Function and metabolism
Biochemical comparison of eggs
and tissues between wild and pond-reared
Penaeus vannamei brood stock
with multiple spawnings
Elena Palacios Mechetnov, Ilie S. Racotta
Centro de investigaciones biologicas del Noroeste (Cibnor), divisiôn de biologia marina,
Apartado postal 128, 23000 La Paz, BCS, México - iracotta@cibnor.mx
Because of increasing importance of shrimp mariculture, optimization
of maturation in captivity needs special attention to obtain high quality
seed stock. The present work examines, from a biochemical point of
view, two issues of this process: the use of pond-reared brood stock and
the influence of consecutive spawns. For this purpose, spawners were
individually tagged and followed for several months to trace the number
of spawns each female had. Samples of egg and nauplii were obtained
periodically for biochemical analysis. Wild females, which had higher
body weight, presented an overall higher productivity compared to
pond-reared ones in terms of number of spawns and percentage of
females with multiple spawns. However, fertilization and hatching rates
were slightly higher for spawns from pond-reared shrimps. Egg and
nauplii from wild and pond-reared females had a similar biochemical
composition, suggesting that no substantial differences in spawn quality
exists between both sources. Nauplii length was higher in pond-reared shrimp, which could indicate a higher developmental rate. At the
end of the production period, females were sampled and biochemical analysis was done in several tissues. Wild females had higher levels
of acylglycerides and cholesterol in hemolymph, and of total lipids in
hepatopancreas. In contrast, pond-reared spawners had higher carotenoid
content in hepatopancreas and ovaries. These differences cannot be
attributed to diet since all animals were similarly fed for more than three
months. It seems likely that differences in lipid assimilation and metabolism could exist between sources, which remain to be elucidated.
The number of spawns per female was also considered, however no
clear influence were observed on the biochemical variables analysed. The
maturation stage determined by histology was also taken into account
in the analysis to correct for lipid increase as the gonad matured, but
no differences in the maturation capabilities were observed between
sources.
185
Biochemical comparison of eggs
and tissues between wild and pond-reared
Penaeus vannamei brood stock
with multiple spawnings
Elena Palacios Mechetnov, Ilie S. Racotta
Centro de investigaciones biologicas del Noroeste (Cibnor), divisiôn de biologia marina,
Apartado postal 128, 23000 La Paz, BCS, México - iracotta@cibnor.mx
Because of increasing importance of shrimp mariculture, optimization
of maturation in captivity needs special attention to obtain high quality
seed stock. The present work examines, from a biochemical point of
view, two issues of this process: the use of pond-reared brood stock and
the influence of consecutive spawns. For this purpose, spawners were
individually tagged and followed for several months to trace the number
of spawns each female had. Samples of egg and nauplii were obtained
periodically for biochemical analysis. Wild females, which had higher
body weight, presented an overall higher productivity compared to
pond-reared ones in terms of number of spawns and percentage of
females with multiple spawns. However, fertilization and hatching rates
were slightly higher for spawns from pond-reared shrimps. Egg and
nauplii from wild and pond-reared females had a similar biochemical
composition, suggesting that no substantial differences in spawn quality
exists between both sources. Nauplii length was higher in pond-reared shrimp, which could indicate a higher developmental rate. At the
end of the production period, females were sampled and biochemical analysis was done in several tissues. Wild females had higher levels
of acylglycerides and cholesterol in hemolymph, and of total lipids in
hepatopancreas. In contrast, pond-reared spawners had higher carotenoid
content in hepatopancreas and ovaries. These differences cannot be
attributed to diet since all animals were similarly fed for more than three
months. It seems likely that differences in lipid assimilation and metabolism could exist between sources, which remain to be elucidated.
The number of spawns per female was also considered, however no
clear influence were observed on the biochemical variables analysed. The
maturation stage determined by histology was also taken into account
in the analysis to correct for lipid increase as the gonad matured, but
no differences in the maturation capabilities were observed between
sources.
185