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The effects of alkalinity on production performance and biochemical responses of spiny lobster Panulirus homarus reared in recirculating aquaculture system
Get PDFSpiny lobsters (Panulirus sp.) were valuable and one of the most popular Indonesian export commodities. Some approaches were made to increase the quantity and quality of cultivated spiny lobsters. Land-based mariculture with Recirculating Aquaculture System (RAS) was applied to increase lobster harvesting and optimize environmental quality by adjusting water alkalinity. This study aimed to determine the optimum level of alkalinity for spiny lobsters Panulirus homarus rearing in RAS. This study investigated the effects of applying four water alkalinity levels (Control, 125, 200, and 275 mg L-1 CaCO3) on the biochemical responses of P. homarus observed in the hemolymph in terms of Total Hemocyte Count (THC), glucose, total protein, calcium, and pH levels. Furthermore, we also studied the alkalinity effects on lobster production performance parameters in terms of body weight gain, body length, Survival Rate (SR), Specific Growth Rate (SGR), and Feed Conversion Ratio (FCR). Lobsters with an initial weight rate of 58.05±1.69 g and an initial total length rate of 115.33±1.52 mm were reared for 60 days in a recirculation system. Results of water quality parameters such as ammonia, nitrite, nitrate, dissolved oxygen, temperature, and salinity during the study were available for lobster rearing. Different alkalinity levels affected the biochemical responses and production performance of lobsters. The best alkalinity level to reared Panulirus sp. in the recirculation system during this study was 200 mg L-1 CaCO3 so that it could achieve the highest survival rate of 86.67% with SGR 0.60±0.01 % day-1
Bacillus velezensis LG37: Functional verification of GlnL and analysis of the ammonia assimilation metabolic pathway
Get PDFHigh concentrations of ammonia have toxic effects on bred animals. In aquaculture, the possibility of using Bacillus preparations to remove ammonia nitrogen in aquaculture water through assimilation has been generally recognized. In this study, to analyze the metabolic pathways of ammonia assimilation in Bacillus, the characteristics and pathways of ammonia assimilation of Bacillus velezensis LG37 stored in the laboratory were analyzed. The results showed that the rate of ammonia assimilation by LG37 in a minimal medium could reach 94.2% at 20 h, and the highest assimilation rate was 95.4% within 60 h. In a minimal medium, the growth rate of LG37 in the glutamine group was significantly faster than that in the ammonia group, but the expression of glnL showed opposite results. The gene expression level of glnL in the ammonia group was significantly higher than in the glutamine group. glnL overexpression (OEglnL) and deletion (ΔglnL) strains were constructed by CRISPR/Cas9 technology and using the pHT1K vector, respectively. The expression levels of glnL in LG37, OEglnL, and ΔglnL strains were determined by RT-qPCR. The glnL gene expression levels were ordered as follows: OEglnL > LG37 > ΔglnL. In all three strains (LG37, ΔglnL, and OEglnL) and at different ammonia concentrations, the expression levels of glnL were consistent with glnA and glnB levels, showing a positive correlation. However, the expression levels of glnK and glnR in different strains hardly changed significantly
Assembling the superior biofloc tilapia strains for industry
Get PDFThe decreasing productivity and increasing environmental pressure on intensive tilapia culture in open waters, especially in floating net cages, have forced the development of a biofloc system for tilapia farming. This study aimed to develop the superior tilapia strain suitable for the biofloc system and to observe their productivity and economic profitability under commercial scale in the biofloc system. The selective breeding activity was carried out on 100 families reared and mated in hapa (a double-walled contrivance in which an inner hapa, made of mosquito netting material, is installed within an outer one made of whole cloth) in the biofloc pond for three generations. The individual selection was conducted at the age of 6 months on the characters of standard length and body weight with the best 10% of the top part of the population as a reference for the formation of the next generation. After three generations, the offspring obtained from mass spawning were grown out in round-limen ponds and square-concrete ponds for productivity and profitability observations. The results showed that heritability values of the biofloc tilapia strain were 0.4196 (standard length, SL) and 0.4898 (body weight, BW). The average response selection of BW and SL was 13.04% and 6.11%, respectively. Biomass gain was obtained between 19.29–28.83 kg/m3. The production multiply value was 8.07-13.59x. The average daily weight growth was between 2.8g-3.0g. The Benefit-Cost ratio is valued from 1.81 to 2.71. The superior tilapia biofloc strain has a moderate heritability value. When it is raised in a biofloc ponds system at different volumes, it significantly affects the productivity on biomass, body weight, and multiplication value. Also, it is advantageous when applied on an industrial scale
Identifying (In)Definiteness in Vietnamese Noun Phrase
Get PDFThis paper aims to settle the issue of whether những, các, một are articles in Vietnamese as argued by Nguyen T. C. (1975), Nguyen H. T. (2004), a.o. First, we adopt Dayal (in prep.)’s cross-linguistic questionnaire of (in)definiteness since this questionnaire offers us a set of useful tests to diagnose definiteness and indefiniteness from a crosslinguistic perspective. Second, we broaden up the empirical landscape by contrasting the interpretation of nominal constructions which have the so-called overt (in)definite markers (các-CLF-N, những-CLF-N, and một CLF N) with that of nominal constructions without them (including bare N and CLF-N, numeral(>1)-CLF-N), in order to see if the (in)definiteness effect truly comes from the presence or absence of these three markers, or from something else. We then conclude that (i) những and các are plural markers, (ii) only một seems to be a likely candidate for an indefinite article, and (iii) bare nouns and numerals are not genuine indefinites: the former denotes kinds, while the latter can be interpreted as definite, which sets Vietnamese apart cross-linguistically
Effect of replacement of fishmeal by soybean products with attractants supplementation on the growth performance, feed utilization, body composition, plasma physiological responses and hepatic antioxidant abilities of juvenile golden pompano Trachinotus ovatus
Get PDFA feeding experiment was carried out to develop a practical diet with low fishmeal for juvenile golden pompano (Trachinotus ovatus) by substituting fishmeal protein with soybean products mixture. Six isocaloric (17.6 KJ g−1) diets were designed by replacing 0 (FM100), 5 (FM95), 10 (FM90), 15 (FM85), 20 (FM80), and 25% (FM75) of the fishmeal with soybean products mixture (SPM) (soybean meal and soybean protein concentrate). The experiment diets were supplemented with 1.5%, 3%, 4.5%, 6% and 7.5% squid paste as attractants or palatability enhancer. The experimental fish (6.9 g) were cultured in sea cages (1.0 m × 1.0 m × 1.5 m) with 25 fish in each cage. Fish were fed the corresponding experimental diets to satiation twice daily for 8 weeks. At the end of the feeding experiment, no differences were found in the final weight and weight gain (WG) of fish fed FM100, FM85, FM80, and FM75 diets (P > 0.05). The WG was significantly (P < 0.05) better in the fish-fed FM95 diet compared to FM100 and FM75 diets. FCR in diet FM95 and FM90 was significantly (P < 0.05) than that of FM80 and FM75, but these values were not significantly different from those in other treatments. Although the condition factor value in diets FM90, FM85, and FM80 was significantly (P < 0.05) higher than that of FM100, these values were not significantly different from the rest of the other groups. There was no statistical difference in SGR, FR, VSI, and survival rates among different dietary treatments. The plasma AST activity was significantly lower in fish fed FM90 diet compared to fish fed with control, FM85, FM80, and FM75 (P < 0.05). There was no significant difference in plasma AST among all dietary treatments except FM95 and FM90. In contrast, the plasma AKP activity showed the opposite trend. Compared with the control, the fish-fed FM80 and FM75 diets had significantly decreased plasma cholesterol, triglyceride total protein, albumin, and globulin level (P < 0.05) while significantly increasing plasma COR levels (P < 0.05). There was no significant difference in ALT, Urea and glucose values among all treatments. No statistical difference was observed among the FM100, FM80, and FM75 treatments for those of plasma LYZ activity, C3, and C4 levels. The hepatic T-AOC and SOD activities were significantly increased in fish fed the FM90 diet (P < 0.05) compared to those in fish fed with FM100 diet. According to the current experiment, it can be concluded that SPM supplemented with SP could partially substitute fishmeal (25%) for juvenile golden pompano without any adverse symptoms
Panel Finding Aid: Voices of Our Kūpuna Panel, 2001
Get PDFPanel finding aid of Voices of Our Kūpuna Panel, 2001 with Nona Beamer, George Naope, Puluelo Park at the Edith Kanakaole Stadium, Waiakea, Hilo, Hawaiʻi Island on July 30, 2001. Panel footage is available in the Hula Preservation Society library. For questions regarding materials referenced herein, and/or Access & Use of content, please contact them
Aeromonas allosaccharophila, an emerging opportunist pathogen for farmed hybrid sturgeon (Acipenser baerii × Acipenser schrencki), in southwest China
Get PDFAeromonas allosaccharophila belongs one of the causative agent of Aeromonas disease in teleosts. Here, we reported on multiple outbreaks of A. allosaccharophila with mortality up to 80% in farmed hybrid sturgeon in Sichuan, China, from 2019 to 2021. This was the first study to A. allosaccharophila from diseased hybrid sturgeons by phenotypic characterization and 16S rRNA analysis. The typical clinical signs of these fish were intestinal segments empty and often with yellow mucus or swelling. Histopathological observation of diseased fish infected with A. allosaccharophila showed the intestinal villus structure disappeared and the intestinal mucosa epithelium was necrotic and shed. Experimental infection indicated that A. allosaccharophila was the pathogen responsible for the mortalities. Antibiotic sensitivity test results showed that A. allosaccharophila was resistant to ampicillin, neomycin, tetracycline, and penicillin, while sensitive to sulfamethoxazole, streptomycin, florfenicol, enrofloxacin, and cefoxitin. Our findings provide references for the disease diagnosis and treatment