Marine lipids
Reproductive exhaustion in shrimp
(Penaeus vannamei) reflected in egg
biochemical composition and larval
survival and growth
Elena Palacios Mechetnov, Ilie S. Racotta
Centro de investigaciones biolôgicas del Noroeste (Clbnor), divisiόn de biologia marina,
Apartado postal 128, 23000 La Paz, BCS, México - iracotta@cibnor.mx
An important drawback of shrimp reproduction in captivity is the
deterioration of reproductive performance and larval quality over time
under sustained induced reproduction, known as reproductive exhaustion. Spawn quality or larval performance, especially during the early
non-feeding stages, is closely related to adequate transfer of lipids and
other nutrients to the eggs. For this reason, the present study analysed
the effect on several variables of time spent in production by the brood
stock. Spawns were obtained at three different times during a commercial hatchery period: 15, 45, and 75 days after spawner stocking
and eyestalk ablation. Production variables, general biochemical composition, specific lipid classes and fatty acid composition of eggs and
nauplii were determinecl. As time in production increased, fecundity
increased, probably as a result of spawners’ growth. However, fertilization rate was decreased towarcl the end of the production period, and
lower levels of several biochemical components of the eggs and nauplii
were observed. A nauplii condition index (NCI) calculated from nauplii
acylglycerol levels, percentage of viable nauplii, and nauplii length
declined with increasing time in production. Reproductive exhaustion
was reflected in diminished spawn quality not only during embryonic
and early larval development stages but also on further larval stages.
Larval survival during culture to post-larvae was higher in recently
ablated spawners (15 days) and decreased in larvae obtained from
spawners 45 and 75 days after ablation. In addition, final post-larvae
condition or quality estimated by survival to a salinity stress was also
lower in relation to time in production of the spawners. Disruptions in
lipid metabolism and transfer to eggs related to reproductive exhaustion
of spawners are reflected on a reduced larval fitness, a consequence with
major production implications in commercial hatcheries.
186
Reproductive exhaustion in shrimp
(Penaeus vannamei) reflected in egg
biochemical composition and larval
survival and growth
Elena Palacios Mechetnov, Ilie S. Racotta
Centro de investigaciones biolôgicas del Noroeste (Clbnor), divisiόn de biologia marina,
Apartado postal 128, 23000 La Paz, BCS, México - iracotta@cibnor.mx
An important drawback of shrimp reproduction in captivity is the
deterioration of reproductive performance and larval quality over time
under sustained induced reproduction, known as reproductive exhaustion. Spawn quality or larval performance, especially during the early
non-feeding stages, is closely related to adequate transfer of lipids and
other nutrients to the eggs. For this reason, the present study analysed
the effect on several variables of time spent in production by the brood
stock. Spawns were obtained at three different times during a commercial hatchery period: 15, 45, and 75 days after spawner stocking
and eyestalk ablation. Production variables, general biochemical composition, specific lipid classes and fatty acid composition of eggs and
nauplii were determinecl. As time in production increased, fecundity
increased, probably as a result of spawners’ growth. However, fertilization rate was decreased towarcl the end of the production period, and
lower levels of several biochemical components of the eggs and nauplii
were observed. A nauplii condition index (NCI) calculated from nauplii
acylglycerol levels, percentage of viable nauplii, and nauplii length
declined with increasing time in production. Reproductive exhaustion
was reflected in diminished spawn quality not only during embryonic
and early larval development stages but also on further larval stages.
Larval survival during culture to post-larvae was higher in recently
ablated spawners (15 days) and decreased in larvae obtained from
spawners 45 and 75 days after ablation. In addition, final post-larvae
condition or quality estimated by survival to a salinity stress was also
lower in relation to time in production of the spawners. Disruptions in
lipid metabolism and transfer to eggs related to reproductive exhaustion
of spawners are reflected on a reduced larval fitness, a consequence with
major production implications in commercial hatcheries.
186