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mtCO1-based population structure and genetic diversity of Pacific oyster *Crassostrea gigas* populations acquired from two farms in South Korea
Get PDFSince the early 1990s in South Korea, climatic and anthropogenic factors have incurred the reduction of the wild seeds of the Pacific oyster, Crassostrea gigas, which raised concerns about losing genetic diversity and accelerating genetic deterioration. We assessed the genetic diversity of C. gigas populations from two farms (Tongyeong and Gadeokdo) on the southern coast, where about 80% of the cultivated oysters in Korea are produced. Tongyeong showed slightly higher diversity than Gadeokdo, but both populations had a similar genetic structure characterized by low nucleotide diversity. Comparative haplotype analyses provided data supporting genetic features of the populations that include (1) weak genotype-locality relationship, (2) low levels of gene flow between populations, and (3) possible seasonal fluctuation of genetic variation within a population. Furthermore, the highly alike haplotype network patterns were observed between the wild and farm populations as well as among the populations in neighboring countries, which suggests that the genetic structure is conserved between wild and hatchery populations, and geographic proximity has minimal influence on the genetic composition
Application of fuzzy model for the shelf-life determination of whole sea bass (<em>Dicentrarchus labrax</em>) under refrigerated temperatures
Get PDFIn this study, microbiological deterioration of whole sea bass stored at refrigerator temperatures (4°C) was determined through fuzzy modeling. Total Mesophilic Aerobic Bacteria (TMAB), Total Psychrophilic Aerobic Bacteria (TPAB), Lactic Acid Bacteria (LAB), *Pseudomonas sp*., and Enterobacteriaceae counts were observed during 12 days of storage. Quality Index Method (QIM) was used for sensory analysis of the samples and shelf life was determined according to sensory deterioration. The growth of the microorganisms was statistically significant (p\<0.05) at the end of the storage period. Additionally, significant differences (p\<0.05) were observed for QI scores after the 8^th^ day of the storage in whole sea bass stored under refrigerated conditions. A total of 12 rules were determined in the fuzzy logic application. Mamdani was used as the fuzzy type for fuzzy modeling, and centroid was used as the defuzzification method. Fuzzy membership values were computed using triangular membership functions. According to the research results, the shelf life of sea bass fish was determined as 8 days from the time of 12 days storage. As a result, it was observed that the sensory score could be determined by using Fuzzy logic (R^2^=0.96) according to microbiological parameters in sea bass stored in refrigerator conditions. In this context, it was concluded that Fuzzy logic could be used in shelf-life estimation in seafood products
Notes on Luma, a Southern Ngwi Language in Laos
Get PDFThis paper provides a geographic, ethnographic, and linguistic background on Luma, a lesser-known language belonging to the Akoid subgroup of Southern Lolo/Ngwi in Phongsaly Province, Lao PDR. Luma has two dialects, Luma Eushi /əsʲi/ and Luma Proper, which is also called Luma Pala. Suggestions for further research on phonology, grammar, historical-comparative studies and classification are included
Molecular cloning and expression profiles of MnSOD and CAT genes from the turbot <em>Scophthalmus maximus</em>
Get PDFManganese superoxide dismutase (MnSOD) and catalase (CAT) could eliminate reactive oxygen species (ROS) and maintain the reduction-oxidation balance in cells. This study aimed to investigate their functions in turbot (Scophthalmus maximus) response to the *Vibro anguillarum* challenge. SmMnSOD, the full-length liver cDNA of MnSOD from *S. maximus*, was cloned by fast amplification of cDNA ends (RACE). Sequencing of nucleotides indicated that the SmMnSOD cDNA was 1267 base pairs with a 684-base-pair open reading frame, encoding a 228 amino acid protein with 28 amino acid residues. The SmMnSOD sequence contains MnSOD signatures (DVWEHAYY) and probable N-glycosylation sites (NVT, NHT, and NLS). The deduced sequence of SmMnSOD revealed sequence homology between 85.3% and 92.9% with those of other species. A phylogenetic study found that SmMnSOD clustered with other fish MnSOD, indicating that SmMnSOD was a member of the MnSOD family. The SmMnSOD transcript was discovered by qRT-PCR in the gill, stomach, head-kidney, muscle, liver, intestine, and heart of *S. maximus*, with the highest expression in the liver. Upon intervention by *V. anguillarum*, the liver and head kidney transcript levels of SmMnSOD were up-regulated at 12 and 48 h, whereas the temporal expression profiles of the CAT transcript increased at 6 and 24 h. As the pathogenic bacterial stress processing was prolonged to 72 h, the liver and head kidney transcript levels of SmMnSOD and CAT decreased gradually. Thus, SmMnSOD was triggered and may be related to *S. maximus*' immunological responses against *V. anguillarum*
Structure, sequence and phylogenetic analysis of the complete chloroplast genome of the brown algae <em>Saccharina sp.</em> ye-E (Laminariaceae: Phaeophyceae) from Sakhalin Oblast, Russia
Get PDFFor this investigation, the chloroplast genome of Saccharina sp. ye-E from Russia was uncovered and annotated with Illumina sequencing data to examine the phylogenetic relationship of Saccharina in Laminariaceae from a molecular biology perspective. Analysis of the structural characteristics, simple repeat sequence (SSR) loci, relative species differences, codon preference, and phylogenetic relationships was conducted. The results revealed that the chloroplast genome of Saccharina sp. ye-E had a length of 130,624 bp, containing 139 protein-coding genes (PCGs), 6 ribosomal RNAs (rRNAs) and 57 transfer RNAs (tRNAs) genes, and a total GC content of 31.1%. There were 15 SSR loci in the genome. Effective codon number (ENC) and codon adaptation index (CAI) both indicated the strong codon randomness and codon preference. The phylogenetic tree, based on the complete chloroplast genomes of 10 brown algae, showed that four species of Saccharina genus formed a clade, with Saccharina sp. ye-E and Saccharina latissimi having the most related genetic affinity. It is believed that the determination of the chloroplast genome of Saccharina sp. ye-E will be beneficial for future algal genetics evolution and systematic studies in the Laminariaceae
Growth and nutritional health of <em>Pterophyllum scalare</em> juveniles: Unleashing the benefits of feeding with <em>Artemia</em> sp. in aquariums
No full textPterophyllum scalare is a popular ornamental fish species, but current rearing methods result in high mortality, low fertility, disease incidence, and slow growth in aquarium conditions. Research on co-feeding for ornamental fish at the juvenile or adult stage needs to be completed. This study implemented a "snacking" feeding strategy using Artemia sp. to evaluate changes in fish survival rate, growth performance, and enzyme activity related to digestion, antioxidants, and immunity in a recirculating aquaculture system. Two feeding strategies were tested: one group was fed a commercial diet plus Artemia sp. (0.1% of diet) as “snacking,” and another group was fed only the commercial diet as normal. “Snacking” with Artemia sp. enhanced fish's survival and growth performance, with higher relative weight rate, standard length, and total length than the control group. Specific growth rates for weight, standard length, and total length were also more significant in the supplemented group compared to the control group. The activity of amylase, superoxide dismutase, and glutathione peroxidase was substantially higher in the supplemented group. Adding Artemia sp. as a supplement under a “snacking” feeding strategy to the control diet was beneficial for P. scalare juvenile rearing and can guide managing recirculating farming activities