Finfish Culture Research Articles

Aquaculture and Diseases with Emphasis on Finfish Culture

Aquaculture and Diseases with Emphasis on Finfish Culture

Tetracycline resistance potential of heterotrophic bacteria isolated from freshwater fin-fish aquaculture system

This study investigated the tetracycline resistance potential of heterotrophic bacteria isolated from twenty-four freshwater fin-fish culture ponds in Andhra Pradesh, India. A total of 261 tetracycline resistant bacteria (tetR) were recovered from pond water, pond sediment, fish gills, fish intestine, and fish feed. Bacteria with high tetracycline resistance (tetHR) (n=30) that were resistant to tetracycline concentrations above 128 μg mL-1 were predominantly Lactococcus garvieae followed by Enterobacter spp., Lactococcus lactis, Enterobacter hormaechei, Staphylococcus arlettae, Streptococcus lutetiensis, Staphylococcus spp., Brevundimonas faecalis, Exiguobacterium profundum, Lysinibacillus spp., Stutzerimonas stutzeri, Enterobacter cloacae, and Lactococcus taiwanensis. Resistance to 1024μg mL-1 of tetracycline was observed in L. garvieae, S. arlettae, Enterobacter spp., B. faecalis. Tet(A) (67%) was the predominant resistance gene in tetHR followed by tet(L), tet(S), tet(K), and tet(M). At similar concentrations of exposure, tetracycline procured at the farm level (69.5% potency) exhibited lower inhibition against tetHR bacteria compared to pure tetracycline (99% potency). The tetHR bacteria showed higher cross-resistance to furazolidone (100%) followed by co-trimoxazole (47.5%) and enrofloxacin (11%). The maximum threshold of tetracycline resistance at 1024μg mL-1 was observed in S. arlettae, Enterobacter spp., B. faecalis, and L. garvieae and tet(A) was the major determinant found in this study.

Anatomy and histological evaluation of the reproductive system of marine calanoid copepod Centropages furcatus from a mass culture perspective

Marine finfish culture is a priority area for future human food security. Although many marine finfish species have been domesticated and successful breeding and spawning in captive conditions are achieved, the larval rearing from hatchling to fingerling stage to the desired level is yet to be achieved. One of the essential impediment factors in this process is the availability of suitable live feed for the finfish larvae. The traditional live feeds (Artemia nauplii and rotifers) must be more adequate in size spectrum and nutritive value to many marine finfish larvae. In nature, copepod nauplii, copepodite stages, and adults constitute the preferred food of marine finfish larvae. Copepod size spectrum, nutritive value and swimming movements make them ideal live prey items for fish larvae. Nevertheless, the high-density culture of copepods is challenging due to their sexual reproduction and high species-specific variability. Further, adequate knowledge of the candidate species' food and feeding habits, reproductive biology, and life cycle strategies should exist. With this objective present study describes the female and male reproductive system, oogenesis and spermatogenesis, egg production, and reproductive potential of a candidate calanoid copepod species, Centropages furcatus. This basic information will help develop mass culture protocol for this species.

Marine Finfish Aquaculture Planning Using MCDM and Numerical Modelling Tools to Aide Industry Expansion along the North Borneo West Coast

Site selection is the foundation of sustainable finfish culture, and in the tropics, there are vast offshore areas where this is needed. This study is the first to identify areas for marine finfish culture along the North Borneo West Coast using outputs from hydrodynamic modeling coupled with GIS and Multiple-Criteria Decision Making Analysis. Site selection criteria included: water depth, current speed, significant wave height, sensitive habitats, reported fishing grounds, government-based exclusion zones, oil & gas consents, and navigation routes. Of an initial 2.55 million ha, 1.05 million ha was eliminated from consideration based on physical characteristics alone. Of the 1.50 million ha identified to satisfy physical and hydrodynamic criteria for surface-oriented farms, a further 0.06 million ha was eliminated due to sensitive habitat and government exclusion zones. The remaining 1.44 million ha was found suitable for surface pen farming and 0.61 million ha for submerged pen farming. Much of this potential area is shared with capture fishery grounds, oil & gas consents, and navigation routes that will require further assessments (e.g. EIAs) to determine specific impacts to those industries. Those areas not in multi-user conflict makes up 0.57 million ha and 0.28 million ha for surface and submerged farms respectively.

Energy Efficiency for Florida Aquaculture Facilities: Variable Frequency Drives

Energy consumption is often a primary contributor to the cost of operation in aquaculture. Even on a moderately sized farm, excessive energy consumption can be a limiting factor in the success of an aquaculture business. Reducing operational costs can increase total profitability. Identifying inefficient energy use and implementing energy-efficient technologies can help reduce the total cost of operation. This publication is one in a series that details techniques and methods for reducing energy consumption to decrease operational costs on aquaculture facilities. In many aquaculture practices, especially finfish culture, water must be moved from one location to another. Pumping water often accounts for a significant portion of a facility’s energy use and operational costs. This publication discusses how variable frequency drives can be used to reduce energy consumption of pumps.

Effects of Black Soldier Fly, Hermetia illucens (Linnaeus, 1758), Larvae Incorporated Feed on Histomorphology, Gut Microbiota and Blood Chemistry of Cultured Fishes: A Review

Inadequate availability and unreasonable prices made fish meal an unreliable feed ingredient in aquaculture. Consequently, researchers have tested different plant and animal-derived protein sources as an option over the fish meal. The black soldier fly, Hermetia illucens (Linnaeus, 1758), larva, has been identified as a reliable protein source for fish meal replacement. Many studies have revealed the growth and microbiological impacts of H. illucens larvae as a protein source in finfish culture. However, a review of knowledge on histopathology, haematology and microbial changes modulated by H. illucens larvae when incorporated as a feed ingredient in finfish aquaculture is not available. Therefore, this study reviews the effects on the histopathology, haematology and gut-microbial properties of finfish fed diet incorporated with H. illucens larvae. A review of different finfish species tested up to 100 % inclusion of H. illucens larvae meal in their diets revealed mixed results in blood chemistry, gut microbiota, and gut histology. Most studies stated common positive effects such as reduced plasma cholesterol levels, increased microbial diversity, and increased intestinal absorption up to 50 % incorporation level. Despite the possibility of incorporating H. illucens larvae meal without any negative impacts on some carnivore fish species, most studies disclosed adverse effects beyond 50 % fish meal replacement due to high chitin and crude fat levels in H. illucens larval diets.

Microbial diversity and composition in acidic sediments of freshwater finfish culture ponds fed with two types of feed: a metagenomic approach.

Microbial community profile associated with acidic pond sediments (APS) (pH = 3·0-4·5) of freshwater finfish aquaculture ponds (n = 8) was investigated. Sediment DNA extracted from the eight APS were subjected to high-throughput sequencing of V3 and V4 regions which yielded 7236 operational taxonomic units (OTUs) at a similarity of 97%. Overall results showed higher proportion of bacterial OTUs than archaeal OTUs in all the APS. Euryarchaeota (23%), Proteobacteria (19%), Chloroflexi (17%), Crenarchaeota (5·3%), Bacteroidetes (4·8%), Nitrospirae (3·2%), Nanoarchaeaeota (3%) which together constituted 75% of the microbial diversity. At the genus level, there was high preponderance of methanogens namely Methanolinea (5·4%), Methanosaeta (4·5%) and methanotrops, Bathyarchaeota (5%) in APS. Moreover, the abundant phyla in the APS were not drastically affected by the administration of chicken slaughter waste (R-group ponds) and commercial fish feed (C-group ponds), since 67% of the OTUs generated remained common in the APS of both the groups of ponds. There was a minimal difference of 24-26% of OTUs between C-group and R-group ponds, suggesting the existence of a core microbial community in these ponds driven by acidic pH over the years. This study concludes that microbial diversity in pond sediment was influenced to a lesser extent by the addition of chicken slaughter waste but was majorly driven by acidic nature of the pond.

Effect of Dietary Lysine and Methionine Supplementation on the Growth and Physiological Responses of Pearlspot Fingerlings, Etroplus suratensis

Background: Successful and sustainable culture of finfish and shellfish depends on the use of nutritionally balanced, low-cost and eco-friendly feeds. This experiment was conducted to evaluate the effect of dietary supplementation of lysine and methionine on the growth and physiological responses of juvenile pearlspot, Etroplus suratensis. Methods: Fingerlings with an average initial body weight of 8.7±0.04 g were distributed to the 300 L FRP tank (n=30 pieces/tank). The pearl spot fingerlings were fed with isonitrogenous (25% Crude protein) feeds supplemented with methionine (1.8, 2.2 and 2.6 g/100 g of diet) and lysine (0.5, 0.9 and 1.3 g/100 g of diet). The growth performance and physiological response of the fishes were assessed. The feeding trial was conducted for a period of 60 days. Result: The methionine supplemented diets at 2.2 g/100 g (T2) and Lysine supplemented diet at 0.9 g/100 g (T5) yielded the best results within the treated groups in terms of average body weight gain, FCR (feed conversion ratio), SGR (specific growth rate), PER (protein efficiency ratio) and FER (feed efficiency ratio). The maximum mean body weight gain recorded in methionine supplemented diet was 20.68±0.20 g in T2 and the maximum mean body weight gain recorded in lysine supplemented diet was 19.6±0.15 g in T5. The mean body weight gain in control was recorded as 12.12±0.20 g. The present study revealed that methionine incorporation at 2.2 g/100 g (T2) and lysine incorporation at 0.9 g/100 g (T5) resulted in better growth performance of the pearl spot Etroplus suratensis fingerlings. Results of challenge tests confirmed that V. anguillarum could act as a primary pathogen for pearlspot reared in freshwater. In the present study, the Hb, RBC, MCV, MCH and MCHC were also affected by dietary methionine and lysine supplementation and were found significantly (p less than 0 .05) higher in fish fed methionine at 2.2% and lysine at 0.9% of diet, indicating that dietary methionine and lysine supplementation activates immune response and promotes fish health. Second-order polynomial regression analysis of weight gain against dietary methionine and lysine levels indicated that the optimum dietary methionine and lysine requirement for maximum growth and feed utilization of pearlspot fingerlings was methionine at 2.2% and lysine at 0.9%.

Research Before Policy: Identifying Gaps in Salmonid Welfare Research That Require Further Study to Inform Evidence-Based Aquaculture Guidelines in Canada.

Aquaculture is a growing industry worldwide and Canadian finfish culture is dominated by marine salmonid farming. In part due to increasing public and stakeholder concerns around fish welfare protection, the first-ever Canadian Code of Practice for the Care and Handling of Farmed Salmonids was recently completed, following the National Farm Animal Care Council's (NFACC) rigorous Code development process. During this process, both the Scientific (responsible for reviewing existing literature and producing a peer-reviewed report that informs the Code) and Code Development (a diverse group of stakeholders including aquaculture producers, fish transporters, aquaculture veterinarians, animal welfare advocates, food retailers, government, and researchers) Committees identified research gaps in tandem, as they worked through the literature on salmonid physiology, health, husbandry, and welfare. When those lists are combined with the results of a public “top-of-mind” survey conducted by NFACC, they reveal several overlapping areas of scientific, stakeholder, and public concern where scientific evidence is currently lacking: (1) biodensity; (2) health monitoring and management, with a focus on sea lice infection prevention and management; (3) feed quality and management, particularly whether feed restriction or deprivation has consequences for welfare; (4) enclosure design, especially focused on environmental enrichment provision and lighting design; and (5) slaughter and euthanasia. For each of these five research areas, we provide a brief overview of current research on the topic and outline the specific research gaps present. The final section of this review identifies future research avenues that will help address these research gaps, including using existing paradigms developed by terrestrial animal welfare researchers, developing novel methods for assessing fish welfare, and the validation of new salmonid welfare indices. We conclude that there is no dearth of relevant research to be done in the realm of farmed salmonid welfare that can support crucial evidence-based fish welfare policy development.

Growth and Absorption Response of Perna viridis (Lin, 1758) To Fish Farm Water Quality in Valladolid

The extractive species, Perna viridis has been integrated into the existing commercial finfish culture of Chanos chanos and Trachinotus blochii in Valladolid, Carcar Bay, Eastern Cebu, Philippines, following the Integrated Multitrophic Aquaculture (IMTA) concept.

Citrus microcarpa extract as bio-immunostimulator for Edwardsiellosis in red hybrid tilapia culture

This paper described the application of Citrus microcarpa extract as bio-immunostimulator in red hybrid tilapia against Edwardsiellosis infection. Edwardsiellosis due to Edwardsiella tarda is one of the well-known bacterial diseases in aquaculture which leads to significant economic losses. The increasing antibiotic resistant cases among pathogenic bacteria led to many commercial antibiotics no longer effective in controlling bacterial diseases in aquaculture. Hence, in the present study was carried out to evaluate potential of C. microcarpa extract as immunostimulator against Edwardsiellosis infection in red hybrid tilapia. Comparison in terms of cumulative mortalities and antibody response against E. tarda among group of fish received C. microcarpa extract at different concentrations (CM1-1, 1 g kg-1 of fish; CM-2, 2 g kg-1 of fish and CM-4, 4 g kg-1 of fish) and group of fish received no medicated commercial feed (control) was carried out in the present study. Enzyme linked immunosorbent assay (ELISA) was used to monitor antibody response of fish that received medicated feed. The results of the present study showed that the values of antibody response against E. tarda of fish after seven days received C. microcarpa extract (CM-1, 0.113 ± 0.02 OD; CM-2, 0.14 ± 0.02 OD; CM-4, 0.173 ± 0.03 OD) were significantly higher (P < 0.05) compared to fish from group of control (0.0 OD). Whereas cumulative mortality of fish from group of control (53.3 ± 11.5 %) was significantly higher (P < 0.05) compared to fish from all of groups received C. microcarpa extract (CM-1, 13.3 ± 5.8 %; CM-2, 13.3 ± 5.8 % and CM-4, 6.7 ± 5.8 %). The results indicated the potential of C. microcarpa extract as immunostimulator in finfish culture.

Evaluating the potential bioextractive capacity of South Florida native macroalgae Agardhiella subulata for use in integrated multi-trophic aquaculture (IMTA)

With the expansion of marine aquaculture throughout the world comes a need for solutions to improve the economic viability and environmental sustainability of farming operations. Integrated multi-trophic aquaculture (IMTA) has been identified as a promising method of farming that typically combines multiple cultured species in connected systems in an effort to decrease the concentration of nutrients expelled as waste products from intensive finfish culture while also increasing commercial profits via subsequent extractive biomass production. This study examined the effectiveness of South Florida native red macroalgal species Agardhiella subulata for use as a productive, nutrient-extracting species for IMTA in the Atlantic, Gulf of Mexico, and Caribbean regions. When cultured in a pilot-scale, land-based IMTA system for replicated 15 day trials with American red snapper, Lutjanus campechanus, A. subulata grew up to 14.4% d−1 and significantly decreased the concentration of all measured dissolved inorganic nutrients in the effluent water. The average percent (% ± SE) removal of nutrients were: 68.8 ± 4.8 ammonia, 94.5 ± 1.3 nitrate, 96.6 ± 2.0 nitrite, and 93.2 ± 3.1 phosphate from primary culture effluents. Further evidence of A. subulata fitness for commercial IMTA practices is shown through significantly high bulk nitrogen tissue concentration of experimental (nutrient-enriched) compared to control (un-enriched) groups. Results of this study demonstrate the efficient growth and nutrient removal capabilities of A. subulata when used in IMTA applications with marine finfish production in warm water environments, as may be encountered in marine aquaculture projects in the Atlantic, Gulf of Mexico and Caribbean regions.

Integrated culture of Eucheuma denticulatum, Perna viridis, and Crassostrea sp. in Carcar Bay, Cebu, Philippines

The three high-value extractive species, Eucheuma denticulatum, Perna viridis and Crassotrea Eucheuma denticulatum, Perna viridis and Crassotrea sp, have been integrated into the existing commercial finfish culture of Chanos chanos and Trachinotus blochii in the Carcar Bay, Eastern Cebu, Philippines, following the Integrated Multitrophic Aquaculture (IMTA) concept. Two sampling sites (573 m apart) were selected; the experimental site, and control site. Biomass and growth rates of all three extractive species were measured monthly, along with physico-chemical parameters in the two sites, monitored for a period of up to one year for E. denticulatum and seven-month for P. viridis and Crassostrea sp. Results showed that both seaweed and P. viridis adopted in the fish farming site, where water temperature, salinity, pH, dissolved oxygen were found to be well within the optimal range of the three species. Growth of each species, however, aside from the seasonal changes in the weather pattern that influenced water movement, was mainly affected by the presence of epiphytes, predators and fouling organisms that were present during culture. These factors have reduced their potential biomass and growth rates. The introduction of the extractive species in the fish farm appeared to have checked the adverse effects of fish culture activities whose daily inputs of commercial feeds, could led to the suspended solids. The levels of ammonia at 0.5 m (average: 0.05 mg/L) in the experimental site was observed to be lower than that of the control site, whereas the levels of nitrate (ave: 0.23 mg/L) and phosphate (ave: 0.15 mg/L) in the same depth remained relatively high suggesting that these nutrients were not absorbed much by E. denticulatum. The use of IMTA concept, which is found to work well in the culture of milkfish/pompano with the integration of locally-available extractive species, should be promoted and expanded in the Philippines.

The Southern Bluefin Tuna Mucosal Microbiome Is Influenced by Husbandry Method, Net Pen Location, and Anti-parasite Treatment.

Aquaculture is the fastest growing primary industry worldwide. Marine finfish culture in open ocean net pens, or pontoons, is one of the largest growth areas and is currently the only way to rear high value fish such as bluefin tuna. Ranching involves catching wild juveniles, stocking in floating net pens and fattening for 4 to 8 months. Tuna experience several parasite-induced disease challenges in culture that can be mitigated by application of praziquantel (PZQ) as a therapeutic. In this study, we characterized the microbiome of ranched southern Bluefin Tuna, Thunnus maccoyii, across four anatomic sites (gill, skin, digesta, and anterior kidney) and evaluated environmental and pathological factors that influence microbiome composition, including the impact of PZQ treatment on microbiome stability. Southern bluefin tuna gill, skin, and digesta microbiome communities are unique and potentially influenced by husbandry practices, location of pontoon growout pens, and treatment with the antiparasitic PZQ. There was no significant relationship between the fish mucosal microbiome and incidence or abundance of adult blood fluke in the heart or fluke egg density in the gill. An enhanced understanding of microbiome diversity and function in high-value farmed fish species such as bluefin tuna is needed to optimize fish health and improve aquaculture yield. Comparison of the bluefin tuna microbiome to other fish species, including Seriola lalandi (yellowtail kingfish), a common farmed species from Australia, and Scomber japonicus (Pacific mackerel), a wild caught Scombrid relative of tuna, showed the two Scombrids had more similar microbial communities compared to other families. The finding that mucosal microbial communities are more similar in phylogenetically related fish species exposes an opportunity to develop mackerel as a model for tuna microbiome and parasite research.

Socio-economic analysis of finfish culture in cages in coastal waters of Kerala, southwest coast of India

Marine biology,marine ecology,Phytoplankton, marine algae, zooplankton, nekton, benthos, corals and coral reefs, ecology, zoogeography and systematics, primary production and experimental work on ecosystem including energy flow at different trophic levels, population dynamics and theoretical models, recycling of matter, influence of environmental factors on metabolic activity, marine microbiology, mariculture and experimental work on propagation of cultivable species, biology of fishes, marine reptiles, sea birds and mammals, physical, chemical, geological and meteorological features of the environments related to marine biology, marine environmental damage caused by pollution and engineering works, underwater observations, conservation of living resources, modifications in methodology and techniques and development of new apparatus related to marine sciences

Use of dry ice for the shipping and packaging of cryopreserved giant grouper Epinephelus lanceolatus spermatozoa

The cryopreservation is an important technology for the preservation of spermatozoa in the marine finfish culture industry. However, the high cost of producing appropriate sperm because of broodstocks maintenance and point-to-point transportation can be a major financial burden. The present study was conducted to determine the temperature changes during transferring the cryopreserved spermatozoa of giant grouper Epinephelus lanceolatus from liquid nitrogen to dry ice and their effect on the viability and the motility rate of the spermatozoa. The cryopreserved spermatozoa were transferred from the liquid nitrogen tank into the closed styrofoam box containing dry ice for shipping. The temperature exchange was recorded and the viability and motility rate of spermatozoa were measured. Within 56 h, the temperature of the cryopreserved spermatozoa was recorded at −43.5 ± 4.8 °C, nearly 30 °C warmer than the beginning of the experiment, −70.15 ± 2.90 °C. The present study revealed a high percentage of viability and motility rate of cryopreserved spermatozoa of E. lanceolatus, which were transported inside the styrofoam box using dry ice (−79 °C) as a cooling medium for 48 h and immersed back into the liquid nitrogen after 24 h and 48 h.

Optimizing diets to decrease environmental impact of Nile tilapia (Oreochromis niloticus) production

Aquaculture is one of the most thriving animal production sectors, and Nile tilapia (Oreochromis niloticus) farming represents 8% of total finfish culture. However, the industry sustainability depends on the development of cost-effective and environmental friendly feeds. This study aimed to reduce dietary protein levels in diets for juvenile tilapia and to minimize diet environmental impact while maximizing biological efficiency. A growth trial was performed using five isoenergetic plant protein-based diets with decreasing levels of crude protein: 360, 340, 320, 300 and 280 g/kg diet (D360, D340, D320, D300 and D280, respectively). Dietary protein utilization was assessed by metabolic trials using a radiolabelled amino acid mixture. Tilapia in all treatments showed similar growth performance and feed intake. Feed conversion ratio was significantly higher in fish fed the D280 than the D360 diet, while no differences were found for other treatments. Protein retention was significantly higher in tilapia fed the D300 than the D360 diet. Amino acid catabolism increased in fish fed the D360 diet, though without significant differences in muscle amino acid retention. This study demonstrates that dietary protein levels can be reduced to 300 g/kg diet without hindering tilapia growth and feed conversion ratio, while reducing environmental nitrogen losses.

Sustainable Aquaculture Futures

Sustainable Aquaculture Futures

Intercropping of marine finfish in shrimp ponds: A maiden feasibility study.

Diversification of shrimp farming with marine finfish in a farmer participatory research model was attempted. The study is intended to find an economically viable finfish culture during the fallow period of shrimp farms. The Silver pompano, Trachinotus blochi iintercropped with Pacific white shrimp, Litopenaeus vannamei culture in coastal shrimp ponds was assessed for growth, survival, and economic viability. During the grow-out period of 100 days, fishes grew from 40.23 ± 1.40 g to 256.56 ± 1.08 g in weight and 12.83 ± 0.19 cm to 25.11 ± 0.09 cm in length. The daily weight gain (DWG) and daily length gain (DLG) were 2.16 g/day and 0.12 cm/day, respectively. Relative growth rate (RGR) and specific growth rate (SGR) recorded for weight was 537.80% in 100 days and 1.85% per day, respectively. Pompano has exhibited its sturdiness and adaptability to the land-based culture system as evidenced by an overall survival percentage of 89.8% including nursery and grow-out phases. The realized feed conversion ratio was 1.94. The culture period of 100 days is found to be enough to attain a desirable harvest size of 250 g. The projected production potential of the experimental demonstration farm of 4500 m2 water spread area for culture was 16.2 tonnes/cycle with a benefit-cost ratio (BCR) of 1.34 over operational cost. The present participatory trial empirically proved the viability of Silver pompano as an intercrop in coastal shrimp ponds. Thus, the introduction of Pompano in shrimp ponds is recommended and can be promoted for sustainable intercropping with shrimp farming along the Indian coast for improving people’s livelihoods.

Cage culture of Oreochromis Mossambicus (Tilapia) in back water of river Godavari, Nanded, Maharashtra India

Cage culture practice is an important technology for culture of finfish and non fin fish organisms. It is gaining importance day by day. This was a first attempt to check the suitability of cage culture in back water of Godavari. This water remains present up to March and April; hence this experiment was carried out from October 2012 to April 2013 (180 days) at Dhangar Takli on the bank of river Godavari. Results showed that Oreochromis mossambicus fish was useful fish for cage culture practice in this area. Although, the Monosex culture of Oreochromis mossambicus may be more applicable because this fish is prolific breeder. If we alter the breeding of fish then this will may help to increase the growth of the fish. Oreochromis mossambicus commonly called as freshwater pomfret. People of this area consume this fish is in high quantity; hence for high production this cage culture method may be helpful.