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1.
Yoshihisa Ohashi Masamichi Nakajima Narueron Sukumasavin Uthairat Na-Nakorn Nobuhiko Taniguchi 《Fisheries Science》2006,72(5):1066-1071
ABSTRACT: The Mekong giant catfish is one of the largest freshwater fish in the world, and is endemic to the Mekong basin. Recently, the number of Mekong giant catfish has drastically decreased. In this study, seven microsatellite DNA markers of the Mekong giant catfish were developed for evaluation of the species' genetic diversity. Mendelian inheritance of four of seven markers was confirmed using offspring (F1) produced from one pair. Number of alleles per locus in the founder population ranged 1–4 with a mean of 2.8, and that in F1 ranged 1–2 with a mean of 1.6. The expected heterozygosity in the founder population ranged 0–0.66 with a mean of 0.38, and that in F1 ranged 0–0.5 with a mean of 0.28. The mean expected heterozygosity in the founder population is apparently lower than that in Pangasius bocourti and other freshwater species, but higher than that in endangered species. In the future, the microsatellite data in this study will be used in minimal kinship approaches, because these individuals constitute the basic seed for release into wild in an effort to conserve the native population of Mekong giant catfish. 相似文献
2.
Akira P Takagi Satoshi Ishikawa Thuok Nao Sitha Hort Masanori Nakatani Mutsumi Nishida Hisashi Kurokura 《Fisheries Science》2006,72(4):750-754
ABSTRACT: Although the bronze featherback Notopterus notopterus is an important fish in South-East Asia, the population structure has not been investigated. In this study, genetic diversity and population structure of the bronze featherback were examined using nucleotide sequence analysis of the mitochondrial DNA control region for 332 fish collected from Tonle Sap Lake and the Mekong River in Cambodia. The average nucleotide diversity (π) of all samples was 0.033, and the Mekong River samples had higher nucleotide diversity (0.034) than Tonle Sap Lake samples (0.028). The nucleotide diversity between the lake and river samples varied from 0.029 to 0.037. The genetic differentiation between the river and lake populations was also supported by the pairwise F -statistic values and hierarchical analysis of molecular variance, indicating that the Tonle Sap Lake population is genetically isolated from the population in main stream of the Mekong River. 相似文献
3.
华南6水系与澜沧江-湄公河攀鲈线粒体ND2基因的遗传多样性分析 总被引：2，自引：0，他引：2
测定了中国华南6水系及澜沧江(云南勐腊)-湄公河流域(柬埔寨洞里萨湖)的125尾攀鲈(Anabas testudineus)线粒体部分ND2基因1 010 bp序列,分析发现39个变异位点和12个单倍型,总遗传多样性较低(h=0.369,π=0.003 8),推测可能经历过严重的瓶颈效应;中国攀鲈群体遗传多样性更低(h=0.282,π=0.000 4),处于边缘区的中国攀鲈群体是造成低遗传多样性的主要原因。在单倍型网络图中柬埔寨和中国攀鲈各自聚类,具有明显地理结构和谱系结构,推测地质运动和气候变化导致基因交流受阻所致。核苷酸错配图和中性检验表明中国群体经历过种群扩张,时间约为(5.94~4.13)万年前。华南水系群体间基因交流通畅,不存在明显分化;但与云南澜沧江群体间分化大而显著(FST=0.775,P0.01),AMOVA分析显示变异主要来自组群间(77.41%),推测二者分化时间约为(4.0~2.8)万年前,云南群体受末次冰期的影响,基因交流受阻而出现分化。中国群体和柬埔寨群体可作为2个管理单位进行保护;就中国群体而言,韩江水系群体遗传多样性最高,建议优先保护;澜沧江与华南水系间群体分化显著且遗传多样性极低,建议对澜沧江水系群体进行保护,以避免种质资源灭绝。 相似文献
4.
Annual sex hormonal profiles, gonad development and age determination of 18 (13–14 kg body weight) and three (145–226 kg body weight) Mekong giant catfish (MGC) (Pangasianodon gigas, Chevey) reared in earthen ponds in Chiang Mai and from the Mekong River in Chiang Rai, Thailand, respectively, were investigated. The hormonal profiles were determined from blood samples of the fish by electrochemiluminescence immunoassay during May to August in 2000. The highest testosterone levels of 0.06 ng mL?1 in both sexes and the highest oestradiol of 47.8 and 14.23 pg mL?1 in females and males, respectively, were observed in May. The gonadosomatic index was found to be 0.07 for males and 0.38 for females from ponds in comparison with 2.27 for males and 8.29 for females from the Mekong River. Higher development stages of spermatocytes and oocytes of the cultured fish in May than in February and November were demonstrated. No mature germ cells were obtained from either the males or females, indicating no sexual maturity. The average age of fish was determined from the annual rings of the cross‐section of the pectoral fins by a stereomicroscope. The average age of fish in earthen pond determined from the annual ring was 8 years, which agreed with the actual culture records, while those from the Mekong River were 21 years. This information will be beneficial for the breeding programmes and conservation of the MGC. 相似文献
5.
To investigate the extent of genetic differentiation among wild populations of the Pacific cod Gadus macrocephalus, we have examined genetic polymorphism at five locations within Korean waters [Boryeong in the West Sea (WC-BR); Jinhae Bay
in the South Sea (SC-JH); Jumunjin (EC-JM), Jukbyeon (EC-JB), and Bangeojin (EC-BJ) off the eastern coast of Korea] using
mitochondrial DNA (mtDNA) control region and microsatellite DNA (msDNA) markers. Nucleotide sequence analysis of 584 bp in
the variable portion of the 5′ end of the mtDNA control region revealed 27 variable nucleotide sites among 184 individuals,
which defined eight, three, and 11 haplotypes in the western, southern, and eastern coast populations, respectively. The mtDNA
analysis revealed a low variability but significant local differentiation among populations from these three areas within
Korean waters. msDNA analysis also revealed moderate polymorphism in the wild populations, with a mean of 13.8–22.6 alleles
per locus for the five msDNA markers and observed (and expected) heterozygosities of 0.755 (0.825) for the WC-BR, 0.793 (0.810)
for the SC-JH, 0.920 (0.905) for the EC-BJ, 0.783 (0.865) for the EC-JB, and 0.804 (0.812) for the EC-JM populations. Analysis
of msDNA loci indicated that Pacific cod sampled at the WC-BR, SC-JH, and EC-JB sites belong to genetically distinct populations.
However, no significant difference was found between the Pacific cod population from SC-JH and that from EC-BJ. Consequently,
three genetically distinct populations, namely, WC-BR, SC-JH and EC-BJ, and EC-JB, were identified using msDNA analysis. These
results indicate that genetically distinct populations of Pacific cod are present in Korean coastal waters where spawning
aggregations occur. 相似文献
6.
Uthairat Na-Nakorn Wongpathom Kamonrat Thawatchai Ngamsiri 《Aquaculture (Amsterdam, Netherlands)》2004,240(1-4):145-163
The Thai walking catfish, Clarias macrocephalus Günther, 1864, is economically important to Thailand. It occupies marshes and swamps that are severely endangered due to population expansion and natural populations are thought to be suffering from massive back-crossing with the C. macrocephalus×C. gariepinus hybrids. Therefore, a study on genetic diversity of this species is required to enable efficient conservation and management plans. In this study, 25 natural populations were collected throughout the country, 12 populations from provinces locate in the Chaophraya river basin in the center of the country, 5 from the Mekong river basin, 1 from the east and 7 from the south. One population of hatchery origin was obtained from the Department of Aquaculture, Kasetsart University in Bangkok.
Twelve isozymes and one protein system were analyzed. Among 18 loci resolved, 8 were polymorphic. The number of alleles per locus, average polymorphism and individual polymorphism were significantly higher in collections from the Chaophraya river basin than from the Mekong, east and south. The hatchery population also had relative high genetic variation. Six out of twenty-six populations differed significantly from Hardy-Weinberg equilibrium after Bonferroni correction. None of loci pairs showed significant linkage disequilibrium after Bonferroni correction. The Fst value across loci was highly significant from zero. A neighbor-joining tree reveals that populations from the south were genetically distinct from the remaining populations.
Alleles peculiar to the African catfish [C. gariepinus (Burchell, 1822)] genome were observed in 12 of the natural populations and the hatchery population. This is evidence of genetic introgression which has probably persisted for several generations, since there was no significant genotype disequilibrium between the macrocephalus and gariepinus alleles at three diagnostic loci. 相似文献
7.
Hiromichi Mitamura Yasushi Mitsunaga Nobuaki Arai Thavee Viputhanumas 《Fisheries Science》2008,74(5):1034-1039
Twenty-eight immature hatchery-reared Mekong giant catfish Pangasianodon gigas tagged with acoustic transmitters were released in the Mekong River, Thailand from 2002 to 2004. Twenty-four and four fish
were tagged with normal transmitters and pressure-sensitive transmitters, respectively. Five to seven automated monitoring
receivers were used for monitoring the post-release movements. The tagged catfish could be detected for up to 97 days, the
first detection taking place at the release point, where the fish remained for several days. Sixteen tagged fish (57%) were
not detected at any later point. These fish may have passed along the opposite (Laos) side of the river without notice because
the width of the river was larger than the detection range of the transmitter. The remaining 12 tagged fish (43%) could be
detected by the receivers installed, excluding the release point receiver. Of these 12 tagged fish, six showed long-distance
(30–80 km) upstream movements and one long-distance (50 km) downstream movement. These seven fish (25%) were detected only
during the daytime, suggesting that the Mekong giant catfish is diurnal. 相似文献
8.
Large‐scale patterns of fish diversity and assemblage structure in the longest tropical river in Asia 
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下载免费PDF全文 Although the Mekong River is one of the world's 35 biodiversity hot spots, the large‐scale patterns of fish diversity and assemblage structure remain poorly addressed. This study aimed to investigate the fish distribution patterns in the Lower Mekong River (LMR) and to identify their environmental determinants. Daily fish catch data (i.e. from December 2000 to November 2001) at 38 sites distributed along the LMR were related to 15 physicochemical and 19 climatic variables. As a result, four different clusters were defined according to the similarity in assemblage composition and 80 indicator species were identified. While fish species richness was highest in the Mekong delta and lowest in the upper part of the LMR, the diversity index was highest in the middle part of the LMR and lowest in the delta. We found that fish assemblages changed along the environmental gradients and that the main drivers affecting the fish assemblage structure were the seasonal variation of temperature, precipitation, dissolved oxygen, pH and total phosphorus. Specifically, upstream assemblages were characterised by cyprinids and Pangasius catfish, well suited to low temperature, high dissolved oxygen and high pH. Fish assemblages in the delta were dominated by perch‐like fish and clupeids, more tolerant to high temperatures, and high levels of nutrients (nitrates and total phosphorus) and salinity. Overall, the patterns were consistent between seasons. Our study contributes to establishing the first holistic fish community study in the LMR. 相似文献
9.
Going,going, gone? Loss of genetic diversity in two critically endangered Australian freshwater fishes,Scaturiginichthys vermeilipinnis and Chlamydogobius squamigenus,from Great Artesian Basin springs at Edgbaston,Queensland, Australia 下载免费PDF全文
下载免费PDF全文 Leanne K. Faulks Adam Kerezsy Peter J. Unmack Jerald B. Johnson Jane M. Hughes 《水产资源保护:海洋与淡水生态系统》2017,27(1):39-50
- 相似文献
10.
为进一步了解鲇这一广布种的遗传多样性与种群遗传结构,阐明该经济鱼类的种群历史动态,本研究对我国长江(上游、中游)、珠江、福建、海南、辽河地区的野生鲇样本进行mtDNA Cytb基因序列测定与种群遗传多样性和遗传结构分析。结果显示,在所分析的216个序列样本中,共检测出78个单倍型,其中Hap_45在鲇不同群体中分布最为广泛;鲇总群体具有较高的单倍型多样性(Hd=0.948±0.009)和核酸多样性(Pi=0.017 99±0.000 55),暗示了其自然种群数量的相对稳定;单倍型系统发育与网络关系图分析显示,78种单倍型被分为4个分支,且不同单倍型分布相对集中,划分为4个谱系。中性检验与错配分析表明,不同水系野生鲇种群(4个谱系)在约晚更新世时期(0.04~0.05百万年)经历过近期种群扩张事件。 相似文献
11.
12.
ABSTRACT: Polymerase chain reaction (PCR) restriction fragment length polymorphism analysis of mitochondrial DNA was applied to the genetic structure and evolutionary history of the more ancestral Pangasianodon hypophthalmus ( n = 82), and the recently speciated catfish Pangasius bocourti ( n = 90) from the Cambodian Mekong River. Both pangasiids were characterized by a lack of genetic population structure that may result from high levels of contemporary gene flow. Genetic diversity was lower in P. hypophthalmus than in P. bocourti . However, a different evolutionary history was inferred for both species based on genealogical and demographic analyses (mismatch analysis, Tajima's D- and Fu's F S -tests). The genetic profile of the more ancestral P. hypophthalmus shows indications of a recent population bottleneck, whereas the recently speciated P. bocourti shows signatures of historical population expansion. This study stresses the importance of preserving the migration routes in the Cambodian Mekong basin in order to maintain the genetic diversity and long-term integrity of both species. 相似文献
13.
Genetic population evaluation of two closely related flatfish species, the rare barfin flounder and spotted halibut, along the Japanese coast 总被引：3，自引：1，他引：3
María Del Mar Ortega-Villaizán Romo Masato Aritaki Shigenori Suzuki Minoru Ikeda Takashi Asahida Nobuhiko Taniguchi 《Fisheries Science》2006,72(3):556-567
ABSTRACT: Barfin flounder and spotted halibut have been selected as target species for stock enhancement in Japan. Understanding the genetic condition of the wild stock is a principal requirement in any stock enhancement program. The genetic variability of barfin flounder and spotted halibut, and the population structure of spotted halibut were evaluated using microsatellite DNA markers (msDNA) and the control region of the mitocondrial DNA (mtDNA). Barfin flounder and spotted halibut showed high genetic variability at the msDNA level. Barfin flounder A was 16.7 and H e was 0.860; spotted halibut A n ranged from 7.7 to 10.2 and H e ranged from 0.710 to 0.774. At the mtDNA level, high haplotype ( h = 0.922) and low nucleotide (π = 0.002) diversities were observed for barfin flounder; however, low haplotype and nucleotide diversities ( h = 0.603–0.620 and π = 0.001–0.002), and very low haplotype and nucleotide diversities ( h = 0.193 and π = 0.0003) were observed for spotted halibut in the north and south locations, respectively. Slight genetic differentiation among spotted halibut sampling locations was observed from the msDNA. MtDNA analyses showed genetic differentiation between north and south locations, but not within them. The designation of north-specific and south-specific management units in the future stock enhancement activities of spotted halibut is recommended. 相似文献
14.
Population genetic structure in penaeid prawns 总被引：14，自引：0，他引：14
J A H. Benzie 《Aquaculture Research》2000,31(1):95-119
Genetic data are available for 27 species of penaeid prawn. Collected largely for fisheries purposes, they include information on several species of importance to aquaculture. Most studies used allozymes, but a small number have used mtDNA, random amplified polymorphic DNAs (RAPDs) and/or microsatellites. The DNA‐based markers have revealed far greater levels of variation compared with the allozyme data. However, in the few cases for which joint information is available, the mtDNA and microsatellite information tended to confirm the spatial patterns of variation detected by allozymes. These revealed little genetic variation over long distances (thousands of kilometres) for many species, but relatively major shifts in gene, or genotype, frequencies over relatively short distances (hundreds of kilometres). Much of the genetic structure in wild populations appears to reflect historical events on large biogeographical scales, rather than resulting from patterns of present‐day dispersal. Genetic variation in cultured stocks is generally less than in wild ones, the extent of the reduction being dependent upon broodstock management procedures. There is no conclusive evidence that aquaculture escapees have altered the genetic constitution of wild stocks of Penaeus monodon in Thailand. Nevertheless, the occurrence of strong patterns of geographic variation in wild stocks suggests that more detailed planning will be required to maintain this diversity, and to determine how best to capture its benefits for aquaculture. 相似文献
15.
Nian Xu Zhong Yang Yanfu Que Fang Shi Bin Zhu Meihua Xiong 《Journal of the World Aquaculture Society》2013,44(4):520-527
Chinese Sucker, Myxocyprinus asiaticus, is a valuable and endangered freshwater species in China. We investigated genetic diversity and differentiation of four M. asiaticus broodstock populations using 10 microsatellite loci. Three populations showed weak genetic differentiation among them. The other and the most distant population exhibited the lowest genetic diversity. It was inferred that wild M. asiaticus ancestry in the Yangtze River had sufficient gene flow among localities, while under the situation of population decline and fragmentation, restocking programs without genetic management might aggravate loss of genetic diversity and increase genetic differentiation. Maintenance of population connectivity among localities requires real attention in future restocking efforts. 相似文献
16.
ABSTRACT: In order to assess a daily change of genetic variability during spawning season, hatched larvae of red sea bream sampled on different dates were assayed by polymorphic markers such as microsatellite DNA (msDNA) and mitochondria DNA (mtDNA) control region. Based on the microsatellite loci, the average number of alleles per locus ranged between 13.7 and 18.3. The expected heterozygosities ranged between 0.843 and 0.919. A total of 23 mtDNA haplotypes were detected via digestion of mtDNA D-loop sequences with five endonucleases: Taq I, Alu I, Mbo I, Rsa I and Hinf I. Significant fluctuation of genetic variability during spawning season was detected by both types of DNA markers. It was suggested that the genetic variability was maintained by pooling the seed fish collected on different spawning dates in a hatchery. 相似文献
17.
Leyla Crdenas Andrea X. Silva Antonios Magoulas Josefina Cabezas Elie Poulin F. Patricio Ojeda 《Fisheries Research》2009,100(2):109-115
The Chilean jack mackerel Trachurus murphyi, is a pelagic fish from the Carangidae family that is distributed in the South Pacific Ocean. Because this species constitutes an important economic resource across the South Pacific and plays an important ecological role in this ecosystem there is a growing interest in determining its population structure. In this study, we used molecular markers (mitochondrial DNA sequences and microsatellites) from Chilean jack mackerel samples to investigate its genetic population structure across the South Pacific Ocean. The mitochondrial DNA did not detect a genetic structure in T. murphyi populations in the Pacific Ocean, but revealed very low haplotype diversity and a short genealogy history compared to other small-pelagic species. The same general pattern of a lack of genetic structure was found with microsatellite loci; however, a large genetic diversity was revealed with microsatellite markers. The present results did not support the existence of different stock units for T. murphyi across the South Pacific Ocean but a more holistic approach will be necessary to determine an adequate management strategy for this fishery. 相似文献
18.
Genetic structure of Irish freshwater pearl mussels (Margaritifera margaritifera and Margaritifera durrovensis): Validity of subspecies,roles of host fish,and conservation implications 下载免费PDF全文
下载免费PDF全文 Juergen Geist Evelyn Moorkens Ian Killeen Sarah Feind Bernhard C. Stoeckle Áine O. Connor Ralph Kuehn 《水产资源保护:海洋与淡水生态系统》2018,28(4):923-933
19.
Hiromichi Mitamura Nobuaki Arai Yukiko Yamagishi Yuuki Kawabata Yasushi Mitsunaga Metha Khachaphichat Thavee Viputhanumas 《Fisheries Science》2009,75(1):175-182
The horizontal and vertical movements of eight immature hatchery-reared (F2) Mekong giant catfish Pangasianodon gigas were monitored using acoustic telemetry in the Mae Peum reservoir, Thailand, from September to December 2005. All tagged
fish were successfully monitored throughout the study period. All fish moved throughout the reservoir for approximately 1 month
after release. Subsequently, their utilized areas became small, and the fish utilized deep areas of the reservoir. The fish
displayed diel spatial movement patterns between deep areas in the day and shallow areas in the night. The vertical movements
of the fish were related to the environment declination such as existence of hypoxic water and thermocline. Our results suggest
that the establishment of a protected area in addition to conventional fisheries regulations may sustain the fish population
in this reservoir. 相似文献
20.
Alexsandre Gutiérrez-Barragán Francisco Javier García-De León Alejandro Varela-Romero Carlos Alonso Ballesteros-Córdova José Manuel Grijalva-Chon Enrique De la Re-Vega 《水产资源保护:海洋与淡水生态系统》2021,31(11):3334-3341
- The Yaqui catfish, Ictalurus pricei, is the only native ictalurid species described from north-west México and south-west USA. It is an endangered species owing to the decline and loss of most of its historical populations, mainly because of competition and hybridization with the non-native channel catfish, Ictalurus punctatus. The Arroyo Cajón Bonito is one of the few remnant populations of Yaqui catfish in the Yaqui River basin, and it is threatened by the presence of channel catfish that escaped from private culture facilities.
- Phylogenetic analysis of two mitochondrial and two nuclear genes was used to detect evidence of hybridization with channel catfish in a collection of 20 catfish from Arroyo Cajón Bonito. Fourteen putatively pure Yaqui catfishes, five hybrids and one channel catfish were detected.
- This study further highlights hybridization between channel and Yaqui catfish as the main threat to the remaining Yaqui catfish populations. We recommend urgent evaluation of the remnant populations of native catfish elsewhere and their current conservation status.