V. Culture
ICES mar. Sei. Symp., 201: 138-142. 1995
Review of some aspects of marine fish larviculture
Patrick Sorgeloos, Marleen D ehasque, Philippe Dhert, and Patrick Lavens
Sorgeloos, P., Dehasque, M ., Dhert, P., and Lavens, P. 1995. Review of some aspects
o f marine fish larviculture. - ICES mar. Sei. Symp., 201: 138-142.
Dependable availability of quality fry to stock grow-out production systems has been
one of the most critical factors in the commercial success of industrial production of
fish and shellfish. Large-scale production of marine fish fry was realized only from the
1980s onwards. Although Japan was the pioneer with the red sea bream ( Pagrus
m ajor), the most competitive hatchery methods were eventually developed in Europe
for the sea bass (Dicentrarchus labrax) and the gilthead sea bream (Sparus aurata).
Improved knowledge of larval dietary requirements, not the least with regard to (n-3)
highly unsaturated fatty acids (H U FA s), combined with the adoption of live-food
enrichment protocols allowed the successful transition from pilot to commercial-scale
larviculture. Initially based on an empirical approach, larviculture nutrition research
today is of a multidisciplinary nature. T here are good indications that the more
fundamental approach will lead to significant progress in hatchery outputs. The larval
dietary regimes will eventually be adjusted as a function of the cultured species and/or
specific developmental stages, e.g., changes in the enrichment protocols for Brachionus and A n e m ia , the selected formulation of substitution diets, and/or the adoption of
co-feeding techniques. The area that has been most neglected so far, but might
provoke the biggest impact in future hatchery technology is microbiology. Also the
prophylactic and therapeutic use of antibiotics and other chemotherapeutics is
expected to undergo significant improvements in the near future. In addition, it is very
likely that better broodstock conditioning and feeding can ensure improved and
constant larval qualities. Finally, improved zoo techniques will make fish larviculture
more predictable and more cost-effective, e.g., adoption of modular hatchery systems,
selection and use of new materials, reduction of the so-called “ human factors” by
increased automation, etc.
P. Sorgeloos, M. Dehasque, P. Dhert, and P. Lavens: Laboratory o f Aquaculture and
Artem ia Reference Center, University o f Ghent, R ozier44, B-9000 Ghent, Belgium [tel:
(+ 32)92643754, fax: (+32) 92644193]
Introduction
Large-scale production of marine finfish was pioneered
by the Japanese, with the red sea bream (Pagrus major).
Since the 1960s the Japanese Prefectural Institutes of
Fisheries have been involved in sea bream mass produc­
tion (Hirano and Oshima, 1963). In Europe and the
U SA research in marine fish larviculture started at the
same time, be it on a more modest scale (Morris, 1956;
Riley, 1966). The expertise developed at British and
French research institutes eventually led to the setting­
up of the first commercial hatcheries of the European
sea bass (Dicentrarchus labrax), the gilthead sea bream
(Sparus aurata) and the turbot (Scophthalmus maximus)
in the early 1980s.
Today, Japan is still the biggest producer with about
200 million fry produced per year; i.e., sea bream
(Pagrus major) and Japanese flounder (Paralichthys
olivaceus) making up 70% of the total production, the
rest consisting of puffer ( Takifugu rubripes), rockfish
(Sebastes schlegeli), mud dab (Lim anda yokoham ae)
and several other species (Fukusho, 1993). E urope is
in second place, but with much more competitive
hatchery outputs. In 1993, hatcheries in the Mediter­
ranean were expected to produce more than 100 mil­
lion fry of bass and bream (Stephanis and Divanach,
1993).
In this review, we overview what we consider to have
been, and to some extent still are, important bottlenecks
in the successful larviculture of marine fish.
Marine fish larviculture
ICES mar. Sei. Symp., 201 (1995)
Nutritional requirements
Without doubt, the most significant progress achieved
during the last decade has been the result of improved
nutrition, more particularly through the manipulation of
the fatty acid profile of the live prey, Brachionus and
Artemia (reviews in Sorgeloos and Léger, 1992; Lavens
et al., 1994). However, we have been misled by the most
widely used food item, the brine shrimp A rtem ia, of
which more than 2000 metric tonnes of cysts are cur­
rently m arketed annually for feeding in fish and shellfish
hatcheries. As the studies of W atanabe et al. (1983) and
Léger et al. (1985) revealed, the presence of the fatty
acid 20:5(n-3) (eicosapentaenoic acid or E PA ) deter­
mined the suitability of a given Artemia source for suc­
cessful production of marine fish larvae. Because of
these findings, major emphasis was placed on increasing
the E P A levels in the live prey Brachionus and Artemia
by using algae or, emulsified and particulate enrichment
products (review in Léger et al., 1986).
However, more attention should have been paid to
the levels of 22:6(n-3) (docosahexaenoic acid or D H A )
when evaluating the results of feeding tests with differ­
ent Artemia preparations on E uropean sea bass larvae
(Lisac et al., 1986): good survival appeared to be corre­
lated with high E P A levels in the diet; however, the best
growth was achieved in the diets with the highest D H A
levels. Recent studies with various species have revealed
the importance of D H A and more particularly the re­
quirem ent for high D H A /E P A ratios in promoting
growth, stress resistance, and pigmentation (Lavens et
al., 1995; Kraul et al., 1992; Reitan et al., 1994; and
M ourente et al., 1993). Whereas in the past satisfactory
results were achieved with D H A /E P A ratios of less than
1, the emphasis today is on attaining levels of 4 and
higher in the live prey Brachionus and Artemia (D hert et
a i , 1993). As pointed out by Sargent et al. (1993), neural
tissues contain elevated concentrations of D H A and it is
likely that the DHA-deficient live prey that has been
offered to date has resulted in fish with poor perform­
ance with regard to visual perception of the prey and
other behavioural aspects.
The requirement in the larval diet for (n-3) H U FA s
might also vary as a function of larval quality. This is
illustrated with turbot larvae at first-feeding. In early
spawning adults, when egg and larval quality are gener­
ally at their best, the requirement for D HA-enriched
rotifers is limited to two days only, whereas late in the
season, when poor-quality larvae prevail, the turbot
larvae need to be offered DHA-rich rotifers for a longer
period (D hert et al., 1995). Furtherm ore, Harel et al.
(1994) documented a clear effect of the fatty acid com­
position of the maternal diet on the egg quality of Sparus
aurata. We recently found that, in their early larval
development, turbot can turn black as a result of
139
stressed conditions, e.g., unsuitable light conditions or
elevated larval densities (Lavens et a l., 1995). Recovery
to a normal colour appears to be a function of the (n-3)
H U F A composition of the diet, i.e ., slow when offered a
coconut-enriched Brachionus, fast when feeding E PA
and D H A enriched diets.
It is clear that in the area of larval nutrition most
attention has been paid to the qualitative and quantita­
tive (n-3) H U F A requirements; further work is required
to verify ratios of n-3/n-6/n-9 fatty acids, and especially
to evaluate the effects of other lipid classes, not the least
the phospholipids which might alter the requirements
for (n-3) H U FA s. Aside from the lipids it is clear that
many other dietary components deserve more attention
in future larviculture nutrition research, e.g., different
vitamins (recent work by Merchie et al. (1995a, b, c)
illustrates significant effects in growth and/or stress re­
sistance with vitamin C in different species), free amino
acids, pigments, etc.
In our opinion, the challenge remains of analytically
and biologically unravelling those components in wild
copepods which are responsible for their excellent diet­
ary value for marine larval fish. The aim of this would be
to eventually allow their incorporation in Brachionus
and/or Artemia. Similarly, the use of “green w ater” in
the commercial rearing of most marine fish species
requires further study. Various hypotheses are worth
pursuing, e.g. a source of micro-nutrients, source of
immunostimulants, water quality conditioner, micro­
biological conditioner.
Formulated diets
The ultimate goal in commercial marine fish larvi­
culture is to be able to rely on formulated dry diets
right from start-feeding; however, for most species of
marine fish this remains wishful thinking. Nonetheless,
good progress has been reported at the experimental
level, with artificial diets for start-feeding of some
Japanese fish species (Kanazawa, 1993) and in advanc­
ing early weaning to 400 day degrees and less in the
E uropean sea bass (Person-Le Ruyet, 1993; Devresse
et al., 1991). We are convinced that application of the
co-feeding principle, i.e., supplementing live food with
formulated compounds, in the early larval stages might
provide opportunities for better identification of quali­
tative/quantitative dietary requirements (e.g., with
components such as phospholipids that cannot be
manipulated easily in the live-food fraction). This
might also allow for a possible reduction of live-food
requirements, eventualy resulting in improved outputs
as compared to a diet consisting of live food only
(Lavens et a i , 1995).
140
P. Sorgeloos et al.
Microbial control
A n area that urgently deserves more attention is the
microbial flora of marine fish hatcheries. With upscaling
and expansion of commercial fish larviculture, hatcher­
ies have been plagued by an increased incidence of
microbial diseases, often claimed to be caused by Vibrio
spp. (several pers. comm, with marine fish hatchery
operators in the M editerranean). Similar to practices in
marine shrimp hatcheries, the indiscriminate use of anti­
biotics in prophylactic treatm ent of the fish tanks has
resulted in the development of resistant strains and the
need to switch to other antibiotics, a practice which is
doomed to fail (Brown, 1989).
Verdonck et al. (1994) and Verdonck and Swings
(1995) performed an extensive sampling campaign in
three marine fish hatcheries in the M editerranean during
the first 30 days of rearing of sea bass (Dicentrarchus
labrax) and sea bream (Sparus aurata) larvae; i.e., the
microbial diversity and quantitative presence were
recorded, as well as the relationship between the micro­
flora of the culture water, the live food, and the coloniz­
ation of the larval intestine during development. The
microbial diversity appeared to be enormous (over 1200
bacterial strains were characterized) and varied from
season to season as well as from hatchery to hatchery.
Quantitative data revealed the presence of 100-10000
bacteria per rotifer and per brine shrimp nauplius. The
bacterial numbers found in the gut of larvae increased
with age and feeding regime from 1000 to 100000 per
fish larva. They also noted that the numbers found on a
Vibrio-specific TCBS-medium were always 10 to 100fold lower than the total counts on a marine agar culture
medium, except in cases of mortality outbreaks, when
the values were similar. The fact that the composition of
the microflora in the intestine of healthy fish was not an
exact copy of the microflora found in the culture water or
the live food might be an indication of selective coloniz­
ation of the gut or the existence of so-called probiotic
bacteria.
The major surprise of the microbiological study was
the important input of bacteria (and potentially fish
pathogens) via the live-food chain. New measures
should be considered to reduce bacterial loads as well as
to selectively manipulate the microflora both in the live
feeds produced in the hatchery and in the culture water
prior to stocking of the fish larvae. Selected bacterial
inoculation of the culture tank prior to stocking with the
larvae would not only reduce the chances of opportun­
istic bacteria becoming dominant, but eventually have a
beneficial effect on first colonization of the fish larva’s
gut.
In general, strict hygienic measures should be taken in
hatcheries. Furtherm ore, regular disinfection and dryout of the complete culture circuit (including all piping)
ICES mar. Sei. Sym p., 201 (1995)
between production cycles should be implemented. In
this respect new hatcheries should consider the use of
modular systems rather than having all culture units in
one building.
When antibiotic treatm ent is justified for therapeutic
reasons, the drugs should not be added to the culture
tank but rather oral biomedication applied using Bra­
chionus and/or Artemia as a carrier for the antibiotics
ingested from an emulsified or particulate preparation.
Doses ranging from 20 to 100 ppm sulfadrugs can be
incorporated in sea bass and turbot larval tissue respect­
ively within less than 4 h after feeding Artemia metanauplii boosted with the antibiotics (Chair et al., 1991;
Chair et al., submitted). The therapeutic efficacy of this
oral delivery system has been docum ented by Chair et al.
(1995) and D hert et al. (1995) with turbot larvae chal­
lenged with a Vibrio anguillarum pathogen.
Conclusion
The intensification of hatchery activities brought about
new problems not experienced on the experimental
scale, e.g., in relation to upscaling of life-food produc­
tion, washing and cleaning of live food, intensity of
manual labour, etc. To date, limited attention has been
paid to improved zoo techniques, which might make
marine fish larviculture more predictable and more costeffective, e.g., selection and use of new materials (i.e.,
stainless-steel welded-wedge filters instead of woven
filters for Artemia washing) (Léger and Sorgeloos,
1992), increased automation to reduce the so-called
“ human factor” often responsible for reduced perform ­
ances after several months of operation, etc.
In the past decade, marine fish hatcheries have
evolved from hit and miss ventures into profitable enter­
prises. In Europe, market saturation of bass, bream, and
even turbot fry has been reached faster than was antici­
pated (Sorgeloos and Léger, 1992); i.e., fry prices have
dropped to US$ 0.75 and less per larva (Stephanis and
Divanach, 1993).
Although there is still room for further improvement,
especially with regard to cost-effectiveness, present-day
hatchery technology for marine fish species has proven
to be widely applicable, in terms of both geographic
location and fish species. The list of commercially culti­
vated species is growing rapidly (e.g., various bass and
bream species, turbot, Japanese flounder, fugu, milkfish, mullet) and many candidate species will hopefully
soon join this list, e.g., dolphin fish mahi-mahi, various
grouper species, Atlantic halibut, red snapper, cod,
wolffish.
A cknow ledgem ents
This research was sponsored by the Belgian National
Science Foundation, the Belgian Ministry for Science
ICES mar. Sei. Sym p., 201 (1995)
Policy, the Belgian Administration for Development
Cooperation, the European Community, SINTEF, and
IN V E Aquaculture S.A.
References
Brown, J. 1989. Antibiotics: their use and abuse in aquaculture.
World Aquacult. 20(2): 34-43.
Chair, M ., D ehasque, M ., Sorgeloos, P., Nelis, H ., and De
Leenheer, A. 1995. Live-food mediated drug delivery as a
tool for disease treatment in larviculture: a case study with
turbot (Scophthalmus maximus). J. World Aquacult. Soc.,
26(2): 217-219.
Chair, M ., Nelis, H. J., Léger, P., Sorgeloos, P., and De
Leenheer, A. Accumulation of trimethoprim, sulfamethoxa­
zole and N-acetylsulfamethoxazole in fish and shrimp fed on
medicated Artemia. (Submitted).
Chair, M ., Rom dhane, M., Dehasque, M ., Nelis, H ., De
Leenheer, A ., and Sorgeloos, P. 1991. Live-food mediated
drug delivery as a tool for disease treatment in larviculture.
II. A case study with European seabass. In Larvi ’91 - Fish
and Crustacean Larviculture Symposium, pp. 412-414. Ed.
by P. Lavens, P. Sorgeloos, E. Jaspers, and F. Ollevier. Eur.
Aquacult. Soc., Spec. Publ. No. 15, Ghent. 427 pp.
Devresse, B., Candreva, P., Léger, Ph., and Sorgeloos, P.
1991. A new artificial diet for the early weaning of seabass
(Dicentrarchus labrax) larvae. In Larvi ’91 - Fish and Crusta­
cean Larviculture Symposium, pp. 178-182. Ed. by P.
Lavens, P. Sorgeloos, E. Jaspers, and F. Ollevier. Eur.
Aquacult. Soc., Spec. Publ. No. 15, Ghent. 427 pp.
D hert, P., Lavens, P., Dehasque, M ., and Sorgeloos, P. 1995.
Improvem ents in the larviculture of turbot Scophthalmus
m axim us: zootechnical and nutritional aspects, possibility for
disease control. In T urbot culture: problems and prospects,
pp. 32-46. Ed. by P. Lavens and R. A. M. Remmerswaal.
Eur. Aquacult. Soc., Spec. Publ. No. 22, Ghent. 358 pp.
D hert, P., Sorgeloos, P., and Devresse, B. 1993. Contributions
towards a specific D H A enrichment in the live food Brachio­
nus plicatilis and Artem ia sp. In Fish farming technology, pp.
109-115. Ed. by H. Reinertsen, L. A. Dahle, L. Jørgensen
and K. Tvinnereim. A. A. Balkema, Rotterdam. 482 pp.
Fukusho, K., 1993. Mass larval rearing technology of marine
finfish in Japan: 9. In Book of Abstracts, National Seminar W orkshop on Breeding and Seed Production of Cultured
Finfishes in the Philippines, 4 -5 May 1993, SE A FD E C /
A Q D , Tigbauan, Philippines.
H arel, M., Tandler, A ., and Kissil, G. Wm. 1994. The kinetics
of nutrient incorporation into body tissues of gilthead seabream (Sparus aurata) females and the subsequent effects on
egg composition and egg quality. Br. J. Nutr. 72: 45-58.
Hirano, R., and Oshima, Y. 1963. On the rearing of larvae of
marine animals with special reference to their food organ­
isms. Bull. Japan. Soc. Sei. Fish., 29(3): 282-297.
Kanazawa, A. 1993. Importance of dietary docosahexanenoic
acid on growth and survival of fish larvae. In Finfish hatchery
in Asia: Proceedings of finfish hatchery in Asia ’91, pp. 8795. Ed. by C. S. Lee, M. S. Su, and I. C. Liao. TML
Conference Proceedings 3. Tungkang Marine Laboratory,
Tungkang. 252 pp.
Kraul, S., Nelson, A ., Brittain, K., A ko, H ., and Ogasawara,
A. 1992. Evaluation of live feeds for larval and postlarval
mahimahi Coryphaena hippurus. J. World Aquacult. Soc.
23(4), 299-306.
Lavens, P., Sorgeloos, P., Dhert, P., and Devresse, B. 1995.
Larval Foods. In Broodstock management and egg and larval
Marine fish larviculture
141
quality, pp. 373-397. Ed. by N. R. Bromage and R. J.
Roberts. Blackwell, Oxford. 424 pp.
Léger, P., Bengtson, D. A ., Simpson, K. L., and Sorgeloos, P.
1986. The use and nutritional value of Artem ia as a food
source. Oceanogr. Mar. Biol. ann. Rev., 24: 521-623.
Léger, P., and Sorgeloos, P. 1992. Optimized feeding regimes
in shrimp hatcheries. In Marine shrimp culture: principles
and practices, pp. 225-244. Ed. by A. W. Fast and L. J.
Lester. Elsevier, New York. 862 pp.
Léger, P., Sorgeloos, P., Millamena, O. M ., and Simpson, K.
L. 1985. International study on Artemia. XXV. Factors
determining the nutritional effectiveness of A rtem ia: The
relative impact of chlorinated hydrocarbons and essential
fatty acids in San Francisco Bay and San Pablo Bay Artemia.
J. exp. mar. Biol. Ecol. 93: 71-82.
Lisac, D ., Franicevic, V ., Vejmelka, Z ., Buble, J., Léger, P.,
and Sorgeloos, P. 1986. International study on Artemia.
XLIII. T he effect of life food fatty acid content on growth
and survival of sea bream (Sparus aurata) larvae. Paper
presented at the conference Ichthyopathology in Aquacul­
ture, 21-24 October, Inter-University Center, Dubrovnik.
Merchie, G ., Lavens, P., D hert, P., Pector, R ., Mai Soni, A.
F ., Abbes, M ., Nelis, H . , Ollevier, F ., De L eenheer, A . , and
Sorgeloos, P. 1995a. Live food m ediated vitamin C transfer
to Dicentrarchus labrax and Clarias gariepinus. In Proceed­
ings of the E IFA C W orkshop on Methodology for D eterm i­
nation of Nutrient Requirem ents in Fish, Eichenau, G e r­
many, 29 June to 1 July 1993. J. Appl. Ichthyol. (In press).
Merchie, G ., Lavens, P., Verreth, J., Ollevier, F., Nelis, H .,
D e Leenheer, A ., Storch, V., Sorgeloos, P. 1995b. The
effect of supplemental ascorbic acid in enriched live food for
Clarias gariepinus larvae at startfeeding. Aquaculture. (In
press).
Merchie, G ., Lavens, P.. Verreth, J., Ollevier, F., Pector, R.,
Nelis, H ., D e Leenheer, A ., Storch, V ., and Sorgeloos, P.
1995c. The effect of graded levels of supplemental ascorbic
acid in enriched live food fed to Clarias gariepinus larvae. In
Proceedings of the 6th International Symposium on Fish
Nutrition and Feeding, H obart, Australia, 4 -7 O ctober
1993. Aquaculture. (In press).
Morris, R. W. 1956. Some aspects of the problem of rearing
marine fish. Bull. Inst. Oceanogr., 1082: 1-61.
M ourente, G ., Rodriguez, A ., Tocher, D. R ., and Sargent, J.
R. 1993. Effects of dietary docosahexaenoic acid (D H A ;
22:6n-3) on lipid and fatty acid composition and growth in
gilthead sea bream (Sparus aurata L.) larvae during firstfeeding. Aquaculture, 112: 79-98.
Person Le Ruyet, J., Fischer, C., and Thébaud, L. 1993. Sea
bass (Dicentrarchus labrax) weaning and ongrowing onto
sevbar. In Proceedings of IV International Symposium on
Fish Nutrition and Feeding, Fish Nutrition in Practice, pp.
623-628. Ed. by S. J. Kaushik and P. Luquet. IN R A
editions, Paris. 972 pp.
Reitan, K. I., Rainuzzo, J. R ., and Olsen, Y. 1994. Infiuenceof
lipid composition of live feed on growth, survival and pig­
mentation of turbot larvae. Aquacult. Int., 2: 1-16.
Riley, J. D. 1966. Marine fish culture in Britain, VII. Plaice
(Pleuronectes platessa L.) post-larval feeding on Artem ia
salina L. nauplii and the effects of varying feeding levels. J.
Cons. perm. int. Explor. Mer, 30: 204-221.
Sargent, J. R., Bell, J. G ., Bell, M. V., H enderson, R. J., and
Tocher, D. R. 1993. The metabolism of phospholipids and
polyunsaturated fatty acids in fish. In Aquaculture: Funda­
mental and Applied Research, pp. 103-124. Ed. by B. Lahlou and P. Vitiello. Coastal Marine Studies No. 43, American
Geophysical Union, Washington, DC.
Sorgeloos, P., and Léger, P. 1992. Improved larviculture out­
142
P. Sorgeloos et al.
puts of marine fish, shrimp and prawn. J. World Aquacult.
Soc., 23(4): 251-264.
Stephanis, J., and Divanach, P. 1993. Farming of M editerra­
nean finfish species, present status and potentials. In Book of
Abstracts “ World Aquaculture ’93“ , pp. 290-291. Ed. by M.
Carillo, L. Dahle, J. Morales, P. Sorgeloos, N. Svennevig,
and J. Wyban. Eur. Aquacult. Soc., Spec. Publ. No. 19,
G hent. 632 pp.
V erdonck, L., and Swings, J. 1995. Microbial problems related
to marine fish hatcheries in southern Europe: a case study. In
ICES m ar. Sei. Sym p., 201 (1995)
Memorias II Congreso Ecuatoriano de Acuicultura. pp. 197—
199. Ed. by J. Calderon and P. Sorgeloos. CE N A IM ,
Escuela Superior Politecnica del Litoral, Guayaquil. 306 pp.
Verdonck, L., Swings, J., Kersters, K., D ehasque, M., Sorge­
loos, P., and Léger, P. 1994. Variability of the microbial
environment of rotifer (Brachionus plicatilis) and Artem ia
production systems. J. World Aquacult. Soc., 25(1): 55-59.
W atanabe, T ., Kitajima, C., and Fujita, S. 1983. Nutritional
values of live organisms used in Japan for mass propagation
of fish: a review. Aquaculture, 34: 115-143.