 |
 |
Field trials with commercial grower – In
planned tests, we compared the growth rates of diploid,
induced triploids, and 4Cs Natural Triploids.
Commercial plantings are also in the field and the
reported experience (Taylor United) has been rapid
growth of 4Cs Natural
Triploids.
|
|
|
Expectations for triploid oysters – In
some environments where conditions are unfavorable,
induced triploids seem to perform worse than diploids.
This has been a general observation throughout the
industry. Because of this expectation, 4Cs
Natural Triploids were tested in productive and unproductive
bays in the Pacific Northwest of the US in scientific
fashion. 4Cs Natural Triploids performed better than
induced triploids.
|
|
|
Survival – In
the low productivity site, all groups survived equally
well to market size (see tables below). In the high
productivity site, 4Cs Natural
Triploids had the
highest survival.
|
|
|
Growth – In
the low productivity site, 4Cs
Natural Triploids grew better
than induced triploids, and about the same as diploids.
In the high productivity site, 4Cs
Natural Triploids surpassed both diploids and induced triploids in
growth rate.
|
|
|
Yield – A
comparison of yield of meats from the three groups
indicates that 4Cs Natural Triploids yielded more
meat than induced triploids in all cases.
- Low: diploid = 4Cs
Natural Triploid > induced
triploid
- High: 4Cs Natural
Triploid >> diploid > induced
triploid
|
|
|
Overall – It seems that 4Cs
Natural Triploids have the edge over induced triploid in the
field as well as in the hatchery. In some cases the
extra productivity of 4Cs Natural
Triploids is surprisingly
high, as in productive sites. This probably indicates
a “hybrid vigor” effect.
|
LOW PRODUCTIVITY ENVIRONMENT
Yield of oysters by ploidy group in Netarts Bay for meat
weight. Yield was calculated as a product of average
weight and number of oysters harvested at the end of
the 26 month grow out period.
|
Relative yield (%) |
Ploidy
group |
Survival
(%)
|
Ave.
wt.
(g)
|
No.
oysters
|
Yield
(kg)
|
vs.
2n
|
vs.
3n CB
|
| |
DIPLOID |
84.8 |
8.8 |
1018 |
8.958 |
-- |
|
INDUCED
TRIPLOID |
86.1 |
7.8 |
1033 |
8.057 |
-10
|
|
4Cs
NATURAL TRIPLOID |
86.2
|
8.5
|
1034
|
8.789
|
-1.9
| +9.1
|
HIGH PRODUCTIVITY ENVIRONMENT
Yield of oysters by ploidy group in Netarts Bay for meat
weight. Yield was calculated as a product of average
weight and number of oysters harvested at the end of
the 26 month grow out period.
|
|
|
|
|
Relative yield (%) |
Ploidy
group |
Survival
(%)
|
Ave. wt.
(g)
|
No.
oysters
|
Yield
(kg)
|
vs.
2n |
vs.
3n CB
|
|
DIPLOID |
60.6 |
18.7 |
727 |
13.595 |
-- |
|
INDUCED
TRIPLOID |
53.5 |
18.9 |
642 |
12.134 |
-11 |
|
4Cs NATURAL
TRIPLOID
|
66.3
|
22.3
|
793
|
17.684
|
+30 |
+46
|
|
