Selective breeding of
Pacific white shrimp (Litopenaeus vannamei) for growth and resistance
to Taura Syndrome Virus
B.J. Argue, S.M. Arce, J.M. Lotz, S.M. Moss-2002
Aquaculture, 204(3-4): 447-460
Abstract:
From 1995 to 1998, the Oceanic Institute operated a
breeding program for Pacific white shrimp, Litopenaeus vannamei,
based on a selection index weighted equally for growth and resistance to
Taura Syndrome Virus (TSV). In 1998, two separate breeding lines were
established. One line was selected 100% for growth (Growth line) and a
second line was selected on an index weighted 70% for TSV resistance and 30%
for growth (TSV line). After one generation of selection, select shrimp from
the Growth line were 21% larger than unselected control shrimp (24.2 vs.
20.0 g). The half-sib heritability (h2) estimate for
growth was 0.84±0.43(s.e.) and realized h2 was 1.0±0.12.
Females were 12.7% larger than males. Shrimp tails accounted for 65.1% of
total body weight and males had a significantly higher percent tail than
females (65.7% vs. 64.5%; P<0.001). Half-sib h2
for percent tail was 0.15±0.12. In the TSV line, there was an 18.4%
increase in survival to TSV between select and control shrimp after one
generation of selection (46.4% vs. 39.2%). Realized h2 for
TSV resistance was 0.28±0.14 and h2 on the underlying
scale was 0.30±0.13. However, select shrimp in the TSV line were 4.6%
smaller than control shrimp (22.6 vs. 23.7 g) and there was a negative
genetic correlation between mean family growth and mean family survival to
TSV [
-0.46±0.18(s.e.)]. Percent females per family ranged from 39.7% to 69.2%
and averaged 51% female, but h2 for sex ratio was zero,
indicating that it is not feasible to select for a higher percentage of
females. Significant improvements in growth and TSV resistance can be made
in L. vannamei through selective breeding; however, the
negative genetic correlation between growth and TSV resistance must be
considered when developing breeding plans.
(The Oceanic Institute, 41-202 Kalanianaole Hwy.,
Waimanalo, HI 96795, USA, Tel.: +1-808-488-6554; fax: +1-808-488-4502,
e-mail: argueb001@hawaii.rr.com)