One cryptic species of grey mullet (Mugil cephalus mitotype: NWP3) from Taiwan’s waters is worth cultivating for large roes using aquaculture

The grey mullet, Mugil cephalus, is an important aquaculture species in Taiwan. They were thought to be a single fish species in terms of the morphology‐based taxonomy; however, three cryptic species of grey mullet (mitotype: NWP1, NWP2 and NWP3) have been identified within the Taiwan waters. In general, the NWP2 females are known to have small body sizes with large developed ovaries regardless of the cultivation time, whereas the NWP1 females have large body sizes with small ovaries. In this study, the NWP3 females are found to have significantly larger body and ovary weights than do the NWP2 females under the same aquaculture conditions. Therefore, even though the NWP2 females are good fish for producing large ovaries, this study indicates that the NWP3 females have even more potential to produce huge ovaries than do the NWP2 females.     

Novel decaplex PCR assay for simultaneous detection of scallop species with species‐specific primers targeting highly variable 5′ end of the 16S rRNA gene

Scallops (family Pectinidae) comprise species of high commercial value, supporting both commercial fisheries and mariculture activities. Accurate and reliable molecular methods for the species level identification are of outstanding utility for taxonomic and food authentication surveys. The mitochondrial 16S rRNA gene has been used to design species‐specific primers for identification of different bivalve species. However, the low interspecific variability at the 3′ end of this gene has limited its utility and only few scallop species have been assessed. In this study, we used the high variable 5′ end of the 16S gene to develop a novel decaplex PCR assay that enabled a fast and accurate identification of eight commercially important scallop species in a single PCR reaction. A total of 285 individuals including fresh and manufactured samples from eight different processed presentations from 11 different scallop species were collected representing diverse locations around the world. Our assay accurately identified all the analysed samples at the species level. Furthermore, to enhance the utility of our assay, the PCR product amplified by the family specific primer set that was utilized as positive control was also used for the identification of unknown (non‐target) scallop species by DNA sequencing analysis. In its present form, our multiplex PCR method can be of great utility for different types of studies involving scallop species and for research institutes and governmental agencies that regulate seafood authentication around the world.