Copepods as live food organisms for marine fish larvae

Copepods as live food organisms for
marine fish larvae
By 1J. O. Evjemo, 2K. I. Reitan and 1Y. Olsen
1 Trondhjem
Biological station,
Norwegian University of Science and Technology (NTNU),
Trondheim, Norway
2 SINTEF, Fisheries and Aquaculture, 7465 Trondheim, Norway
Hopp til første side
First feeding of marine fish larvae using
copepods
Stolt Sea Farm AS,
Rubbestadneset
Bømlo, Norway
Hopp til første side
Semi-intensive production of cod (Gadus morhua L.)
and halibut (Hippoglossus hippoglossus L.) larvae
Meøypollen in Lofoten, Norway
Lofilab AS,
Lofoten, Norway
Hopp til første side
Wide range of zooplankton species,
size and developmental stages
■
■
■
Photo: Tora Bardal, NTNU
Early spring dominated by nauplii and copopodid
stages
Late spring and summer - higher numbers of
adult stages
Chemical composition is variable
Hopp til første side
Total lipid content in Temora longicornis and
Calanus finmarchicus from late April until
late June – early July
(data from different years)
Total lipid content (% of DW)
30
20
Total lipid content
Total lipid content
Total lipid content
10
0
C. finmarchicus
20
10
Total lipid content
Total lipid content
0
Photo: Tora Bardal, NTNU
T. longicornis
April
May
June
July
Hopp til første side
DHA content (mg g-1 DW)
Absolute and relative content of DHA in
T. longicornis, C. finmarchicus and Eurytemora sp.
T. longicornis
Eurytemora sp.
C. finmarchicus
30
20
10
Major fatty acid in
the copepods:
DHA,
EPA,
16:0
% DHA of total fatty acids
0
40
30
20
10
0
April
May
June
April
May
June
July
5/6
June
11/6
Hopp til første side
Absolute and relative content of EPA in
T. longicornis, C. finmarchicus and Eurytemora sp.
EPA content (mg g-1 DW)
T. longicornis
C. finmarchicus
Eurytemora sp.
20
10
% of total fatty acids
0
30
20
10
0
April
May
June
April
May
June
July
5/6
June
11/6
Hopp til første side
Fatty acid profiles of different live food organisms
Artemia franciscana nauplii (newly hatched) and after
enrichment with two enrichment diets
Common copepods from northern coastal waters
mg g-1 DW
300
lipids that are not fatty acid
saturated fatty acids
mono unsaturated
sum n-6
other n-3
20:5n-3 (EPA)
22:5n-3
22:6n-3 (DHA)
250
200
150
100
% of total fatty acids
50
0
100
80
60
40
20
0
A. franciscana
Acartia sp.
C. finmarchicus
Eurytemora sp.
T. longicornis
Hopp til første side
Protein content in different live food organisms
A. franciscans nauplii (newly hatched) and after enrichment
Common copepods from northern coastal waters
Protein content (% of DW)
100
80
60
40
20
0
A. franciscana
C. finmarchicus
T. longicornis
Eurytemora sp.
Acartia sp.
Hopp til første side
% DHA (of total fatty acids)
DHA content in cultivated and wild live
food organisms during starving conditions
A. fransiscana (12°C)
B. plicatilis (18°C)
60
T. longicornis (12°C)
Eurytemora sp. (10°C)
50
40
30
20
10
0
20
40
60
80
100
120
Time (hours)
Hopp til første side
Lossrate of total lipid content, EPA and DHA during
starving conditions in various live food organisms
Loss rate expressed as % reduction day-1 of different lipid
components in T. longicornis, Eurytemora sp. and
A. franciscana during starvation at 12.5°C ± 1
Loss rate (% day-1)
T. longicornis
Total lipid content
EPA
DHA
18
26
14
Eurytemora sp.
A. franciscana
12
17
10
11
15
51
SLR = ln(Qt / Q0)/t
%LR = (eSLR - 1) ⋅ 100
Hopp til første side
Why are copepods superior to enriched Artemia sp. in
first feeding of halibut larvae?
DHA content in halibut larvae
(% of total fatty acids)
DHA content in halibut larvae (H. hippoglossus) fed
Artemia sp. and T. longicornis
DHA content in live food organisms:
T. longicornis
Enriched Artemia sp.
Juvenile Artemia sp.
38% of tot. FA
15% of tot. FA
16% of tot. FA
Photo: Institute of Marine Research, Bergen
larvae fed T. longicornis
larvae fed enriched Artemia sp.
larvae fed juvenile Artemia sp.
50
40
30
20
10
0
0
10
20
30
Time (days)
Hopp til første side
40
Relationship between the DHA content (% of total fatty
acids) in different live food organisms and in halibut
larvae (H. hippoglossus)
% DHA in halibut larvae
50
% DHA in larvae = 0.98(% DHA in live food organism) + 0.55
2
r = 0.95
40
30
20
10
0
0
10
20
30
40
% DHA in live food organism
Photo: Institute of Marine Research, Bergen
Hopp til første side
Lessons learned after 10 years use of marine copepods
in Norwegian marine larvaeculture
■
Nutritional quality of copepods are considered as optimal
◆
◆
◆
■
Availability (restricted to 4 months)
◆
■
■
Lipid and fatty acid content
Protein content
vitamins and minerals
density and species composition are highly variable
Production number of fish fry (200 000 - 800 000 year -1)
To obtain profitable whole year production of fish fry intensively
produced live food organisms must be recommended
Hopp til første side
Intensive production of live food
organisms
■
■
■
Copepods might be used as a supplement during certain
periods of the year
Production of Artemia sp. and rotifers must be given high
priority
Develop new enrichment diets for marine cold water fish
species
◆
establish a main reference from copepod analysis and further
develop intensive live food production (Artemia sp. and B. plicatilis)
Hopp til første side
Conclusions
T. longicornis, Acartia sp. and Eurytemora sp. had a
total lipid content close to 10%
HUFA level ranging from 55% to 62% of total lipid
content
The dominant fatty acids were DHA (25.5 - 42%),
EPA (15.1 - 24%) and 16:0 (8.4 – 12%)
In variuos stages of C. finmarchicus the dominant
fatty acids were DHA (17 - 31%), EPA (17 - 23%)
and 16:0 (9 - 16%)
During early spring the lipid content increased
more than 50% and adult stages had a total lipid
content close to 25% of DW
Size and species composition can be highly variable
Hopp til første side
Conclusions
In the copepods the protein content varied between 52.4 and 57.6% of
DW, and is significantly higher than in A. franciscana (p< 0.005)
There is a close relationship between the percent DHA content in the
halibut larvae and in different live food organisms fed to the larvae.
High DHA content in the live food organism was reflected by a high
DHA content in the larvae and vice versa
There are significant differences in the lipid content and the
distribution of fatty acids in the marine copepods examined and
enriched A. franciscana. The copepods are characterised by a relatively
low lipid content and a high n-3 HUFA content.
Through proper enrichment diets the nutritional value of cultivated live
food organisms will reach the requirements of the larvae
Hopp til første side
Further perspectives
■
■
Ongoing research programme
”Calanus” (2001 - 2005)
Harvesting and use of zooplankton
as a bio-resource for fish feed and
industrial raw material
◆
Copepod - oil for Artemia sp. and rotifer
enrichment
In the Norwegian Sea it is estimated 200 mill ton of
Euphausids, C. finmarchicus and Amphipods. If 0.5%
of the biomass is harvested (1 mill ton) this is the same
amount of biomass used for fish meal and oil in
Norway today
■
Hopp til første side

Download Report