New polymorphic microsatellite loci revealed for the dusky shark Carcharhinus obscurus through Ion Proton double-digest RAD sequencing
The non-model shark species, dusky shark Carcharhinus obscurus, is a bio-economically and recreationally important shark in many areas of its range. Despite of the fishery importance of C. obscurus few genetic resources are currently available for the species. Here, we report on the isolation of eight novel microsatellite loci from C. obscurus using a double-digest restriction site associated DNA (RAD) sequencing approach on the Ion Proton semiconductor platform (ddRADseq-ion). We characterised the loci in 26 individuals and all loci were polymorphic, exhibiting 5–10 alleles (average 6.6), and observed and expected heterozygosities of 0.385–0.962 and 0.479–0.847, respectively. We found that all pairs of loci were in linkage equilibrium and conformed to Hardy–Weinberg expectations. The loci reported in this study are only the second set of microsatellite loci ever characterized for C. obscurus and will be valuable for molecular ecology studies for this vulnerable species.
KeywordsCarcharhinus obscurus Double-digest Dusky shark Ion Proton Ion Torrent Microsatellites Population genetics RAD sequencing
The financial assistance of the National Research Foundation (NRF) of South Africa towards this research is hereby acknowledged. Opinions expressed and conclusions arrived at, are those of the authors and are not necessarily to be attributed to the NRF.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
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Research involving human participants and/or animals
Sharks were collected by field scientist according to protocols and research permit (RES2014/01) approved by the Department of Agriculture, Forestry and Fisheries (DAFF), South Africa. The sampling strategies implemented in our study complied with the Convention on the Trade in Endangered Species of Wild Fauna and Flora (http://www.cites.org/).
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