Marine lipids
Effect of ablation on reproductive
performance and biochemical composition
of eggs, nauplii, and spawner tissues
in Penaeus vannamei
I.S. Racotta, E. Palacios Mechetnov, D. Carreno
Centro de investigaciones biolôgicas del Noroeste (Cibnor), divisiôn de biologia marina,
Apartado postal 128, 23000 La Paz, BCS, México - iracotta@cibnor.mx
Unilateral eyestalk ablation considerably enhances larval production in
penaeid shrimps. However, little is known about the physiological
alterations produced by this procedure and its effect on egg quality. In
the present study, ablated and unablated females were stocked for two
months during which productive and biochemical variables of eggs
and nauplii were compared. After this period, females were sacrificed
to analyse ovary histology, biochemical variables in hemolymph, hepatopancreas, and gonad, and specific lipid classes and fatty acid composition in gonad. The proportion of spawning females and the spawning
frequency was greater for ablated temales. Productive fraits for each spawn
(i.e. number of eggs and nauplii, fertilization, and hatching rates) were
similar for both groups. Ablated females produced spawns that had
higher acylglycerol levels m eggs and lower total lipids m nauplii IV,
but no differences were obtained for other biochemical components.
Since eggs and nauplii were collected from females that spawned for the
lirst time and others that spawned up to tlie six times, the influence of
spawning order was also evaluated. Only total carotenoid levels in eggs
were decreased as an effect of multiple spawns, a decrease observed
only in spawns from ablated females. In females sampled at the end of
the experiment, lactate and hemocyanin levels were lower in ablated
females but no differences were obtained for acylglycerol, cholesterol,
glucose, and proteins in hemolymph between groups. No major differences between groups were observed for biochemical components in
hepatopancreas and ovaries, except for a higher carotenoid content in
the hepatopancreas of ablated shrimps. These data indicate that eyestalk ablation does not affect spawn quality when evaluated as productive and biochemical traits, although some differences could occur at the
lipid metabolism level. Similarly, long-term effects of eyestalk ablation
and the associated continual rematurations do not disrupt the overall
availability of several biochemical components in tissues involved in
the reproductive process.
184
Effect of ablation on reproductive
performance and biochemical composition
of eggs, nauplii, and spawner tissues
in Penaeus vannamei
I.S. Racotta, E. Palacios Mechetnov, D. Carreno
Centro de investigaciones biolôgicas del Noroeste (Cibnor), divisiôn de biologia marina,
Apartado postal 128, 23000 La Paz, BCS, México - iracotta@cibnor.mx
Unilateral eyestalk ablation considerably enhances larval production in
penaeid shrimps. However, little is known about the physiological
alterations produced by this procedure and its effect on egg quality. In
the present study, ablated and unablated females were stocked for two
months during which productive and biochemical variables of eggs
and nauplii were compared. After this period, females were sacrificed
to analyse ovary histology, biochemical variables in hemolymph, hepatopancreas, and gonad, and specific lipid classes and fatty acid composition in gonad. The proportion of spawning females and the spawning
frequency was greater for ablated temales. Productive fraits for each spawn
(i.e. number of eggs and nauplii, fertilization, and hatching rates) were
similar for both groups. Ablated females produced spawns that had
higher acylglycerol levels m eggs and lower total lipids m nauplii IV,
but no differences were obtained for other biochemical components.
Since eggs and nauplii were collected from females that spawned for the
lirst time and others that spawned up to tlie six times, the influence of
spawning order was also evaluated. Only total carotenoid levels in eggs
were decreased as an effect of multiple spawns, a decrease observed
only in spawns from ablated females. In females sampled at the end of
the experiment, lactate and hemocyanin levels were lower in ablated
females but no differences were obtained for acylglycerol, cholesterol,
glucose, and proteins in hemolymph between groups. No major differences between groups were observed for biochemical components in
hepatopancreas and ovaries, except for a higher carotenoid content in
the hepatopancreas of ablated shrimps. These data indicate that eyestalk ablation does not affect spawn quality when evaluated as productive and biochemical traits, although some differences could occur at the
lipid metabolism level. Similarly, long-term effects of eyestalk ablation
and the associated continual rematurations do not disrupt the overall
availability of several biochemical components in tissues involved in
the reproductive process.
184