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Abstract. Prehadi, Sembiring A, Kurniasih EM, Arafat D, Subhan B, Madduppa HH. 2015. DNA barcoding and phylogenetic reconstruction of shark species landed in Muncar fisheries landing site in comparison with Southern Java fishing port. . Sharks are one of main fisheries commodity that are currently exploited on a large scale because of their high economic value. The identification of sharks has been a difficult one due to the specimen's similarity in morphology and mostly have had key diagnostic features removed. This study aimed to identify and to review the status of sharks, and also to reconstruct the shark species that were landed at South Java fishing port using molecular approaches. The DNA amplification was using cytochrome oxidase I mitochondrial of locus and 600-700 basepairs. A total of seven species from 59 individuals was identified including Alopias pelagicus, Carcharhinus falciformis, C. sorrah, C. amblyrhynchos, Galeocerdo cuvier, Atelomycterus marmoratus, and Spyrna lewini. The diversity of shark species landed in Muncar during the last 2 years has been decreased. The identified sharks species in this study sites were about 18% of all Indonesian sharks. The result of this study is expected help the Government to manage shark fisheries in Indonesia.

DNA metabarcoding is an increasingly popular technique to investigate biodiversity; however, many methodological unknowns remain, especially concerning the biases resulting from marker choice. Regions of the cytochrome c oxidase subunit I (COI) and 18S rDNA (18S) genes are commonly employed “universal” markers for eukaryotes, but the extent of taxonomic biases introduced by these markers and how such biases may impact metabarcoding performance is not well quantified. Here, focusing on macroeukaryotes, we use standardized sampling from autonomous reef monitoring structures (ARMS) deployed in the world's most biodiverse marine ecosystem, the Coral Triangle, to compare the performance of COI and 18S markers. We then compared metabarcoding data to image‐based annotations of ARMS plates. Although both markers provided similar estimates of taxonomic richness and total sequence reads, marker choice skewed estimates of eukaryotic diversity. The COI marker recovered relative abundances of the dominant sessile phyla consistent with image annotations. Both COI and the image annotations provided higher relative abundance estimates of Bryozoa and Porifera and lower estimates of Chordata as compared to 18S, but 18S recovered 25% more phyla than COI. Thus, while COI more reliably reflects the occurrence of dominant sessile phyla, 18S provides a more holistic representation of overall taxonomic diversity. Ideal marker choice is, therefore, contingent on study system and research question, especially in relation to desired taxonomic resolution, and a multimarker approach provides the greatest application across a broad range of research objectives. As metabarcoding becomes an essential tool to monitor biodiversity in our changing world, it is critical to evaluate biases associated with marker choice.

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