排序方式： 共有19条查询结果，搜索用时 406 毫秒
1.
G F Arcos A M Ibarra C Vazquez-Boucard E Palacios & I S Racotta 《Aquaculture Research》2003,34(9):749-755
The present study analyses some biochemical variables in haemolymph proposed as predictive indicators of the maturation capability following eyestalk ablation. Haemolymph of captive females was obtained before and 8 days after eyestalk ablation, and levels of haemocyanin, total proteins, glucose, lactate, cholesterol, triacylglycerides and vitellogenin were determined. Biochemical variables were also analysed in the hepatopancreas at the end of the experiment. Females were grouped as immature (previtellogenic stage) and mature (vitellogenic and cortical stages) based on histological analysis done 8 days after eyestalk ablation. To analyse haemolymph variables before eyestalk ablation in relation to maturation capability, immature females were classified as those with a low maturation capability and mature females as those with a high maturation capability. Females of high maturation capability had significantly higher vitellogenin levels before eyestalk ablation than females of low maturation capability. No significant differences were found for the other biochemical variables. Vitellogenin was also higher in mature than in immature females at the end of the experiment. These results indicate that vitellogenin levels in haemolymph could be used as possible predictive criteria of maturation capability, possibly because they reflect the degree of ovarian development at the time of eyestalk ablation. 相似文献
2.
Elena Palacios Ilie S. Racotta Horacio Heras Yanic Marty Jeanne Moal Jean-François Samain 《Aquaculture International》2001,9(6):531-543
In this study, lipid classes and fatty acid composition were determinedin eggs of P. vannamei as a function of survival to zoeaIII stage. Spawns were reared individually to zoea III and grouped, accordingtotheir final survival to this larval stage, into spawns of high and lowsurvival.Eggs of individual spawns were analyzed for lipid and fatty acid composition ofneutral and polar lipids and the results were then grouped according tosurvivalto zoea III. The lipids within each group (high and low survival to zoea III)were pooled for the separation of phospholipids and the analysis of their fattyacid composition.Higher levels of triglycerides, carotenoids, and linoleic (18:2n-6) acid ineggs were associated with improved survival to zoea III. Linoleic acid washigher in spawns from the high survival group in both neutral and polarfractions and in most of the phospholipid classes analyzed. Docosahexanoic acid(DHA) was not related to survival to zoea, probably because its content washighenough (> 15% of total fatty acids) to satisfy embryo and early larvaldevelopment needs. A high content of eicosapentaenoic acid (EPA) was found inphosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylserine, andphosphatidylinositol compared to other phospholipid classes, suggesting aspecific role of EPA in these lipids. These results describe the specificphospholipid composition of penaeid eggs and could (potentially) be used aspredictive indicators of larval quality for research and production purposes. 相似文献
3.
Sperm Quality Over Consecutive Spermatophore Regenerations in the Pacific White Shrimp Litopenaeus vannamei 总被引：1，自引：0，他引：1
Bertha P. Ceballos-Vázquez Benjamin Aparicio-Simón Elena Palacios Ilie S. Racotta 《Journal of the World Aquaculture Society》2004,35(2):178-188
The reproductive potential of males plays an important role in the productivity of captive penaeids. Males present a large variability in their reproductive potential, and thus the selection of appropriate males for reproduction is highly desirable. The present study compares sperm quality at the beginning of the experiment (baseline values) with variations in sperm quality as a result of consecutive spermatophore regenerations. This was done to evaluate possible predictive criteria for optimal sperm quality based on morphological and biochemical criteria in pond-reared Pacific white shrimp Litopenaeus vannamei males. Sperm quality was similar between left and right spermatophore. Sperm count and proportion of normal sperm increased by 86 and 65% (P < 0.05) respectively, from baseline values to third spermatophore regeneration. Proportion of dead sperm progressively decreased with consecutive regenerations, attaining values 33% lower by the third regeneration, compared to baseline values. This indicates that no decrease in sperm quality occurs in L. vannamei during consecutive regenerations and that the existing spermatophores at stocking of males should be expelled to have higher sperm quality in regenerated spermatophores. Furthermore, this procedure allows selecting individuals with high baseline sperm quality based on significant correlations between baseline and regenerated sperm quality observed in the present work. Baseline values of glucose concentration in the hemolymph were positively correlated to baseline values of sperm count (r = 03, P < 0.05). In contrast, baseline values of several lipids in the hemolymph were negatively correlated to several traits of sperm quality at first sampling (baseline values) or at first regeneration. These results are discussed in terms of nutritional requirements of males and of possible predictive criteria of sperm quality. 相似文献
4.
Miguel A Hurtado Ilie S Racotta Olivia Arjona Mónica Hernández-Rodríguez Ernesto Goytortúa Roberto Civera & Elena Palacios 《Aquaculture Research》2006,37(13):1316-1326
Litopenaeus vannamei (Boone) grown in ponds are exposed to salinities of less than 5 g L?1 during inland shrimp culture or to more than 40 g L?1 from evaporation and reduced water exchange in dry, hot climates. However, dietary requirements for shrimp grown in low or high salinities are not well defined, particularly for fatty acids. Feeding shrimp postlarvae with highly unsaturated fatty acids (HUFA) enhances tolerance to acute exposure to low salinity, as a result of better nutritional status, or/and specific effects of HUFA on membrane function and osmoregulation mechanisms. This study analysed the effect of HUFA supplementation (3% vs. 34%) on L. vannamei juveniles reared for 21 days at low (5 g L?1), medium (30 g L?1) and high salinities (50 g L?1). Juveniles grown at 5 g L?1 had lower survival compared with controls (30 g L?1) or shrimp grown at 50 g L?1, but no significant effect on survival was observed as a result of HUFA enrichment. In contrast, growth was significantly lower for shrimp grown at 50 g L?1, but this effect was compensated by the HUFA‐enriched diet. Osmotic pressure in haemolymph was affected by salinity, but not by HUFA enrichment. Shrimp fed HUFA‐enriched diets had significantly higher levels of eicosapentaenoic acid and docosahexaenoic acid in hepatopancreas and gills. These results demonstrate that growth at high salinities is enhanced with diets containing high HUFA levels, but that HUFA‐enriched diets have no effect on shrimp reared at low salinities. 相似文献
5.
Elena Palaclos Ilie S. Racotta Marcial Villalejo 《Journal of the World Aquaculture Society》2003,34(4):466-477
The present study compares three scales for evaluation of ovary development stage in wild and pond-reared shrimp. An external visual scale was assessed according to color and size of ovaries observed through the exoskeleton in live shrimp by staff of a commercial hatchery. Shrimp were then sacrificed to obtain gonadosomatic index, and gonads were scaled according to their color and size upon dissection. Finally, a portion of ovaries was processed for histological analysis, from which oocyte diameters were obtained, and females were evaluated with another scale based on cytological organization of gonads and on frequency of oocyte sizes. The certainties of the external and internal scales were analyzed, based on differences in gonadosomatic index and oocyte diameter and by comparison with the more accurate scaling obtained by histological analysis. The external scale was, in general, less accurate than the internal scale. Maturation stage in pond-reared shrimp was underestimated or overestimated more frequently than in wild shrimp. The implications for hatchery operation and possible reasons are discussed. Pond-reared shrimp were found to have a non-linear relation between gonad weight and body weight, but this relation was linear for the larger wild shrimp. This reduced the validity of gonadosomatic index in pond-reared shrimp, which were still growing. Thus, oocyte diameter, which was not affected by body weight in growing shrimp, represents a more accurate numeric measure of ovary development. Spermatophores were found attached to the thelycum in females only at the cortical stage of maturation, independent of origin. However, a significant proportion of fully mature, pond-reared shrimp did not have an attached spermatophore, possibly indicating lower mating success or poorer spermatophore adherence in these shrimp. 相似文献
6.
In this study, triacylglycerol, cholesterol and glucose were measured in nauplii of Penaeus vannamei (Boone) to explain high and low survival rates from nauplii to zoea in a commercial hatchery. Triacylglycerol and glucose levels were significantly higher in nauplii that had increased survival rates to zoea. No significant differences were found in nauplii size or cholesterol levels. The influence of the long-term effect of ablation of broodstock on the biochemical composition of egg and nauplii was also determined. As the days after ablation increased, the glucose and triacylgyceride level in eggs, and the glucose levels in nauplii decreased. The broodstock had higher fecundity and body length 96 days after ablation, but the more recently ablated broodstock (18 days) produced the largest nauplii, which could indicate a higher development rate. A nauplii condition index was calculated from nauplii triacylglycerol levels, percentage of viable nauplii and nauplii length. A decline in this condition index was observed with increased days after ablation. The biochemical composition of egg and nauplii can be associated with the physiological status of the broodstock. In turn, the hatching success and survival to zoea are affected by the fuel levels. The differences in egg and nauplii fuels from broodstock with different time after ablation suggest that reproductive exhaustion of the broodstock is also related to insufficient metabolic fuel which, in turn, has an effect on larval viability. 相似文献
7.
Abstract— The effects of serotonin (5-HT) and the stress of repeated sampling on Penaeus vannamei hemolymph levels of glucose, lactate, triacylglycerol, cholesterol, and total protein were examined. For this purpose, a baseline hemolymph sample was taken and then shrimp were injected with 5-HT (50 μg/shrimp) or saline after which repeated individual samples were taken at 30, 60, and 120 min. Glucose levels tripled in both saline- and serotonin-treated shrimp when compared to baseline values, without any difference between both groups. In contrast, lactate level rose significantly only in the 5-HT group. The levels of this metabolite were significantly higher than in the salineinjection group for all time points. Triacylglycerol decreased in both groups and no substantial differences were observed in cholesterol and protein levels. The results indicate that repeated sampling stress produces strong hyperglycemia and that 5-HT does not produce an additional increase in glucose levels. However. this monoamine strongly increased lactate levels, a response that can be distinguished from stress and probably attributed to glycolysis. 相似文献
8.
Nairoby Pacheco‐Carln Danitzia A. Guerrero‐Tortolero Lucero B. Cervantes‐Montoya Ilie S. Racotta Rafael Campos‐Ramos 《Aquaculture Research》2021,52(1):77-93
Constant and oscillating egg incubation temperatures on embryonic development and early larval morphology were studied in longfin yellowtail (Seriola rivoliana Valenciennes). We investigated the effects of constant temperatures from 16 to 32°C on embryo development and larval morphology at hatch, and whether oscillating temperature during embryogenesis could lead to larval morphological variations. After hatching, larval morphology and development during yolk sac (YS) utilization were examined in larvae at constant temperatures and larvae at 25°C that had oscillating temperature during egg incubation. Hatching rates were > 75%, only decreasing to ~ 50% at 30°C. At constant temperatures, the largest larvae occurred at 22 and 24°C. The oscillating temperature did not affect the timing of embryo development but resulted in larger and smaller larvae with a smaller and bigger YS, respectively, with a similar hatching time. Therefore, a growth response occurred in embryos during a window of development before hatching, depending on the adaptive response to temperature (spawn‐specific). After hatching, most of the YS was absorbed within 24 hr in all treatments, and the growth of the larval head was a priority with an optimal development at 26°C. There was compensatory growth in smaller larvae resulting in similar sizes after YS utilization, but larvae showed variations in body structure that could be important in further aquaculture research. 相似文献
9.
Elena Palacios Ilie S. Racotta Horacio Heras Yanic Marty Jeanne Moal Jean-François Samain 《Aquaculture International》2002,9(6):531-543
In this study, lipid classes and fatty acid composition were determinedin eggs of P. vannamei as a function of survival to zoeaIII stage. Spawns were reared individually to zoea III and grouped, accordingtotheir final survival to this larval stage, into spawns of high and lowsurvival.Eggs of individual spawns were analyzed for lipid and fatty acid composition ofneutral and polar lipids and the results were then grouped according tosurvivalto zoea III. The lipids within each group (high and low survival to zoea III)were pooled for the separation of phospholipids and the analysis of their fattyacid composition.Higher levels of triglycerides, carotenoids, and linoleic (18:2n-6) acid ineggs were associated with improved survival to zoea III. Linoleic acid washigher in spawns from the high survival group in both neutral and polarfractions and in most of the phospholipid classes analyzed. Docosahexanoic acid(DHA) was not related to survival to zoea, probably because its content washighenough (> 15% of total fatty acids) to satisfy embryo and early larvaldevelopment needs. A high content of eicosapentaenoic acid (EPA) was found inphosphatidylethanolamine, lysophosphatidylethanolamine, phosphatidylserine, andphosphatidylinositol compared to other phospholipid classes, suggesting aspecific role of EPA in these lipids. These results describe the specificphospholipid composition of penaeid eggs and could (potentially) be used aspredictive indicators of larval quality for research and production purposes. 相似文献
10.
Fabiola G Arcos Elena Palacios Ana M Ibarra & Ilie S Racotta 《Aquaculture Research》2005,36(9):890-897
In this study, we determined the influence of the time broodstock spend in reproduction, and the effect of consecutive spawnings (spawning order) on larval quality of Litopenaeus vannamei. Spawns were sampled at days 1–4, 18–20 and 38–40 after unilateral eyestalk ablation and ordered according to the number of spawns or spawning order (1–11) of each female. Larvae were reared individually to 2‐day‐old postlarvae (PL2); spawn and larval quality was determined in terms of fecundity, fertilization, hatching, morphometric traits, ammonium stress resistance applied at zoea, salinity stress resistance applied at postlarval stages, and survival during culture. Fecundity was not affected by consecutive spawns, whereas it increased with time spent in production. Nauplii length and survival to zoea and mysis stages decreased with time spent in production, whereas no consistent influence of consecutive spawning was observed. Survival to PL2, and to the ammonia and salinity stress tests did not decrease with increasing time in production or spawning order. This study separated the specific influence of time spent in production (which negatively affects larval quality) and consecutive spawns (which had no effect or had an inconsistent effect), and reinforced previous suggestions that selection of females with multiple spawn capacity would be desirable for production purposes. 相似文献