Microstructures of barbels and bony plates of Satyrichthys laticeps (Actinopterygii: Peristediidae)

Barbels are sensory-appendage near the mouth of many fishes including Cyprinidae, Ictaluridae and Peristediidae and commonly used for identification of the species. Similarly scales and bony plates of fishes also being used in taxonomic studies. Satyrichthys laticeps commonly called armoured searobins, is a deep-sea peristediid that distributed in the Indo-West Pacific region of the world. However, surface structures of has been unknown. The aim of this study is to reveal the microstructures of barbels and bony plates of S. laticeps, occurring in the Andaman Sea of Thailand, for the first time by using a scanning electron microscopy method. The chin barbels were characterised by a pebble-like surface whereas lip barbels resemble wooden texture. Taste bud-like organs were only visible in chin barbels. Bony plates from heads contained small semispheres around spine. In dorsolateral of posterior body, pits appeared at the apices, and semispherical buds were present in the middle and basal parts of tubercles. The study results may be important in understanding the physiology in peristediid fish

The Effects of Flood Pulse on the Spatial and Temporal Dynamics of Fish Diversity in the Raphiphat Canal, Thailand

This paper analyzes the effects of flood pulse on the spatial and temporal dynamics of fish diversity in the Raphiphat canal, Thailand, resulting from a study carried out in the period from May to December 2021. The fish samples were collected every month, covering the pre-flooded season (May to August) and the flooded season (September to December) on the rainy seasons at eight sampling stations. Fish were caught using cast nets with a mesh size of 1.5 cm and 2.5 cm, and gill nets with a mesh size of ¾ inch, 1.5 inches, and 2 inches. All data were analyzed to find out the fish diversity indices. A multivariate method of cluster analysis was used for data analysis. The result indicated that there was a total of 4,998 individual fish representing 33 species belonging to 25 genera and 14 families. The four most dominant fish varieties in the Raphiphat canal in terms of amount were Puntioplites proctozystron, Barbonymus gonionotus, Cyclocheilichthys enoplos, and Oreochromis niloticus which were distributed at all research stations. For temporal dynamics of fish diversity, the average species richness was 15.74±7.18. The highest species richness was found in August, and the lowest species richness was found in June. The H´ index 2.46±0.47 was found in December to May. The relative evenness index (J´) was 0.91±0.03 and varied between December and May. The cluster analysis each month in the Raphiphat canal can divide the fish community into 5 clusters.

Genome survey report of Thai ricefish (Oryzias minutillus) (Actinopterygii: Beloniformes)

Thai ricefish (Oryzias minutillus) is the smallest species in the Oryzias genus, widely distributed throughout Thailand. They are important in the trophic level of food webs within freshwater ecosystems. However, knowledge about the molecular data of this fish is lacking. Therefore, in this study, we surveyed the genome data of Thai ricefish collected from Mae Hong Son Province, Northwestern Thailand. In the initial assembly, the total genome and mitochondrial genome of Thai ricefish were 824 Mb and 16,954 bp, respectively. The total sizes of contig and scaffold were 547.7 and 585.9 Mb, respectively. The total genome size per mitochondrial size was 0.049. Phylogenetic relationship of Thai ricefish and related species of Oryzias was constructed based on mitochondrial genome. The nucleotide similarity of all genes in the mitogenome of Thai ricefish was compared with the related species of Oryzias from nucleotide database of the National Center for Biotechnology Information. The results provide data that increase knowledge of molecular genetics and a basis for further work on fish in genus Oryzias

The Decrease of Rouleaux Formation of Red Blood Cells in Healthy Human by Water-Soluble Chlorophyll as Revealed by Scanning Electron Microscopy

Objective: In present study, we examined rouleaux formation of red blood cells before and after drinking water-soluble chlorophyll as anantioxidant. Method: In blood smear, red blood cells of 20 volunteers were examined before and after drinking water-soluble chlorophyllby using a light microscope, erythrocyte sedimentation rate (ESR) and scanning electron microscopy (SEM). Results: The rouleauxformations were modularly found in 30 and 60 min. In contrast, those formations rarely appeared in 45 min. ESR values of both sexesafter drinking water-soluble chlorophyll for 45 min were significantly lower than those before drinking. In SEM, before drinking watersolublechlorophyll, rouleaux formations were found. After drinking water-soluble chlorophyll for 45 min, however, those formationsdisappeared. Conclusion: The results suggest that water-soluble chlorophyll may be able to decrease rouleaux formations of red bloodcells in healthy volunteers.Keywords: water-soluble chlorophyll, rouleaux formation, red blood cell, scanning electron microscopyThai Pharm Health Sci J 2009;4(4):450-455

Expression levels of hormone receptors and bone morphogenic protein in fins of medaka

金沢大学環日本海域環境研究センター生物多様性研究部門In the genus Oryzias, the morphologies of the dorsal and anal fins are typical secondary sex characters. In the Japanese medaka (Oryzias latipes) and Thai medaka (Oryzias minutillus), androgen receptor (AR) expression levels in the dorsal, anal, and pectoral fins were higher in males than in females. Conversely, in both species estrogen receptor (ER) β expression levels in the dorsal and anal fins were higher in females than in males. AR and ERβ expression levels in the dorsal and anal fins of sex-undeterminable individuals of Thai medaka were intermediate between those in normal male and female Thai medaka. There was no difference in the bone morphogenic protein (Bmp) 2b expression level between male and female Japanese medaka. In contrast, the Bmp2b expression level in the dorsal fin of sex-undeterminable individuals was lower than in normal male and female Thai medaka. It is thus clear that androgen and estrogen regulate the sex-dependent characters of fin morphology in both Oryzias species. In sex-undeterminable individuals of Thai medaka, the low levels of Bmp2b expression in the dorsal fin are evidence that androgen and estrogen are necessary for adequate expression of Bmp2b in the normal development of at least the dorsal fin. © 2009 Zoological Society of Japan.全文公開20100

Using Morphology and Genomic Template Stability (GTS) to Track Herbicide Effect on Some Submersed Aquatic Plants

This study aimed to detect the genotoxic effects of glyphosate on aquatic plants by the RAPD-PCR technique. Native aquatic plants were screened for herbicide testing. The aquatic plant amounts and species were counted and a comparison was made between natural ponds and paddy fields for a total of 17 sites; paddy fields (site 1-10), ponds beside paddy fields (site 11-14), and natural ponds (site 15-17). At each studied site, 5 randomized sampling plots of 2 x 5 m size were performed. Generally, the natural ponds contained more aquatic plant diversity than the paddy fields. However, some species such as Najas graminea Del. and Ceratophyllum demersum Linn. were found only in the paddy fields and natural ponds, respectively. The effect of glyphosate and butachlor on aquatic plants was observed. Changes in color and morphology were found to be related to higher dose treatment. The RAPD profiles were analyzed for the study of genomic template stability (GTS). Results indicated that the GTS of Hydrilla verticellata was lowest (7.14 %GTS), followed by Utricularia aurea lour (30.77 %GTS), N. graminea Del. (38.71 %GTS), and Nitella sp. (59.38 %GTS). These results confirmed the effects of herbicides on abnormal morphology and DNA instability. In addition, results of genotoxicity of glyphosate on some aquatic plants (Hydrilla verticellata, Utricularia aurea lour, and N. graminea Del.), and macroalgae (Nitella sp.) verified that the method of RAPD-PCR could be used as a biomarker to detect herbicide contamination in aquatic ecological systems

Molecular assessment and transcriptome profiling of wild fish populations of Oryzias mekongensis and O. songkhramensis (Adrianichthyidae: Beloniformes) from Thailand.

Among the fish of the genus Oryzias, two species are frequently used as model animals in biological research. In Thailand, Oryzias mekongensis is usually found in natural freshwater near the Mekong Basin in the northeast region, while O. songkhramensis inhabits the Songkhram Basin. For differential morphological identification, the coloured bands on the dorsal and ventral margins of the caudal fin are used to distinguish O. mekongensis from O. songkhramensis. However, these characteristics are insufficient to justify species differentiation, and little molecular evidence is available to supplement them. This study aimed to investigate the molecular population and transcriptome profiles of adult O. mekongensis and O. songkhramensis. In the molecular tree based on cytochrome b sequences, O. mekongensis exhibited four clades that were clearly distinguished from O. songkhramensis. Clade 1 of the O. mekongensis population was close to the Mekong River and lived in the eastern portion of the upper northeast region. Clade 2 was far from the Mekong River and inhabited the middle region of the Songkhram River. Clade 3 was positioned to the west of the Songkhram River, and clade 4 was to the south of the Songkhram River Basin. After RNA sequencing using an Illumina HiSeq 2500 platform, the gene category annotations hardly differentiated the species and were discussed in the text. Based on the present findings, population dispersal of these Oryzias species might be associated with geographic variations of the upper northeast region. Molecular genetics and transcriptome profiling might advance our understanding of the evolution of teleost fish