Intensive Culture Ponds Research Articles

The effects of lotus-fish co-culture on the gut microbiome of Hefang crucian carp (Carassis auratus)

Gut microbiome plays an important role in host's development and reproduction. Lotus-fish co-culture (LFC) is a popular integrated agriculture–aquaculture farming system in China. However, there is still a relative dearth of information on how changes of aquaculture modes will affect the fish gut microbiome. In the present study, metagenomic sequencing was used to compare gut bacteria of the hybrid fish Hefang crucian carp (Carassius cuuieri ♀ × C. auratus var. red ♂) cultured in LFC and intensive pond culture (IPC) systems. The results indicated that aquaculture modes exerted great influences on the fish gut bacterial community. A significantly higher gut bacterial diversity was found in LFC than that in IPC (P < 0.05). The relative abundances of Actinobacteria and Chloroflexi were apparently higher in LFC than those in IPC, whereas Planctomycetota, Firmicutes, and Verrucomicrobia showed opposite patterns. Besides, gut bacterial metabolic potentials involved in energy metabolism, carbohydrate metabolism, amino acid metabolism, environmental information processing, and cellular processes were significantly increased in LFC compared to those in IPC. On the contrary, the bacterial functional potentials related to nucleotide metabolism, DNA mismatch repair, as well as homologous recombination were significantly stimulated in the IPC system. Source‐tracking analysis suggested that fish gut bacterial community in IPC was originated mainly from water sources, whereas the gut bacterial community in LFC was originated from more unknown sources and soil sources. Our results provided new insight into the influence of aquaculture modes on the microbial community diversity and functionality in aquatic animals and highlighted the importance of environment microbiome in reshaping the gut microbes.

The impact of aquaculture system on the microbiome and gut metabolome of juvenile Chinese softshell turtle (Pelodiscus sinensis).

The commercial aquatic animal microbiome may markedly affect the successful host's farming in various aquaculture systems. However, very little was known about it. Here, two different aquaculture systems, the rice-fish culture (RFC) and intensive pond culture (IPC) systems, were compared to deconstruct the skin, oral, and gut microbiome, as well as the gut metabolome of juvenile Chinese softshell turtle (Pelodiscus sinensis). Higher alpha-diversity and functional redundancy of P. sinensis microbial community were found in the RFC than those of the IPC. The aquaculture systems have the strongest influence on the gut microbiome, followed by the skin microbiome, and finally the oral microbiome. Source-tracking analysis showed that the RFC's microbial community originated from more unknown sources than that of the IPC across all body regions. Strikingly, the RFC's oral and skin microbiome exhibited a significantly higher proportion of generalists and broader habitat niche breadth than those of the IPC, but not the gut. Null model analysis revealed that the RFC's oral and skin microbial community assembly was governed by a significantly greater proportion of deterministic processes than that of the IPC, but not the gut. We further identified the key gene and microbial contribution to five significantly changed gut metabolites, 2-oxoglutarate, N-acetyl-d-mannosamine, cis-4-hydroxy-d-proline, nicotinamide, and l-alanine, which were significantly correlated with important categories of microbe-mediated processes, including the amino acid metabolism, GABAergic synapse, ABC transporters, biosynthesis of unsaturated fatty acids, as well as citrate cycle. Moreover, different aquaculture systems have a significant impact on the hepatic lipid metabolism and body shape of P. sinensis. Our results provide new insight into the influence of aquaculture systems on the microbial community structure feature and assembly mechanism in an aquatic animal, alsohighlighting the key microbiome and gene contributions to the metabolite variation in the gut microbiome-metabolome association.

Population analysis of total vibrio and heterotrophic bacteria in water and sediment to support intensive shrimp culture expansion in Pasangkayu Regency, West Sulawesi Province, Indonesia

Shrimp is important aquatic food source for human around the world and cultured widely to fulfill shrimp demand that continues to increase along with the increased world’s community. Shrimp is included in crustacea without adaptive immunity, which becomes the main problem that causes shrimp to be vulnerable against pathogenic infection and attack either from virus or bacteria as one of which is Vibrio harveyi. Vibrio harveyi are luminous Gram-negative heterotrophic bacteria that inhabit marine environment which represent a preference for temperate and tropical waters including Indonesian waters. Vibrio harveyi is one of pathogens that becomes the main failure in shrimp culture industry. Vibrio harveyi attacks host that has immune system disruption due to less water quality environment. Data and information about the existence of Vibrio bacteria in water area as this water area will be utilized as standard water source for shrimp culture activity, which becomes very important to determine the water management standard model and prevent disease and culture failure. Based on this condition, further study aimed was performed to identify the Vibrio harveyi and heterotrophic bacteria concentration in Pasangkayu District waters, West Sulawesi Province, Indonesia. The study was performed by the survey method. The study results showed that the total vibrio bacteria (TBV) in waters was among 2.25 × 102 – 1.51 × 104 cfu/mL, total heterotrophic bacteria (TPC) was among 7.19 × 103 – 9.04 × 103 cfu/mL. The TBV/TPC ratio in waters was among 6.53 – 10.62%. TBV in the sediment was among 3.5 × 101-1 × 106 cfu/mL. TPC in the sediment was among 1.955 × 105 - 1 × 109 cfu/mL. The TBV/TPC ration in the sediment was among 0.20% - 14.20%. The vibrio bacteria can be used as low water quality bioindicator for main intensive culture pond water source when the TBV/TPC ratio in waters is above 10%. The TBV/TPC values in the Pasangkayu District waters were mostly still below 10%. This condition indicates intensive pond expansion possibility. To expand the culture pond without disrupting the water environmental balance, a preventive effort is required to suppress the TBV/TPC ratio by increasing the installation performance of organic waste processing in each intensive pond culture cluster.

Effects of dietary P:E ratio and Rhizoclonium in two stocking densities on growth and profitability of Nile tilapia in intensive pond culture

Two onsite tests were carried out to determine the effects of varying dietary protein to energy (P:E) ratio in intensive culture of Nile tilapia in two different places at two stocking densities. In both field trials, three diets were used namely commercial (CM) diet, control (CO) diet containing no Rhizoclonium and a diet containing Rhizoclonium replacing 52% of soybean meal (RLP); the diets contained decreasing P:E ratio of 21, 16 and 12 gMJ-1, respectively. The first trial was conducted in Aklan, Philippines at a stocking density of 17 fishm-2 while the second was in Pangasinan, Philippines at 27 fishm-2. In both trials, the three diets were fed for 2 months to 3 replicate cages of Nile tilapia, all of which were randomly placed in about 1.0 ha fresh water fish pond. In the first trial in Aklan, at 17 fish m-2 stocking density, no significant differences in the parameters were observed except in the absolute growth rate (AGR) in which the RLP dietary treatment exhibited a higher value than did either the CM or the CO diet. In Pangasinan, at 27 fish m-2 stocking density, significant differences in TFI, DFI and SGR were observed, all the other parameters were statistically similar. The RLP group exhibited lower total feed intake (TFI) and daily feed intake (DFI) but higher specific growth rate (SGR) than did either the CM or CO diet. In either stocking densities, feed cost was the main determinant of profitability in which the RLP group resulted in significantly highest profitability i.e., lowest total production cost, highest gross income and highest profit and profit margin. Although profit was significantly higher in the higher stocking density, profit margin was significantly higher in the lower stocking density. There was no statistical interaction between dietary treatment and stocking density as analyzed by two-way analysis of variance.

Effects of dietary P:E ratio and Rhizoclonium in two stocking densities on growth and profitability of Nile tilapia in intensive pond culture

Two onsite tests were carried out to determine the effects of varying dietary protein to energy (P:E) ratio in intensive culture of Nile tilapia in two different places at two stocking densities. In both field trials, three diets were used namely commercial (CM) diet, control (CO) diet containing no Rhizoclonium and a diet containing Rhizoclonium replacing 52% of soybean meal (RLP); the diets contained decreasing P:E ratio of 21, 16 and 12 gMJ-1, respectively. The first trial was conducted in Aklan, Philippines at a stocking density of 17 fishm-2 while the second was in Pangasinan, Philippines at 27 fishm-2. In both trials, the three diets were fed for 2 months to 3 replicate cages of Nile tilapia, all of which were randomly placed in about 1.0 ha fresh water fish pond. In the first trial in Aklan, at 17 fish m-2 stocking density, no significant differences in the parameters were observed except in the absolute growth rate (AGR) in which the RLP dietary treatment exhibited a higher value than did either the CM or the CO diet. In Pangasinan, at 27 fish m-2 stocking density, significant differences in TFI, DFI and SGR were observed, all the other parameters were statistically similar. The RLP group exhibited lower total feed intake (TFI) and daily feed intake (DFI) but higher specific growth rate (SGR) than did either the CM or CO diet. In either stocking densities, feed cost was the main determinant of profitability in which the RLP group resulted in significantly highest profitability i.e., lowest total production cost, highest gross income and highest profit and profit margin. Although profit was significantly higher in the higher stocking density, profit margin was significantly higher in the lower stocking density. There was no statistical interaction between dietary treatment and stocking density as analyzed by two-way analysis of variance.

Impact of Rice-Catfish/Shrimp Co-culture on Nutrients Fluxes Across Sediment-Water Interface in Intensive Aquaculture Ponds

Exchange of nitrogen and phosphorus across sediment-water interface plays an important role in the management of nutrient recycling in the aquaculture pond. In this study, a plot experiment was conducted to study the effect of rice-catfish/shrimp co-culture on the micro-profile of oxygen (O2), pH and nutrient exchange across sediment-water interface in the intensive culture ponds. The results showed that rice-catfish co-culture increased the concentration and penetrating depth of O2, but decreased the pH value across the sediment-water interface, compared with catfish monoculture. Additional rice cultivation significantly reduced the flux rates of ammonium (NH4+) and nitrate (NO3−) across sediment-water interface in the catfish and shrimp ponds. The flux rates of NO2− and soluble phosphorus (PO43−) showed no significant difference between rice-catfish/shrimp co-culture ponds and catfish/shrimp monoculture ponds. Rice only affected the dissolved inorganic nitrogen and phosphorus fractions in the sediment. The concentrations of NH4+ were significantly lower in the sediment of co-culture ponds than in the monoculture ponds. Additional rice cultivation also significantly reduced the content and percentage of dissolved inorganic phosphorus in the sediment of catfish ponds.

Effects of Rice-Fish Co-culture on Oxygen Consumption in Intensive Aquaculture Pond

Rice-fish co-culture has gained increasing attention to remediate the negative environmental impacts induced by intensive aquaculture. However, the effect of rice-fish co-culture on oxygen depletion has rarely been investigated. We constructed a rice-fish co-culture system in yellow catfish (Pelteobagrus fulvidraco) and freshwater shrimp (Macrobrachium nipponense) ponds using a new high-stalk rice variety, and conducted a field experiment to investigate the effect of rice-fish co-culture on water parameters and oxygen consumption. The results showed that rice-fish co-culture reduced the nutrients (total nitrogen, ammonia-N, total phosphorous and potassium) and the dissolved oxygen content in fish and shrimp ponds. However, they showed similar seasonal change of dissolved oxygen in the water of fish and shrimp ponds. Rice-fish co-culture reduced the total amount of oxygen consumption and optimized the oxygen consumption structure in pond. The respiration rates in water and sediment were significantly reduced by 66.1% and 31.7% in the catfish pond, and 64.4% and 38.7% in the shrimp pond, respectively, by additional rice cultivation. Rice-fish co-culture decreased the proportions of respiration in sediment and water, and increased the proportion of fish respiration. These results suggest that rice-fish co-culture is an efficient way to reduce hypoxia in intensive culture pond.

Effect of dietary protein to energy ratio on performance of nile tilapia and food web enhancement in semi-intensive pond aquaculture

When fish have only access to formulated feed, the optimal dietary protein to energy ratio (P:E) for tilapia ranges between 18 and 23 g.MJ−1. In pond culture, where natural foods complement administrated feed, increasing the carbon:nitrogen (C:N) ratio stimulates the natural food productivity. This study assessed if lowering the dietary P:E ratio (and thus increasing the C:N ratio of the feed input in the pond) below the optimal P:E ratio affects fish productivity, food web dynamics and nitrogen balances in semi-intensively managed tilapia ponds. Twelve ponds, each divided into three equally-sized compartments, were assigned to test the effect of two diets, which differed in P:E ratio (19 vs. 14 g.MJ−1). Three feeding levels (no, “low” and “high”) were nested in each pond in a split plot design. Initial fish biomass was 1166 (±16) g.compartment−1 and the experiment lasted 60 days. Decreasing P:E ratio enhanced tilapia production and specific growth rate (P < .05; 1195 vs. 985 g.compartment−1 and 1.76 vs 1.55%.d−1). Body composition of tilapia was unaffected by diet and feeding level. Despite the difference in performance, final fat content was 5% of body weight and unaffected by treatments. Averaged over both diets, survival and feed conversion ratio increased with increasing feeding level (P < .001). Diet composition did not alter measured water quality, and abundance and diversity of the related parameters of the food web. The total amount of N accumulated in the pond− was lower with the low P:E ratio diet (i.e., low protein diet). The data on N gain and N balance at the pond level suggest that the food web productivity was stimulated by reducing the dietary P:E ratio below the reported optimal levels in the literature. It is hypothesized that the optimal dietary P:E ratio is dependent on the culture intensity (extensive, semi-extensive or intensive pond culture).

Acinetobacter piscicola sp. nov., isolated from diseased farmed Murray cod (Maccullochella peelii peelii).

A taxonomic study was carried out on strain LW15T, which was isolated from the external lesions of diseased farmed Murray cod (Maccullochella peelii peelii) from an intensive culture pond. Cells of strain LW15T were Gram-negative, facultative-anaerobic, non-motile, and both coccobacillus- and bacillus-shaped. Growth was observed at NaCl concentrations of 0-2 % (w/v) (optimum, 0 %), 4-32 °C (optimum, 25-28 °C) and pH 5.0-9.0 (optimum, 7.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LW15T was affiliated to the genus Acinetobacter, showing the highest similarity to Acinetobacter guillouiae CIP 63.46T (97.7 %) and other Acinetobacter species with validly published names (93.5-97.6 %). Whole-genome sequencing and phylogeny reconstruction based on a core set of 1061 Acinetobacter genes indicated that strain LW15T was most closely related to the clade formed by A. guillouiae CIP 63.46T and Acinetobacter bereziniae CIP 70.12T and distantly related to any of the described species of genus Acinetobacter. Furthermore, strain LW15T could be distinguished from all known Acinetobacter species by its ability to assimilate β-alanine and l-arginine, but not d-glucose. The principal fatty acids were C18 : 1ω9c, C16 : 0 and C16 : 1ω7c/C16 : 1ω6c. The major respiratory quinone was Q-9. Polar lipids of strain LW15T comprised diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, four phospholipids, aminolipid and two unknown lipids. Based on its phenotypic and genotypic data, strain LW15T represents a novel species of the genus Acinetobacter, for which the name Acinetobacterpiscicola sp. nov. is proposed. The type strain is LW15T (=MCCC 1K03337T=CICC 24241T=KCTC 62134T=JCM 32101T).

지수식 양식장의 수온, 사육밀도, 어체크기가 필리핀산 뱀장어(Anguilla bicolor pacifica) 성장에 미치는 영향

지수식 양식장의 수온, 사육밀도, 어체크기가 필리핀산 뱀장어(Anguilla bicolor pacifica) 성장에 미치는 영향

Role of pond lining in dynamics of Sulphur recycling bacteria in pacific white Shrimp, Penaeus Vannamei grow out culture ponds

The present investigations compares observations on the trend of total heterotrophs, total vibrios and the sulphur cycling bacteria in earthen and lined white legged shrimp Penaeus vannamei culture ponds and the influence of farm level interventions like application of exogenous probiotics. The mean total bacterial counts (TBC) of pond water and sediments were close to or above 6 log CFU/ml. The sediment samples of earthen ponds showed slightly significantly higher (P < 0.01) TBC than the water samples. The total presumptive vibrio count was 2 log 0.73 ± 0.05 CFU/ml and 2 log 3.67 ± 0.98 CFU/ml in earthen and lined ponds, respectively, which were significantly different (P < 0.01). The sulphur cycling bacteria that is sulphur-oxidising bacteria (SOB) and the sulphur-reducing bacteria (SRB) were significantly lower (P < 0.01) in lined pond compared with earthen ponds throughout the culture period. There was no significant difference in SOB and SRB populations within the systems throughout the culture period indicating their balanced role of these bacterial populations in well-managed intensive culture ponds. It can be concluded that plastic lining ponds provide better management and healthier environmental conditions and sulphur cycling bacteria can be used as an indicator of pond environmental conditions. Also, the farm level interventions like application of probiotics play a significant role in maintaining the healthier pond environment.

Ot sazanı (Ctenopharyngodon idella valenciennes) yetiştiriciliğinde kullanılan havuz suyunun salata-marul üretiminde kullanılabilirliği üzerine bir araştırma

The aquaponics is a bio-integrated food production system that, aquaculture (fish production in intensive culture ponds) and hydroponics (plant growing in water with nutrient solution) plant production are made together. This study was designed in the shape of a closed system; two different feeding dose (3% and 4% of the live weight of the pool) Grass carp ( Ctenopharyngodon idella Valenciennes ) feed with cultivation used pool water, Nutrient Film Technique (NFT) in the form of the nutrient solution system designed as a lettuce-salad ( Lactuca sativa ) group of crops to investigate the applicability of the system with the aim of cultivating the effects upon and carried out.

Nutrient removal ability and economical benefit of a rice-fish co-culture system in aquaculture pond

Integrated culture of fish with crops has gained increasing attention to remediate the nutrients pollution of aquaculture. However, rice-fish co-culture system has rarely been investigated. In this study, we constructed a rice-fish co-culture system in the pond by using a new high-stalk rice variety, and conducted an on-farm experiment to examine the nutrients removal efficiency and economical benefit of this system. The results showed that this system significantly reduced the nutrients levels in the water and bottom soil in pond comparing with fish monoculture. The contents of total nitrogen (TN), ammonia-N, nitrate-N, nitrite-N, total phosphorus (TP) and orthophosphate (OP) were 70.63%, 60.27%, 54.86%, 71.54%, 85.05% and 78.54% lower in the water of rice-fish co-culture than fish monoculture pond, respectively. And the contents of ammonia-N, TP and OP in the bottom soil were also respectively reduced by 91.14%, 36.99% and 58.57% under rice-fish co-culture system. The total cost was only increased by 2.88%, but the net income was enhanced by 114.48% for rice-fish co-culture than fish monoculture, which was primarily attributed to extensive rice cultivation. These results suggested that rice-fish co-culture in pond was an efficient method to mitigate the eutrophication in an intensive culture pond, and also a potential new way to increase rice production for food security and extra income for fish farmers.

The Quality Control of Eutrophic Culture Sediment by Immobilized Cells and Conditions Manipulation

The sediment in intensive culture pond is overloaded by substantial unused nutrients and is conventionally discharged into adjacent coastal areas, which is detrimental to environment. This paper produced a preliminary quality control experiment to mitigate pollution of culture sediment by immobilized Bacillus sp. HSW cells on the composite carrier of sodium alginate and artificial zeolite. Glucose and calcium peroxide respectively were used to improve the sediment conditions of C/N ratio and oxygen level. The sediment quality was monitored periodically for 30 days. The results showed that biocontrol by immobilized Bacillus sp. HSW cells alone would be infeasible. However, the immobilized cells would better perform under controlled conditions. The significant decreases for total nitrogen (TN), total ammonia nitrogen (TAN), and organic nitrogen (ON) were observed at 71%, 91% and 64%, respectively. The phosphorus precipitated as phosphate raised approximately 120 mg/kg, and 60% of organic phosphorus was removed in 30 days. Moreover, the total bacteria abundance presented an obvious increase for over an order of magnitude, which was positive relationship (p &lt; 0.01) to the removal rates of ON and OP. Therefore, the immobilized cells accompanied by environmental manipulation are promising for biocontrol of culture sediment.

Effects of Two Environmental Best Management Practices on Pond Water and Effluent Quality and Growth of Nile Tilapia, Oreochromis niloticus

The trajectory of aquaculture growth in sub-Saharan Africa has necessitated closer attention to the use of environmental best management practices (BMPs). Two BMPs in particular, water reuse and floating feeds, are being promoted for adoption by pond fish farmers in sub-Saharan Africa. In this study, we investigated: (1) the effect of water source and feed type on water quality; (2) the effect of water source and feed type on tilapia growth; and (3) the quality of potential effluents from ponds using different water source and feed types. The study was conducted in Ghana using on-farm experiments involving monitoring of water quality and growth of Nile tilapia Oreochromis niloticus for 160 days. Although considered low-intensity production systems, nutrients and solids in the study ponds exceeded levels expected in intensive culture ponds by wide margins, whereas BOD5 was within the range for semi-intensive ponds. Floating feed was associated with higher water quality, especially dissolved oxygen, and higher growth, but water source did not significantly affect growth. Water reuse appears to be a viable BMP for sustainable aquaculture in the region, but the use of floating feed as BMP will depend on the economic profitability of floating feed use.

Effect of Low-lying Land Environment on Abundance of Cotton Spider Mites and Total Phenolic Content of Leaves and their Relationship

The possible advantage of cotton production established in low-lying land area over intensive culture pond was systematically investigated by comparing the abundance of cotton spider mites on these plants to that in conventional production areas at the Jiangbei farm, Hubei Province, China, over the period 26 May and 11 September 2011. Cotton fields (Ezamian No. 24F1) recently grown at low-lying land area supported significantly lower populations of cotton spider mites than conventional long established cotton fields. There were no significant differences in mite populations between cotton fields established in low-lying land area in the current year or 1 or 2 years earlier. The pest control advantage provided by pond areas was present whether or not acaricides were used. The total phenolic content of cotton leaves differed occasionally between treatments but did not seem to have affected the abundance of mites. The number of eggs, larva-nymph-adults, egg-larva-nymph-adults, the percentage of host plants colonized by cotton spider mites and the plant damage index were independent of the total phenolic content in leaves. The results are discussed in relation to integrated pest management and the mineral balance hypothesis.

A modified water quality index for intensive shrimp ponds of Litopenaeus vannamei

A modified water quality index (WQI) was used to evaluate the water quality of intensive culture ponds of Litopenaeus vannamei. Multivariate statistical technique, principal component analysis (PCA), was applied to interpret the large complex water quality data set generated over a span of 120 days (from 1st July to 28th October, 2008) with weekly monitoring of 11 variables in four different shrimp ponds. The PCA revealed three, four, three, and three latent factors that accounted for 82.843%, 81.6%, 81.629%, and 84.801% of the total variance in the water quality data sets from each of the four shrimp ponds, respectively. The varifactors indicated that the variables responsible for water quality deterioration were mainly related to organic matter group (COD and BOD5), natural condition group (pH and T), and nutrient group (TAN, Chl-a and DIP) in intensive shrimp ponds. A modified WQI based on the varifactors was applied to evaluate the water quality in shrimp culture ponds. The result revealed that the overall water quality in the shrimp ponds were mainly excellent during the early period and deteriorated in the mid to late period. The WQI evaluates water quality synthetically; furthermore, it reveals the outcome when some of the other variables deteriorate significantly. Thus, this study illustrates the necessity and usefulness of multivariate statistical techniques for interpreting large and complex data sets regarding water quality in shrimp culture pond. Furthermore, the evaluation results revealed that the modified WQI can be used as a tool for determining water quality.

뱀장어(Anguilla japonica) 적정 사육관리를 위한 양식기술 현황

This study was conducted to investigate the production, elver stocking, rearing facilities and rearing method of eel culture to determine aquaculture management conditions for optimal rearing of eel Anguilla japonica. The production of eel culture was evaluated by the proportion of eels from the main inland fin fish species production in Korea. Elver stocking was assessed by the elver stocking densities of pond and recirculation culture. Rearing facilities were investigated according to the rearing tank size proportion of the pond and recirculation culture. We selected sample farms by region and by size. We visited sample farms and recorded the number of elvers stock for pond area, size of tanks, feed and feed quantity, and the size and number of harvest eels. The production capacity of Jeollanam-do and Jeollabuk-do were 71.9% and 21.3% respectively. This production quantity represented 93.2% of the total Korean eel production quantity. In Jeollanam-do, there are 236 eel farms, 202 pond farms, and 34 recirculation aquaculture facilities. The elvers' first density data by each aquaculture method revealed that elvers' first density varied more in recirculation system farms, as compared to pond aquaculture. In intensive pond farms, the elvers' first density decreased as the size of farm increased. There was a correlation between the size of tank(x) and the facility of a water wheel for dissolved oxygen in pond culture systems(y=0.022x-0.494; <TEX>$R^2$</TEX>=0.860). Another strong correlation was found between the weight of eel(x) and eel density(y) in pond culture systems(y=283.5x-0.27; <TEX>$R^2$</TEX>=0.992). Finally, there was a strong correlation between the length of eel(x) and the weight of eel(y) in intensive pond culture(y=0.0005x-3.2783; <TEX>$R^2$</TEX>=0.9775). The final survival rate did not differ significantly among pond sizes and culture types.

Do stocking densities affect the gut microbiota of gibel carp Carassius auratus gibelio cultured in ponds?

The aim of the present study was to evaluate the intestinal microbial communities of gibel carp (Carassius auratus gibelio) cultivated in two beach ponds at different stocking densities. The two ponds were both ~3.33 hm 2 in acreage and ~1.5 m in depth. The stocking densities included one intensive with 2 fish m –3 while the other treated as semi-intensive with 1 fish m –3 . The gut microbiota (both allochthonous and autochthonous) were sampled after 135 days of feeding. Denaturing gradient gel electrophoresis (DGGE) of PCR-amplified 16S rRNA gene segments was used to evaluate the bacterial community. Actinobacteria, Cyanobacteria, Firmicutes, Fusobacteria, Proteobacteria and some unclassified_bacteria taxa were identified in gut samples and feed. Similar bacterial communities (C s=0.83) were observed with respect to the autochthonous and allochthonous gut microbiota of gibel carp cultured in the intensive culture pond. In contrast to these results, some difference (C s =0.61) was observed in the gut microbiota of fish reared in the semi-intensive culture pond. Our results indicated that the difference in the bacterial communities between allochthonous bacteria and gut associated bacteria of gibel carp was not constant and was modulated by the stocking density.

Oxygen Consumption of White Shrimp (Litopenaeus vannamei) and Model of Oxygen Management in Intensive Culture Pond

&lt;p&gt;This study was conducted to determine oxygen consumption level of white shrimp (&lt;em&gt;Litopenaeus vannamei&lt;/em&gt;) and the model of oxygen management in intensive culture pond. Shrimp in weight of 5 gram were maintained in 20 liter of water in density 6 tails/container. Water quality was measured every 2 hours for 6 hours. Other experiments were done using shrimp in weight of 8, 10, 12 and 15 gram per tail, in density 4 tails/container. The results of study showed that oxygen consumption levels of white shrimp was higher after feeding than before feeding. Oxygen consumption levels of smaller shrimp were higher than that of bigger shrimp. Regression model of oxygen consumption levels before and after feeding were linear. Correlation between oxygen consumption and shrimp weight reached 92.5%. &lt;/p&gt; &lt;p&gt;Keywords: white shrimp, &lt;em&gt;Litopenaeus vannamei&lt;/em&gt;, oxygen, respiration, intensive pond&lt;/p&gt; &lt;p&gt; &lt;/p&gt; &lt;p&gt;ABSTRAK&lt;/p&gt; &lt;p&gt;Penelitian ini dilakukan untuk mengetahui tingkat konsumsi oksigen udang vaname (&lt;em&gt;Litopenaeus vannamei&lt;/em&gt;) dan model pengelolaan oksigen pada tambak intensif. Udang dengan bobot sekitar 5 gram dimasukkan ke dalam wadah tertutup berukuran 20 liter dengan kepadatan 6 ekor/wadah. Kualitas air diukur setiap 2 jam selama 6 jam. Perlakuan tersebut juga dilakukan pada udang dengan kelompok berat 8, 10, 12 dan 15 gram, dengan kepadatan 4 ekor/wadah. Hasil penelitian menunjukkan bahwa tingkat konsumsi oksigen udang vaname sesudah makan relatif lebih tinggi daripada sebelumnya. Tingkat konsumsi oksigen udang ukuran kecil relatif lebih tinggi daripada yang berukuran lebih besar. Model persamaan regresi tingkat konsumsi oksigen pada udang yang tepat sebelum dan sesudah makan adalah linear. Korelasi antara konsumsi oksigen dengan bobot udang mencapai 92,5%. &lt;/p&gt; &lt;p&gt;Kata kunci: vaname, &lt;em&gt;Litopenaeus vannamei&lt;/em&gt;, oksigen, respirasi, tambak intensif&lt;/p&gt;