BackgroundAs one of the most popular and valuable commercial marine fishes in China and East Asian countries, the Chinese black porgy (Acanthopagrus schlegelii), also known as the blackhead seabream, has some attractive characteristics such as fast growth rate, good meat quality, resistance to diseases, and excellent adaptability to various environments. Furthermore, the black porgy is a good model for investigating sex changes in fish due to its protandrous hermaphroditism. Here, we obtained a high-quality genome assembly of this interesting teleost species and performed a genomic survey on potential genes associated with the sex-change phenomenon.FindingsWe generated 175.4 gigabases (Gb) of clean sequence reads using a whole-genome shotgun sequencing strategy. The final genome assembly is approximately 688.1 megabases (Mb), accounting for 93% of the estimated genome size (739.6 Mb). The achieved scaffold N50 is 7.6 Mb, reaching a relatively high level among sequenced fish species. We identified 19 465 protein-coding genes, which had an average transcript length of 17.3 kb. By performing a comparative genomic analysis, we found 3 types of genes potentially associated with sex change, which are useful for studying the genetic basis of the protandrous hermaphroditism.ConclusionsWe provide a draft genome assembly of the Chinese black porgy and discuss the potential genetic mechanisms of sex change. These data are also an important resource for studying the biology and for facilitating breeding of this economically important fish.

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Black porgy (Acanthopagrus schlegelii) belongs to the order Perciformes, the family Sparidae and the genus Acanthopagrus. It is an essential marine aquaculture fish, with an oblong and flat body and holds the characteristics of fast growth, good meat quality, strong disease resistance and strong adaptability to various environments (Zhu & Zhu, 2014). Fish growth traits refer to the growth-related traits such as body weight, body length, head length, body width, body height and tail stalk length of individual fish. The faster the fish grow, the less time is needed for breeding until market size, the lower the economic cost and the higher the yield at harvest, which can be beneficial for meeting market demands, and increase the economic and ecological benefits of fish breeding (Yin et al., 2020). Therefore, growth traits are not only one of the economic traits that best reflects the growth status of the fish, but it is also a very important reference indicator for the development of fish farming. With the development of aquaculture, the research on growth traits has received more and more attention.

With the development of 5G technology, contemporary technologies such as Internet of Things (IoT) and Big Data analyses have been widely applied to the sport industry. This paper focuses on the design of a portable, self-powered, flexible sensor, which does not require an external power supply. The sensor is capable of monitoring speed skating techniques, thereby helping professional athletes to enhance their performance. This sensor mainly consists of Polyvinylidene Fluoride (PVDF) with polarization after a silvering electrode and a flexible polyester substrate. Flexible sensors are attached to the push-off joint part of speed skaters and the ice skate blade. During motion, it produces different piezoelectricity signals depending on the states of motion. The monitoring and analyzing of the real-time sensor signals will adjust the athlete’s skating angle, frequency, and push-off techniques, thus improving user training and enhancing performance. Moreover, the production of piezoelectric signals can charge the capacitor, provide power for small electronic equipment (e.g., wireless device), and extend the applications of wearable flexible sensors to the Big Data and IoT technologies in the sport industry.

F1 hybrids may have heterosis in a wide range of traits, such as environmental adaptation or growth condition. To facilitate research on F1 hybrids of Acanthopagrus schlegelii ♂ × Pagrus major ♀, differentially expressed genes of the whole body transcriptome between F1 hybrids and parents were analysed using Illumina high‐throughput sequencing. The results showed that genes related to development and immune process had significantly expressed in F1 hybrids. It revealed that F1 hybrids had quick growth and strong resistance to disease versus A. schlegelii and P. major. This is the first report on the transcriptome of A. schlegelii, P. major and their F1 hybrids at 1 month of age and provides an important foundational data for studying molecular mechanisms of heterosis.