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1.
This paper reports preliminary studies designed to evaluate hybridization through natural mating and artificial insemination between female Penaeus japonicus Bate, 1888 and male Penaeus kerathurus Forskäl, 1775. Although both species were able to mature in captivity, natural copulation was not achieved. Different techniques, including manual squeezing in the base of the fifth pair of pereiopods, electrical stimulation and dissection, were used for the artificial insemination experiments. However, only dissection gave spermatophores. Stained sperm showed no malformations and its viability was very high. Seven out of 10 inseminations (70%) produced eggs, but the development of embryos was abnormal. It is suggested that the high genetic distance between these species is responsible for these results.  相似文献   

2.
Vitrification is a fast freezing method with promising results for penaeids sperm cryopreservation. This study evaluated the efficiency of three cryoprotectant solutions for sperm vitrification and artificial insemination with cryopreserved spermatophores of Litopenaeus vannamei. The cryoprotectant solutions tested were 30% methanol, 2% soy lecithin, and 30% methanol?+?2% soy lecithin. Fully mature females were artificially inseminated with vitrified and fresh spermatophores as a control group. The vitrification method was efficient in maintaining high rates of sperm survival and membrane integrity. Although the egg fertilization was successfully attained by artificial insemination with cryopreserved spermatophores, low hatching rates suggested that possible DNA fragmentation of sperm cells should be further investigated. This is the first report of artificial insemination using vitrified sperm in penaeids.  相似文献   

3.
Sperm quality, as determined by visual examination and by reaction with “egg-water” was not significantly different (P > 0.05) for sperm obtained by electro-ejaculation from ablated or non-ablated pond-reared Penaeus monodon. Nor was sperm quality different between pond-reared and wild-caught prawns. Normal sperm, determined by appearance, ranged from 17.1 to 21.0%, while reactive sperm ranged from 1.5 to 3.0%. There were, however, significant correlations (P < 0.01) between spermatophore weight and prawn weight (r= 0.73, N= 434). Male prawns weighing 4150 g produced on average spermatophores weighing 22.7 mg and containing 0.8 million sperm, while prawns weighing 61-90 g produced on average spermatophores weighing 56.6 mg with 2.5 million sperm. Ablation did not increase spermatophore size or sperm quality, although it significantly increased mortality of ablated males. Male prawns could be re-ejaculated at about weekly intervals with no change in sperm quality. Wild-caught female prawns artificially inseminated with spermatophores from electro-ejaculated males produced normal spawns with 51% average egg fertilization, and 41% nauplii hatch success. Nauplii hatch success following spawning increased from >60% for newly inseminated females to near zero after 30 days post-insemination, indicating spermatophore depletion and/or deteriorated sperm quality during spermatophore storage in the thelycum. The findings of the present study indicate that electro-ejaculation and artificial insemination are relatively simple and practical methods for improving captive reproduction performance of closed-thelycum prawns such as P. monodon, and that pond-reared and wild-caught males produced sperm of similar quality.  相似文献   

4.
Spermatophore deterioration in pond-reared Penaeus vannamei was studied, and spermatophore quality was evaluated and improved. Sperm production of males collected from grow-out ponds was increased by two techniques: eyestalk ablation using a fresh frozen maturation diet (13% body weight); and laboratory culture using a diet of the formulated feed Nicovita Plus (3% body weight/ d) and frozen squid (2%). Findings are complementary to previous reports that eyestalk ablation improves quality of spermatophores in young (25.7 g) males. The timing of eyestalk ablation for activation of the endocrine mechanism, leading to improved spermatophore quality was also explored. After eyestalk ablation, performed between postmolt and intermolt stages, 26 g males required a minimum of three spermatophore regenerations or 42 d to significantly increase spermatophore size and sperm count. On the other hand, the laboratory culture (2.5 mo) technique improved the quality of spermatophores in successive regenerations for non-ablated males. In the present study, subadult P. vannamei produced spermatophores which, if not transferred or manually ejaculated, gradually deteriorated (successive stages are described), while a new compound spermatophore was being synthesized.  相似文献   

5.
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6.
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   

7.
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   

8.
A variety of natural foods have been reported to induce ovarian maturation of penaeid shrimp. In this study, conducted from 19 June to 11 September 1980, four single-food diets (clams, shrimp, squid, and worms) and one composite diet consisting of all four foods were fed to Penaeus vannamei in 3.7-m diameter indoor circular tanks. The shrimp, averaging 28 g, were stocked at a rate of 6.9 m-2 with a 1:1 male to female ratio. Unilateral eyestalk ablation was performed on half of the females in each tank. Tanks received one turnover of water volume daily and the water temperature and salinity averaged 27.0°C and 28.6 ppt, respectively. Daily photoperiod was maintained at 13 hours of light. Ovarian maturation, spawning, molting rate, and survival were monitored daily and growth and gonad size were measured at termination. The composite diet was the best overall diet, while squid was the best single-food diet, followed by shrimp, worms, and clams. No maturation of unablated females was observed with the exception of one female that developed to stage 3. Although the size of the shrimp was considered marginal for spawning, 5 mated females were observed, but only one (squid treatment) produced viable nauplii. After termination of this study, all shrimp were fed the composite diet for 41 days. During this period, ovarian maturation and spawning occurred in the previously unproductive treatment receiving only clams, and growth rate of shrimp in all previously single-food treatments increased 4 to 7 fold. The composite diet was also fed to two tanks of P. stylirostris (mean initial weight = 45.4 g) for a period of 118 days. During that time, 50 spawns were obtained with up to 3 spawns per female. A total of 4.3 × 105 P. stylirostris nauplii were produced.  相似文献   

9.
The effect of unilateral eyestalk enucleation on induction of rapid spawning was investigated in Penaeus japonicus. Spawning rate was 50% in enucleated prawns where the optic nerve was not severed. Spawning rate was 20% in intact prawns. There was no mortality in either group. Unilateral eyestalk enucleation may prove to be an effective method for inducing P. japonicus to spawn rapidly.  相似文献   

10.
This study has investigated the influence of unilateral eyestalk ablation on the survival, molting frequency, fecundity, reproductive output, and fertility of M. amazonicum females. We divided 96 females into with ablation and without ablation groups with six replicates. Water quality, growth, survival rate, intermolt period, molts number, and ovigerous females over a 90-day period were monitored. Unilateral eyestalk ablation reduced intermolt period by 30% and increased molts number, ovigerous females, and reproductive output. Our findings indicate that unilateral eyestalk ablation positively influences reproduction in M. amazonicum and is appropriate for females of this species having a body length of ≥ 70 mm.  相似文献   

11.
In a preliminary experiment on the induction of sexual maturity in Penaeus kerathurus by unilateral eyestalk ablation, spawning was obtained in 94% of the females treated. The time necessary to reach the spawning stage appeared to be closely related to the stage of natural physiological development of the gonads and the length of the photoperiod, the period between ablation and spawning decreasing from 69 days for females treated in November to about 10 days for females treated at the beginning of their natural reproductive period in May/June. Spawning after treatment was repeated up to eight times, sometimes at intervals of less than 10 days, without showing a decrease in the amount of fertile spawn. The mean number of fertile eggs per spawn was 78.400, which is not significantly different from the corresponding mean obtained previously after thermal stimulation of almost mature breeders; the hatching percentage, 67%, was also similar. Often only the anterior and median lobes of the ovaries are included in the spawning process. The discharged spawn is nearly always completely free of matrix material. It is anticipated that induction by eyestalk ablation could allow a considerable extension of the growing season and of the area suitable for culture.  相似文献   

12.
Two studies were conducted to evaluate the effects of unilateral eyestalk ablation and diet on the reproductive performance of wild populations of Farfantepenaeus aztecus. In both studies, females in two treatments were unilaterally ablated while those in the control treatment were not. Shrimp in the non‐ablated treatment and one of the unilaterally ablated treatments received frozen bloodworms (8% BW day−1) and frozen squid (12% BW day−1). The bloodworm component of the diet of the third unilateral ablation treatment was replaced with frozen adult enriched Artemia sp. Ablated female population spawning per night, in both studies, was higher than non‐ablated spawning (8.5 and 8.9 vs. 2.6%; 7.4 and 7.5 vs. 2.7% respectively; P<0.05). Replacement of bloodworms with adult enriched Artemia sp. had no negative effect on the number of eggs spawned per ablated female (124 000 vs. 115 000 eggs spawn−1; 144 000 vs. 151 000 eggs spawn−1 respectively; P>0.05). The life span of ablated females fed adult enriched Artemia sp. was 8 and 40 days longer than ablated females fed bloodworms for the first and second studies respectively. Replacement of bloodworms with adult enriched Artemia sp. resulted in higher hatch and larval survival rates (Nauplius 1 to Zoea 1) (55.0% vs. 46.9% and 44.8% vs. 37.2%), respectively, P<0.05.  相似文献   

13.
Chilled storage of spermatozoa in fish has been extensively investigated for many years, but limited research was focused on crustacean species. Chilled storage of spermatophores of black tiger shrimp Penaeus monodon is needed to generate consistent and reliable supply of spermatozoa for subsequent use. The objective of this study was to develop a protocol for the chilled storage of black tiger shrimp spermatophores and to evaluate bacterial propagation during chilled storage of spermatophores. In the first experiment, spermatophores were selected and preserved using four different extenders, namely mineral oil, Ringer's solution, phosphate buffer and 0.85% sodium chloride, and stored at low temperature (2‐4 C) for 42 d without antibiotic supplementation. Results showed that mineral oil was the best extender for chilled storage of spermatophores, since the highest percentage of viable sperm (58.3 ± 2.9%) was observed with this extender at the end of experiment (day 42). Bacillus sp., Staphylococcus sp., and Pseudomonas aeruginosa were identified as the predominant bacteria occurring during chilled storage, and the total bacteria count gradually increased during the experiment. In the second experiment, spermatophores were preserved in the mineral oil with four concentrations of the antibiotic, penicillin‐streptomycin (0.1%,1%, 2%, and 3%). There was no significant difference (P 0.05) in the percentage of viable sperm among treatments with 0.1%,1 %, 2%, and 3% antibiotics. The total count of Bacillus sp., Staphylococcus sp., and P. aeruginosa in the antibiotic treated groups significantly decreased (P < 0.05) to undetectable levels by day 14 of the experiment. Fertility studies from artificial insemination indicated that P. monodon spermatophores preserved with mineral oil for 7‐8 d at 2‐4 C were capable of fertilizing eggs with hatching rates similar to the controls. This study suggests that chilled storage of spermatophores is a feasible approach for the management and spawning of black tiger prawn broodstock or other Invertebrate species that produce spermatophores.  相似文献   

14.
The present study compares the relative costs of stocking ponds with postlarvae from wild or domesticated Kuruma shrimp, Penaeus japonicus (Bate), broodstock. Wild broodstock were obtained from a commercial trawler. Domesticated broodstock were reared to harvest size (wet weight = 25 g) on a commercial farm and then transferred to controlled environment tanks where they were grown to a final wet weight of 50 g. The costs of stocking ponds with postlarvae were calculated from the observed reproductive output, the costs of purchasing wild broodstock and the costs of domesticated broodstock production in the controlled environment facility. Domesticated P. japonicus spawned comparable numbers of eggs to wild broodstock of similar size, but hatching success was significantly lower. A total of 12 domesticated P. japonicus broodstock would be needed to produce the postlarvae to stock a 1-ha pond, compared to only six wild broodstock. However, the much higher relative costs of wild broodstock means that the cost of using their postlarvae would be Aus$851 per pond compared to Aus$390 for domesticated broodstock. The present authors conclude that the use of domesticated P. japonicus broodstock could be a cost-effective alternative to wild broodstock in Australia and in other countries where P. japonicus is farmed.  相似文献   

15.
The application of artificial insemination techniques as a way to overcome the lack of mating of the closed thelycum Farfantepenaeus paulensis under large scale conditions is reported. The performance of artificially inseminated females (49.4±11.6 g) maintained in conventional versus unisex maturation systems was compared. Groups of unilaterally eyestalk-ablated females were artificially inseminated with one compound spermatophore soon after molting. The percentage of fertilized spawns increased from 26% before the use of artificial insemination to 57% afterwards. The reproductive performance of inseminated females held in conventional or unisex maturation systems showed no significant differences. Artificial insemination was considered a practical approach to overcome the lack of mating of F. paulensis under large-scale conditions with acceptable reproductive performance. The results also indicate the possibility of holding females separately from males, which could mean significant improvements in maturation systems through the increase in the stocking density of spawning females.  相似文献   

16.
日本对虾亲虾的暂养、性腺促熟及幼体培育   总被引：3，自引：0，他引：3  
本文报告了对日本对虾亲虾进行暂养及切除其单侧眼柄,同时配合适当的生态条件促其性腺成熟等技术措施,并进行了幼体培育。亲虾暂养成活率为83％;促熟率为76.2％;出苗2032.6万尾。  相似文献   

17.
Wild immature Penaeus indicus females (11.5 ± 3.1 g body weight) were ablated by pinching, cautery or tying of one eyestalk, and stocked with control (unablated) females and males (9.2 ± 1.5 g) in a 12-m3 maturation tank. Full ovarian maturation and spawning were attained 4 days after ablation/stocking in all treatments, with a peak at 5–6 days. Seventy-five percent of ablated and unablated females spawned during the study period. Average egg numbers from complete spawns increased with size of females for all treatments. There was no significant difference in fecundity of complete spawns from the various treatments. However, hatch rates of unablated P. indicus were significantly higher than eyestalk-pinched females but not those ablated by cautery and tying. Similarly, survival after the 15-day period was lowest among pinched females.  相似文献   

18.
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   

19.
Oocyte maturation and gonadosomatic index (GSI) of eyestalk ablated Penaeus monodon females collected from the wild and from two first‐generation domesticated lines were assessed. Frequency and diameter of the different oocytes, and the intensity of oocyte atresia, were compared among groups through histological assessments of the sections of the middle ovarian lobe. Digitized images from ovary sections were used to record the frequency and diameter of different oocyte types. Spawning performance of the three groups were expressed in terms of the percentage of females that spawned at least once (productive females), time from eyestalk ablation to first spawning (latency period) and the number of spawnings per female stocked. Final ovarian maturation was attained in all groups, as indicated by the presence of mature oocytes with cortical rods (cortical oocytes), dark‐green ovarian colour and high GSI values (5.83–6.86%). However, domesticated groups presented significant larger immature oocyte types (previtellogenic and yolky oocytes) and smaller cortical oocytes compared with wild females, indicating a reduced vitellogenic activity during final oocyte maturation. Additionally, the frequency of atresia was comparatively higher for both domesticated groups, which could be related to their inferior spawning performance. The implications of these results on the reproductive potential and development of domesticated P. monodon are discussed.  相似文献   

20.
This 12‐month preliminary study investigated the development of sexual characters, primary sexual maturity, ovarian maturity and spawning performance of pond‐reared Penaeus merguiensis in relation to culture conditions in south‐east Queensland, Australia. Post‐larvae of P. merguiensis were produced and cultured in two 60‐m3 tanks during the first 14 weeks. Before winter, they were harvested and stocked in three different overwintering facilities: a 200‐m2 covered pond, two 60‐m3 outdoor tanks and a 15‐m3 indoor, recirculated tank at a stocking density of 10 individuals m?2. The development of sexual characters was found to be similar to that reported previously in wild P. merguiensis. Males matured at younger ages and smaller sizes than females. Overall, the average size at primary sexual maturity of pond‐reared P. merguiensis was 23.1 mm carapace length for males (possessed spermatophores) and 29.3 mm for females (being impregnated). Water temperature and the availability of natural food strongly influenced prawn growth, maturity rate and their subsequent spawning performance. Growth, maturity rate and spawning performance of prawns in the covered pond were significantly higher than in the other overwintering facilities. Prawns started mating at 6–7 months, reached full ovarian maturation and spawned as early as about 8 (peaked at 9–11) months from hatching, producing high fecundity and viable larvae. There was a strong relationship (P < 0.001) between prawn size and fecundity. The results of this study suggest a potential for using pond‐reared broodstock P. merguiensis for hatchery production and for domestication or selective breeding programmes.  相似文献   

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