Indoor Aquaculture Research Articles

Disinfection effect of povidone-iodine in aquaculture water of swamp eel (Monopterus albus).

The swamp eel (Monopterus albus) is an important commercial farmed fish species in China. However, it is susceptible to Aeromonas hydrophila infections, resulting in high mortality and considerable economic loss. Povidone-iodine (PVP-I) is a widely used chemical disinfectant in aquaculture, which can decrease the occurrence of diseases and improve the survival. However, environmental organic matter could affect the bactericidal effectiveness of PVP-I, and the efficacy of PVP-I in aquaculture water is still unknown. In this paper, disinfection assays were conducted to evaluate the effectiveness of PVP-I against the A. hydrophila in different types of water. We found that the effective germicidal concentration of PVP-I in outdoor aquaculture water was 25 ppm for 12 h. In indoor aquaculture water with 105 CFU/mL bacteria, 10 ppm and 20 ppm of PVP-I could kill 99% and 100% of the bacteria, respectively. The minimal germicidal concentration of PVP-I in Luria-Bertani broth was 4,000 ppm. Available iodine content assay in LB solutions confirmed that the organic substance had negative impact on the effectiveness of PVP-I, which was consistent with the different efficacy of PVP-I in different water samples. Acute toxicity tests showed that the 24 h-LC50 of PVP-I to swamp eel was 173.82 ppm, which was much higher than the germicidal concentrations in outdoor and indoor aquaculture water, indicating its safety and effectivity to control the A. hydrophila. The results indicated PVP-I can be helpful for preventing the transmission of A. hydrophila in swamp eel aquaculture.

Assessing the effect of size-grading for rearing young-of-the-year white-clawed crayfishAustropotamobius pallipes

Crayfish growth rates can vary considerably among individuals from the same brood, and social dominance hierarchies in crustacean species occur frequently. These hierarchies can reduce growth and survival when rearing communal groups. Size-grading and single-sex culturing are the methods used to combat this. A 160-day experiment took place on 288 young-of-the-year captive-born Austropotamobius pallipes, within a closed-circuit, indoor aquaculture facility. Crayfish were reared in three treatments (a) equal numbers of large males + small females (LMSF); (b) equal numbers of small males + large females (SMLF); (c) individuals of the same size, equal sex ratio; plus two control groups of single-sex, same sized individuals. Female survival in the LMSF was significantly reduced (52.8%, SD = 20.7%), whereas overall survival in all other groups was high (83.1%, SD = 15.1%). Male growth (6.3 mm, SD = 0.6 mm) was greater than female growth (4.9 mm, SD = 0.9 mm) across all groups. Cheliped autotomy was significantly greater (8.8%) in males (26.7%, SD = 8.9%) than females (17.9%, SD = 2.7%). This study suggests that young-of-the-year juvenile male A. pallipes grow faster and are more aggressive than females. Large males will suppress and reduce survival in smaller females whereas small males, when housed with larger females, will still grow faster than the females. We suggest that it is sex and not size that is the main factor that causes dominance hierarchies and growth suppression within juvenile A. pallipes. Maintaining juvenile A. pallipes in single-sex groups is optimal to ensure high survival and growth rates.

Pathogenesis of mixed infection by Spironucleus sp. and Citrobacter freundii in freshwater angelfish Pterophyllum scalare

The present study was carried out to identify and describe the pathology of the freshwater angelfish Pterophyllum scalare during chronic mortality in an in-door aquaculture system. Scraping of the integument and gills and the collection of intestinal contents to search for external and internal parasites were performed. Kidneys were collected aseptically for the microbiological analysis and the isolates were subjected to antibiotics to test for susceptibility. Subsequently, necropsy for macroscopic assessment and collection of internal organs for histopathology were performed. The fish exhibited lethargy, lip tumor, hemorrhage and liver granuloma. No ectoparasites were diagnosed. Endoparasites of the genus Spironucleus were found in large numbers in the intestine of the affected fish. In the microbiological analysis, Citrobacter freundii was isolated from the kidney and identified by colony PCR. This bacterium showed susceptibility to three of the eight antibiotics evaluated: ciprofloxacin, cefoxitin and tetracycline. For the pathological analysis, liver and spleen granulomas were present. In the intestinal tissue, a large and unusual amount of mast cells and their free granules were described and discussed in detail. The present study showed that mast cells play an important role during the chronic infection of freshwater angelfish.

Pre-soaking of the feed pellets: a trick for successful feed utilization in juvenile green turtles (Chelonia mydas Linnaeus, 1758).

Pre-soaking of the feed pellets in water can improve feed utilization in juvenile green turtles (Chelonia mydas Linnaeus, 1758), but the pre-soaking has not previously been optimized. This study aimed to optimize the water amount used for pre-soaking the pellets. The experiments followed a completely randomized design with three replications of each dietary treatment group. Initially 10-day-old green turtles (20-22g body weight) were treated in an indoor aquaculture system for 3months. The dietary treatment pellets were pre-soaked with 0.3, 0.5 or 0.7 (v/w) relative amounts of water that are here termed soaking ratios. At the end of experiment, there were no significant differences in survival (96% on average) and growth (average body weight 75.34g and specific growth rate 2%/day, on average) of turtles in three dietary treatments (p>0.05). Feed utilization was the best in turtles fed with 0.7 pre-soaked ratio, as indicated by significant reductions (p<0.05) in the feeding rate (7.44% body weight/day) and the feed conversion ratio (1.12g feed/g gain). Digestion was also improved by the induction of faecal digestive enzymes as well as the faecal thermal properties. The rapid growth did not negatively affect the general haematological parameters of reared turtles. These findings indicate that the pre-soaking of feed pellets at the optimal soaking ratio (1:0.7 w/v of pellet to water) can contribute through improved feed utilization of green turtles.

Combined effect of photoperiod and self-feeder on the growth performance of striped knifejaw, Oplegnathus fasciatus

This two-factor experiment incorporating three photoperiods (12L:12D, 16L:8D and 24L:0D) and two feeding methods (manual and self-feeding) was carried out to determine their effect on the growth performance of striped knifejaw, Oplegnathus fasciatus. Thirty juveniles were stocked into each 300L tanks in triplicate for each treatment and fed a commercial diet for 10weeks. Two-way ANOVA revealed that both photoperiod and feeding method have significant effect on the final mean weight, weight gain (%) and feed efficiency (FE) (P<0.05); however, their interaction did not produce any significant effect (P>0.05). Although the growth parameters didn't have significant difference between manual and self-feeding in fish exposed to 12L:12D photoperiod (P>0.05), fish under other two photoperiods showed significant improvement under self-feeding system compared to manual feeding (P<0.05). Final mean body weights in fish under 16L:8D and 24L:0D were 119.7 and 124.0g at manual feeding; however, increased to 128.0 and 133.7g, respectively at self-feeding system. While two daily peaks of feed intake were observed in 12L:12D and 16L:8D photoperiods when self-feeders used, 24L:0D photoperiod showed only one morning peak. At the end, there was no significant difference in different stress indicators such as cortisol, glucose and total protein among the treatments (P>0.05). Finally, the results suggested that the extended (16L:8D) and continuous (24L:0D) photoperiods, and the provision of self-feeder could significantly improve the growth performance of striped knifejaw without changing the stress response. Statement of relevanceThis is the first report on the combined application of photoperiod manipulation and self-feeder on striped knifejaw, which revealed that the combination would help to improve the growth performance significantly. The indoor aquaculture industry, at least, will be benefited from the important insights achieved from this study to stimulate the growth performance of this commercially important species, which has great consumer demand in Japanese market.

Identification of Skeletal Deformities in Far Eastern Catfish, Silurus asotus under Indoor Aquaculture Condition.

For the 2 years of farming, at the indoor circulating aquaculture system, four kinds of skeletal deformities were found among 60 Far Eastern catfish, Silurus asotus. Deformities saw jawbone’s luxation, abnormality of upper lip and malocclusion. Spinal deformity was most fatal deformities with low weight and small length. Jawbone’s luxation had 1 maxilla and 2 mandibles. Abnormality of upper lip had just lip was back over. Malocclusion’s left maxilla and right maxilla were not balanced. This experiment was any deformities in this species through the deformity can grasp how it affects.

Effects of Sorting on Cannibalism in Catfish (Clarias gariepinus) Rose in Concrete Tanks in Maiduguri, North-Eastern Nigeria

This research study was carried out on the effects of cannibalism in catfish (Clarias gariepinus; commonly called “Tarwada” in Hausa language), rose in indoor aquaculture, at the hatchery complex, NIFFRI, Maiduguri. The experiments were designed into three treatments; ‘A’ no sorting (control), ‘B’ daily sorting and ‘C’ weekly sorting, performed after stocking with two replications. Randomly sourced, sampled brood stocks (2 males and 2 females). Standard method was used to induce breeding of Clarias gariepinus by using Ova-prim and fry were obtained. The Juveniles catfish were sorted, counted and stocked into tanks. Their average weight were taken (2.45kg) and density of 100 fish / m2 was tested in each treatment, water parameters, survival rate, growth performance, rates and effects of cannibalism in Clarias gariepinus were determined. Treatment A had the highest mean weight (11.45g ± 2.4), cannibalism rate (40%), with lowest survival rate (60%). Highest survival rate was observed in C (86%), while optimum growth performance was observed in B (4.2g, 5cm, and 8cm). Results revealed that cannibalism is high in treatment A, less in C (2%), same with shooters. High cannibalism in Clarias gariepinus juveniles has been established, this could be controlled by frequent sorting (daily). Further studies are to be conducted on the cost implication of controlling cannibalism in outdoor aquaculture.

Liposarcoma in clownfish, Amphiprion ocellaris Cuvier, produced in indoor aquaculture.

Clownfish, Amphiprion ocellaris Cuvier, produced and grown in an experimental indoor aquaculture facility, presented with lipomatous tumours. A total of 14 affected fish were examined. Based on the total number of fish at the aquaculture facility at the time of outbreak of this pathology, the scope of the incident is estimated to be 1 of 300 fish. The tumours were characterized by the presence of mature adipocytes of variable sizes, lipoblasts and by an invasive behaviour, which affected internal organs, muscle, central nervous system and, in one case, an eye. Detailed macroscopic and histopathological features are presented. The suggested diagnosis is that of a well-differentiated liposarcoma, a diagnosis so far never applied to fish. The limited outbreak of the neoplasm lasted a few months in 2011 and did not recur. Possible factors leading to this phenomenon, notably the metastasis, are discussed.

Bioaugmentation with a proprietary facultative bioculture in a two-phase anaerobic digestion process of cobia fish wastes from indoor aquaculture system

Bioaugmentation with a proprietary facultative bioculture in a two-phase anaerobic digestion process of cobia fish wastes from indoor aquaculture system

Effects of light spectrum on growth and stress response of rainbow trout Oncorhynchus mykiss reared under recirculating system conditions

Fish growth and physiology may be affected by light spectrum, which can be easily manipulated in indoor aquaculture facilities, and especially recirculating water systems, with little cost. Since data related to light spectrum and widely reared fish are still few, the present study aimed to investigate the effects of coloured light on growth performance and stress response to confinement of rainbow trout Oncorhynchus mykiss. Fish (145.3±1.5g) were reared under white (full spectrum, fluorescent lamps), red (605nm) and blue (480nm) light (lamps covered with appropriate filters) for 111 days under recirculating water systems (150lx, 12L–12D). At the end of the experimental period and for each light treatment, fish were either subjected for 1h to confinement stress or remained undisturbed (control groups). Total length of the fish reared under red light was greater than that of the other regimes, whereas other growth parameters showed a similar trend but were not significantly different from one another. Carcass proximate composition was not affected by light spectrum. Fish exposed to confinement showed typical primary (high cortisol) and secondary (high glucose and haematocrit, liver lipid mobilization, osmotic and ionic disturbances, blood acidosis, etc.) stress responses. Nevertheless, in fish reared under blue light, stress-induced cortisol increase was lower and liver lipids mobilization was absent compared with white light (significant interaction). Present results indicate that if stressors are kept to a minimum then red light could be suggested for the intensive rearing of rainbow trout.

Comparing indoor wastewater-fed aquaculture with two conventional wastewater treatment plants using adopted sustainable process indices

Highly aggregating 'Sustainable Process Indices' (SPI) were calculated for an indoor wastewater-fed aquaculture and two conventional wastewater treatment plants to make a direct comparison between the three facilities possible. The goal was to find out which technology would be better suited for use in a sustainable economy. The SPI provides a type of 'ecological footprint' for the three facilities on the basis that, in a sustainable economy, solar energy would be our main energy source and that surface area would become the limiting factor for economic development, because the transformation of solar energy into other forms of energy, products or services requires area. SPI calculations consider the area necessary for the sustainable dissipation of byproducts and wastes of a process into the environment. The SPI thus uses area as its basic unit for comparisons between different technologies, products or services. Energy consumption, as well as treatment performance (both the quality and quantity of treated effluent), and multi-functionality of facilities were key variables in determining how much area a wastwater treatment plant would need to be embedded sustainably into the environment. The calculated SPIs reveal that the wastewater-fed aquaculture requires the least area to be embedded sustainably into the environment, therefore, it would be better suited for use in a sustainable economy compared to the two conventional wastewater treatment plants.

The Otelfingen Aquaculture Project

ABSTRACT A wastewater-fed, partly indoor aquaculture plant (36 basins, 360 m2 and 420 m3 in total) was designed in Otelfingen/Zurich, Switzerland. It was charged with the effluent from a methanization plant processing organic household waste and started operation in spring 1998. The aim of the successive arrangement of the different modules and steps was to efficiently recycle water-borne nutrients in the form of aquatic biomass products, such as floating (ornamental) macrophytes, fish, zoo- and phytoplankton, suitable for selling on the Swiss market. Besides treating the effluent (total organic carbon [TOC], total nitrogen, nitrate [NO3-N], ammonium [NH4-N], and total phosphorus concentrations being 670 g/m3, 255 g/m3, 150 g/m3, 95 g/m3, and 52 g/m3, respectively) according to Swiss law requirements, the research focused on the search for suitable aquatic organisms and their testing at different environmental conditions. During the 16-week experimental period, a total of 2,150kg fresh weight (FW) ofbiomass (97% as floatingmacrophytes) was harvested. This way, 176 g/week nitrogen and 47 g/week phosphorus wereeliminated by assimilation, corresponding to 25-35% of the system's inflow. Due to relatively high evapotranspiration rates (on average 35.4 mm/week) and for water reconditioning purpose in the fish stocking basins, fresh water was added. Nevertheless, the system's final effluent was very low (21% of total inflow plus rainfall) and was carrying only about 2% and 0.5% of the input loads of nitrogen and phosphorus, respectively. Hence, the elimination rate was significantly above the average performance of a conventional system normally applied in Middle Europe, althoughthe concentration values of most parameters in the outflow were comparable. Macrophyte production (and thus nutrient assimilation) was close to theoretical maxima in basins with high nutrient levels. Both plankton and fish growth were, at their best, only moderately satisfying. The semi-continual planktonic microalgae culture, and therefore also zooplankton culture, could be improved if the light absorbing humic substances were removed in a pre-treatment. Under given conditions (i.e., temperate climate) fish would rather play an accompanying role in the ecological production process. A wastewater-fed aquaculture facility resembles an integrated production plant rather than a wastewater disposal site. In addition to that, it has potential to prove advantageous over the highly developed conventional wastewater treatment plants established in Middle Europe. Further research in this field is essential and also recommended, considering political programs like Agenda 21, which contemplate the need for sustainable strategies for handling resources.

Overwintering of the Inland Silverside in Southern Illinois

Abstract The objectives of this study were to determine if the inland silverside Menidia beryllina could survive over winter in southern Illinois, north of its native range, and if power-plant cooling reservoirs or aquaculture systems could be used to maintain brood stocks of the species during especially cold winters. Inland silversides survived several consecutive winters in unheated Illinois reservoirs, but not a relatively severe winter. They did survive the severe winter in a cooling reservoir. They were successfully maintained over winter in indoor intensive aquaculture systems, at temperatures above 15°C, when they were fed a prepared diet. Thus, cooling reservoirs and indoor aquaculture facilities are potential sources of inland silversides for stocking unheated reservoirs in the spring.