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1.
ABSTRACT

The shrimp hatchery industry worldwide has placed immense interest on the production of closed-life cycle broodstock from farm stock. Unfortunately, majority of the studies have proven that pond-reared broodstock are inferior to their wild counterparts in terms of reproductive performance, spawn quality and post-hatching performance. In the present study, reproductive performance, egg, and nauplii quality of wild and pond-reared Indian white shrimp, Fenneropenaeus indicus, broodstock were analyzed. Biochemical analyses were done with egg and nauplii from both the sources, in an attempt to explain the difference in their performance. Results indicated better reproductive performance by wild females compared to pond-reared ones. The wild eggs contained higher total lipid, and vital HUFAs namely EPA (Eicosapentaenoic acid), DHA (Docosahexaenoic acid) and ARA (Arachidonic acid). However, one of the dominant PUFA, 18:2 (n-6) was high in pond broodstock eggs. Biochemical analysis also indicated that glucose, carotenoids, and triacylglycerol content were significantly higher (P < 0.001) in wild eggs. But, egg protein and triacylglycerol content did not record significant difference between the egg samples. The percentage viable nauplii, nauplii length and triacylglycerol content were all significantly higher (P < 0.05) with wild nauplii. This study proves the better nutritional profile of wild eggs and nauplii in terms of analyzed biochemical components. But, as our knowledge on specific nutrient requirement for successful reproductive performance and offspring quality is limited, the better performance of wild eggs could not be attributed to any single nutrient. Meanwhile, it could be presumed that all the deficient nutrients collectively contributed to the poor reproductive performance and spawn quality.  相似文献   

2.
Eggs from a F1 cultured broodstock of sole were compared with eggs from wild‐caught breeders throughout one spawning season, to evaluate if egg quality may be affected by culture‐related conditions. Fourteen batches of eggs from cultured broodstock and 17 batches from wild‐caught sole were compared with respect to fatty acid (FA) composition, egg size, fertilization rate and hatching rate. Based on a multivariate analysis of the FA profiles, it was possible to discriminate between culture and wild inheritance. Eggs from cultured broodstock had high levels of C20:1(n‐9), C18:2(n‐6) and C18:3(n‐3), whereas eggs from wild fish had high levels of C16:1(n‐7), C20:4(n‐6) and C20:5(n‐3). Differences in FA profiles were most likely related to dietary differences. Fertilization and hatching rates were generally low and lowest in eggs from cultured broodstock, but not related to FA composition. Larval growth of one batch from each group was compared. Larval growth was not correlated to broodstock origin, FA composition or egg or larval size. However, larval survival was significantly lower for larvae from cultured broodstock.  相似文献   

3.
Broodfish were reared for 6 months in underground brackish water (11 ppt), and the quality of eggs and semen was evaluated in comparison to broodfish held in fresh water. Fry produced by the broodfish in brackish water (S) and freshwater (F) were then reared in different salinities (1, 4, 7, and 10 ppt). Broodfish successfully matured and spawned in underground brackish water, and gonad quality was better than of the broodfish in fresh water (p < 0.01). Growth indices of fry produced by both groups decreased with increasing salinity (p < 0.01). Survival was not affected by the salinities tested. Underground brackish water can be used as a source to induce successful sexual maturation and to produce high-quality gonads.  相似文献   

4.
An experiment was conducted for 8 weeks at the Cantho University, Vietnam, to determine the acceptable level of mangrove leaf litter load and its effect on water quality, growth and survival rate of tiger shrimp (Penaeus monodon). Shrimps were cultured in plastic tanks containing 50 L of brackish water (salinity of 15‰). Leaf litter of Rhizophora apiculata, Avicennia officinalis, Excoecaria agallocha and Acacia auriculiformis were loaded to tanks at rates of 0.0 (control), 0.125, 0.25, 0.5, 1.0 and 2.0 g L− 1 with and without aeration. Tiger shrimp post-larvae (PL; 0.05 ± 0.01 g) obtained from the shrimp hatchery of Cantho University were stocked at a density of 20 PL per tank and fed with pelleted feed containing 38% protein at a rate of 10% body weight (BW) day− 1.

The high leaf-loading rates significantly reduced dissolved oxygen (DO) and survival rates of shrimp in the non-aerated treatments, and all shrimps died after 2 days in the treatments with loading rates above 0.5 g L− 1. Leaf litter loads significantly increased tannin content, chemical oxygen demand (COD), H2S and pH in the aerated treatments. Stepwise regression analysis showed COD, tannin and H2S concentrations had negative effects on shrimp growth in the aerated treatments. Tannin concentration was found to be highest in the treatments with Excoecaria (32 mg L− 1) and Avicennia (24 mg L− 1) leaves. However, there were no significant differences in growth and survival rates of shrimp among the aerobic treatments loaded with different leaf types. The results of this study showed that moderate load of mangrove leaves could play an important role in promoting shrimp growth and survival in aerobic condition. Mangrove leaves at a loading rate of 1 g L− 1 positively influenced both the survival and growth rate of shrimps.  相似文献   


5.
Abstract – Body length, age, egg size, embryo salinity tolerance and length at hatching of the freshwater (salinity <0.1 ppt, Lake Peipsi) and brackish-water (salinity 2–6 ppt, Pärnu and Matsalu Bay) ruffe, Gymnocephalus cernuus (L.), were examined to reveal their reproductive success in moderate salinity. Eggs of females originating from brackish water were significantly larger than eggs of freshwater females. No correlation between egg size and female size and age was found in brackish-water populations. In the freshwater population there was a small negative correlation between egg size and female size, but no correlation with female age. Fertilisation by sperm of males of different origin (brackish water or freshwater) produced no significant differences at any critical developmental stage (fertilisation, gastrulation, hatching) in the development of eggs from brackish-water or freshwater females at 3.3, 5.5, 7.7 and 9.9 ppt salinity. Survival rates in different salinity depended only on female origin; embryonic salinity tolerance was higher in ruffe inhabiting brackish water. Obviously, embryo salinity tolerance in ruffe is determined by egg qualities.  相似文献   

6.
In this study, an effort was made to cure the pigment deficiency syndrome (PDS) exhibited by pond‐reared Fenneropenaeus indicus (H.Milne Edwards) broodstock, using the blue‐green algae Spirulina as a carotenoid source in diet. The PDS symptoms included bleaching of ovary and reduced early larval performance. Biochemical analysis indicated reduced quantity of total carotenoids in egg and nauplii from the females with PDS. When PDS females were fed 30 g kg?1Spirulina‐supplemented diet immediately after the appearance of symptoms, the egg and nauplii carotenoid values improved gradually and attained the pre‐PDS values after a minimum of 4 week period. Spirulina supplementation also improved significantly (P < 0.05) the spawn quality (hatch per spawn, nauplii per spawn, nauplii viability) and larval quality indices (P < 0.05). The egg and nauplii protein values exhibited a trend similar to carotenoids, confirming the influence of latter on protein stability previously reported by researchers. The study confirms the bioavailability of carotenoids from Spirulina to shrimp broodstock and recommends its regular inclusion in diet to preclude carotenoid deficiency‐related problems in shrimp hatcheries.  相似文献   

7.
Persian sturgeon eggs were fertilized with different levels of salinities (0.5, 2, 4, 6, 8, 10, 12?ppt), and then each group was incubated in the same salinity until hatch. The fertility (%), hatching rate as well as larvae cumulative mortality rate and abnormality (%) were measured. Our Results revealed that Persian surgeon eggs could be fertilized in the different salinity concentrations but not more than 4?ppt. Moreover, hatching rate decreased with increase in salinities more than 2 and 4?ppt, respectively, and no larvae hatched in 6?ppt salinity. According to these results, the salinity tolerance threshold for Persian sturgeon larvae hatching in brackish water is less than 4?ppt.  相似文献   

8.
The present study assessed the effects of different types of feeds and salinity levels on water quality, growth performance, survival rate and body composition of the Pacific white shrimp, Litopenaeus vannamei, juveniles in a biofloc system. Shrimp juveniles (2.56 ± 0.33 g) were cultured for 35 days in 300 L fibreglass tanks (water volume of 180 L) with a density of 1 g/L in six treatments. Three sources of feed (100% formulated feed, mixture of 66.6% formulated diet and 33.3% wet biofloc, and 100% wet biofloc) and two levels of salinity (10 and 32 ppt) were considered in two control groups and four biofloc treatments. Water quality parameters in the biofloc treatments were significantly better than control groups (p < .05). The highest increase in growth performance and survival rate were obtained in salinity of 32 ppt and mixed feed sources. Analysing the proximate composition of body shrimp indicates an increase in lipid and ash levels in biofloc treatments, which was more evident in the salinity of 32 ppt. In addition, the proximate analysis of shrimp body showed significant differences between biofloc treatments and control groups (p < .05). The highest FCR was found in the treatment with salinity level of 10 ppt and fed only with floc. Overall, it was found that the artificial diet supplemented with biofloc at the salinity of 32 showed better performance in the juvenile stage of Pacific white shrimp.  相似文献   

9.
Although a stenohaline freshwater fish, the stinging catfish Heteropneustes fossilis, is also available in the freshwater fringes of the coastal areas of Bangladesh, the tolerance of this species to variable environmental salinity has not been thoroughly investigated. Based on median lethal salinity (MLS‐50 96 h), three sublethal salinity levels (3 ppt, 6 ppt and 9 ppt) and a control (0 ppt), each with three replications were selected to observe the effects of mildly brackish conditions on the fish for a period of 90‐day exposure. Better growth and survival were found up to 6 ppt compared with control. Salinity more than 6 ppt appeared unsuitable for H. fossilis fingerling due to increased mortality and reduced growth. To determine biochemical alterations, a few important physiological parameters were observed after 90 days of exposure. Glycogen level of liver and muscle in the fish reared at 9 ppt salinity decreased significantly (P < 0.05) as compared to the control. Glucose level in blood and liver was also found to be increased in fish with increase in salinity. ALP and ATPase activities were reduced significantly in both muscle and liver tissues at higher salinity, indicating the stress mitigation effect. However, all the biochemical parameters were found in normal condition up to 6 ppt compared with control. This evidence suggests that H. fossilis can sustain and grow well below 6 ppt and can be a potential candidate for culture in coastal areas after heavy downpour when the salinities level falls to 6 ppt or lower.  相似文献   

10.
This study was conducted to determine the effects of dietary highly unsaturated fatty acids (HUFA) on flame angelfish (Centropyge loriculus) reproduction, and egg and larval quality. In the experiment, formulated diets containing 1.8, 2.9 or 3.6% n‐3 HUFA were fed to flame angelfish broodstock (n = 4) for 5 months. Mean fecundity (daily egg production), egg fertilization rates and embryo viability were used as indicators of egg quality. In addition, mean egg diameter, oil globule diameter, per cent hatch, larval size at hatch, per cent survival to yolk exhaustion and larval size at yolk exhaustion were recorded for each treatment. Flame angelfish fed the diet containing 3.6% n‐3 HUFA exhibited significantly increased fecundity, fertilization rates and embryo viability than fish that were fed the other two formulated diets. Egg diameter, egg oil globule diameter, larval size at hatch, larval survival to yolk exhaustion and larval size at yolk exhaustion from the 3.6% n‐3 HUFA broodstock treatment group were not significantly different from those derived from the Control broodstock treatment. These data revealed that flame angelfish egg quality could respond rapidly (within weeks) to maternal dietary changes. Results from this study further support that dietary HUFA composition can significantly affect broodstock reproductive performance as well as subsequent performance of eggs and larvae.  相似文献   

11.
Pseudodiaptomus species are major live feeds for the early stages of economically important marine fish in hatcheries in the South China Sea. However, we know little about the combined effects of multiple environmental parameters such as salinity and temperature on copepod productivity. To address the issue, we cultured a tropical coastal copepod Pseudodiaptomus incisus in one of 24 combinations of 8 salinities (5, 10, 15, 20, 25, 30, 35 and 40 ppt) and 3 temperatures (26, 30 and 34°C). We determined development, biomass of all stages, fecundity, percentage of females with hatched eggs and 30 hr nauplii production. Overall, the biomass, fecundity and nauplii production of P. incisus were highest at the salinity of 15–20 ppt, especially at 26°C. P. incisus showed a lower performance at both lower and higher salinities. Elevated temperatures resulted in faster development, but lower biomass, fecundity and nauplii production. Especially, nauplii production was reduced by 74% at 35–40 ppt and 34°C compared to at 15–20 ppt and 26°C. Our study provides essential information for optimizing the biomass culture of P. incisus.  相似文献   

12.
This study measures the effect of protein and lipid levels in broodstock diet on the quality of juvenile Cherax quadricarinatus. Diets with different contents of crude protein (180, 250, 310, 370 g kg?1) and lipids (30 and 70 g kg?1) were offered to female crayfish. Juveniles were used to assess initial weight (IW), biochemical composition (BC) and survival to stress tests (ST). After 50 days, growth was estimated. No significant effects of broodstock diet on IW and BC of juveniles were detected. Protein content (PC) significantly influenced growth (P < 0.05), with an optimum level of 250 g kg?1, representing a weight gain of 1.17 g (98.08% body weight). PC significantly influenced survival of juveniles exposed to ST (P < 0.05). Results from fitting dose–response models indicated that maximum survival was obtained with PC above 261, 258 and 312 g kg?1 for hypoxia, salinity, ammonia tests. No significant effect of dietary lipid level was observed on growth and survival to ST, except for greater survival to ammonia ST at lipid content of 70 g kg?1. We recommend feed with PC of 260 g kg?1 to simultaneously enhance growth and quality of juveniles.  相似文献   

13.
Larvae of Metapenaeus monoceros (Fabricius) at protozoea 1 (PZ1) stage were stocked in 2‐L glass flasks to investigate the effects of various salinities (25, 30, 35, 40, 45, 50 and 55 ppt) on growth and survival until the post‐larval (PL) stages. The PZ larvae were not able to tolerate a sudden salinity drop of over 10 ppt. Yet, an abrupt salinity increase of over 10 or even 15 ppt did not cause mortality. The PZ larvae were successfully acclimated to different test salinities at a rate of 4 ppt h?1. The larvae displayed better tolerance to high rather than low salinities. The lowest and highest critical salinities appeared to be 22 and 55 ppt respectively. Taking into account survival, growth and development results, the optimal salinity for the larval culture of M. monoceros inhabiting the Eastern Mediterranean was 40 ppt. At this salinity, the PZ1 larvae were successfully cultured until PL1 stage within 11 days with 68% survival on a feeding regime of Tetraselmis chuii Kylin (Butcher) (20 cells μ L?1), Chaetoceros calcitrans Paulsen (50 cells μ L?1), Isochrysis galbana Parke (30 cells μL?1) and five newly hatched Artemia nauplii mL?1 from M1 onwards at 28 °C.  相似文献   

14.
This study investigated the effect of n‐3 to n‐6 fatty acid ratios in broodstock diets on reproduction performance, fatty acid composition of eggs and gonads of tongue sole Cynoglossus semilaevis. Broodstock were fed five isonitrogenous and isoenergetic diets for 60 days. The supplemented lipids were prepared by a combination of fish oil and soybean oil inclusion FO (fish oil); FSO1 (fish oil: soybean oil = 7:1); FSO2 (fish oil: soybean oil = 2.2:1); FSO3 (fish oil: soybean oil = 1:1); FSO4 (fish oil: soybean oil = 1:4.3) as lipid sources with different n‐3 to n‐6 fatty acid ratios 10.40, 5.21, 2.81, 1.71 and 0.87. Results showed that relative fecundity, fertilization rate and survival rate of larvae at 7 days posthatching were all higher in broodstock fed FSO1 and FSO2 diet and significantly (P < 0.05) decreased in groups fed FSO3 and FSO4 diets. The best result in starvation tolerance test was obtained in FSO2 diet. The present study suggests that n‐3 and n‐6 PUFA ratio in broodstock diet has a considerable effect on spawning performance, egg and larval quality for C. semilaevis.  相似文献   

15.
土池低盐度水体河蟹生态育苗试验   总被引：4，自引：0，他引：4  
2003年3~5月,在上海崇明进行了河蟹(Eriocheirsinensis)在低盐度水体的土池中育苗实验,主要技术措施包括亲本的强化培育、施肥养水、敌害生物的控制和利用、活饵料的科学使用和水质调控等。结果表明:(1)亲本强化培育可以提高其生殖性能;(2)土池育苗中各期幼体的变态时间长于工厂化育苗,因而总的出苗时间比工厂化育苗长5~7d;(3)通过综合管理措施,在低盐度(9~12)条件下河蟹土池生态育苗单产和出苗率分别为(60·18±30·17)kg/hm2和(3·12±1·55)%,总的出苗时间为(25·2±1·9)d。  相似文献   

16.
Laboratory experiments were conducted to determine the effect of salinity on embryonic development and hatching in Neobenedenia melleni , a monogenean ectoparasite of seawater-cultured (37 ppt) Florida red tilapia ( Oreochromis urolepis hornorum × O. mossambicus ). Eggs, collected from adult monogeneans at 37 ppt, were exposed to different salinities (0, 6, 12, 18, 24, 30 and 37 ppt) for 48, 72 or 96 h. Varying degrees of post-treatment development and hatching occurred when natural seawater conditions were restored. Hatching success generally declined with decreasing salinity and increasing duration of exposure. Under all durations of exposure, hatching success remained relatively high (≥ 69.6%) at salinities of 24 ppt and above, but declined markedly (≤ 32.5%) at lower salinities. Hatching did not occur in eggs exposed to fresh water (0 ppt) for 72 and 96 h. The most effective treatments in preventing hatching, other than prolonged exposure to fresh water, were 96 h exposures to low-salinity brackish water. Percent hatch after 96 h exposure to 6, 12 and 18 ppt was 5.5, 11.9 and 5.8%, respectively.  相似文献   

17.
The aim of this study was to evaluate the growth and survival of pacu, Piaractus mesopotamicus, larvae reared in different salinities and to determine the Artemia nauplii life span in freshwater and in saline water. First feeding 5‐d‐old pacu larvae were reared in freshwater or at 2, 4, 6, 8, 10, 12, and 14 ppt salinities. The larvae were reared in 1.5‐L aquaria at a density of 10 larvae/L with three replicates per treatment. After 10 d of rearing, significant differences (P < 0.05) were observed for growth and survival. Larval growth was higher at 2 and 4 ppt, and survival at 2 ppt was 100%. In freshwater and at 4, 6 and 8 ppt, the survival was 91.1, 93.3, 73.3, and 39.9%, respectively. At higher salinities, there was 100% mortality after 2 h (12 and 14 ppt) and 8 h (10 ppt) of exposure. The slightly saline water of at least 2 ppt increased the Artemia nauplii life span compared to the life span in freshwater. Later, in a second trial, 5‐d‐old pacu larvae were reared in freshwater and at 2 and 4 ppt salinities during the first 5 or 10 d of active feeding, and then the fish were transferred to freshwater. At the end of 15 d, larval growth was lower in freshwater (42 mg) than in treatments 2 and 4 ppt (59–63 mg). The abrupt transfer of fish from freshwater to slightly saline water and the return to freshwater did not affect the survival rates (89–97%). The larvae were able to adapt to these saline environments and handle abrupt changes in salt concentration. We concluded that salinity concentration of 2 ppt can be used for pacu larval rearing, allowing the Artemia nauplii lifetime to last longer and cause faster fish growth.  相似文献   

18.
The broodstock of spotted Babylon snail, Babylonia areolata, were conditioned in indoor tanks under two seawater systems (static system and flow‐through system) and five types of foods (fish, shrimp, squid, green mussel and formulated diet). High survival and good feeding was found from broodstock conditioned in all treatments of seawater systems and diets. All broodstock showed active behaviour with no signs of stress as exhibited by active movement and feeding, protrusion of siphonal tube and constant egg laying throughout the experiment. Two‐way analysis of variance showed that there were no significant differences (P>0.05) in the total yield of egg capsules, size of egg capsules, size of newly hatched larvae and growth of larvae among broodstock B. areolata conditioned in the seawater system and diet treatments, but there were significant differences (P>0.05) in the frequency of egg capsule laying, number of fertilized eggs/embryos per capsule, total yield of fertilized eggs/embryos and final survival of larvae among broodstock B. areolata conditioned in the diet treatments. We present initial evidence that the seawater system had a stronger influence on the egg production and quality of broodstock B. areolata than conditioning diets.  相似文献   

19.
This study was carried out to examine the effect of Artemia urmiana nauplii enriched with HUFA, and vitamins C and E on stress tolerance, hematocrit, and biochemical parameters of great sturgeon, Huso huso juveniles. Cod liver oil (EPA 18% and DHA 12%), ascorbyl-6-palmitate and α-tocopherol acetate were used as lipid, and vitamin C and E sources, respectively. Beluga juveniles at the stage of first feeding (69.7 ± 5.9 mg body weight) were randomly divided into five treatments and three tanks were assigned to each diet. All fish groups were fed non-enriched Artemia for the initial 5 days and then fed enriched Artemia for 7 days. Juveniles were fed with Artemia enriched with HUFA + 20% vitamin C (C group); HUFA + 20% vitamin E-enriched Artemia nauplii (E group); HUFA + 20% vitamin C + 20% vitamin E (C and E group); HUFA without vitamins (HUFA) and non-enriched Artemia (control). After the period of enrichment, Juveniles were fed with Daphnia sp. from the 13th to the 40th day. At day 40, the fish were transferred directly from fresh water (0.5 ppt) to brackish water (6 ppt for 4 days and 12 ppt for 2 days) and warm water (from 27 to 33°C) to evaluate juvenile resistance to salinity and thermal shocks. Moreover, all treatments were separately exposed to freshwater in tanks with the same capacity as used for osmotic and thermal tests (as fresh water control). The addition of vitamins C, E, and C + E to HUFA significantly increased fish resistance to 12 ppt salinity and temperature stress tests, whereas survival was not significantly different among challenges at 6 ppt. There was no significant difference in the hematocrit index under stress conditions. Enrichment had significant influence on plasma Na+ level in the C group on the 4th day at 6 ppt. Na+ and Ca2+ concentrations in C, E, and C and E groups on the 1st day at 12 ppt, and Ca2+ level in E group on the 2nd day at 12 ppt were lower than the other groups. The glucose level in the C and C and E groups was lower than the other treatments on the 1st day at 12 ppt and the 2nd day at 33°C. Regardless of Artemia enrichment, plasma ions (Na+, K+, Ca2+, and Mg2+) and glucose concentrations in fish exposed to salinity stress tests were higher than fish in fresh water. Glucose concentration in plasma also increased after 2 days at 33°C. Although most of our results were not significantly different, the use of vitamins C, E, and HUFA in Artemia enrichment can improve Juveniles tolerance under stress conditions, and regardless of enrichment, these data show that beluga juveniles are partly sensitive to high salinity and temperature.  相似文献   

20.
The influence of three different environmental salinities (seawater, SW: 38 ppt salinity; brackish water, BW: 12 ppt; and low salinity water, LSW: 6 ppt salinity) on the growth, osmoregulation and metabolism of young gilthead sea bream (Sparus aurata L.) was studied over a period of 100 days. 480 inmature fish (20 g mean body weight) were randomly divided into six tanks of 2500 l (80 fish per tank) and maintained under three different salinities (38 ppt, 12 ppt and 6 ppt) in an open system. Every three weeks, 10 fish from each tank were anesthetized, weighed and lenghed. At the end of experiment, 10 fish from each tank were anesthetized, weighed and sampled for plasma, brain, gill and liver. Gill Na+, K+-ATPase activity, plasma osmolality, ions (sodium and chloride), glucose, lactate, protein and triglyceride, and hepatosomatic index were examined. In addition, levels of glycogen, lactate, ATP and activities of potential regulatory enzymes (hexokinase, pyruvate kinase, glycogen phosphorylase, and glucose 6-phosphate dehydrogenase) were assesed in liver, brain, and gill. BW-acclimated fish showed a better growth with respect to SW- or LSW-acclimated fish (12 > 38 > 6 ppt). The same relationship was observed for weight gain and specific growth rate. Osmoregulatory parameters in plasma (osmolality, Na+ and Cl− levels) were similar in SW- and BW-acclimated fish but significantly higher than those of LSW-acclimated fish. Gill Na+, K+-ATPase activity showed lower values in intermediate salinity (6 > 38 > 12 ppt). No changes were observed in metabolic parameters analyzed in plasma, whereas only minor changes were observed in metabolic parameters of liver, gills and brain that could be correlated with the higher growth rates observed in fish acclimated to BW, which do not allow us to attribute the best growth rate observed at 12 ppt to lower metabolic rates in that salinity.  相似文献   

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