Globally, at the rate of 1-2 percent per annum, mangrove coverings are disappearing and 35 percent have been lost in the last 20 years due to changes in climate and human activities. No mangrove-associated crabs were found when the mangroves were artificially transplanted 25 years ago in the Vellar estuary. This mangrove ecosystem was sampled for brachyuran biodiversity estimation, species abundance, composition and evaluation of the effectiveness of DNA barcoding in brachyuran crabs species identification. A total of 2844 crabs were collected, representing 35 species within 8 families belonging to 20 genera. Four brachyuran crab species, that is, Uca lactae, U. Triangularis, Selatium brockii, and Neosarmatium asiaticum account for >70% of the total abundance. An approximate 87.5% of crab species estimated to occur by various species estimator were recovered in the present study. Between Uca lactea and U. triangularis, the maximum association index value was observed (97.7%). Cluster analysis grouped the sampled stations according to the types of mangrove species, clearly influencing the structure and composition of the brachyuran crabs. In general, vegetative cover composed of multiple species of mangroves is preferred for the abundance of all collected crabs species, and particularly Neosarmatium asiaticum. Analysis of DNA barcoding indicates that 40% of the brachyuran species gathered in this sample were first barcoded. The advent of new high-throughput sequencing technologies will change bio-monitoring applications and surveys drastically in the near future, making reference datasets like ours relevant.

中文翻译：

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人工创建的红树林环境中水chy蟹的多样性，系统发育和DNA条形码

在全球范围内，由于气候和人类活动的变化，在过去的20年中，红树林的覆盖率正在以每年1-2％的速度消失，并且损失了35％。25年前，在Vellar河口人工移植红树林时，未发现与红树林相关的螃蟹。对该红树林生态系统进行了采样，以评估短臂蟹的生物多样性，物种丰富度，组成以及评估DNA条形码在短臂蟹物种识别中的有效性。总共收集了2844只螃蟹，代表了20个属8个科中的35种。四种短毛蟹物种，即Uca lactae，U。Triangularis，Selatium brockii和Neosarmatium asiaticum占总丰度的> 70％。大约87。在本研究中，估计有5％的螃蟹物种通过各种物种估算器被发现。在Uca lactea和U. triangleis之间，观察到最大的联合指数值（97.7％）。聚类分析根据红树林物种的类型对采样站进行了分组，从而明显影响了短臂蟹的结构和组成。通常，由于所有收集到的螃蟹物种特别是亚洲新骨蟹的数量丰富，因此优选由多种红树林组成的营养覆盖物。DNA条形码分析表明，该样品中收集的40％的Brachyuran物种首先被条形码化。新的高通量测序技术的出现将在不久的将来极大地改变生物监测的应用和调查，使像我们这样的参考数据集成为现实。