The stable supply of renewable energy is imperative in many countries lacking domestic energy production. Thus, green energy will likely dominate future energy development trends. Taiwan’s thriving aquaculture industry presents an opportunity to integrate fisheries with electricity generation by transforming aquaculture into a symbiotic fishery–photovoltaic structure that provides stable, clean energy with potential economic benefits. This integrated model offers several advantages, such as temperature regulation and mobility, without needing to use land. However, several unexplored issues warrant further investigation. This study assessed the solar shading effects within the symbiotic fishery–photovoltaic model by comparing the growth of Litopenaeus vannamei and Chanos chanos under mixed cultivation conditions in an integrated system versus traditional fishponds. No substantial growth differences occurred for C. chanos between the systems. However, the body weight of L. vannamei was notably higher in traditional ponds versus the integrated system. Beyond evaluating the species’ growth, the aquatic environments were compared between the systems. The integrated model maintained a higher dissolved oxygen content and had lower ammonia and nitrite nitrogen levels than traditional co-cultivation. Moreover, this study provides valuable insights into the impacts of solar shading on the symbiotic fishery–photovoltaic model, shedding light on its potential benefits for nations lacking self-produced energy. Fishery–electricity symbiosis is a mutually beneficial integration of aquaculture and photovoltaics.

Blue swimmer crabs (Portunus pelagicus) primarily inhabit the coastal regions of Southeast Asia. This study aimed to examine their population genetic structure, phylogeography, and historical demography by applying partial sequences to the control region in the mitochondrial DNA. The analysis focused on 6 populations comprising 166 individual samples collected from Taiwan (Kezailiao Kaohsiung (KK) and Penghu (PH)), mainland China (Xiamen (XM) and Hong Kong (HK)), Vietnam (Hanoi (VN)), and Singapore (SGP). The estimated nucleotide diversity (π) for all of the samples was 0.062, with values ranging between 0.018 (PH) and 0.045 (HK). Our study collected 116 haplotypes and classified them into lineages A and B. The XM, HK, VN, and SGP populations made up lineage A, and the PH and KK populations comprised lineage B. For each lineage, the results highlighted indications of demographic expansion. Lineage A can be traced back to the second-to-last interglacial period, while lineage B possibly originated in the last glacial period. There were significant differences in the F_ST values among the six populations, except for the pairs HK–XM and PH–KK. In conclusion, the phylogeography and genetic structure of P. pelagicus in Southeast Asia were potentially affected by the Pleistocene glacial cycles and human introduction. These findings further highlight the possible dispersal routes of P. pelagicus throughout Southeast Asia.

The three-spot swimming crab (Portunus sanguinolentus) is mainly distributed in South East Asia. An analysis of mitochondrial control region partial sequences allows us to determine the population genetic structure, phylogeography and historical demography of this species in East Asia. The seven populations, which included 110 individuals, were collected from mainland China (Shanghai, SH, Xiamen, XM and Hong Kong, HK), Taiwan (Yilan, YL, Taichung, TC, Donggang, DG) and Singapore (Singapore, SGP). The nucleotide diversity (π) of all individuals was 0.01149, with values ranging from 0.00372 (SGP) to 0.01345 (YL). In total, 90 haplotypes have been identified, which can be divided into two major lineages: lineage A consists of specimens from SH, YL, XM, TC and DG, and lineage B corresponds to specimen from SGP. From the second to the most recent interglacial period, population expansion was observed in each lineage. However, a low level of genetic differentiation was also observed in the three-spotted swimming crab, P. sanguinolentus, according to F_ST values. Our results suggest that several past and present habitat configurations have shaped the genetic patterns of P. sanguinolentus until now. During Pleistocene glaciations, when sea levels were low, this species may have moved along the coast from Southeast Asia to China. It first colonized the Hong Kong area during this era. After sea levels rose and shorelines receded, it subsequently spread to the coast of mainland China.

Morphometric disparities were employed to characterize the geographical variations in and elucidate the phylogeography of Portunus sanguinolentus in East Asia. In this study, a comprehensive assessment was undertaken based on measurements from 833 individual crabs. These crabs were sampled from eight distinct locations, namely Kyushu (KS), Fuzhou (FZ), Yilan (YL), Xiamen (XM), Tainan (TN), Hong Kong (HK), Vietnam (VN), and Singapore (SG). Twelve morphometric measurements were standardized based on size using the allometric method. A cluster analysis and a canonical variate analysis (CVA) were then conducted for a data analysis. Randomization tests were subsequently performed to validate the morphometric differences observed among the groups. The analytical results classified the eight sampled populations into at least two distinct clusters. The first cluster included three samples from China (specifically FZ, XM, and HK), while the second cluster consisted of samples from East Asia (including KS, YL, TN, VN, and SG). The CVA revealed a tripartite division into three groups: the mainland China group (FZ, XM, and HK), the Kuroshio group (KS, YL, and TN), and the Southeast Asia group (VN and SG). The observed morphometric variations between these broad groups were statistically significant for both genders. These differences may be attributed to evolutionary origins, geographical events, or environmental adaptations. This study highlights the effectiveness of morphometric techniques in providing comprehensive insights into species delimitation and philogeographic relationships.

This study delves into the fascinating morphological diversity and population groups of the Crucifix crab (Charybdis feriatus), a species steeped in the cultural and spiritual significance of recreational fisheries across East and Southeast Asia. It is known in the West as the “Crucifix crab” due to the distinct cross pattern on its shell. In this research, we collected 759 specimens from seven estuarine locations: Kyushu (Japan), Shanghai, Xiamen, Hong Kong (China), Yilan, Kaohsiung (Taiwan), and Singapore. Using advanced statistical methods, including canonical variate analysis (CVA) and hierarchical clustering, we identified three distinct population groups: the Northeast Asian group (NAG), the Kuroshio tributary group (KTG), and the Southeast Asian group (SAG). Significant morphological differences were found between these populations, suggesting that the crab’s adaptation to varying sea environments is as unique as its symbolic cross-shaped marking. The canonical variate analysis revealed that the first two eigenvalues explained 88% of the total variance (61% and 27%, respectively) in females and 80% in males (62% and 18%, respectively). The key morphometric traits CP1 (frontal teeth) and CP4 (posterior margin) showed the highest variability (correlation coefficients ranging from 0.76 to 0.82, p < 0.001). Interestingly, the traits CP1 (frontal teeth) and CP4 (posterior margin) emerged as key drivers of allometric growth variation, further enriching our understanding of this species.