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1.
Experiments were conducted comparing the reproductive performance of ablated female shrimp Pleoticus muelleri fed either a fresh frozen diet (ND) (clam, prawn, squid) and the same diet supplemented with 15% of an artificial diet (SD) (54% protein, 13% lipid, 7% moisture). The shrimp were maintained in 3500‐L tanks (12 h light‐12 h dark photoperiod, temperature 18–20°C, pH 7, salinity 31 g L?1, ammonium <0.2 mg L?1, and sea water exchanged at 100% per day) for 45 days. Significant differences in weight gain were determined between ablated females fed ND (37.2%) and SD (26.4%). No significant differences in the average duration of the intermolt period (19±2 days) were recorded. Females fed SD showed signs of maturation 20 days after ablation, with spawning occurring 1 day later, as long as ablated females fed ND reached maturation 4 weeks after did not occur. The number of eggs per spawn varied from 136 000 to 345 000; the percentage viability ranged between 39.3% and 99.3% with an average of 78.5%. The results indicated that a suitable formulated diet together with eyestalk ablation promotes maturation of P. muelleri in captivity.  相似文献   

2.
ABSTRACT

Due to the low nauplii production of cultivated broodstock, and to reduce the dependence on the wild stock, an experiment was carried out with 400 adult blue shrimp, Penaeus stylirostris, from wild and cultivated (F6) populations. Four treatments, each in duplicate, were applied: (1) wild females and males (W-W); (2) wild females and cultivated males (W-C); (3) cultivated females and wild males (C-W); and (4) cultivated females and males (C-C). More than 300 individual spawns were monitored to evaluate the egg and nauplii production per female. Mixed model ANOVA for factorial arrangements (4 × 3 × 23 and 3 × 23) were conducted. The factors considered besides the treatments were: rematuration (number of successive spawnings for a female), ovarian maturity, integrity of the spermatophore attached (complete spermatophore, “wings,” or “remnant”) and condition of spawning (partial or complete). The introduction of both wild females and males was a successful measure to improve the overall egg and nauplii production. Both mixed populations outperformed the cultivated broodstock, but were inferior to the wild stock (average production of eggs and nauplii: W-W-l 12,713 and 34,682, respectively; W-C-l 13,215 and 22,038, respectively; C-W-82,702 and 11,715, respectively; C-C-66,948 and 7,653, respectively). Populations with wild females produce a larger number of eggs, and wild males contribute to higher hatching rates. Other observations indicate the need to select for spawning only those females showing an advanced degree of ovarian maturity, having a complete spermatophore attached to the thelycum, and spawning completely.  相似文献   

3.
Second generation Penaeus vannamei broodstack, pond-reared and wild populations, were compared for spawning frequency and several variables associated with reproductive performance. For this purpose, 470 pond-reared and 237 wild-caught individually tagged females were stocked with males of the same origin in ten maturation tanks in a commercial hatchery, and several productivity variables were recorded over time. Results of the analysis indicate that wild shrimp had higher mating and spawning frequencies compared to pond-reared broodstock. The number of nauplii per spawn was higher for wild shrimp, but fertilization and hatching rates were higher for pond-reared spawners. A larger proportion of nonmating females were found in pond-reared shrimp; whereas, wild females had a higher potential for multiple matings. The spawn quality (fertilization and hatching rates, percentage of viable spawns, and number of nauplii) in consecutive matings did not decline substantially. The present study indicates that selection of females with multiple spawning capabilities can be an important commercial strategy to improve nauplii production over the short term. Pond-reared broodstock can be an adequate source for applying this strategy because of their year-round availability and an overall acceptable reproductive performance.  相似文献   

4.
The life cycle of the penaeid shrimp, Penaeus stylirostris, was completed in captivity with the production of F2 generation nauplii. Over one million F2 generation nauplii were harvested from the F1 generation represented by laboratory-reared adult shrimp. The studies were completed in a laboratory simulated, tropical environment for maturation and spawning, and in pond systems located in a temperate environment for growout of the F1 generation.  相似文献   

5.
The present study analyzes the reproductive performance of three size classes of wild (average weight of 46.5, 55.0, and 63.2 g) and three size classes of pond-reared (18.4, 21.3, and 25.1 g) Penaeus paulensis females. Unilaterally eyestalk ablated females were placed for 70 d in 3.6 m diameter tanks at 6 individuals/m2 and a 1.2:1 female-male ratio. Number of spawns, eggs, nauplii, fertilization and hatching rates were recorded every second day. The length of unfed protozoea I larvae was also recorded. Larger broodstock shrimp tended to suffer higher mortality rates. Smaller, pond-reared females started spawning at 28.2 ± 4.1 g. The number of eggs and nauplii per spawning event were not significantly different between experimental groups (P > 0.05), but due to their higher spawning frequency, small wild females (46.5 ± 3.7 g) outperformed medium (55.0 ± 1.8 g) and large ones (63.2 ± 7.0 g). No relationship between protozoea length and spawner size was found. Optimum size for the maturation of wild P. paulensis females was estimated to be from 30 to 60 g. It is suggested that the use of this size range can potentially enhance nauplii production of P. paulensis .  相似文献   

6.
For production of shrimp larvae in a commercial hatchery, multiple spawning of females is highly desirable, provided spawn quality is not affected. Using biochemical and production approaches, 349 females were individually followed, and 69 spawns were sampled over a 3‐month period. The quantity of eggs and nauplii per spawn was greater in females with multiple spawns. Several indicators of spawn quality, such as fertilization and hatching rates, per cent of viable spawns, and morphometric characteristics of eggs and nauplii were not affected by consecutive spawns. Analyses of egg and nauplii biochemical composition indicate that adequate transfer of nutrients to eggs is not compromised with successive rematurations and spawnings. Strategies that focus on the selection of shrimp with multiple spawning capacities could be a promising approach to increasing larvae production.  相似文献   

7.
This 97-day study, conducted during midwinter using a recirculating water system, was designed to evaluate the effect of light intensity and male and female eyestalk ablation on reproduction of P. vannamei and P. stylirostris. Four light intensities were established using various levels of fluorescent lighting (bright, 14.7 μEm-2s-1; moderate, 4.4 μEm-2s-1; dim, 0.6 μEm-2s-1; and dark, 0.0 μEm-2s-1) and the fifth consisted of artificial lighting supplemented with natural light through a translucent skylight (skylight, 4.7–9.3 μEm-2s-1). Unilateral eyestalk ablation was performed on all male P. vannamei in one of each pair of tanks within a treatment. In addition, half of the females in each tank were unilaterally ablated. Ovarian maturation, spawning, molting rate, and survival were monitored daily within each tank. Growth and gonad development were measured at termination. The optimum light intensity for P. stylirostris appeared to be lower than that for P. vannamei. P. stylirostris matured and spawned more frequently in the skylight and dim treatments than in the moderate, dark, and bright treatments. P. vannamei matured and spawned more frequently in the skylight, bright, and moderate treatments than in the dim and dark treatments. Natural light supplementation beneficially affected reproduction of both species. Male eyestalk ablation increased gonad size and doubled mating frequency of P. vannamei in comparison to unablated controls. This is the first documentation of increased penaeid shrimp reproduction by unilateral eyestalk ablation of males. Even more significant may be recognition that male gonadal development is a limiting factor in reproduction of shrimp in captivity.  相似文献   

8.
The effect of supplementing dehydrated seaweed Ulva clathrata (20 g/kg) in the squid fraction of a formulated fresh diet on the reproductive performance of Litopenaeus vannamei broodstock was evaluated in two commercial hatcheries (A and B). The origin of broodstock, use of ablation on females, tank/culture conditions (for maturation, spawning, and larval rearing) were different between hatcheries. Daily mortality was higher (< .01) for females in the control group compared to Ulva‐fed group of hatchery A, where females were ablated. No differences in mortality were found for unablated females in hatchery B, or with males from either hatchery. In hatchery A, broodstock fed Ulva produced more eggs (an increase in +5% compared to control, < .05) and nauplii per female (+18%, < .01). In hatchery B, broodstock fed Ulva produced significantly more eggs (+26%, < .05) and nauplii per day (+33%, < .05). In hatcheries A and B, eggs from broodstock fed Ulva had increased hatching rates (+13 and +7%, respectively, < .001 in both cases). The number of spawns per day had a tendency to be higher in broodstock fed Ulva in both hatcheries, but the difference did not reach statistical significance (+14% for hatchery A and +20% for hatchery B). Dehydrated U. clathrata appears therefore as a functional additive in L. vannamei maturation diets that enhances the reproductive performance at commercial scale, regardless of the management conditions.  相似文献   

9.
Dietary Effects on Sperm Quality of Litopenaeus vannamei Broodstock   总被引:1,自引:0,他引:1  
A 56‐d feeding trial was conducted to investigate the effect of diet on sperm quality of Pacific white shrimp Litopenaeus vannamei broodstock. Dietary treatments consisted of a combination of 75% dry maturation diet and 25% fresh‐frozen squid (dry‐weight basis). Supplemental nutrients of the maturation diet were selectively deleted and replaced with wheat starch to produce the following treatments: 1) 75% basal maturation diet plus 25% squid (control); 2) 75% maturation diet without supplemental vitamins plus 25% squid; 3) 75% maturation diet without supplemental cholesterol and phospholipids plus 25% squid; 4) 75% maturation diet without supplemental astaxanthin plus 25% squid; and 5) a fresh diet composed of 60% squid and 40% Maine bloodworms. Shrimp fed the control diet and the diet without supplemental astaxanthin had significantly higher mean (± SEM) change in sperm count (4.6 ± 3.2 million sperm cells and 2.9 ± 2.5 million sperm cells, respectively), with respect to baseline (8.7 ± 1.0, 6.4 ± 1.0, 9.0 ± 1.3, 6.6 ± 0.7, and 6.0 ± 0.8 million sperm cells for treatments 1, 2, 3, 4, and 5, respectively), than shrimp fed the diet without supplemental vitamins (‐1.7 ± 2.6 million sperm cells), but not significantly higher than those of shrimp receiving the diets without supplemental cholesterol‐phospholipids (1.2 ± 2.5 million sperm cells) and the fresh diet (1.3 ± 1.6 million sperm cells). Dietary deficiencies also were reflected in weight gain of shrimp fed the diet without supplemental vitamins (‐2.0 g) and the fresh diet (‐0.8 g). which were significantly lower than weight gain of shrimp fed the control diet (1.1 g) and the diet without supplemental cholesterol‐phospholipids (0.8 g). No significant differences were detected among treatments for percentage of abnormal sperm and survival data. Results demonstrated a significant effect of diet on reproductive quality of male L. vannamei and indicated that the typical combination of fresh‐food organisms used is not nutritionally optimal for male broodstock.  相似文献   

10.
This study evaluated the reproductive performance, physical condition and tissue biochemical composition of wild‐caught Farfantepenaeus paulensis kept for 50 days in maturation tanks provided with sand or hard substrate. The use of sand in F. paulensis maturation tanks had limited impact on the performance and biochemical composition of broodstock. Females in the hard‐bottom tank produced more spawns and more eggs in total, but those kept in the presence of the sand substrate produced a larger number of nauplii because an improvement in mating success was observed. An increased survival of females was also related to the presence of the sand substrate, which agrees with improvements in water quality and the physical condition of females. On the other hand, sourcing mature females was more difficult and time consuming in sand‐bottom tanks. The decision on whether or not to use sand substrates in F. paulensis maturation tanks must take into account not only productivity and animal welfare but also considers ease of operation and costs. These findings may have implications for the design of maturation systems for closed thelycum species.  相似文献   

11.
The effects of two diets with different lipid composition (squid Loligo gahi and one commercial pellet for breeders) on reproductive performance and egg lipid composition of brill (Scophthalmus rhombus) were compared. A total of 36 adult brill weighing 1482 ± 432 g were randomly distributed in the experimental tanks. A flow‐through system composed of four tanks with 4.2 m2 of bottom area (5.0 m3 × 1.2 m water depth) was used. The experiment lasted for approximately 5 months (168 days). From the four mature females fed squid, three ovulated. Five females fed pellets matured and ovulated. Total ovulations were of 10 and 44, by the three females fed squid and the five ovulating female fed pellets respectively. Egg viability was higher, although not significantly, for females fed pellets. This indicates that pellets could be a better food for breeding females. In general, the egg total lipid content and the lipid classes composition did not seem to be affected by diet. In contrast, results indicate that not only diets but also individual females, regardless of the diet consumed, are determinant for egg fatty acid composition, clearly modulating their composition.  相似文献   

12.
Outdoor microcosm tanks were used to grow the penaeid blue shrimp, Litopenaeus stylirostris, in Brunei Darussalam. The tanks were cylindrical, free standing fiber glass tanks of 1827 L water holding capacity and had a self-cleaning mechanism. In three eight-week feeding trials, juvenile shrimp of 0.9–4.3 g were stocked at a density of 28 shrimp/m2. At the end of each trial, survival rates exceeded 80%. Growth rates ranged from 1.19 to 2.46 g/week. Water quality remained stable and within suitable ranges for L. stylirostris growth in all trials. The tanks had algae and bacterial floc developing within a few days of starting the trials. Fourteen commercial shrimp feeds, each containing more than 40% crude protein, were tested in the trials. In spite of the presence of natural food organisms, significant feed-related differences among treatments were found in each trial. In conclusion, microcosm tanks support excellent growth and survival of L. stylirostris and are appropriate for conducting trials to evaluate feeds for pond growout.  相似文献   

13.
Aquaculture production of the cleaner shrimp Lysmata amboinensis, a high‐valued marine ornamental, has been problematic because of prolonged larval development punctuated by periods of mortality. Broodstock maturation diets have been shown to affect fecundity and offspring quality and early survival. The common practice in shrimp culture is the use of fresh frozen foods supplemented with artificial diets. The objective of the study was to identify a suitable maturation diet (natural or artificial) for L. amboinensis. Six diets, comprised of squid, mussel, adult Artemia, a commercial feed, and combinations of the aforementioned, were fed to L. amboinensis for four reproductive cycles. Broodstock fed the squid–mussel diet lost a large proportion of the eggs during incubation, with decreased larval production (P < 0.05). In contrast, broodstock fed Artemia retained the highest proportion of the egg mass; however, hatchability was poor, resulting in low larval numbers per hatch. The Artemia and squid–mussel diets produced significantly fewer larvae than the combination or commercial diets (P < 0.05). In L. amboinensis, a maturation diet consisting of natural feeds alone resulted in poor reproductive performance and partial or complete replacement with an artificial diet was feasible.  相似文献   

14.
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   

15.
The white seabream, Mylio berda, was induced to spawn spontaneously by hormone injections of synahorin or human chorionic gonadotropin for over 3 months between December and April in Hong Kong. Fertilized eggs were also obtained during the peak spawning period between February and March through natural spawning or artificial insemination. The hatched larvae were reared in 500-1 circular tanks and fed initially on rotifers, Brachionus sp., followed by brine shrimp nauplii or copepod nauplii and finally weaned onto fish meat. Larval rearing trials for growth and survival to 60 days produced larvae of average length, 26.2 mm, at survival rates ranging from 1.32 to 11.62%.  相似文献   

16.
Two trials were conducted to evaluate the growth, survival and hepatopancreas histology of the Argentine red shrimp Pleoticus muelleri (Bate, 1888) fed different levels of vitamin E and butylated hydroxytoluene (BHT) in a semipurified diet. The diets contained 0, 100, 600 or 1500 mg vitamin E kg?1 and 16 mg BHT kg?1 diet (trial 1) and 0, 1250, 1500, 1750 or 2000 mg vitamin E kg?1 diet, squid mantle and vitamin‐free diet as a control (trial 2). After 30 days (trial 1), survival ranged between 43% and 64%, and the percentage weight gain of the shrimp varied from 22% to 31% with no significant differences among treatments (P<0.05). After 40 days (trial 2), survival of shrimp fed the diet with no vitamin E and squid mantle was significantly lower (62%) than the other treatment (86–90%). Shrimp fed diets containing vitamin E from 1250 to 1750 mg kg?1 exhibited increased weight gain (34–65%); however, a significant difference was observed for shrimp fed the diet containing 2000 mg kg?1. Histological results yielded differences among treatments. In shrimp fed 1750 mg kg?1 of vitamin E, the functional morphology of the organ was normal, with abundant secretion in the tubules. Signs of malnourishment such as cellular and nuclear retraction, desquamation of cells and hipertrofia, were evident in the hepatopancreas of shrimp fed the other diets. The results indicate that optimal vitamin E requirement for P. muelleri under the present experimental conditions appears to be approximately 1750 mg vitamin E kg?1 diet.  相似文献   

17.
This study compared the feed preference and growth response of Litopenaeus vannamei to chemoattractants. A diet with 3% fishmeal was supplemented with either 3% salmon meal (POS), 3% soy protein concentrate (NEG), 3% krill meal (KRM), 3% squid meal (SQM), 3% shrimp head meal (SHM), 3% shrimp meal (SM), 3% squid liver meal (SLM), or 5% liquid sardine hydrolysate (SAH). Shrimp with a body weight (BW) of 0.99 ± 0.08 g were stocked at 100 animals/m2 in 56 tanks of 1 m3 and fed 10 times daily for 74 days. Feed preference was evaluated by feeding shrimp of 10.87 ± 1.82 g in excess twice a day for 10 days in two separate feeding trays allocated in 50 tanks of 0.5 m3. Survival reached 93.3 ± 5.80% and was unaffected by supplementation. Final BW was the highest for shrimp fed the KRM‐supplemented diet (11.97 ± 0.93 g), followed by POS (11.11 ± 0.77 g) and SQM (11.01 ± 1.17 g). Diets SHM, SM, SLM, and NEG showed a lower shrimp BW than POS, but were not statistically different among them. Shrimp fed the SAH diet achieved the lowest BW (10.06 ± 1.02 g). The highest gained yield was obtained with diets KRM and POS. No statistical difference was observed in shrimp yield among other diets. The lowest feed conversion ratio (FCR) was achieved with shrimp fed KRM (1.31 ± 0.05) when compared to diets SHM (1.47 ± 0.05), SAH (1.47 ± 0.07), and SLM (1.45 ± 0.17). Two‐by‐two comparisons indicated that shrimp preferred SHM and KRM, except when these were compared to SQM and SLM. No difference in feed preference was found between diets with SQM and SLM. SAH was the least preferred raw material in all comparisons. Results indicated that KRM acts as a powerful feeding effector and growth enhancer in fishmeal‐challenged diets for whiteleg shrimp. A dietary supplementation with 3% KRM is more effective than the same dose of any other chemoattractant evaluated.  相似文献   

18.
Effects of total dietary lipid (TDL) on reproduction of Penaeus srylirostris were compared using a series of diets ranging from 7.8% to 13.9% TDL. In addition, a commercial feed was compared to the experimental feeds, and a single fresh diet component (squid as 40% of diet) was compared to a multiple fresh component portion (squid, bloodworms, shrimp, and brine shrimp as 40% of diet). The control diet consisted of the four fresh components in equal proportions. Significant differences among diet treatments during 87 days of evaluation were observed for mean percent hatch, number of nauplii per spawn, and percent females mating per night. A new parameter, protozoea I length, was evaluated also and appeared to be a sensitive measure of treatment differences. In general, the all-fresh component diet (control) and diets with multiple fresh components performed better than those with a squid-only component. Among the three diets varying only in total lipid content, the middle level (11.1% TDL) treatment means were significantly higher (P < 0.05) than the highest lipid treatment (13.9% TDL) based on number of nauplii per spawn, percent females mating per night, and protozoea length. The middle level treatment means were also higher than the low lipid level tested (7.8% TDL) for these parameters, but only protozwa length was significantly higher (P < 0.01). In the best treatment (100% Fresh), there were 189,000 ± 10,300 eggs per spawn (mean ± SE), 103,000 ± 10,400 nauplii per spawn, 51.3 ± 4.3 percent hatch (N = 64), and 7.0 ± 0.7 percent females mating per night (N= 174). The High Lipid treatment, in which the poorest results were obtained, produced 164,000 ± 11,100 eggs per spawn, 39,000 ± 9,400 nauplii per spawn, 23.0 ± 4.8 percent hatch (N = 40) and 3.9 ± 0.5 percent females mating per night (N= 174). Results indicate that dietary lipid levels affect reproduction and that 10% to 11% total lipid produced better results than 7.8% and 13.9%.  相似文献   

19.
Growth rate, soluble-protein content and digestive-enzyme activities were studied in Litopenaeus vannamei (Boone, 1931) early post-larvae under six feeding regimens, which included combinations of freshly hatched Artemia nauplii, an artificial diet and algae. Growth (0.11 mg DW day−1) and soluble-protein content (61.8 μg protein larvae−1 at PL10) of post-larvae fed mixed diets were significantly higher (P < 0.05). An artificial diet used alone or co-fed with algae caused the lowest growth (0.03–0.05 mg DW day−1) and soluble-protein content (13.7–15.5 μg protein larvae−1 at PL10). Trypsin-like activity was higher (up to 10 times) in post-larvae fed Artemia nauplii and an artificial diet alone or plus algae. The artificial diet stimulated chymotrypsin activity, apparently in response to squid meal present in this diet. Amylase activity increased when post-larvae were fed the artificial diet. This was apparently related more to the origin of the starch than to the total carbohydrate level of the diet. No obvious relationship was found between enzyme activity and growth in any feed combination. Based on growth and soluble-protein content, we determined that partial substitution (50%) of Artemia nauplii by artificial diet and the use of algae co-fed beyond the first post-larval stage benefits growth and the nutritional state of L. vannamei post-larvae.  相似文献   

20.
Microbound feeds have been well accepted by shrimps and farmers in many penaeid shrimp hatcheries. The present study focused on an adequate level of replacement of Artemia nauplii and microalgae by a microbound diet for rearing Litopenaeus setiferus (Burkenroad) larvae. A microbound diet (MBD) consisting of fishmeal, squid meal, shrimp meal, yeast meal and soybean meal was used. The first experiment was designed to obtain the optimum level of MBD to complete the live feeding schedule, from Protozoea (PZIII) to Mysis (MIII). The experimental levels of the microbound diet tested were 2, 4, 6 and 8 mg MBD L?1 day?1. The next step was to determine the Artemia nauplii replacement level from PZI to MIII by MBD. These experiments were carried out either in the presence (Experiment 2) or in the absence of algae (Experiment 3). Four replacement levels were tested: 0% (4 mg MBD L?1 day?1: 1 Artemia nauplii mL?1), 40% (5.5 mg MBD L?1 day?1: 0.6 Artemia nauplii), 60% (6.5 mg MBD L?1 day?1: 0.4 Artemia nauplii) and 100% (8 mg MBD L?1 day?1: 0 Artemia nauplii). In all experiments growth, survival, development, quality index (QI) and performance index (PI), were used to determine the optimum concentration of microbound diet. Results showed that 6 mg MBD L?1 day?1 can be recommended as a complement to live food for L. setiferus larvae from PZIII to MIII. In the presence of algae, maximum growth and survival may be obtained in 40–60% (5.5–6.5 mg MBD L?1 day?1) of Artemia nauplii replacement levels. In the absence of algae, the Artemia nauplii replacement resulted in slower development, less salinity resistance, lower growth and lower survival than was obtained in larvae fed with algae.  相似文献   

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