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1.
In this study, we used artificial insemination to generate hybrid groups of fish [MC‐F1(MA♀×CA♂) and MC‐F2(MC‐F1♀×♂)] by intergeneric crosses of Megalobrama amblycephala (MA) and Culter alburnus (CA); sequential backcrosses [CAM‐B1 (CA♀×MC‐F1♂) and MCC‐B1 (MC‐F1♀×CA♂)] were also performed. All these hybrids showed high rates of fertilization, hatching and survival (p > 0.05). For genetic traits, compared with those of the M. amblycephala and C. alburnus parental lines (Table 1), the fertilization rate, hatching rate and 7‐day survival rate of MC‐F1(MA♀×CA♂), MC‐F2(MC‐F1♀×♂), CAM‐B1 (CA♀×MC‐F1♂) and MCC‐B1 (MC‐F1♀×CA♂) by artificial insemination exhibited similar high rates (p > 0.05). The morphology of the four hybrids MC‐F1/F2, CAM‐B1 and MCC‐B1 were intermediate between those of their parents. Compared with their parents of MA and CA, weight gain rate (WG), specific growth rate (SGR) and protein efficiency ratio (PER) of hybrids MC‐F1/F2, CAM‐B1 and MCC‐B1 were significantly (p < 0.05) increased and feed conversion ratio (FCR) was significantly (p < 0.05) decreased after 3 months feeding. Moreover, protein content of muscle for MC‐F1/F2, CAM‐B1 and MCC‐B1 was significantly (p < 0.05) higher and carbohydrate content of muscle was significantly (p < 0.05) lower than their parents. The females and males of the four hybrids had normal gonadal development. In this study, we successfully generated intergeneric and backcross hybridization lines with fertile potential among fish of the Cultrinae subfamily and these hybrids had obvious heterosis in terms of growth performance, feed utilization and muscle quality.  相似文献   

2.
The Hong Kong oyster (Crassostrea hongkongensis) and the Portuguese oyster (Crassostrea angulata) are important aquaculture species in southern China. To understand the potential feasibility of hybridization between the two species, two‐by‐two factorial cross‐experiments were conducted in Shenzhen (Guangdong province). An asymmetry in fertilization was revealed: C. hongkongensis eggs could be fertilized by C. angulata sperm, but the reciprocal cross was not possible. The fertilization and hatching success in the C. hongkongensis females × C. angulata males (HA) cross was lower than the two intraspecific crosses. Moreover, hybrid larvae had a slower growth rate than those from parental progenies due to genome incompatibility. However, the size of the spat and adult growth were greater than those of the two parental progeny, with obvious heterosis during the grow‐out stage. The survival advantage of hybrids was examined at all times. The surprising finding was that all hybrids were completely fertile, meaning they could produce normal and functional gametes. Genetic analysis by molecular markers was applied to confirm that the HA spat were true hybrids. Our results revealed that the interspecific hybridization between C. hongkongensis and C. angulata is completely successful in one direction. Furthermore, hybrids are viable, fast growing and completely fertile, which provides a promising method for the genetic improvement of oysters as a new aquaculture stock in southern China.  相似文献   

3.
Hybridization was used to take advantage of desirable traits in offspring. In the present study, we applied the cryopreserved Epinephelus lanceolatus sperm into interspecific hybridization with E. moara. Successful hybridization between these two species was achieved and cultured in 23–24°C seawater (34‰). There was no difference in survival rate between hybrid (E. moara ♀ × E. lanceolatus ♂) and non‐hybrid (E. moara ♀ × E. moara ♂) at 24 hrs post hatch (HPH), but less hybrid (14.35 ± 8.02%) hatched than non‐hybrid (93.60 ± 1.65%), which might be due to irregularity cell cleavage and skeletal deformities from the formation of embryonic body to the later embryonic development. Similar phenomenon was found in hybrid embryos from fertilization with fresh sperm, indicating that species variations between parents, rather than cryopreserved sperm, resulted in deformities in embryos. Mean hatch time of the hybrid was 1 hr faster than that of E. moara. The hybrid was 1.95 ± 0.06 mm in total length when newly hatched and reached 38.00 mm at 58 days post hatch (DPH), which showed faster growth than E. moara (recorded in the previous study). Considering its faster growth, E. moara × E. lanceolatus hybrid was a potential breeding production in aquaculture. Over 212,000,000 larvae have been produced and launched in the market since 2015. The results of this study also shed some lights on further comparative studies in grouper hybrid performance.  相似文献   

4.
Two introduced abalone species are currently produced in Chile, red abalone Haliotis rufescens and Japanese abalone Haliotis discus hannai. However, red abalone accounts for 99% of total production, while the Japanese abalone has not adapted well to Chilean coastal waters. This study reports the hatching, growth and thermal tolerance performance in interspecific hybrids produced between red (R) and Japanese (J) abalone. Our results show that egg age and sperm concentration were critical factors to produce hybrids. The cross R♀ × J♂ showed a fertilization rate of 55.3 ± 3.5% using 20‐min‐old eggs and sperm concentrations of 14 × 106 cells mL?1, while the reciprocal cross (J♀ × R♂) was not successful. Further, larval development stages were similar in RR, JJ and RJ hybrid abalones. Among the experimental trials, settlement rate varied from 12.3% to 18.6% and final survival from 20.1% to 31.7%, being the RJ hybrid rates intermediate between parental species. The final shell lengths were similar between RR and RJ hybrids, but significantly higher in JJ abalones. In addition, thermal tolerance was ascertained due its pivotal role for the abalone physiology. Thus, RJ hybrids showed the highest HSP70 gene expression and offers new possibilities to expand Chilean abalone production in warm waters zones.  相似文献   

5.
Artificial hybridization was performed between Rutilus frisii kutum and Abramis brama orientalis of the Caspian Sea. Synchronization of spawning of female broodstock of both species was induced by injection of carp pituitary extract. Reciprocal crossings between R. frisii kutum ♀×A. brama orientalis ♂ (RA) and A. brama orientalis ♀×R. frisii kutum ♂ (AR) produced viable hybrid larvae without any clear particular pre‐ or postzygotic isolation phenomena. RA and AR hybrid larvae were reared to fingerling stage with survival rates of 22.5 and 28% and average weight of 6.8 ± 0.17 g and 9.0 ± 0.79 g, respectively. A heterosis of 45% was calculated for weight at fingerling stage. RA and AR hybrid fingerlings were cultured in polyculture along with Chinese carps for 6–7 mo and reached an average weight of 190–195 g and 235–255 g, respectively. Karyotyping of these hybrids revealed a modal diploid number of 2n = 50 for both groups, which is similar to those of the parental species. Discriminant function analysis on 28 morphometric and meristic characteristics of two parental species as well as their hybrids could separate these groups at highly significant level (P < 0.001). These results indicated an overall intermediate inheritance of the studied characters.  相似文献   

6.
Scale drop and muscle necrosis disease with high mortality widely occurred recently in the hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂), a crucial cultured marine fish species in China. In this study, 30 Harveyi clade isolates of 27 Vibrio harveyi strains were isolated from diseased hybrid groupers in the south‐east and north‐east coastal areas of China. A total of 22 V. harveyi strains were determined to be pathogenic, and most challenged fish died within 2 days of infection; surviving individuals exhibited scale drop and deep dermal lesions as naturally diseased fish. Although five typical virulence genes, including luxR, toxRVh, chiA, serine protease and vhh widely existed in V. harveyi, no obvious correlation was established between virulent strains and virulence genes harboured in them. Furthermore, multiple antibiotic resistance was widely exhibited in Harveyi clade strains, particularly for penicillins, polypeptides, lincomycins, acetylspiramycin, streptomycin, metronidazole and bacitracin. And the multiple antibiotic resistance indices were gradually decreased from southern to northern areas of China. This study demonstrated that the pathogenic V. harveyi with multiple antibiotic resistance is highly prevalent in hybrid grouper in China, which requires particular attention.  相似文献   

7.
太平洋牡蛎与近江牡蛎的种间杂交   总被引：9，自引：4，他引：5  
为了评估太平洋牡蛎与近江牡蛎能否产生远缘杂种优势,于2010年5月,以成熟的两种牡蛎亲本为材料开展了2×2远缘杂交研究,由长牡蛎自繁组GG(Crassostrea gigas♀×C.gigas♂)、近江牡蛎自繁组AA(C.ariakensis♀×C.ariakensis♂)、正交组GA(Crassostreagigas♀×C.ariakensis♂)、反交组AG(C.ariakensis♀×C.gigas♂)4个实验组组成。分析了子代早期表型性状和杂种优势,并对杂交子代进行了遗传鉴定。结果表明:GA杂交组与AG组的受精强度具有不对称性。幼虫浮游期间,表型性状的中亲杂种优势几乎为0,GA组生长与存活性状表现出积极的单亲杂种优势,而AG组则具有明显的远交衰退现象;幼虫早期表型性状受到母本效应影响,而后减弱。变态期间,GA组变态率较高,得到了大量杂交稚贝;而AG组变态率极低,仅获得了72个杂交稚贝。稚贝培育期间,稚贝表现出中亲生长劣势与存活优势;GA组具有明显的单亲生长与存活优势,而AG组则表现出生长劣势并具有一定程度的存活优势。利用复合COI及ITS2鉴定了种间杂交子结果表明:正反交组杂交子均为真正意义上的两性融合杂交子。实验获得了具有显著杂种优势的GA组杂交子,为现有牡蛎的遗传改良提供了新的方向。  相似文献   

8.
This study compared the spawning performance of four crosses between the salt‐tolerant tilapia Oreochromis spilurus and the fast‐growing genetically improved farmed tilapia (GIFT) strain of the Nile tilapia Oreochromis niloticus: (1) O. spilurus♀×O. spilurus♂ (SS); (2) Nile ♀× Nile ♂ (NN); (3) Nile ♀×O. spilurus♂ (NS) and (4) O. spilurus♀× Nile ♂ (SN). In each cross, males and females having mean weights of 157 and 115 g, respectively were stocked in 0.43 m3 tanks at a male to female ratio of 1:3. Seeds (unhatched eggs, yolk‐sac fry and free swimming fry) were harvested biweekly for 127 days. Viable spawns resulted from all crosses. The NN cross produced the highest total seeds tank?1 (2890), seeds (kg female)?1 day?1 (48.3), seeds m?2 day?1 (23.3) and seeds female?1 day?1 (7.9), followed by the SS and SN crosses. The NS cross had the lowest fecundity. Lower spawning parameters in the NS and SN crosses may be attributed to the lower social compatibility between the males and females compared with that of the pure parents. The survival and growth of the offspring from the four crosses will be compared in seawater (37–40 g L?1) to assess whether hybrid vigor was produced.  相似文献   

9.
The present study was conducted to investigate the effects of Bacillus pumilus on the growth performance, innate immunity and digestive enzymes of the giant freshwater prawn, Macrobrachium rosenbergii. Prawns (mean weight: 1.81 ± 0.01 g) were fed different levels of B. pumilus at doses of 0, 1 × 107, 1 × 108 and 1 × 109 CFU/g to produce one control group and three experimental groups (G1, G2 and G3), respectively. After a 60‐day experimental feeding period, the results showed that the final weight, weight gain rate (WGR) and specific growth rate (SGR) were significantly higher in experimental groups than in the control (p < 0.05), whereas these improvements did not differ significantly (p > 0.05) among experimental groups. The improvements in phagocytic activity, respiratory burst (RBs) activity and the activity of catalase (CAT), nitric oxide synthase (NOS) and acid phosphatase (ACP) were significantly higher in G2 and G3 than in the control and G1 (p < 0.05). Further, the activity of CAT, NOS and ACP significantly increased with an increase in the dietary level of B. pumilus (p < 0.05). The activity of phenoloxidase (PO) in G3 was significantly higher than that in the control (p < 0.05). The activity of amylase was significantly higher in the groups G2 and G3 than that in the control group. G3 improved the activity of protease compared with the control (p < 0.05). In conclusion, the results of this study indicated that the potential use of B. pumilusat a dose of 1 × 108 CFU/g feed could improve the growth, immunity and digestive enzymes of M. rosenbergii.  相似文献   

10.
Reciprocal, interspecific hybrids of Clarias gariepinus and Clarias anguillaris were produced via hypophysation and dry stripping. Two-week-old fry (0.06 ± 0.02 g) of the parental Clarias species and their interspecific hybrids were stocked in duplicated 1 m3 hapas suspended in outdoor earthen ponds (16 m2) for a rearing period of 56 days. Growth and survival of the hybrids was intermediate to the faster growing and better surviving C. gariepinus and the more slowly growing and more vulnerable C. anguillaris parental lines. The weight gain attained by C. gariepinus, C. anguillaris, C. gariepinus (♂)?×?C. anguillaris (♀), and C. anguillaris (♂)?×?C. gariepinus (♀) were 3.18 g, 2.99 g, 3.16 g and 3.05 g, respectively. Among hybrids, the growth of C. gariepinus (♂)?×?C. gariepinus (♀) was higher than the reciprocal C. anguillaris (♂)?×?C. gariepinus (♀). Heterosis for growth was a negligible 0.65% and for survival was negative (?5%). C. gariepinus appears to be the best species for aquaculture in terms of growth rate and survival.  相似文献   

11.
Experimental crossings were made between tetraploid loach (Misgurnus anguillicaudatus, T for short) and diploid large‐scale loach (Paramisgurnus dabryanus, P for short), resulting in T×T, T×P and P×P crosses (female before male). Meanwhile, a part of T×P cross was cold shocked to inhibit second meiosis (T×P‐0 for short). Fertility rate, hatching rate and survival rate of T×T, T×P, P×P and T×P‐0 were measured. Flow cytometry and chromosome count were taken to identify ploidy statuses of the four crosses. Results showed that T×T, T×P and P×P were, respectively, tetraploidy (4n = 100), triploidy (3n = 74) and diplody (2n = 48), while 89.19 per cent of T×P‐0 of 12 months old were pentaploidy (5n = 124, T×P‐0‐5n for short) and the others were triploidy. Morphological data of the four crosses of 12 months old showed that morphological characteristics of T×P and T×P‐0‐5n loach were between those of their parents, while T×P‐0‐5n loach presented a smallest head length/body length. Total lengths of T×P and T×P‐0‐5n were significantly larger than those of T×T and P×P, showing hybrid vigour. This study will provide valuable information for production of polyploidy loach and breeding programmes of the two loaches and other closely related species.  相似文献   

12.
O‐GlcNAc transferase gene (OGT) was considered as the sole rate‐limiting enzyme in the O‐GlcNAc modification. In the present study, the OGT gene of hybrid grouper (Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂) was cloned and characterized, and its expression in response to dietary carbohydrate level and acute glucose treatment was investigated. The full‐length of OGT (GenBank accession no. KY656469 ) was 4,063 bp, including a 302 bp 5′untranslated terminal region (UTR), a 3,165 bp coding region that encoded 1,054 amino acids residues and a 596 bp 3′ UTR. The highly conservation of OGT gene between fish and mammals was also observed through multiple sequences alignment and phylogenetic analysis. O‐GlcNAc transferase gene was ubiquitously expressed in all detected tissues with highest expressions in brain and liver, to a lesser degree, in eye, heart, kidney and intestine. The increasing dietary carbohydrate from 8.02% to 16.08% had no significant effect on the mRNA expression of OGT. However, the expression of OGT was slightly elevated at 6 hr post‐glucose injection, and the elevation became significant at 24 hr time‐point. These data may enhance our understanding on the nutritional regulation of OGT and O‐GlcNAc modification in fish species.  相似文献   

13.
The present study examined the variation in survival, proportion of male morphotypes, female and male proportion, female reproductive status and tag losses in nine crosses from a complete (3 × 3) diallel mating of three populations of Macrobrachium rosenbergii in India. The populations originated from Gujarat (north‐west), Kerala (south‐west) and Odisha (east), representing different agro‐ecological regions in India. Progeny from 60 families (4773 juveniles) were individually tagged and reared for 16–17 weeks in earthen ponds. Binary logistic regression was used to analyse the data. Survival rate was greatest (0.88) for Kerala × Odisha (KO; the first letter represents the sire), whereas it was lowest (0.75) for both Kerala × Kerala (KK) and Gujarat × Kerala (GK). Significantly greater proportions of large male morphotypes were observed in KK cross and in combinations involving Kerala population. The highest proportion of immature females, as well as of non‐berried females, was observed in the Odisha × Odisha (OO) cross. Tag loss was greatest for KK (0.35) and lowest for GG (0.19). We found significant variations among crosses for all studied traits suggesting the possibility of including them in genetic improvement programmes of this species.  相似文献   

14.
The Pacific oyster Crassostrea gigas is a representative bivalve mollusc that is widely cultured in the world and is the largest molluscan group cultured in China. In order to assess the feasibility of improving survival of C. gigas through genetic selection, the heritability and genetic correlations for growth and survival traits between different life stages were examined. Genetic parameters were estimated based on intraclass correlations of 49 full‐sib families (29 half‐sib families) in larvae (4 and 20 days after fertilization) and spat (140 days after fertilization) stages. The heritability for growth traits in larvae and spat was 0.30–0.86 and 0.53–0.59, respectively, and varied with ages. The heritability of survival was low in larvae (0.13 ± 0.05 and 0.17 ± 0.04, respectively for 4 and 20 days after fertilization) but medium (0.39 ± 0.07) in spat, suggesting that selection for increasing spat survival was feasible. The genetic correlation between growth traits within age was medium to high and positive (ranging from 0.47 to 0.96, respectively, between shell length (SL) and shell height (SH) at 20 days and between SL and SH at 140 days after fertilization), suggesting that selection to improve single growth trait will cause positive response in another growth traits in C. gigas. The genetic correlations between survival and growth traits at 140 days were low but positive (ranging from 0.23 to 0.27, respectively, between survival and SH and between survival and SL at 140 days after fertilization), suggesting that selection for survival may not have a negative response in growth. Overall, this study suggests that survival traits should be taken as improving target of next selection breeding programme in C. gigas.  相似文献   

15.
Effects of Bacillus cereus BC‐01, Lactobacillus acidophilus LAG01, Clostridium butyricum CBG01 and their combinations as supplementation on the growth performance, digestive enzyme activities and serum non‐specific immunity of hybrid grouper (Epinephelus lanceolatus ♂×E. fuscoguttatus ♀) were assessed. Seven different diets, that is one control diet (basal feed without any probiotics, CT) and six treatment diets containing single B. cereus (Bs), L. acidophilus (Ls) and C. butyricum (Cs) at 1.0 × 109 cfu/kg feed, and also their combinations in equal proportion at 1.0, 2.0 and 3.0 × 109 cfu/kg feed (BLC1, BLC2 and BLC3) were prepared respectively. After 60‐day feeding trial, the final weight, specific growth rate,food consumption, food conversion efficiency and apparent digestibility coefficient of fish in Ls and BLC3 were significantly higher compared with the control (p < .05). The activities of pepsin and trypsin in the intestine of fish for Ls and BLC3 were significantly higher relative to the control (p < .05). Relative to controls, significantly enhanced amylase and lipase activities in proximal intestine except for Cs and BLC1 and lipase activities in distal intestine except for Cs were observed (p < .05). Meanwhile, activities of superoxide dismutase in the serum of fish for all treatments, lysozyme and catalase in Ls and BLC3, and glutathione peroxidase except for Cs were significantly enhanced (p < .05). Based on the above, dietary supplementation of single L. acidophilus at 1.0 × 109 cfu/kg or combination of three strains at 3.0 × 109 cfu/kg for hybrid grouper is recommended.  相似文献   

16.
To investigate the mechanism underlying the difference of dietary protein requirements among Erythroculter ilishaeformis line, Ancherythroculter nigrocauda line and their hybrid F1 (E. ilishaeformis♀×A. nigrocauda ♂), juvenile fish of these three species with initial body weight (5.86 ± 0.10 g) were fed the six isoenergy diets with different dietary protein/carbohydrate ratios (P/C ratios were 0.56, 0.78, 1.11, 1.61, 2.52 and 4.43, respectively) for 8 weeks. The results showed that the hybrid culter had the higher weight gain rate (WGR), protein efficiency ratio and protein deposition ratio compared with its parents lines; using WGR as a response criteria, the dietary carbohydrate tolerant level of juvenile E. ilishaeformis line, A. nigrocauda line and their hybrid was 24.3%, 28.5% and 29.7%, respectively, and the optimal P/C ratio was 1.69, 1.35, 1.22 and respectively. Dietary carbohydrate activated hepatic protein kinase B (Akt), dietary protein activated hepatic target of rapamycin (TOR) and the induction of mRNA expression of hepatic phosphoenolpyruvate carboxykinase and pyruvate kinase showed a similar change in hybrid F1 and its parents. A. nigrocauda had the highest enzymes activities in intestinal protease and amylase, and hybrid culter had the highest intestinal lipase activities. Our results demonstrated that the hybrid culter has the better protein‐sparing effects by increasing carbohydrate metabolism than its parent lines.  相似文献   

17.
This study was carried out to assess the effects of Pediococcus acidilactici on zebrafish (Danio rerio). Different levels of P. acidilactici including 0, 1 × 106, 2 × 106, 4 × 106 and 8 × 106 colony‐forming unit per g of the diet (cfug?1) were examined in fish with 120 ± 10 mg weight for 60 days in a completely randomized design. The results showed that the best growth indices were recorded in group 4 × 106 cfug?1 (p < 0.05). The highest number of total viable count and lactic acid bacteria of intestine were found in group 4 × 106 cfug?1 (p < 0.05). The maximum activity of digestive enzymes including amylase, lipase, protease and alkaline phosphatase was observed in group 4 × 106 cfug?1. The highest activity for superoxide dismutase was recorded in group 4 × 106 cfug?1 while catalase, glutathione peroxidase and glutathione reductase showed the highest activity in group 8 × 106 cfug?1. The most growth inhibition zone of Aeromonas hydrophylla, Flavobacterium columnare, Vibrio anguillarum and Edwardsiella tarda was found in group 4 × 106 cfug‐1 (p < 0.05). Therefore, P. acidilactici as a probiotic improved growth and immunity of the zebrafish and could be used by zebrafish farmers.  相似文献   

18.
Positive and negative interploid triploids of blunt snout bream (Megalobrama amblycephala) were produced by reciprocal crossing autotetraploids with diploids. Fertilization and hatching rate of negative interploid triploid, 2n♀× 4n♂, at different reproductive ages was similar to that of control, but higher than that of positive interploid triploid, 4n♀× 2n♂. Additionally, the development rate of embryos of the positive interploid triploid, 4n♀× 2n♂, was slower than that of control and the negative interploid triploid, 2n♀× 4n♂. Gonad growth of the positive and negative interploid 3n was significantly (P<0.01) affected by parents, and spawning could not be induced both in females and males at the 2+ age. The negative interploid 3n (2n♀× 4n♂) had a significantly higher survival rate than the positive interploid 3n (4n♀× 2n♂), but close to the level of the control (P<0.05). The daily growth rate of the negative interploid 3n was similar to that of the good breed ‘Pujiang No. 1’ blunt snout bream (2n) during the early life stages.  相似文献   

19.
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20.
The Kumamoto oyster (Crassostrea sikamea) and the Portuguese oyster (C. angulata) are important aquaculture species which naturally coexist along the southern coast of China. To understand the potential feasibility of hybridization between the two species, we conducted two‐by‐two factorial cross‐experiments in Beihai (Guangxi province), and also compared the survival and growth of the hybrids to that of the two parental progenies during the grow‐out period from July 2014 to July 2015. Genetic analysis confirmed that the hybrid spats were true hybrids. Additionally, the biochemical composition of the 1‐year‐old oyster progenies was determined. In July 2015, the mean shell height of the hybrids was 42.98 ± 6.29 mm, which was higher than that of the Kumamoto oyster progeny. The cumulative survival rate of the hybrids was 26.37 ± 1.32%, which was higher than that of the progeny of the Portuguese oyster. Mean lipid content of the hybrids was 13.65 ± 1.63% of dry weight, which showed obvious heterosis compared to those of the two parental progenies. Observation of gonads revealed that all hybrids were completely fertile. Furthermore, relative expression of the lipid homeostasis genes, SREBP (sterol regulatory element‐binding proteins), PPARα (peroxisome proliferator‐activated receptor) and INSIG (insulin‐induced gene) were found to vary between parental progenies and the hybrids, thus providing a possible reason for difference in the lipid contents of these experimental groups. Overall, the hybrids were viable, rich in lipid and completely fertile and thus could serve as a promising aquaculture stock for oyster breeding in southern China.  相似文献   

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