advantages of microalgae,
their wider use is hampered by difficulties in
culturing, storage, and high costs. Microalgae
culture can consume a significant fraction of the
resources of a hatchery, and requires special
equipment, skilled labour, and a large alloca-
tion of space that is unproductive during the
seasons when live feeds are not needed.
Low-cost open-pond culture methods
carry high risks of contamination and culture
failure due to the impossiblity of tightly con-
trolling culture conditions, and the most highly
prized high-PUFA strains such as Isochrysis and
Pavlova require indoor culture.
It is very difficult to synchronize microalgal
production with live feed requirements to
prevent feed shortages or wasteful overpro-
duction, and it is difficult to accurately dose
algae cultures directly into live feed cultures.
If the algae are harvested and concentrated,
the tightly-packed cells can deteriorate rapidly
in refrigerated storage. Some microalgae have
been freeze- or spray-dried, but dried cells
are subject to protein denaturation, and when
they are rehydrated the leaching of water-
soluble substances can rapidly deplete their
nutritional value, as with other dry feeds.
Microalgae concentrates
The best solution to these problems
can be the use of commercially-available
refrigerated or frozen algae concentrates
or ‘pastes’ (Guedes & Malcata 2012,
Shields & Lupatsch 2012). These products,
which are actually viscous liquids, have
proven to be effective feeds for rotifers,
Artemia, shellfish and other filter-feeders,
as well as for greenwater applications.
In products formulated to provide a
long shelf-life, the concentrated microalgae
are suspended in buffer media that pre-
serve cellular integrity and nutritional value,
although the cells are non-viable. When
concentrates with well-defined biomass
densities are employed, the algae can be
accurately dosed into live feed cultures
with a metering pump, and non-viability
confers the advantage that the products
pose no risk of introducing exotic algal
strains. The best refrigerated products typi-
cally have a shelf-life of 3-6 months, and
frozen products several years. This means
that a reliable supply of algae can be kept
on hand, available for use in any season or
if an unexpected need arises. Algae costs
become predictable, and often prove to
be less than on-site production when total
production costs and inefficiencies are
accounted for.
Although costs of liquid algae concen-
trates are higher than for dried algae or
formulated feeds, they offer all the nutritional
advantages of live cultures. The nutritional
quality of live feeds can be no better than
the food sources used to produce them.
Success of early larvae is so critical to the
success of a hatchery that even a relatively
small improvement in survival or growth rate
can yield great benefits.
Outlook
Live feeds remain indispensable for
larviculture of many fish. Although micro-
algae are among the costliest food sources
used to produce live feeds, their many
advantages justify the cost for hatcheries
producing high-value fish. Research contin-
ues to better characterise the nutritional
properties of various algae strains and to
optimise algae production technologies.
We can anticipate that introduction of
novel algae strains and nutritionally-opti-
mised combinations of strains, along with
improved feeding protocols, will ensure
that microalgae remain the food of choice
for production of the highest-quality live
feeds.
References
www.aquafeed.co.uk/referencesIAF1303
FEATURE
Naturally ahead
MYC OFIX
Myco
toxin Ri
sk
M
a
n a g e M
ent
Mycofix®
More protective.
Mycotoxins decrease performance and interfere
with the health status of your animals.
Mycofix®
is the solution for mycotoxin risk management.
mycofix.biomin.net

AQUAFEED
6 ISSUES
International Aquafeed is published six times a year, bringing you in-depth features, industry news,
events, book reviews and more.
As well as your personal copy delivered direct to your address, subscribers to International
Aquafeed also receive a free copy of the International Aquafeed Directory worth UK£85.
For more information please visit our website.
For a complimentary trial issue, please contact the circulation & subscriptions manager - Tuti Tan -
Email: tutit@aquafeed.co.uk
www.aquafeed.co.uk/subscribe.php
THE AQUAFEED DIRECTORY
The International Aquafeed Directory was launched in 1997 as an easy to use publication for
manufacturers of fish feed to source suppliers. It evolved to become a practical guide to plant and
materials available throughout the world.
It is one of the most comprehensive information sources specifically designed to identify all aquafeed
ingredients, raw feedstuffs, feed additive micro-ingredients, production machinery and plant and
equipment available on the world market.
+
www.aquafeed.co.uk
UK£69 Recieve six issues of International Aquafeed magazine
+ The International Aquafeed Directory & Buyers Guide
16
INTERNATIONAL AQUAFEED DIRECTORY 2012/13
SCIENCE DFO SCIENCE SCI
Saltwater mariculture-aquaculture inQuebec may soon welcome a newarrival: the Spotted Wolffish, athreatened and little-known species thattastes delicious.
In Quebec, commercial fish farmscurrently limit themselves to farmingfreshwater fish, while the maricultureindustry has focused until very recentlyon molluscs. In other parts of the world,saltwater fish farms are located right inthe ocean. Doing so significantly reducesfarming costs and makes themprofitable. In Quebec, installingaquaculture equipment in the ocean is adicey prospect because of ice cover inwinter. Previously, experiments withfarming saltwater fish in tanks revealedthe need for technical expertise as wellas the high cost of production. Today,however, research advances are showingthe potential of the Spotted Wolffish.This new mariculture candidate wasfirst noticed in the early 2000s. At thetime, teams from the Maurice-Lamontagne Institute in Mont-Joli,Quebec, collected their first SpottedWolffish as part of the research projectsthey were conducting with the
Université du Québec à Rimouski andthe Quebec ministry of agriculture,fisheries and food.
First of all, the Spotted Wolffish is afish that adapts well to the conditions itis kept in and is easy to domesticate. Itdevelops quickly at very lowtemperatures and is not very sensitive tochanges in the salinity of the water.Spotted Wolffish can be farmed in highdensities, something that is crucial forthe profitability of an aquacultureoperation (see Figure 2). As well, eventhough the Spotted Wolffish does notreproduce spontaneously in captivity,new generations can be produced everyyear using captive broodstock. And let’snot forget another important quality thisfish possesses: it tastes great.Aside from these obvious advantages,it is important to find out how thisspecies grows in captivity so that itspotential benefit to Quebec’s aquacultureindustry can be properly assessed. Forthat reason, Denis Chabot, a researcher atthe Maurice-Lamontagne Institute, wasapproached by the Société dedéveloppement de l’industrie maricole(SODIM) to carry tests using water tanks.
r
w
a
d
w
ca
Le
de
the
T
of f
de G
Mau
200
thes
hand
resea
cond
those
opera
compa
and I
have b
comme
years
Mont-Jo
slightly
Norway
consider
species;
Maurice-
some roo
Feeding
challenges
in farme
commercia
intended fo
modified. T
wolffish tha
to develo
Researchers
offers enoug
needs of the
the feed doe
bottom of the
when it com
raised in high
Farming saltwater fish inThe Spotted Wolffish show
Figure 2: Spotted Wolffish in farming tank
Photo: Arianne Savoie, Fisheries and Oceans Canada
pg16_DFO_wolffish.qxd 24/8/12 12:30 Page 16

www.aquafeed.co.uk
LINKS
• See the full issue
• Visit the International Aquafeed website
• Contact the International Aquafeed Team
• Subscribe to International Aquafeed
They are what they eat
Enhancing the nutritional value of live feeds
with microalgae
Controlling mycotoxins with
binders
Ultraviolet
water disinfection for fish
farms and hatcheries
Niacin
– one of the key B vitamins for sustaining
healthy fish growth and production
Volume 16 Issue 3 2013 - mAY | Ju Ne
INCORPORATING
fIsh fARmING TeChNOlOGy
This digital re-print is part of the May | June 2013 edition of International
Aquafeed magazine.
Content from the magazine is available to view free-of-charge, both as a full
online magazine on our website, and as an archive of individual features on
the docstoc website.
Please click here to view our other publications on www.docstoc.com.
To purchase a paper copy of the magazine, or to subscribe to the paper
edition please contact our Circulation and Subscriptions Manager on the link
above.
INFORMATION FOR ADVERTISERS - CLICK HERE

EXPERT TOPIC 1303- SHRIMP

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to EXPERT TOPIC 1303- SHRIMP

Similar to EXPERT TOPIC 1303- SHRIMP (20)

More from International Aquafeed

More from International Aquafeed (20)

Recently uploaded

Recently uploaded (20)

EXPERT TOPIC 1303- SHRIMP