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1.
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   

2.
Spermatophore and sperm quality of male Argentine red shrimp Pleoticus muelleri held under laboratory conditions was evaluated using compound spermatophore weight, sperm count and percentage of live sperm as indicators. Thirty-seven males of S to 20 g wet weight were held indoors in a 3-m diameter circular fiberglass tank for 45 d. They were fed fresh squid, clam and pelletized diet. Spermato-phores were obtained by manual ejaculations. Four shrimps were re-ejaculated to verify the subsequent spermatophore regeneration. Spermatophore mean weights were significantly lower for 5–10 g males than for 15–20 g males ( r = 0.998) (P < 0.05). There were no significant differences in sperm count and percent live sperm among the different weight classes (5–15 g, 15–20 g, 20–25 g). The sperm count varied from 2.22 to 5.62 million. No change in sperm quality was seen in re-ejaculated individuals. During the first 2 wk of the experiment, the spermatophores exhibited healthy morphology and colour; by the fifth week evidence of spermatophore deterioration was apparent. Despite the degree of melanization, sperm quality was not affected and the high variability in sperm count indicated that the artificial ejaculation is adequate in this species.  相似文献   

3.
Reproductive performance was evaluated for sexually mature male Penueus vannamei fed one of four diets: 1) commercial 40% protein shrimp growout diet; 2) 100% squid; 3) 50% squid, 25% bloodworms and 25% Artemia; and 4) starvation. Spermatophores were ejaculated manually from tagged males at stocking and every 12 d thereafter. For each half of the compound spermatophore, weight and sperm count were determined. Four methods were used to assay the sperm quality: 1) gross morphology (GM); 2) trypan blue stain (TB); 3) acridine orange stain (AO); and 4) egg water induced reaction (EW). The reaction induced when P. vannamei sperm are exposed to conspecific egg water is grossly similar to that observed in vivo at the surface of the freshly spawned eggs from naturally mated females. Little correlation was found between spermatophore weight and sperm count. The best correlation was found between GM and AO (r2= 0.859, P < 0.01). Many morphologically abnormal sperm did not stain with TB. For most of the spermatophores evaluated; over 80% of the sperm were morphologically normal, were unstained with TB, and were immediately fluorescing light green when stained with AO. When exposed to egg water, sperm from these apparently good quality spermatophores yielded mixed results. The analysis of dietary effects on spermatophore quality were equivocal. Although a significant decline in body weight, spermatophore weight, and sperm count were observed in the starvation treatment as compared to maturation and squid diets, no significant differences were observed in MY of the sperm quality assays.  相似文献   

4.
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   

5.
Electrical stimulation (4–6 V AC) applied near the male gonopores at the base of the fifth pereopods caused expulsion of the spermatophore in Penaeus setiferus, P. stylirostris, and P. vannamei. For healthy animals, some degree of spermatophore expulsion occurred in 80% of the attempts. Complete expulsion of one or both spermatophores occurred in only 47% (29–65%, depending on species). Shrimp with melanized terminal ampullae generally did not expel a spermatophore following electrical stimulation. The technique needs further refinement for routine use with penaeids.  相似文献   

6.
Several male Penucus stylirostris were selected from a 3 ha commercial earthen pond and were individually evaluated for reproductive performance. Indicators measured were compound spermatophore weight, sperm count, and sperm abnormalities.
It was found that spermatophore quality was significantly better for 30–40 g shrimp than for 20–30 g shrimp ( P < 0.05). The higher frequency of abnormalities measured in younger males and the inverse relationship between abnormalities and sperm count indicate that the vas deferens could be the tissue responsible for producing highly abnormal immature semen. It is proposed that male maturation has at least three independently controlled levels of organization: testes maturation, vas deferens maturation, and spermatophore synthesis.
The individual evaluation showed that each male followed a particular response in reproductive quality. Changes in spermatophore weight were not an indicator of sperm density within spermatophores.
Male reproductive tract degenerative syndrome (MRTDS) and male reproductive system melanization (MRSM) did not develop in any shrimp during these experiments.  相似文献   

7.
Abstract— This study was conducted to determine the effect of water temperature on male reproductive tract degenerative syndrome (MRTDS) and male reproductive system melanization (MRSM) in Penaeus setiferus , and to evaluate the effect of water temperature on spermatophore regeneration time and sperm quality in electrically ejaculated adult males. Variation in sperm quality, gonadosomatic index, and histological changes in the reproductive system were used to assess reproductive tract changes in the first experiment. Sperm quality and regeneration time were measured before and after successive regenerations in the second experiment. Sperm quality was stable when shrimp were held at 26 C for 30 d but was reduced when shrimp were held at 30 C. Reproductive tissues of 20% of the shrimp held at 30 C were melanized to some degree but tissue melanization was found in only 2.5% of the shrimp held at 26 C. Spennatophore regeneration time was also affected by temperature. Average times for first spermatophore regeneration were 192 h at 25 C, 152 h at 30 C, and 144 h at 33 C. Sperm quality of regenerated shrimp was not affected at 25 C but was reduced for regenerated animals held at 33 C. Based on these results, we recommend a water temperature between 25 and 27 C to obtain adequate spermatophore regeneration and to maintain healthy male P. setiferus broodstock for at least 30 d.  相似文献   

8.
A technique for electrically inducing spermatophore extrusion from live lobsters (Homarus americanus) is described. When a 12-V stimulus is applied around the coxa of the fifth walking leg, a single spermatophore is extruded through the gonopore. The sperm in extruded spermatophores are morphologically normal and undergo normal acrosome reactions. The technique provides a ready source of viable sperm for in vitro studies on fertilization and for artificial insemination of freshly molted female lobsters. The spermatophore itself is a natural package for sperm storage and may be useful in the future development of lobster sperm banks.  相似文献   

9.
The effects of different diets on spermatophore production and sperm quality were investigated in the river prawn Macrobrachium americanum. River prawns were cultured and fed with three diets for 244 days: fresh food (50% squid meat, Dosidicus gigas and 50% sardine muscle, Sardinops sagax); commercial pellets (35 Purina®); and a 50:50 mixture of both diets. Spermatophore production was recorded every 24 days on average as the percentage of spermatophores produced per extraction per diet, weight and biochemical composition. Sperm quality was measured as the total number of sperm, the proportion of live/dead sperm and normal/abnormal sperm morphology. There were no significant differences in the mean biochemical composition of M. americanum spermatophores for any of the diets. Biochemical composition was 36.3% protein, 25.8% carbohydrate and 4.6% lipids for all data pooled. The weight of spermatophores and sperm counts was not significantly different among diets, nor were there any differences as a function of the male initial total length (p > .05). Male river prawn reproductive exhaustion was observed as a decline in spermatophore production, weight of the spermatophores and the number of sperm cells per spermatophore, with an increasing proportion of dead and abnormal sperm seen throughout the experiment. The recommended period of maintenance in captivity for male broodstock is less than 115 days. It is recommended to feed broodstock males of M. americanum with commercial pellets because no significant differences were detected with the diets tested; pellets are easier to use, ensuring the same spermatophore production and sperm quality that was obtained with fresh food.  相似文献   

10.
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   

11.
Abstract.— Two growth trials utilizing Penaeus vannamei and Penaeus setiferus were conducted at densities of 28.4, 56.8, 85.2, 113.6, 170.4, 227.3 and 284.1/ m2 in an indoor recirculating system. There was an inverse linear relationship between stocking density and growth among both species. The relationship between final weight and stocking density is described by the following linear equation: P. setiferus , Y =−0.00619X ± 4.46, adj. r2= 0.8572;. P. vannamei, Y =−0.00717X ± 7.39, adj. r2= 0.6230. Although the responses in terms of growth depressions were similar, P. setiferus growth was lower than that of P. vannamei . There was an inverse relationship between stocking density and survival for P. setiferus . Survival of P. vannamei was highly variable but was negatively correlated with density. Based on the results of the present study, P. setiferus has a similar tolerance of high density as that of P. vannamei and hence may be suitable for intensive culture systems. However, depressed growth rates of P. setiferus , which do not appear to be due to effects of water quality or density, must be solved if growth rates similar to P. vannamei are to be realized.  相似文献   

12.
To develop an appropriate cryopreservation protocol for spermatophores of black tiger shrimp, Penaeus monodon, three cryoprotectants (dimethyl sulphoxide (DMSO), methanol (MeOH) and ethylene glycol (EG)) at two concentrations (5% and 10%) were examined. Artificial implantation of spermatophores was also carried out to assess the fertilizing ability of fresh and post‐thaw spermatophores. Spermatophores were collected during consecutive regenerations (15‐day intervals) and assessed for qualitative and quantitative changes and also for fertilizing ability by implantation. The mean fertilization rate for artificial insemination using post‐thaw spermatophore was 79.9±3.7%, lower than the fertilization rates observed for artificial implantation using fresh spermatophore and natural mating. Mean hatch rates for fresh spermatophore, frozen‐thawed spermatophore and natural mating were 88.8±0.6%, 87.8±0.4% and 88.3±0.5%, respectively; and there was no difference among the three groups. The mean fertilization rate of spermatophores collected during the first stripping was higher (90.6±0.6) than during the second stripping (85.7±2.6), but the mean hatch rate was not different between the two strippings. The highest mean sperm viability (79.7±0.4%) was obtained from DMSO (5%), with no survival observed in the 10% MeOH treatment. Spermatophore weight, total sperm count and percentage of abnormal sperm were not different between spermatophores collected at the first and second stripping. This is the first study to report high fertilization and hatch rates from cryopreserved spermatophore using artificial implantation of spermatophore before spawning.  相似文献   

13.
Abstract.— Controlled reproduction of penaeid shrimp requires a better utilization of males by sperm quality monitoring and sperm quality improvement. Spermatophores of white shrimp Penaeus vannamei were improved, in terms of increased sperm count, spermatophore weight, and a reduced incidence of sperm abnormalities by a single injection of 17α-methyltestosterone at 0.01 or 0.1 μg/g body weight. 17α-hydroxyprogesterone did not induce a significant improvement in spermatophore quality. These findings indicate that a steroid injection program should be evaluated as a practical way of improving spermatophore quality in commercial operations.  相似文献   

14.
The calorigenic effect of feeding (apparent heat increment, AHI) and post-prandial nitrogen excretion (PPNE) were measured in postlarval (PL 25–30) Penaeus setiferus, P. schmitti, P. duorarum and P. notialis fed a fixed ration of 3 mg/animal using purified diets with 40, 50, 60, or 65% protein. Both AHI and PPNE increased with increasing dietary protein. The contribution of PPNE to AHI varied from 6.1 to 94%, with lesser values for P. setiferus and greater ones for P. duorarum . Also, the AHI coefficient (percentage of ingested energy) increased with increasing dietary protein. The AHI and PPNE coefficients for the four shrimp species ranged from 0.3 to 6.5% and 0.02 to 5.04% of ingested energy, respectively. These results suggest close relationships among protein requirements, the capacity to use dietary proteins as a source of energy, and adaptation by different species to different types of food. The amount of energy used for production of ammonia is proposed as an adequate measure of the part played by dietary proteins in food cost.  相似文献   

15.
To explore the impact of moulting and short‐term chilled storage of spermatophores on the sperm quality for a commercially important penaeid prawn, spermatozoa of Penaeus monodon from early (B‐C), middle (D0‐1) and late (D2‐3) moult stages were compared for sperm quality parameters relating to the structural integrity of plasma membrane (Viab%), acrosome (AR%) and DNA (SDF%) after being stored at 4°C for 0–26 days. The three different sperm extenders used for chilled storage included artificial lobster haemolymph (AH), calcium free saline (CS) and filtered seawater (FS); two storage conditions were applied either as a free sperm suspension or retained within the intact spermatophore. Results showed that (a) the lowest natural AR% was shown for B‐C spermatozoa in CS whereas the highest levels were for B‐C, D0‐1 and D2‐3 spermatozoa in FS and D2‐3 spermatozoa in AH; (b) the calcium ionophore A23187 agent used in this study was able to increase the mean AR% by 6.22%; (c) the Viab% was significantly lower in CS than that in FS; (d) the SDF% significantly increased over the period of chilled storage for B‐C and D0‐1 spermatozoa, while the SDF% of D2‐3 spermatozoa was initially elevated and did not change significantly over time; and (e) there was no difference in sperm quality between two storage conditions. This study has successfully demonstrated the moult‐related variance in the percentages of acrosome‐reacted and DNA‐damaged spermatozoa, providing evidence of moult‐related spermatophore renewal cycle in this species.  相似文献   

16.
A technique for collecting spermatophores from male yabbies (Cherax destructor) is described. This technique consists of applying an electrical stimulus of between 5 and 10 mA and 40–50 Hz around the coxa of the fifth walking leg, and was found to have a success rate of 76% in 100 males tested. Furthermore, this approach enabled the collection of spermatophores from intersex individuals, indicating that intersex animals have the ability to function as males.

Using this technique, it was shown that spermatophore development is correlated with water temperature and that it is possible to elicit spermatophores from males in the non-reproductive season simply by raising water temperatures. The ability to non-invasively collect spermatophores from yabbies will facilitate the development of artificial fertilization techniques in this species.  相似文献   


17.
The objective of this study is to evaluate the effect of body size, temperature and annual cycle on sperm production in Cherax quadricarinatus. Sperm count and sperm mortality were estimated, the reproductive system was weighted, and macro and microscopical analysis of the testes and vasa deferentia were conducted. Sperm count and weight of the reproductive system are strongly related to male size, in contrast to sperm mortality. The spermatophore structure presented macro and microscopical differences between sizes. Males higher in size have more adherent spermatophores. This species has a reproductive cycle related to sperm production. Sperm count and weight of the vasa deferentia rise in summer, while the weight of the testes increases in winter. During the spring, the sperm cord presents a higher density than in other seasons. The temperature seems to affect sperm production being 27 and 29 °C the best assayed conditions. The present results are relevant information to obtain the best sperm viability selecting male size, season of sampling and the best temperature for the reproductive stock and future assays of spermatophore cryopreservation for this species aquaculture.  相似文献   

18.
The objective of the present work was to evaluate the effects of different levels of vitamin E in feed on the spermatophore regeneration and quality of male Penaeus monodon. The experiment was carried out with the four following treatments: the basal diet no added vitamin E, the diet added 200, 600 and 1,000 mg/kg respectively. Spermatophore regeneration and quality were evaluated by spermatophore weight, sperm count and spermatophore absence rates, which male P. monodon were extruded spermatophore for feeding 20 and 40 days. In the experiment, the weight of the twice regenerated spermatophore of the males added to the vitamin E group was higher than that of the untreated control group. The weight of the first regenerated spermatophore with the addition of 1,000 mg/kg group was the highest and significantly higher than the control group (p < .05), but there was no significant difference among the three groups with different levels of vitamin E. The weight of the second regenerated spermatophore with the addition of 600 mg/kg group was the highest, followed by 1,000 mg/kg group, both of which were higher than the control group and the addition of 200 mg/kg group. Within the same group, the regeneration spermatophore weight showed overall upward trend as the feeding time, twice regenerate experiment spermatophore weight with added to the vitamin E groups were significantly higher than the initial value (p < .05), but three spermatophore weight of male shrimp at the control group had no significant difference. The sperm quantity and the percentage of normal sperm of the twice regenerated spermatophore of the males with added to the vitamin E group was higher than that of the untreated control group, and those of the addition of 200 mg/kg group was significantly higher than that of control group (p < .05). The total number of sperm and the percentage of living sperm of male shrimp in the experimental group decreased with the increase of vitamin E in the feed. Within the same group, the total number of sperm and the percentage of living sperm of male shrimp with added to the vitamin E groups showed overall upward trend as the feeding time and were significantly higher than the initial value (p < .05), but the control group was slightly down and had no significant difference. Comprehensive sperm weight, sperm quantity and living sperm percentage of three indicators, that adding 200 mg/kg of vitamin E in feed could effectively promote the spermatophore regeneration in the male P. monodon and improve the sperm quantity. The experimental results provide a scientific basis for the breeding of P. monodon.  相似文献   

19.
Practical Molt Staging of Penaeus setiferus and Penaeus stylirostris   总被引：1，自引：0，他引：1  
Molt staging has many applications in penaeid aquaculture as a routine procedure. Using criteria developed for various crustaceans, a method of rapid molt staging was applied to Penaeus stylirostris and Penaeus setiferus adults. The most useful characters were the degree of epidermal retraction from the setal bases and epidermal retraction from the cuticle coupled with the development of new setae. The duration of the molt cycle of P. stylirostris was 11.5 ± 1.0 days ( N = 5) at 27–29 C. The early postmolt, late postmolt, intermolt, early premolt and late premolt stages were readily determined. For P. stylirostris , the duration of postmolt was 27% of the cycle; intermolt, 17%; and premolt, 56%. The length of the molt cycle of P. setiferus at 27–29 C was 13.6 ± 1.0 days ( N = 21) with postmolt occupying 22% of the cycle; intermolt, 19%; and premolt, 59%. Unilaterally eyestalk enucleated P. setiferus had a significantly shorter molt cycle than intact P. setiferus (11.7 ± 1.21 days vs. 13.6 ± 1.02 days, P < 0.05). There were no differences in molt cycle duration between the sexes, whether enucleated or intact ( P > 0.05). A series of illustrations identifies the key characteristics for determining stage of molt in these penaeids.  相似文献   

20.
Shipping trials were conducted with adult Penaeus setiferus to determine the effect of 24 hour closed shipments on water quality, to evaluate methods of reducing water quality deterioration and to maximize packing density (biomass). Other trials were undertaken with juvenile P. setiferus and adult P. vannamei for comparison. The method utilized 8 L seawater chilled to 18–19 C, inside doubled polyethylene bags held in a Styrofoam box (42 × 42 × 23 cm deep). Gaseous O2 was injected into the water to 8 ppm (for standardization) and into the space above the water. Super-saturation of dissolved oxygen (>20 ppm for 24 hours) had no adverse effect on survival. Initial trials resulted in increased ammonia (from 0.1 to 4–6 ppm NH4-N), increased carbon dioxide (from <2 to 80–100 ppm), increased temperature (from 18–19 to 25–26 C) and decreased pH (from 8.0 to 6.0–6.4). Increases in shipping density (number or biomass of shrimp per L seawater) further intensified water quality deterioration. Carbon dioxide (with concomitant pH decline) is implicated as the major limiting factor during 24 hour closed shipment. Ammonia accumulation was reduced or totally eliminated with addition of AmQuelΘ (Kordon, Inc, Hayward, California), 2 depending on the dosage used. The buffer, Trizma® 8.3 (Sigma Chemical Co, St. Louis, Missouri), 2 limited CO2 buildup and reduced pH decline. Maintenance of low temperature over 24 hours was enhanced with addition of a frozen cold pack placed over the shipping bags. However, the control of ammonia, pH and carbon dioxide by the addition of AmQuel and Trizma did not increase survival, possibly due to toxic effects of the chemicals.  相似文献   

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