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Wu X.,Shanghai Ocean University | Li J.,Huaihai Institute of Technology | Li J.,Shanghai Ocean University | Zhang Q.,Ganyu Fishery Technical Extension Center | And 4 more authors.
Crustaceana | Year: 2014

The swimming crab, Portunus trituberculatus (Miers, 1876) is one of the most common edible marine crabs in East Asia. In this study, a multiple mixed probes hybridization method was used to isolate microsatellites to improve experimental efficiency and streamline the procedure. The mix of biotinylated probes included microsatellite GA, CA and CAT motifs. Fourteen novel polymorphic microsatellite loci were isolated and characterized from a wild population of P. trituberculatus. The number of alleles varied between three and nine, and the observed and expected heterozygosity at population level ranged from 0.542 to 1.000 and 0.616 to 0.851, respectively. Two loci, Ptr1 and Ptr3, significantly deviated from the Hardy-Weinberg equilibrium (P0.01). These informative microsatellite markers could be useful for future population genetic analyses and genome mapping studies in this species. © Koninklijke Brill NV, Leiden. Source


Dong Z.G.,Huaihai Institute of Technology | Dong Z.G.,Shanghai Ocean University | Dong Z.G.,Chinese Academy of Fishery Sciences | Li X.Y.,Huaihai Institute of Technology | And 3 more authors.
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2013

The swimming crab, Portunus trituberculatus (Crustacea: Decapoda: Brachyura), is a large-sized benthic crab species, which is widely distributed in the coastal waters of China, Japan and Korea. FAO data show the world fishing output to be more than 380000 tons in 2010, while the figure for China alone in 2010 amounted to 350000 tons. As a result of artificial mass propagation and improved stock techniques, the farming output also reached 91,000 tons with a farming area of 30000 hectares in 2010. Therefore, the requirement of assessments and conservations of natural genetic resources has become increasingly urgent. The Haizhou Bay is located in Lianyungang coast, Jiangsu Province of China, and as one of the major fishing grounds. The bay was historically famous for the abundance of swiminng crab, but the crab population has been declining due to the over-exploitation. In order to maintain a sustainable stock, releasing of crab produced in hatcheries has been practiced annually to supplement the wild stocks. A large marine farm for swimming crab were constructed for the releasing exercise surrounding a 1700 hm2 aquculture area in the Haizou Bay. In 2009 only, 5839000 individuals of swimming crab were released to the marine farm. However, these practices can cause genetic contamination to the geographically proximate wild stocks when the interbreeding ouccrs between wild poplutions and the released or escaped crabs raised in hatheries. In order to assess the genetic impact of swimming crab farming and popagation releasing on wild stocks in Haizhou Bay, 20 SSR primers designed in our laboratory were used to genetically differentiate swimming crab wild stocks and cultured stocks in Haizhou bay. There were 30 wild swimming crab samples were caught using a gill net in Haizhou Bay (near to Xiaokou village Ganyu haitou town) and 60 cultured individuals obtained from two cultured stocks from aquacultured facilties in Haizhou Bay in Nov., 2011. The results indicated that the genetic diversity of crab from wild stock was higher than that from cultured stocks. The observed heterozygosity Ho value in wild stock was 0-8509, while that in two cultured stocks only were 0.4525 and 0.5283, respectively. The one-way ANOVA showed that the genetic parameters of Ne, Ho, He and PIC in wild crabs were significantly higher than those in cultured stocks (P<0.05), but those genetic parameters between two cultured stocks were not significantly different (P>0.05). The Fst value among these stocks ranged from 0.1085 to 0.1448, which showed a moderately differentiated state. The gene flow Nm ranged from 1-5 to 2.0 and the genetic differentiation state was much significantly higer between the wild stock and cultured stocks than that within cultured stocks. In conclusion, the genetic resource of swimming crab in Haizhou Bay was in a good state, and the impact of swimming crab farming and propagation releasing on the natural genetic resource was not remarkerble which was probably related to short time, scale effects of crab farming and propagation releasing. Source


Su H.,Huaihai Institute of Technology | Su H.,Marine Innovation and Technology | Li X.,Huaihai Institute of Technology | Li X.,Marine Innovation and Technology | And 7 more authors.
Crustaceana | Year: 2015

Using fluorescent AFLP-markers, the genetic diversity and structure of six geographical populations of the swimming crab, Portunus trituberculatus (Miers, 1876), from the coast of China were analysed to assess their genetic resource state. Eight primer combinations generated 925 loci among 85 individuals, and revealed a high polymorphism within these populations that varied from 57.41% (Zhoushan population) to 76.86% (Dalian population). According to the combination of percentage of polymorphic loci (PPL) and Shannon's information index (I), the populations from Zhangzhou, Dongying and Dalian showed more genetic variation than the Lianyungang, Zhanjiang and Zhoushan populations. The gene flow (Nm) and GST across all populations overall were 1.935 and 0.205, respectively, showing moderate genetic differentiation. Differentiation was highest in the Zhoushan and Zhanjiang populations, and the geographical distribution and UPGMA cluster tree were not fully accordant. Neutrality test results revealed that the Zhangzhou population faced a smaller selective pressure than the other five populations (P<0.05). In general, a high genetic diversity among the P. trituberculatus populations was observed along the coast of China, especially in the Zhangzhou, Dongying, Dalian and Lianyungang populations, while a pronounced level (FST > 0.25) of genetic differentiation has occurred between the Zhoushan population and the other populations. Therefore, these findings have the following implications for conservation and genetic improvement: (1) high diversity levels and good genetic resources, especially in the Zhangzhou population, which could lay the foundations for breeding research and genetic improvement; (2) the importance of preventing species escape and gene pool contamination in ex-situ conservation and species introduction programs in the Zhoushan population. © 2015 Koninklijke Brill NV, Leiden. Source

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