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1.
Metabolic (oxygen consumption) rate, opercular abduction rate and tail beat frequency were determined in two strains of diploid and triploid female brook trout (Salvelinus fontinalis) while these fish swam at 0.37±0.02 body lengths per sec in a Blazka respirometer. Total blood hemoglobin level was also measured and opercular condition examined. Total blood hemoglobin levels in diploids and triploids were equal. The opercular abduction rate was the same in diploids and triploids (regardless of whether triploid opercular condition was good or poor) yet triploids had a lower oxygen consumption rate than diploids, indicating that triploids take up less oxygen than diploids per opercular cycle. Tail beat frequency, an indicator of swimming effort, was the same in diploids and triploids, suggesting that triploids require less oxygen than diploids for a similar swimming effort.  相似文献   

2.
Three‐summers‐old all‐female triploid and diploid rainbow trout were compared after one on‐growing season in sea net cages. Slaughter traits of round weight, gutted weight, fillet weight, carcass% and fillet% were measured at three times in November 2017, January and April 2018. The triploid group had lower daily growth coefficient mean (4.25) and higher feed conversion ratio (1.18) than diploids (4.48 and 1.05, respectively) during on‐growing (June–November). In November, no difference of means was found between mature or immature diploids and triploids for any of the weight traits when the effect of vertebrae defects was statistically removed. However, the triploids had attained higher means than mature or immature diploids in gutted and fillet weight by January, suggesting that the loss of muscle mass during early winter was lower in triploids. Sexually maturing diploids (46%) had lower slaughter yield means compared to triploids or immature diploids at each measurement time, and these differences also increased during overwintering. Instead, the means of yield traits remained similar between the triploid and immature diploid groups through the winter. Likewise, fillet redness remained at equally high level in triploids and immature diploids, whereas in maturing diploids this attribute decreased substantially during overwintering. The triploid group had a higher incidence of vertebral defects (12.0%) than diploids (5.3%). The present results demonstrate the potential of triploid trout in producing large‐sized (>2 kg) fillet fish until spring markets. However, more detailed investigations are needed, particularly regarding the animal health and growth efficiency in triploids, relative to their diploid counterparts.  相似文献   

3.
Growth of second-year triploid and diploid bighead carp, Hypophthalmichthys nobilis, was compared in a 189- to 190-day yield trial; the fish were grown separately in 0.04-ha earthen ponds at 625/ha and were also grown communally in 0.05-ha earthen ponds at 640ha. When grown communally, bighead carp were polycultured with channel catfish, Ictalurus punctatus (7,50Oha), and grass carp, Cienopharyngodon idella (40/ha); when they were grown separately, they were polycultured with grass carp at 501ha. When cultured separately, diploids were longer (526 vs 499 mm) and heavier (1,645 vs 1,427 g) than the triploids at harvest, but the differences were not significant (P 5 0.05). When cultured communally, the diploids were significantly longer (519 vs 485 mm) and heavier (1,621 vs 1,321 g) than their triploid counterparts at harvest. Ploidy of all bighead carp was determined after fish were harvested, and 7.9% of the presumed triploids that were stocked separately were actually diploids. Growth of the triploids appeared to be acceptable for commercial use where diploid bighead carp are banned. The efficiency of producing triploid bighead carp must be improved if they are to be cultured in states where bighead carp are illegal.  相似文献   

4.
Triploid rainbow trout exhibit improved survival and extended growth during sexual maturation, compared to their diploid counterparts. However, there have been few benefits demonstrated prior to sexual maturation. This study was undertaken to investigate the possibility of improving growth and survival parameters in triploids through interstrain crosses. Triploids were induced by heat shocking fertilized eggs from intra- and interstrain crosses of two rainbow trout strains. The four triploid groups and their diploid counterpart groups were reared to 233 days post-hatching and analyzed for growth and survival characteristics. Compared with diploids, triploids had significantly (P < 0.05) higher mortalities during the first 100 days post-fertilization, primarily just prior to and after hatching. However, during the remainder of the study triploids exhibited significantly (P < 0.05) lower mortalities than diploids. During the first 50 days of rearing all four triploid groups were significantly shorter and lighter than their diploid counterparts. The growth of the triploid groups later in the study varied considerably. At the conclusion of the rearing phase, one interstrain triploid group was significantly (P < 0.05) longer than its diploid counterpart, although not significantly heavier. The other triploid groups were either significantly smaller than, or equal to the diploids. Analysis of variance indicated that the growth of triploid rainbow trout was significantly affected by maternal strain effects. These results suggest that the use of specific strains and crosses may improve the growth of triploid rainbow trout.  相似文献   

5.
ABSTRACT:   To evaluate the aquaculture performance of triploid barfin flounder Verasper moseri , the sex ratio, maturation, growth and the relative proportion of body parts were examined. The sex ratio of triploids was similar to diploids under communal rearing conditions, but the proportion of female diploids was higher than that of triploids under separate rearing conditions. The gonadosomatic index of triploid females was very low even during the spawning season, and the ovaries were rudimentary. These results suggest that triploid barfin flounder females were sterile. In addition, triploid males produced a small quantity of milt containing very few spermatozoa with abnormal shapes. Spermatozoa obtained from triploids were aneuploidies. When normal eggs were fertilized with sperm from triploid males, no fry developed. These results suggest that triploid barfin flounder males were functionally sterile. Triploid males grew more slowly than diploid males, and triploid females showed similar or slower growth than diploid females, whether reared separately (23 months) or communally (35 months). The ratios of visceral weight to the edible parts for triploid males were similar to those for diploid males, but ratios for triploid females were higher than for diploid females during the spawning period. In conclusion, a significant improvement of growth was not found in triploid barfin flounders.  相似文献   

6.
In a 2-year grow-out trial, triploid Sydney rock oysters, Saccostrea commercialis (Iredale & Roughley), from two initial size grades grew faster (in terms of both mean whole weight and shell height) than the equivalent initial size grades of sibling diploids (P < 0.05). Small size grade triploids caught up with and had significantly heavier (P < 0.05) final whole weights than large size grade diploids after a 2-years grow-out period. The initial size grade had a significant effect on final mean whole weight and shell height for both ploidy types. After the 2-years grow-out trial, the final mean whole weights (but not shell heights) of small and large diploids (35.8 ± 0.6 g and 39.4 ± 0.5 g, respectively) were significantly different (P < 0.05). Small and large triploids grew at a similar rate for the first 18 months despite the significantly (P < 0.05) heavier final mean weight of large grade triploids (48.4 ± 0.8 g and 61.2 ± 0.7 g, respectively). The effect of the initial size grade on subsequent growth of both diploid and triploid oysters which was demonstrated in the present study is of significant commercial value to hatchery and nursery operators as well as growers of single seed oysters. In addition, small-grade triploids appeared to be more valuable in terms of potential growth rate than all diploid grades. There was no significant difference in the final percentage triploidy between small and large grade triploids. A large proportion of diploid/triploid mosaicism was detected in adult oysters.  相似文献   

7.
The tench Tinca tinca is an interesting fish from the viewpoint of polyploidy and related atypical reproduction aspects. Triploid tench were produced artificially. Studies of spermiation as well as of sperm motility and structure were performed on several triploid and diploid males simultaneously with individual experimental crosses with diploid females to define their reproductive capacities. The testes of triploids visually looked less developed in the most of cases with lower sperm production (0.05 cm3 sperm per male), GSI and weight of testes compared to diploids (0.58 cm3 sperm per male). Analysis of variance showed significant influence of ploidy level on the percentage of motile spermatozoa. Triploidy did not change percentage of live spermatozoa and velocity of spermatozoa at the first time of sperm movement. The study of sperm structure by scanning electron microscopy revealed that most sperm cells were of normal structure with some anomalies. Sperm heads of triploid and diploid males were mostly round-shaped, 1.86±0.2 and 1.6±0.18 μm in diameter. The midpiece of triploid spermatozoa was slightly narrower than that of diploid ones with typical cylindrical shape. Flow cytometry revealed sperm cells of triploids to be largely aneuploid (1.47 n) with high mosaic DNA, oscillating from haploid DNA content (1.0 n) to diploid DNA content (1.9 n). Experimental crosses between triploid males and diploid females revealed that these males were capable to stimulate effective development with relatively high level of fertilization and hatching rates from 0 to 70%. In conclusion, triploidization does not seem to guarantee sterility of tench.  相似文献   

8.
Growth and reproduction of triploid and diploid blacklip abalone Haliotis rubra (Leach, 1814) were compared in a 30-month study. Triploidy was induced by inhibition of the second polar body formation using 6-dimethylaminopurine (6-DMAP) or cytochalasin B (CB). There were no significant differences in growth and survivorship between triploid and diploid abalone. However, triploid abalone had a more elongated shell and greater foot muscles than diploid abalone. A slightly curvilinear growth in shell length was conformed to all treatments. While diploid abalone had reached sexual maturity and spawned during the study, gonadal development and gamete maturation were abnormal in triploids. Female triploids lacked an apparent gonad at the macroscopic level but microscopic examination revealed that they had a thin layer of oogonia development. In contrast, male triploids were able to form similar-sized gonads to diploids during most of the reproductive period, but with brown-yellow discolouration and stalled gametogenesis at spermatocyte formation. Sex ratio of triploid abalone did not deviate from 1:1. With the onset of sexual maturation, growth and gonadal maturation occurred concurrently in diploid abalone, and there was no indication that growth of (diploid) abalone was reduced.  相似文献   

9.
Wild caught Asian catfish were spawned manually following HCG injection, and a portion of the eggs were subjected to cold-shock at 4 C for 15 min within 2-min post-fertilization. Nuclear diameter measurements of cold-shocked fish revealed that 96% were triploids (3N), while non-shocked fish were all diploids (2N). During larval and fry culture (first 26 d), triploid fish mortality was =50%, while diploid mortality was =25%. Following 8-mo culture in tanks at three stocking densities, triploid fish survival was significantly greater ( P < 0.05), than diploids, with 84.0% and 57.3%, respectively. Triploid live weight was also significantly greater than diploids, with 69.2 and 45.9 g averages, respectively. Ninety-two percent of diploids had welldeveloped gonads after 8 mo; whereas none of the triploids had mature gonads. Gonads were undifferentiated with 31% of the triploids. These sexually undifferentiated fish had greater growth rates than male or female triploids, and greater growth than all diploids. Carcass weight (gutted) of triploids was 95.8% of live weight, compared with 92.5% for diploids. Lastly, triploids had very few deformities compared with diploids, with 1.3% and 17.6%, respectively. Deformities included curved spines, and humped backs just posterior of the head.  相似文献   

10.
The covariation between diploid and triploid progenies from common breeders was investigated in various progeny-testing experiments where either dams or sires were sampled from rainbow trout, Oncorhynchus mykiss (Walbaum), stocks. Triploidiza tion was found to frequently reduce the performance in the traits studied: body length and weight, growth, coefficient of condition and pyloric caeca number. Triploidization also generated significant interactions with the parental breeding value. These interactions were caused in part by the familial variance not being the same in triploids as in diploids, but also by actual ranking differences between diploid and triploid familial performances. However, the effect of these interactions was minor as compared with the amount of variation common to both ploidy levels (genetic correlations averaged 0.7–0.9). Therefore, selection of diploid breeders appeared efficient enough for improving triploid progeny, unless family selection methods including triploid progeny testing were preferred for other reasons. Lastly, it was observed that variances from maternal origin tended to be larger in triploids, whereas variances from paternal origin tended to be smaller, as compared with diploids. This point was discussed referring to the genetic make-up of triploids and in the scope of dams and sires for selective breeding.  相似文献   

11.
Growth, skeletal structure and muscle composition of cold‐shock‐induced triploid olive flounder Paralichthys olivaceus were investigated. The average values of total length and total weight of triploids were higher than those of diploids from 5 to 11 months posthatch (mph). The growth difference disappeared after 11 mph. The skeletal structure of flounder at 11 mph was observed by X‐ray imaging method. There are four kinds of vertebral deformity including vertebrae fusion, one‐sided compression, two‐sided compression and vertically shifted. The trunk region (V8–18) and tailing end of the vertebral column were the predominant locations of deformity. In general, the frequencies of vertebral deformities in triploids (60.0%) were higher than those in diploids (33.3%, p < 0.05). Both the number of fish with deformed vertebrae and the average frequencies of deformed vertebrae in triploids were significantly higher than those in diploids (p < 0.05). The muscle tissues of diploid and triploid flounder at 11 mph contain the same types of fatty acid and free amino acid profiles. The number of fatty acids with significant higher contents in diploids and triploids was one and ten, respectively (p < 0.05). The contents of free amino acids showed no difference between triploid and diploid fish.  相似文献   

12.
Growth performance, survival and feed utilization of diploid (2n) and triploid (3n) sex‐reversed male and female Nile tilapia were evaluated at maintenance feeding (1% body weight (BW) day?1), fixed feeding (3% BW day?1) and apparent satiation feeding levels in a freshwater recirculation system comprised of thirty‐six 1‐m3 concrete tanks at the Asian Institute of Technology, Bangkok, Thailand. Triploid Nile tilapia (3n) was produced by subjecting fertilized diploid (2n) tilapia eggs to heat shock. After hatching, fish were sex‐reversed to all‐male and all‐female populations by oral administration of 17 α‐methyltestosterone (60 mg kg?1 feed) and ethynylestradiol (100 mg kg?1 feed) respectively. There was significantly higher growth with increased ration levels in both male and female groups. There were no significant differences in final BW, specific growth rate, survival rate, feed conversion ratio and protein efficiency ratio between diploid and triploid fish. Triploids had lower gonad weights than diploids, and this was particularly evident at the satiation feeding level. Triploid fish had a significantly higher apparent net protein utilization and percentage of gutted weight than diploids at all feeding levels. Higher protein utilization efficiency of triploids might be an advantage for commercial tilapia culture but further research is necessary to make such a conclusion.  相似文献   

13.
This study determined biometric and weight parameters and relevant indices of diploid and triploid tench. Altogether, 137 siblings of tench were studied. The effect of ploidy level appeared in significantly better growth of triploids (P<0.001) as to biometric [total length (TL), standard length (SL), body height (BH), body width (BW)] and weight [fish weight (FW), carcass weight (CW)] parameters of T3 of both sexes and of T3+ females. The effect of ploidy level also appeared as significantly higher dressing percentage (DP; P<0.001) of triploid T3 females compared with other groups, significantly higher gonad weight (GW) and gonadosomatic index (GSI; P<0.001) of diploid T3 females, as well as GSI and hepatosomatic index of diploid T3+ females. The effect of sex appeared in significantly higher (P<0.001) biometric (TL, SL, BH, BW) and weight (FW, CW) parameters of T3 females of both ploidy levels, as well as of triploid T3+ females. The effect of sex also appeared as significantly higher DP (P<0.001) of males in diploid T3 fish, as well as of males of both ploidy levels in T3+ fish and significantly higher GW and GSI (P<0.001) of females in diploid T3 fish, as well as of females of both ploidy levels in T3+ fish. This study shows evidence for faster somatic growth and bigger final weight of triploid populations of tench compared with diploids in both age categories T3 and T3+.  相似文献   

14.
This study aimed at evaluating the ploidy effects on growth performances of Chinese shrimp ( Fenneropenaeus chinensis Osbeck, 1765) reared in different salinities under laboratory conditions. In the acute salinity experiment, there was no difference ( P >0.05) in tolerance observed in triploid and diploid shrimp due to abrupt salinity changes. The lethal salinity for 50% of the individuals in 96 h at 23–25 °C was about 2 g L−1 in both triploids and diploids. While for the chronic salinity experiment, statistical analyses confirmed that the differences in growth performances including the specific growth rate (SGR), the feeding rate (FR), feed conversion efficiency (FCE) and intermoult period (IP) between triploid and diploid were related to salinity. Diploid shrimp reared in 20 g L−1 exhibited highest SGR ( P <0.05), while triploids performed well in 20 and 30 g L−1 salinities ( P <0.05). Based on the survival and growth data, the optimal salinity for the culture of diploid F. chinensis should be 20 g L−1 and for triploids it should be between 20 and 30 g L−1.  相似文献   

15.
Induction of triploidy has been suggested as an effective tool to prevent spawning of farmed fish. This experiment examined the growth potential of triploid cod when reared communally with diploid ones after the juvenile stage. Pressure treatment was used to induce triploidy in a batch of cod eggs in April 2009. The resulting offspring were reared separately from their diploid counterparts until they reached the proper size for PIT tagging. At the age of 8 months, an equal number of 115 diploids (135.5 ± 3.95 g) and triploids (93.6 ± 2.63 g) were communally reared in a circular flow-through tank until the age of 22 months. By the end of this rearing period, diploids (1,002.4 ± 39.9 g) were significantly heavier than triploids (654.6 ± 27.7 g), but the specific growth rate did not differ significantly during the growth trial. Gonadal development at the age of 22 months was also lower among triploids than diploids, especially for females (5.3 and 91.9 %) but also for males (32.5 and 72.7 %). Sterility among female triploids was evident by the reduced size and dysfunctional gonads, but gonadal development in male triploids was less suppressed. Prevalence of body deformities was, however, significantly higher among triploids (62.6 %) than diploids (33.9 %). Higher prevalence of deformities in triploid cod underlines the need for further fine-tuning of the triploidization procedure or finding other methods of sterilization. At present, triploid cod are still far from being established as an alternative for commercial production.  相似文献   

16.
This study aimed to evaluate the amino acid-chelated trace elements as dietary supplement to rainbow trout. Three diets were formulated containing trace elements either from the inorganic salt (SF) or amino acid-chelate (AM). Diets 1 (SF) and 2 (AM) contained the same amount of trace elements from inorganic and amino acid-chelates, respectively. Diet 3 (AM-Hf) was added with trace elements from amino acid-chelatex at one-half of their levels in Diets 1 and 2. Each diet was fed for 15 weeks to three groups of 30 fish each, with an average weight of 1.52±0.21 g. Growth of fish was not affected by the treatment (P>0.05). However, bone (P<0.01) and liver (P<0.05) Cu contents were higher in the AM than the SF group. Similarly, hematocrit level (P<0.05) and alkaline phosphatase (ALP) activity (P<0.01) were higher in the chelate-fed fish. Further, DNA polymerase and CuZnSOD expression in the AM group was highly upregulated (P<0.05) compared to the SF fed fish as quantified by RT-PCR. Absorption and whole body retention of Mn and Zn from the AM were higher (P<0.05) than the inorganic salt. Half supplementation of those fed the elements from AM was at par with the full provision from the inorganic source tested.  相似文献   

17.
The physiological effect of temperature on feed intake and haematological parameters after exhaustive swimming in diploid and triploid brown trout (Salmo trutta) was investigated. Trout were exposed to an incremental temperature challenge (2 °C/day) from ambient (6 °C) to either 10 or 19 °C. Feed intake profiles did not differ between ploidy at 10 °C; however, triploids had a significantly higher total feed intake at 19 °C. After 24 days, each temperature–ploidy group was exposed to exhaustive swimming for 10 min. The haematological response differed between ploidy, with the magnitude of the response affected by temperature and ploidy. Post-exercise, acid–base and ionic differences were observed. Plasma lactate increased significantly from rest for both temperature and ploidy groups, but glucose increased significantly at higher temperature. Post-exercise, triploids at 19 °C had significantly higher osmolality and cholesterol than diploids, but differences were resumed within 4 h. Elevated alkaline phosphatase (ALP) and aspartate aminotransferase (AST) in fish at higher temperature suggested greater tissue damage; however, both ploidy responded similarly. Despite no significant differences in deformity prevalence, the type and location of deformities observed differed between ploidy (decreased intervertebral space with higher prevalence in tail area and fin regions for diploids, while vertebral compression, fusion in cranial and caudal trunks for triploids). These results suggest triploids have greater appetite than diploids at elevated temperature and that triploids suffer similar blood disturbances after exercise as diploids. These findings have implications for the management of freshwater ecosystems and suggest that stocking triploid brown trout may offer an alternative to diploid brown trout.  相似文献   

18.
Both MI and MII triploids were successfully produced by heat shock in Chinese shrimp Fenneropenaeus chinensis. The inducing conditions for MI and MII triploids were optimized. The highest inducing rate obtained for MI triploids reached more than 90%, and that for MII triploids reached nearly 100% at the nauplius stage as evaluated using flow cytometry. Comparisons of survival rates at larval stages between triploids and diploids or diploids experiencing treatment and diploids without treatment were performed. At larval stage from nauplii to postlarvae, heat shocks lowered survival at larval stages even if the ploidy was not changed. Ploidy did not affect shrimp larvae survival, and no significant difference was found in the survival of shrimp larvae between MI and MII triploids. Highly significant differences were observed in the morphology of triploids and diploids, and no apparent difference was found in the morphology of MI and MII triploids at the grow‐out stages. Discriminating formulae for triploid and diploid shrimp at grow‐out stage were developed and could be used to distinguish triploids from diploids based on morphological parameters. MI and MII triploids of shrimp have the potential to be used in aquaculture.  相似文献   

19.
This study has investigated the muscle growth of diploid and triploid Atlantic cod (Gadus morhua) juveniles raised in replicate tanks over a period of 29 weeks and analysed at three sampling points (February, June and September). Data for weight, length, condition factor (K), muscle fibre growth and myogenic progenitor cells (MPCs) number were collected and results were analysed in relation to body growth and ploidy status. Diploids were significantly heavier than triploids throughout the trial (~10–20%) and had K in June and September samplings. Over the whole period, the rate of muscle fibres' recruitment was 318 fibres per day and 252 fibres per day for diploid and triploid cod respectively. The larger body weight of diploids resulted in a total number of fast fibre number of 114 979 compared to 91 086 in triploids. The average diameter of the 2.5% of the smallest fibres (2.5th percentile) was higher in diploids than triploids at the start of the trial, with a reversed picture for the average of the upper 2.5% (97.5th percentile) at the end of the trial. The probability density function of the estimated muscle fibre diameters showed similar fibre size distribution between size‐matched diploids and triploids at all sample points. The peak fibre diameter was approximately 25 μm in February and increased to approximately 50 μm in June and September, irrespectively of ploidy. Pax 7 were used as molecular markers for MPCs. A positive correlation between Pax 7+ cells and total body length was observed only among triploid fish at the onset of the experiment.  相似文献   

20.
The aim was to assess whether selection for increased growth rate in Atlantic salmon (Salmo salar) is associated with increased feed intake and/or better feed utilization. Growth responses of offspring from selected and wild lines of Atlantic salmon (initial weight 814±14 g and 533±12 g, respectively) were tested in a 14-week experiment. Selected and wild salmon increased body weight by 79 and 39%, respectively, during the experiment. Relative feed intake (DFI), thermal growth coefficient (TGC) and feed efficiency ratio (FER) were significantly higher in the selected (DFI: 0.67% BW d−1, TGC: 2.96×10−3 and FER: 1.16), than in the wild, line (DFI: 0.48% BW d−1, TGC: 1.39×10−3 and FER: 0.93). FER was positively correlated with mean growth rate (r=0.90, n=6, P<0.05), and differences between the lines indicated a 4.6% increase in FER per generation of selection. Fish of the selected line had a significantly lower intake of protein and energy per kilogram gain, so the higher growth rate of the selected line was the result of both greater feed consumption and more efficient feed utilization for growth. This implies that selection for increased growth rate in Atlantic salmon may improve both of these traits.  相似文献   

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