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1.
We evaluated the suitability of fish waste diet (FWD) for culturing the minute rotifer Proales similis through the observation of their population growth and particle size selective feeding. A total of five treatments either with Nannochloropsis oculata or FWD (0.75 and 0.50 g/L) or the combination of N. oculata and FWD were set up in triplicates. P. similis were cultured in diluted natural seawater (8 g/L salinity) and 26 ± 1°C with the diet treatments being applied randomly. We daily monitored the rotifer density, the number of bacteria and the water quality in all the cultures. The population density of P. similis increased exponentially in all treatments, while the mean growth in FWD 0.75 g/L was significantly higher (p < .05) than that in the control. Addition of N. oculata to FWD resulted to lowered P. similis population growth. Bacterial colony count was high in FWD and introduction of P. similis to the diet decreased their density. The estimated bacteria ingestion rates were generally in the range of 6.03 × 102–1.24 × 104 bacteria/rotifer/hr and there was a positive linear relationship between bacterivory and rotifer population growth. We also observed a shift in the particle size distribution with a reduction in the frequency and concentration of small‐sized particles (<2.5 μm) at day 6. These results accentuate the potential of fish‐processing waste as diet for culturing P. similis which feeds on bacteria and small particles (≤2.5 μm) that are by‐products of degradation of this diet.  相似文献   

2.
ABSTRACT

The Japanese flounder, Paralichthys olivaceus, is one of the most common finfish cultured in Japan and Korea. Despite the relatively high production of fingerlings, some problems remain, mainly related to the larval feeding and cost of maintaining microalgae and rotifers. In order to determine the effects of different diets on the Japanese flounder larval growth and survival, a series of experiments was carried out related to the size and nutritional value of different live feeds. The larvae culture conditions were at 10 or 20 larvae/L in 50 to 2,000 L tanks, with aeration and with or without “green water,” and a temperature range of 18.5 to 22.5°C. The live foods used were microalgae (Chlorella ellipsoidea and Nannochloris oculata), baker's yeast, experimental n-yeasts, oyster trochophore larvae, three strains of rotifer Brachionus plicatilis (L-type, S-type and U-type) and Artemia nauplii. Variations were detected in size, dry weight, and chemical composition of the three strains of rotifers used. The maximum number of rotifers ingested by flounder larvae increased steadily from 7 individuals, at first feeding (3.13 mm), to 42 individuals at 5.25 mm of total length (6 days after first feeding). There was a relationship between larval total length and size of the rotifers ingested. The effect of rotifer size on larval growth and survival appeared to be limited to the first two days of feeding. Of the diets tested in the growth and survival of larval flounder during 14 days after hatching, rotifers fed on C. ellipsoidea and raised in green-water gave the best results. Rotifers cultured on enriched N. oculata and n-yeasts did not support larval growth and caused higher mortalities. The n-yeasts used as rotifer enrichment appeared to satisfy, partially, the nutritional requirement of 7-day-old flounder larvae, as did n-yeast squid wintering oil the requirements of 14-day-old larvae. From 7-9-days after hatching and throughout the second 14-day period, rotifers and Artemia cultured on N. oculata improved the survival of flounder compared with those fed on rotifers cultured on C. ellipsoidea. Moreover, the larval growth did not vary significantly between both microalgae-rotifer feedings. No clear relation was found between total protein, lipid, amino acids and fatty acids of live feeds with the growth and survival of flounder larvae, although the total lipid was higher in C. ellipsoidea than in N. oculata. The Artemia nauplii San Francisco strain appeared to be more suitable for the growth and survival of flounder larvae, than the Utah strain. The nutritional value of Artemia nauplii (Utah strain) for flounder larvae remained unchanged despite the use of either microalgae as nauplii enrichment.  相似文献   

3.
Rotifer growth performance and microbial community changes associated with rotifer cultures were monitored while different feed types (Nannochloropsis oculata paste and the commercial yeast based feed CS-3000), different regimes (daily changes, changes per batch and no changes) and mixtures of three probionts (Phenylobacterium sp.; Gluconobacter sp. and Paracoccus denitrificans) were provided. It was shown that the dominant bacterial species in the cultures receiving either N. oculata or CS-3000 were different. However, in cultures receiving both feeds (either switching between feeds on a daily basis or on a batch basis), a high similarity in microbial community fingerprint was found. The presence of probionts was detected by the end of four batch culture cycles in spite of strong shifts of the bacterial community. By group discriminant analysis, it was found that Phenylobacterium sp. and Paracoccus sp. contributed positively to the CS-3000-fed group, while Gluconobacter sp. contributed positively to the N. oculata-fed group, although they did not appear as very dominant species.  相似文献   

4.

In aquatic seeding production, the feeding regime of fish larvae consists of rotifers to Artemia, while there is a lack of intermediate-sized feed in the range of 350–600 µm. To solve this problem, in our previous study, the euryhaline rotifer Brachionus plicatilis (L-type, Notojima strain) were irradiated with carbon heavy-ion-beams, and large-sized rotifer mutant lines (>?350 µm lorica length) were established. This study aimed to enhance the mutated morphometric characteristics and reproductivity through the combined use of three microalgal species (Nannochloropsis oculata, Tetraselmis tetrathele, and Chlorella vulgaris), and two hormones [juvenile hormone (JH) and gamma-aminobutyric acid (GABA)]. The combination of T. tetrathele and JH was effective in enhancing the mutated phenotype, and the largest lorica length of 344–425 µm was observed with no significant differences in population growth between the wild-type and mutant strains. The combination of N. oculata and GABA enhanced the population growth of the mutant line, and its growth rate was 2.4 times higher than that of the control group (without GABA). This study indicates that the morphometric characteristics and reproductivity of rotifer mutant lines could be regulated by feed and hormone supplementation. These findings can promote the efficient use of mutant rotifer lines in aquaculture facilities.

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5.
Polychaetes are commercially exploited as fishing bait and supplemental diet to crustacean and finfish broodstock. However, scarcity of supply and biosecurity issues limits its use. Polychaete aquaculture has become the best alternative to wild resources. In this study, two different culture techniques (1‐sediment tank throughout the culture period and 2‐nursery tank with bioflocs for 30 days; thereafter, juveniles were transferred to sediment tank until harvest) using two diets [bioflocs (BF) and feed mill sweepings (FS)] were tested to determine the survival, growth and biomass of polychaete Marphysa iloiloensis (Glasby et al., Zootaxa, 2019, 4674) in the grow‐out. The 180‐day trial was conducted in 16 tanks (0.20 m2) stocked with 5,066 ± 575 M. iloiloensis trochophore larvae/tank which were assigned randomly into four culture treatments with four replicates each. The treatments were labelled as: (a) BFS – fed BF in sediment tank for 180 days; (b) BF + BFS – fed BF in nursery tank for 30 days, juveniles were transferred in sediment tank and fed BF for another 150 days; (c) FSS – fed FS in sediment tank for 180 days; and (d) BF + FSS – fed BF in nursery tank for 30 days, juveniles are transferred in sediment tank and fed FS for another 150 days. Results showed that polychaetes in BF + FSS had significantly higher survival than BFS. Polychaetes in both BF + FSS and FSS had significantly higher body weight than BF + BFS and BFS, while biomass in BF + FSS (175.73 ± 42.25 g/tank) was significantly higher compared to other treatments (p < .05). Polychaetes fed with FS had 61%–64% protein and 12%–13% fat, while those fed with BF exclusively had 66%–70% protein and 3.50%–4.50% fat. The findings indicate that FS whether or not BF is included in the diet can improve both survival and growth of polychaetes but significantly higher biomass can be achieved with the combination of BF and FS. Additionally, polychaetes in BF + FSS contained 64% protein and 13% fat. Therefore, BF can be used as an alternative diet to FS in the early life stages of M. iloiloensis and nursery rearing using BF is imperative to increase its biomass in the grow‐out production.  相似文献   

6.
褶皱臂尾轮虫培养若干问题探讨   总被引：2，自引：0，他引：2  
本文就轮虫生产性培养过程中接种密度、投饵量、水质、轮虫生长和营养强化等方面的问题进行探讨,认为:接种密度在用单胞藻培养时应为10～30个/ml,用酵母培养时20～50个/ml;酵母投喂量0 3～0 35g/百万,投喂量不宜过大;酵母投喂的轮虫使用前2d最好用单细胞藻类强化。  相似文献   

7.
An experiment was carried out on turbot larvae fed three different rotifer enrichment diets: Dry Selco, Protein Selco and ICES low-HUFA (an enrichment emulsion containing low amounts of highly unsaturated fatty acids—HUFA). Seven tanks were set up for each diet. After the rotifer stage, approximately seven days after hatching, the larvae were fed newly-hatched Artemia salina nauplii (AT-1; Brazil strain). From day 10, enriched Great Salt Lake Artemia nauplii were introduced. Each set of seven tanks was further subdivided and the larvae fed Arternia nauplii enriched with one of four enrichment diets: Dry Selco, Protein Selco, ICES low-HUFA or Super Selco. The rotifer enrichments had no significant effect on larval growth and survival. The nutritional value of the Artemia stage (day 13 to 26) was more important for the overall larval survival.  相似文献   

8.
Pigfish (Orthopristis chrysoptera Linnaeus) are a commonly used baitfish in the southeastern United States. Aquaculture methods for broodfish spawning and juvenile grow‐out have been developed but there is still a paucity of information regarding larval culture methods. Five, short duration (10 days) experiments were conducted to determine effective strategies to yield high larval survival and growth during early development. Experiment one examined the rotifer enrichments Ori‐Green, DHA Protein Selco, and AlgaMac 3050 as well as a non‐enriched control along with corresponding fatty acid levels in the enriched rotifers and pigfish larvae. Experiment two evaluated three, once daily feeding frequencies of either 5, 10 or 20 rotifers mL?1. Experiment three compared feeding 20 rotifers mL?1 once daily to feeding 5 rotifers mL?1 twice daily. Experiment four examined four different larval stocking densities: 50, 75, 100, or 125 larvae L?1. Experiment five examined green water strategies using either live Tahitian strain Isochrysis galbana (Parke) or Nannochloropsis oculata (Hibberd) paste at either 250 000 or 500 000 cells mL?1 as well as a clear water control. Results indicated rotifer enrichment with DHA Protein Selco and green water application using live T‐ISO at 500 000 cells mL?1 had the highest survival of pigfish during early stages of larval culture. A once daily rotifer feeding regime of 20 rotifers mL?1 and stocking density of 50 larvae L?1 also improved survival. These results provide producers with methods to improve efficiency for pigfish larval culture and provide researchers with new foundational data, such as potential fatty acid requirements.  相似文献   

9.
The occurrence of morphologically immature megalopae, which retain zoeal features such as dorsal spines and furcae of telson, is closely correlated with larval mass mortality during seed production of the swimming crab Portunus trituberculatus in Japanese hatcheries. To determine the cause of immature megalopal morphology, zoeae were reared with various supplementary schedules and density of diets (rotifer, Artemia and phytoplanktons including Chlorella vulgaris and Nannochloropsis oculata). In addition, to assess the relationship between immature morphology and endocrine control, the effect of causative dietary factor was compared with the effect of eyestalk ablation at various timing during zoeal development. Megalopal immature morphology was more distinct in Chlorella‐supplemented groups than in Nannochloropsis‐supplemented groups. High density Chlorella supplementation was associated with the highest incidence of immaturity and resulted in larval mass mortality. The premoult of the third zoeal stage was identified as a critical period at which Chlorella supplementation led to the highest incidence of immaturity. This critical period coincided with the critical period at which larval metamorphosis was regulated by the eyestalk neurosecretory system. Our results suggested that the occurrence of immature megalopal morphology under culture conditions is most likely caused by phytoplankton (especially, Chlorella) supplementation, which disrupts the endocrine regulation. On the basis of our results, we successfully prevented the occurrence of immature megalopal morphology in 500 L tanks by excluding the influence of phytoplankton before the critical period (i.e. discontinuing phytoplankton supplementation and supplying rotifer cultured with non‐phytoplankton materials).  相似文献   

10.
This study focused on methods to reduce bacterial loads in the larval culture tanks of California yellowtail (Seriola lalandi). We conducted two trials to evaluate methods to minimize bacterial loads in the larval rearing water. The first trial examined the use of bentonite clay as a turbidity agent to replace algae in a green water‐type environment. This trial consisted of three treatments: (1) clay with continuous feeding (CCO), (2) clay with batch feedings (CBA) and (3) algae paste with batch feedings (ALG). The results showed that both clay treatments had significantly fewer Vibrio colonies in the water column (CBA – 180 ± 78; CCO – 377 ± 120 CFU mL?1) than the ALG treatment (5692 ± 2396 CFU mL?1) after 14 days of culture. Survival was significantly higher in the CCO treatment (14.1 ± 2.6%) than either the CBA (2.3 ± 0.5%) or ALG treatments (2.8 ± 1.5%). The second trial attempted to limit bacterial loading in the larval culture tank by passively transferring the larvae into an adjacent, clean tank at 1, 5 and 9 days post hatch during the first 2 weeks of culture. The results from this trial showed that after 12 days of culture, water in the transfertank had fewer Vibrio colonies (1025 ± 541 CFU mL?1) than the water in the control tanks (1962 ± 1415 CFU mL?1). Also, survival was significantly higher among larvae that were transferred (43.9 ± 13.5%) than in the control tanks (23.1 ± 6.3%).  相似文献   

11.
A 56‐day experiment was conducted to investigate the effect of no carbohydrate addition applied to control water quality in water‐reusing biofloc systems for tilapia (GIFT Oreochromis niloticus) cultivation. Reusing water‐contained flocs was initially inoculated into six 300 L indoor tanks. Thirty fish (average individual weight 99.62 ± 7.34 g) were stocked in each tank. Glucose was extra added into three tanks (GLU‐tanks) according to biofloc technology, while other tanks were no carbohydrate added (NCA‐tanks). Concentrations of total ammonia nitrogen in GLU‐tanks and NCA‐tanks were fairly consistent and below 4.74 ± 0.35 mg/L. Nitrite concentrations in NCA‐tanks were significantly lower than GLU‐tanks, which were below 0.59 ± 0.10 mg/L during the later culture period. NCA‐tanks achieved a low relative abundance of denitrifiers and high concentrations of nitrate. Soluble reactive phosphorous in NCA‐tanks was consistently increased, which was decreased to a low level in GLU‐tanks. However, growth parameters in NCA‐tanks were similar to GLU‐tanks (p > .05) and reach a high finial density of 24.32 ± 1.04 kg/m3. Cetobacterium sp. was the first‐dominant bacterial genus in all tanks, which was a commonly indigenous bacterium in the intestinal tract of freshwater fish. The results demonstrate the feasibility of no carbohydrate addition in water‐reusing biofloc systems for tilapia.  相似文献   

12.
The changes in the biochemical compositions and enzymatic activities of rotifer (Brachionus plicatilis) and Artemia, enriched and stored at 4°C temperature, were determined. The total starvation period was 16 h and samples were taken at the end of the 8th and 16th hours. In present study, the rotifer and nauplii catabolized a large proportion of the protein during the enrichment period. Lipid contents of both live preys increased during the enrichment period and decreased in nauplii and metanauplii throughout the starvation period but lipid content of the rotifer remained relatively constant during the starvation period. The changes observed in the amino acid compositions of Artemia and the rotifer were statistically significant (P < 0.05). The conspicuous decline the essential amino acid (EAA) and nonessential amino acid (NEAA) content of the rotifer was observed during the enrichment period. However, the essential amino acid (EAA) and nonessential amino acid (NEAA) contents of Artemia nauplii increased during the enrichment period. The unenriched and enriched rotifers contained more monounsaturated fatty acid (MUFAs) than polyunsaturated fatty acid (PUFAs) and saturated fatty acids (SFA). However, Artemia contained more PUFAs than MUFAs and SFA during the experimental period. A sharp increase in the amounts of docosahexaenoic acid (DHA) during the enrichment of the rotifer and Artemia nauplii was observed. However, the amount of DHA throughout the starvation period decreased in Artemia metanauplii but not in Artemia nauplii. Significant differences in tryptic, leucine aminopeptidase N (LAP), and alkaline phosphatase (AP) enzyme activities of Artemia and rotifer were observed during the enrichment and starvation period (P < 0.05). The digestive enzymes derived from live food to fish larvae provided the highest contribution at the end of the enrichment period. In conclusion, the results of the study provide important contributions to determine the most suitable live food offering time for marine fish larvae. Rotifer should be offered to fish larvae at the end of the enrichment period, Artemia nauplii just after hatching and before being stored at 4°C, and Artemia metanauplii at the end of the enrichment and throughout the starvation period.  相似文献   

13.
ABSTRACT

Aquaculture of Japanese flounder, Paralichthys olivaceus, started in the middle 1970s in Japan, and the commercial production became extensive in the early 1980s, with development of seedling production and farming techniques. Annual production in 1996 was 7,692 metric tons, ranked fourth among marine cultured finfish after yellow-tail, red sea bream, and coho salmon. Marine finfish aquaculture in Japan is mostly conducted in floating net cages; however, land-based culture tanks are the prevalent culture system for Japanese flounder. The tanks are circular, square, or octagonal and constructed of various materials: concrete, plastic and/or a combination of the two. Culture tanks are generally inside or covered with shade cloths. Sand-filtered sea water is continually supplied to each tank, with 12 to 24 exchanges daily. Three-gram fish are stocked in the culture tank and raised for 1 to 2 years until they grow to 500-1,000 g. Survival ranges from 60 to 80%. Sardines and sand lance, fresh or frozen, are mainly fed; however, use of moist or dry pellets are increasing recently because of the decline in catch of these fishes. Fingerlings are obtained from commercial hatcheries virtually year-round. The fish utilize almost no dietary carbohydrate as an energy source, and an increase of lipid in the diet did not improve the growth, although it did seem to produce a slight increase in protein efficiency ratio. Therefore, diet for Japanese flounder should contain high percentages of protein (fish meal). Finding alternative protein sources for fish meal in the diet has been researched, and the potential of defatted soybean, corn gluten, feather, meat, and meat bone meals have been examined. The optimum temperature for the growth is 20-25°C. Salinity range of 4.4 to 34.0 ppt did not affect the growth of Japanese flounder at 8 g initial body weight.  相似文献   

14.
In mass culture of Pacific bluefin tuna Thunnus orientalis, a marked growth variation is observed after they start feeding at 6–7 mm in body length (BL) on yolk‐sac larvae of other species, and the growth variation in tuna larvae is a factor leading to the prevalence of cannibalism. To examine the relationship between prey utilization and growth variation, nitrogen stable isotope ratios (δ15N) of individual larvae were analysed. A prey switch experiment was conducted under two different feeding regimes: a group fed rotifers (rotifer fed group), and a group fed yolk‐sac larvae of spangled emperor, Lethrinus nebulosus (fish fed group) from 15 days after hatching (6.87 mm BL). The fish fed group showed significantly higher growth than the rotifer fed group. Changes in the δ15N of the fish fed group were expressed as an exponential model and showed different patterns from those of the rotifer fed group. The δ15N of fast‐growing tuna larvae collected in an actual mass culture tank after the feeding of yolk‐sac larvae was significantly higher than those of the slow‐growing larvae, indicating that slow glowing larvae depended largely on rotifers rather than the yolk‐sac larvae.  相似文献   

15.
Unexpected growth suppression is common in rotifer mass culturing, and bacteria present in culture tanks are believed to be one of the main causes. We used a polymerase chain reaction (PCR)-amplified 16S ribosomal RNA (rRNA) gene finger-printing method to determine the bacterial community composition in water and that in association with rotifers present in tanks when rotifer growth was suppressed. Bacterial 16S rRNA genes representing Nautella sp. and Marinomonas sp. were identified as dominant in control tanks with good rotifer growth. In contrast, the bacterial community composition was more diverse at start-up in tanks where rotifer growth was suppressed. The community composition changed during rotifer cultivation, and bacterial sequences representative of Ruegeria sp. and Hyphomonas sp. were dominant when rotifer growth recovered. These findings indicate that the bacterial community composition varied according to the rotifer growth conditions and suggest that the initial microbial flora present in the culture water may cause rotifer growth suppression.  相似文献   

16.
Abstract A dense nitrifying culture (ABIL) has been examined for its capacity to stimulate rotifer growth in a labscale culture system. The nitrifiers were applied in different ways. When ABIL was added directly to rotifer batch cultures, it gave rise to significantly higher population densities (factor 1.5–2.5 higher, P  < 0.05). The nitrifiers were subsequently examined for their capacity to enhance the start-up of bioreactors, commonly installed in aquaculture rearing tanks. Of the different carrier materials used in these bioreactors, i.e. CaCO3, gravel and a PVC matrix (Bionet), CaCO3 gave by far the best results. In a third set of experiments, effectively nitrifying bioreactor systems were connected to rotifer culture tanks and operated over a period of up to 10 days. It was demonstrated that the ABIL inoculated CaCO3-based bioreactor allowed excellent rotifer growth reaching rotifer densities up to 5500 rotifers per mL. Moreover, a new system in which the ABIL culture was recirculated through hollow fibres was developed and demonstrated to be effective for supporting rotifer growth up to 3500 rotifers per mL. Overall, the use of the dense nitrifying culture either in seed batch cultures, conventional bioreactors or hollow fibre bioreactor systems in support of rotifer cultures was demonstrated to be effective for improving the water quality and the rotifer growth.  相似文献   

17.
The effect of initial channel catfish (Ictalurus punctatus, Rafinesque, 1818) fingerling biomass (1.4, 1.8, or 2.3 kg m?3) on phytoplankton communities, common off‐flavours and stocker catfish production parameters was evaluated in biofloc technology production tanks. Stocker catfish size (145.5–172.6 g fish?1) at harvest did not differ among treatments, but net yield increased linearly as initial biomass increased (R2 = 0.633). Mean total feed consumption increased linearly with initial catfish biomass (R2 = 0.656) and ranged from 10.7 to 15.8 kg m?3. Total suspended solids (TSS) in all treatments increased linearly with total feed addition, and high TSS appeared to impact negatively daily feed consumption. Initial phytoplankton populations were dominated by small colonial green algae and diatoms, and later transitioned to populations dominated by a small, filamentous cyanobacteria and diatoms. Low, variable concentrations of 2‐methylisoborneol and geosmin were present in biofloc tank water during most of the study and two tanks yielded catfish with 2‐methylisoborneol or geosmin concentrations that might be classified as off‐flavour. One isolate of actinomycete was isolated sporadically from some biofloc tanks, but its abundance was not correlated with 2‐methylisoborneol concentration in tank waters. The microbial sources of 2‐methylisoborneol and geosmin in biofloc tanks remain unidentified.  相似文献   

18.
In this paper the author develops a dynamic simulation model and uses it to analyze the economics of pond cultivation of Japanese abalone in Chile. The analysis is done in continuous time by defining discounted free cash flows on the basis of explicit relationships between several biological, technical, and economic functions. In a culture batch starting with 600,000 seedlings when abalone has an average length of 19 mm, and the optimal harvest time is day 763 from stocking, harvesting at that optimum time implies a per-unit cost of production of approximately CH$320 per abalone. This includes consumption of 443,644 kg algae per generation, providing approximately 1.46 kg algae per abalone, and an electric energy requirement of about 433,200 kWh. Even at the optimum time of harvest, the profits are rather low. This explains why Japanese abalone culture has been substantially reduced in the north of Chile. To obtain abalones with an average weight of 100 g, harvest should be on day 1,460, when operating net present value is negative. In addition, the effect of changes of some key parameters on the results is analyzed via a sensitivity analysis.  相似文献   

19.
There is a great interest in establishing mussel farming in Dakhla bay. Selection of suitable sites is more meaningful only if a reliable culture method at proposed site is included. We compared two different culture methods, longline and pole, over 1 year (June 2016 to June 2017). Growth indicators for Perna perna (size and weight growth rates, frequency distributions and estimating growth curves) were analysed from seeding to harvest. The results highlighted the influence of culture method on growth rates of mussels (p < 0.05). At harvest, individuals reared on longline presented higher growth rates and consequently reached greater weight and length values than those reared on pole. Mussels reared at the longline grew 73.2 mm and gained 53.5 g WL (live weight) and 3.3 g Wt (tissue dry weight) after 12 months of cultivation. However, mussels cultured at the pole gained only 52.3 mm, 26.7 g WL and 1.6 g Wt. Aerial exposure of mussels at low tides could explain this reduced performance on pole compared with longline. Size frequency distributions at harvest fitted bimodal distribution in both cultures due to an asymmetric competition among individuals. Effect of density started in both treatments after 7 months of culture when mussels reached 60–70 mm, implying an increment of their food and space requirements. To prevent overcrowding, the initial density should have been reduced through “thinning‐out.” The longline method exhibited high‐performance growth and hence is highly recommended for cultivation of P. perna in Dakhla bay.  相似文献   

20.
The present and commonly used batch culture system (BCS) as adopted by many small‐scale tropical hatcheries is beset by poor rotifer production and sudden crashes. This study aimed to produce nutritive rotifers and evaluate their performance based on the BCS by using phototrophic bacteria (PB) that can be easily and cheaply cultured from palm oil mill effluent (POME), an agro‐industrial byproduct usually discarded as waste. Brachionus rotundiformis given a sole diet of POME‐grown PB (Rhodovulum sulfidophilum) grew as well as on the commercially produced microalgae, Nannochloropsis. Production, growth rate and fecundity of rotifers fed condensed bacterial cells (bPB) and culture broth of bacteria grown in POME (cPB) were evaluated. The best performance in terms of the stated parameters was obtained for rotifers fed 200 mL of cPB in 3 L of culture water; this media sustained a mean rotifer density of 600–900 individuals mL?1 after 3–6 days of culture. The biochemical composition of rotifers fed PB was comparable to those fed microalgae, except that the former contained more polyunsaturated fatty acids.  相似文献   

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