bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic perspective on stress response and disease resistance in aquaculture.
Authors: Cnaani Avner
Published: February 2021

Despite continuous progress and improvements in aquaculture technologies and husbandry techniques, fish diseases remain a major limiting factor in the fish culture industry. The aqua- culture environment exposes fish to repeated acute stress, which leads to physiological respons- es that have suppressive effects on growth, reproduction, and immune capacity. The strong link between stress and susceptibility to diseases in farm animals has long been acknowledged, and parameters of high and low stress response are associated with disease resistance in fish. Few studies on genetic aspects of immune response to stress have been conducted. The estimated heritability of several parameters of the innate immune response is mostly moderate. Quantitative trait loci have been found for different responses to stress conditions. Gene expres- sion studies show that hundreds of genes can be involved in fishes’ physiological and immuno- logical response to stress. This general response to stress is controlled by a few major genes at the top of the pathway, which activate a cascade of reactions, having a significant effect on the overall health of the fish. Selective breeding for disease resistant fish is an attractive strategy for disease prevention and several studies have reported progress in this field. However, the bio- logical pathways of stress response and disease resistance are not well characterized, and their genetic basis and control are still poorly understood. Extensive research is still needed for a bet- ter understanding of these pathways, and this should be a collaborative effort of researchers from different fields: genetics, immunology, pathology, physiology, and endocrinology.
Regulated sex control in commercially important fishes – a physiologicalperspective
Authors: Shelton William L.
Published: February 2021

The management of fish reproduction has resulted in major advancements in the commercial culture of fishes. Artificial propagation has stabilized seed-stock production, and reproductive manipulations in induced sex reversal and ploidy manipulations have provided mechanisms to improve yield. The design and effectiveness of these manipulations are regulated by various physiological factors. The effectiveness of protocols for the induction of gynogenesis, triploidy, and tetraploidy is improved through knowledge of physiological effects on important parameters. Application of the developmental rate based on the mitotic interval (τo) incorporates a standard- ization relative to temperature. Timing of shock with reference to the species-specific τo rela- tionship is effective in clarification and optimization of treatments. Such standardization is impor- tant to any late (endomitotic - Em) shock induction, and in polar-body (Pb) induction for many species. Hormonally induced sex reversal also must be applied relative to an efficacious treat- ment protocol, developed relative to a window of gonadal lability during the genetically directed chronology and physiologically influenced differentiation. Size and/or age are important modify- ing parameters that can be affected by various growth-altering environmental factors such as temperature and density-dependent effects. The consideration of influences that affect physio- logical rates relative to reproductive manipulations provides a more in-depth understanding of protocol effectiveness.
Integration of molecular genetic information into the NCCCWA selective breeding program for rainbow trout
Authors: Rexroad Caird E. III , Palti Yniv , Vallejo Roger L. , Silverstein Jeffery T.
Published: February 2021

The USDA/ARS National Center for Cool and Cold Water Aquaculture (NCCCWA) in Leetown, West Virginia, is working to integrate molecular genetic technologies into a selective breeding program aimed at the genetic improvement of rainbow trout for aquaculture production efficien- cy. Our multidisciplinary approach aims to incorporate genome information with respect to dis- ease resistance and stress, growth, and reproductive physiology into our selective breeding pro- gram. Selective breeding is based on the hypothesis that sufficient genetic variation exists in broodstock to realize genetic improvement through contributions of superior performing germplasm to future generations. Our associated goal is to develop and transfer improved germplasm and technologies to the aquaculture industry. Our approach to implementing molec- ular information into our breeding program is outlined under three objectives: (a) development of a genetic map to reveal chromosomal locations affecting traits associated with aquaculture pro- duction, (b) use of a candidate gene approach to identify and characterize genes affecting impor- tant aquaculture production traits through functional genomic technologies, and (c) development of bioinformatic strategies to implement genetic mapping and functional genomic information into a selective breeding program.
Lessons for aquaculture breeding from livestock
Authors: Weller Joel Ira
Published: February 2021

Investment in breeding is unique because genetic gains are eternal and cumulative. They are never “used up”, and never “wear out”. However, nearly all of the gain is transferred to the national economy. Very little stays with farmers or commercial breeders. Unlike genetic gains, costs are not cumulative. With a profit horizon of 20 years and a discount rate of 0.08, total dis- counted costs will equal total discounted gains if the value of the nominal annual genetic gains is 0.3 of the nominal annual costs. The rate of genetic gain for milk production in dairy cattle has been about 1% per year for the last 20 years. Since the 1950s, rates of genetic gain have increased due to better pedigree information, more traits recorded, more accurate recording, and better statistical methods. From the beginning of modern breeding programs, selection in dairy cattle focused on milk production. From 1985, breeding goals moved towards improving protein yield. In recent years, selection objectives were broadened to include “functional herdlife”, fertil- ity, and health traits. The main reasons behind this shift were quotas and/or price constraints, and increasing concerns associated with the deterioration of the health and fertility of dairy cows. Modern technology complements traditional breeding but does not replace it. To date, nearly all progress in animal breeding has been obtained by traditional trait-based methodology. There is no substitute for accurate data and pedigree recording.
Genetics and genomics - integration of molecular genetics into a breeding program for rainbow trout
Authors: Silverstein Jeffery T. , Weber Gregory M. , Rexroad Caird E. III , Vallejo Roger L.
Published: February 2021

At the National Center for Cool and Cold Water Aquaculture (US Department of Agriculture, Ag. Research Service) in Leetown, WV, we have a broodstock development program now entering the second generation of family-based selective breeding using expected breeding values (EBVs). Our major breeding objectives are faster growth and resistance to Flavobacterium psy- chrophilum, the causative agent of bacterial coldwater disease. For these traits we have devel- oped assays to evaluate phenotypic performance. In addition to our breeding program, we are participating in an international collaboration to develop a microsatellite marker linkage map for the rainbow trout with the intent of identifying quantitative trait loci (QTL) and using them in mark- er (MAS) or gene-assisted (GAS) selection. There are several possible approaches with regard to the types and numbers of markers to develop and the strategies and methods for implement- ing the markers in a selective breeding program. This paper describes the choices we made con- cerning QTL identification for traits of high, low, and unknown degrees of heritability. These traits are plasma cortisol response to a crowding stress (h2 = 0.4), feed intake (h2 = 0.1) and resis- tance to F. psychrophilum (0.3<h2<0.4). In order to identify QTL in a relevant commercially important rainbow trout line, we are making crosses from within our resource population. The development of research family crosses, choice of markers for genome scanning, and planned steps to implementation of these results are described.
State of the art in selective breeding of aquacultured species
Authors: Gjerde Bjarne
Published: February 2021

The first selective breeding programs for aquaculture species that also used sib information in the selection decisions were established in the early 1970s for Atlantic salmon and rainbow trout. Presently there are a total of about 60 such programs for about 20 different species in the world. However, still less than 5% of the world aquaculture production is from genetically improved stocks and most of these programs practice selection for a narrow breeding objective (e.g., growth only). An exception is Atlantic salmon for which close to 100% of the production is from improved stocks and selection is practiced for much broader breeding objectives including as many as 6-10 different traits (growth, sexual maturity, disease resistance, carcass quality, defor- mities) in some of the programs. A sustainable selective breeding program needs reliable genet- ic parameters and economic values for all traits of economic and strategies are important. In published literature there are few reliable estimates of genetic correlations between traits, and no objective study has been performed for economically important species on the derivation of economic values. Studies on the design of cost effective simple (mass selection) and advanced (use of sib information also) nucleus selective breeding programs for aquaculture species are few. More studies should be undertaken that take into account the high fecundity and reproduc- tive characteristics of the species and should be performed at a predefined and acceptable rate of inbreeding. Important also are studies on the effects of new selection algorithms and mating design, new and emerging technologies like DNA-markers for both parental assignment and marker assisted selection, new technologies that can record more of the traits selected for on live breeding candidates, and procedures to obtain unbiased estimates of genetic changes, as well as studies on the long-term effects of a low but significant interaction between genotype and environment on important traits in a competitive market for genetic material. At the multiplier level, additional studies are needed on selection and mating strategies to fully capitalize both on the additive and non-additive genetic effects and how additional strategies like ploidy and sex manipulation may be used to further increase the productivity of the commercial fry. A socio-eco- nomic challenge is the need for some form of legal or biological protection measures to assure a fair share of the revenues from genetic improvement to investors and for further research and development of the breeding programs, while at the same time having access to genetic resources for further development of the programs.
What can history tell us about the future of aquaculture genetics
Authors: Hershberger William K.
Published: February 2021

Historically, genetics has not been a major part of aquatic sciences education or practices. However, it is interesting to note that one of the first animals used for genetic research after rediscovery of Mendel’s results was a Poeciliid, i.e., the guppy. Furthermore, the use of genetic principles and practices for improvement of aquatic species raised under controlled or semi-con- trolled conditions has not become a standard component of aquaculture production, contrary to the situation with other agricultural plants and animals. A number of explanations for the lack of utilization of otherwise accepted genetic approaches will be explored. In addition to the seeming reticence to employ the standard genetic approaches in aquaculture, realization of the purport- ed promise of some of the more recently developed molecular genetic tools has been slower than anticipated. In addition to the difficulties experienced with deployment of this technology, the costs and the need for larger multidisciplinary teams to develop the tools for reliable analy- ses have raised challenges not previously experienced in the field. These factors have led to increased efforts to utilize cooperative approaches to major genetic problems that need to be solved. It would appear that future employment of modern genetic analytical tools to improve aquaculture production will be enhanced and, in fact, further assured via cooperative research ventures.
Impact of Marine Secondary Metabolites (MSM) from Hypnea musciformis as an Immunostimulant on Hemogram Count and Vibrio alginolyticus Infection in the Prawn, Penaeus monodon, at Different Salinities
Authors: Jean José J. , Lipton A.P. , Subhash S.K.
Published: February 2021

Marine secondary metabolites (MSM) from Hypnea musciformis positively affected immune fac- tors in post larvae of the shrimp, Penaeus monodon. Shrimp were raised in one of three salinity levels and infected with one of three doses of virulent Vibrio alginolyticus. When challenged with 105 of 106 V. alginolyticus cells/ml, survival was 100% for both control shrimp and shrimp fed a commercial shrimp feed treated with the MSM extract, regardless of salinity. But, when chal- lenged with 107 V. alginolyticus cells/ml, survival was 0 in control shrimp at all salinities, and 0, 34%, and 15% in shrimp fed treated feed and raised in 7, 17, and 27 ppt salinity, respectively.
Prymnesium parvum, an Ichthyotoxic Alga in an Ornamental Fish Farm in Southern Israel
Authors: Gordon Nurit , Colorni Angelo
Published: February 2021

The haptophyte alga Prymnesium parvum (Prymnesiophyceae) caused “creeping” mortality in ornamental fish, molly (Poecilia sp.) and koi (Japanese carp, Cyprinus carpio), farmed in the Arava Valley in southern Israel. The toxicosis occurred when the water system was changed from flow-through to closed circulation. A moderately high temperature, three-fold increase of salinity, and probable rise in eutrophication created conditions suitable to P. parvum blooms. The system was treated with 10 ppm ammonium sulfate and fish mortality ceased.
Activity of the Digestive Protease, Chymotrypsin, in Larvae of the Cultured Sharpsnout Sea Bream (Diplodus puntazzo)
Authors: Aktulun Sevim , Süzer Cüneyt , Kamaci H. Okan , Coban Deniz , Saka Sahin , Firat Kursat
Published: February 2021

Specific and total activity of the digestive protease, chymotrypsin, was studied in cultured sharp- snout sea bream larvae (Diplodus puntazzo) for 35 days from hatching and in a variety of pH lev- els. Activity was detected upon hatching (2.8±0.34 mm total length), before the onset of exoge- nous feeding. Specific chymotrypsin activity exponentially increased from mouth opening on day 3 until day 25, then dropped until the end of the experiment. Total chymotrypsin activity sharply increased to day 10, then continued to increase, but slightly, until the end of the experiment. As expected, pH strongly affected both specific and total chymotryptic activity in the digestive tracts of larvae. Both were significantly lower when pH was acidic (1.5, 3.0, 4.0) than when it was alka- line (8.0, 9.0, 10.0) although there were no significant differences within either the acidic or the alkaline range. Our results indicate that chymotrypsin activity is capable of digesting protein before mouth opening and may be a valuable tool for better understanding the nutritional capa- bilities of young larvae.
Ontogeny of Fertilized Eggs and Yolk Sac Larvae of Sea Bass (Dicentrarchus labrax)
Authors: Naz Mehmat
Published: February 2021

The biochemical compositions of fertilized eggs, yolk sac larvae, and larvae at the beginning of exogenous feeding of sea bass (Dicentrarchus labrax) were determined. Eggs and yolk sac lar- vae contain more monounsaturated and polyunsaturated fatty acids than saturated fatty acids. Essential and non-essential amino acid contents tended to drop at hatching, then sharply increase by the end of endogenous feeding. Amylase and trypsin activity was detected in fertil- ized eggs. Trypsin activity peaked at the beginning of exogenous feeding. The alkaline phos- phatase activity was lowest in fertilized eggs, higher at hatching, and highest at the end of the experiment. Leucine alanine peptidase activity was higher than other enzymatic activity in all three stages. Aminopeptidase N activity increased until hatching, then stabilized until the begin- ning of exogenous feeding.
Effect of Betaine as a Feed Attractant on Growth, Survival, and Feed Utilization in Fingerlings of the Indian Major Carp, Labeo rohita
Authors: Shankar R. , Murthy Shivananda , Pavadi Prakash , Thanuja K.
Published: February 2021

The study evaluated the efficiency of betaine as a feed attractant on growth, survival, and feed utilization in fingerlings of rohu (Labeo rohita). Betaine was incorporated at 0 (control), 0.25%, 0.50%, or 0.75% in a 30% protein diet and fed to fingerlings for 120 days in a closed and aerat- ed recirculating system. Feed was offered twice daily at a rate of 5% of the fish biomass during the first 15 days and 3% afterwards. Significantly better growth, specific growth rate, survival, food conversion ratio, and protein efficiency ratio were obtained in the group fed 0.25% betaine.
Analysis and Characterization of Expressed Sequence Tag (EST) and Simple Sequence Repeats (SSR) from Red Sea Bream, Chrysophrys major, and Gilthead Sea Bream, Sparus aurata
Authors: Liu Yun-Guo , Chen Song-Lin , Liu Chun-Ying , Li Fang-Zheng
Published: February 2021

A total of 101 and 119 simple sequence repeats (SSR) were obtained from expressed sequence tags (EST) of the red sea bream (Chrysophrys major) and gilthead sea bream (Sparus aurata), respectively. Dimeric repeats were the most abundant class of SSR in both red (70.30%) and gilthead (51.26%) sea bream. Trimeric, tetrameric, and pentameric repeats occurred in decreas- ing proportions, i.e., 21.36%, 6.8%, and 0.97% in red sea bream and 45.38%, 3.36%, and 0 in gilthead. There were no hexameric repeats in EST of either species. The frequency of every class of SSR (dimeric, trimeric, tetrameric, and pentameric) decreased with increasing repeat length. In cross-species amplification of 20 existing microsatellite loci from gilthead sea bream in 20 red sea bream specimens, twelve loci showed positive amplification and four loci showed polymorphic amplification with two or three alleles.
Partial Replacement of Fishmeal with Hazelnut Meal in Diets for Juvenile Gilthead Sea bream (Sparus aurata)
Authors: Emre Yilmaz , Sevgili Huseyin , Sanil Murat
Published: February 2021

Hazelnut meal was evaluated as an alternative protein source to fishmeal in diets of gilthead sea bream with an initial weight of 35.08±0.29 g. Incorporation levels of hazelnut meal were 0% (con- trol), 10%, 20%, 30%, and 40%. Each diet was tested in triplicate for ten weeks. There were no significant differences between the experimental diets and the control in final body weight, weight gain, specific growth rate, or feed and protein efficiency ratios. In addition, the level of hazelnut meal did not significantly affect the whole body composition of the sea bream. In con- clusion, up to 40% hazelnut meal could be included in diets for gilthead sea bream juveniles with- out adverse effects on growth rate or body composition.
Growth Performance, Survival, and Body Composition of Post Larvae of the Freshwater Prawn (Macrobrachium rosenbergii) Fed Graded L-Carnitine Diets
Authors: Singh R.K. , Desai A.S. , Chavan S.L. , Khandagale P.A.
Published: February 2021

The aim of this study was to investigate the efficacy of L-carnitine incorporated diets on growth, specific growth rate (SGR), feed conversion efficiency (FCE), protein efficiency ratio (PER), sur- vival, and body composition of post larvae of the freshwater prawn Macrobrachium rosenbergii. Five diets containing 0, 0.25, 0.50, 0.75, or 1 g L-carnitine/kg diet were fed to post larvae (0.105±0.028 g, 2.21±0.13 cm) for thirteen weeks. The highest SGR (3.42±0.44%/day), FCE (40.40±1.45%), and PER (1.05±0.02) were obtained in the 0.50 treatment. The lipid level in the post larvae was inversely related to the L-carnitine level in the diet (p<0.05). The protein level increased with supplementation until the 0.50 level, then decreased with higher levels. Using second-order polynomial regression analysis, the optimal weight gain, SGR, and FCE were obtained with L-carnitine levels of 0.484 g/kg, 0.466 g/kg, and 0.48 g/kg, respectively. In con- clusion, 0.50 g L-carnitine per kg feed is optimum for good growth in M. rosenbergii post larvae.
Effect of Temperature on Growth and Biochemical Composition (Sterols, α-tocopherol, Carotenoids, Fatty Acid Profiles) of the Microalga, Isochrysis galbana
Authors: Durmaz Y. , Donato M. , Monterio M. , Gouveia L. , Nunes M.L. , Gama Pereira T. , Gokpinar S. , Bandarra N.M.
Published: February 2021

The microalga Isochrysis galbana Parke was grown in 100-l polyethylene bags filled with steril- ized seawater enriched with Wallerstein and Miquel nutrient medium (3:1) at two temperatures (18°C and 26°C), 2.5% salinity, and continuous illumination. Samples of microalgae were exam- ined during the exponential growth, stationary growth, and decay phases (days 18, 35, and 58, respectively). Stigmasterol constituted the main sterol group in all phases in both treatments, except during the exponential growth phase at 18°C. The highest concentration of α-tocopherol was 5.22 mg/100 g DW, reached in the decay phase of algae raised in 18°C. Likewise, the high- est total carotenoid (4.14 mg/g DW) and chlorophyll (2.87 mg/g DW) levels were obtained in algae raised in 18°C, during the exponential phase; the main pigments were chlorophyll a, c1, c2, and fucoxanthin. At 18°C, polyunsaturated fatty acids (PUFA) were the predominant fatty acid group, reaching 37.93% of the total fatty acids in the stationary phase. At 26oC, saturated fatty acids (SAF) were the predominant group of fatty acids. The present study suggests that the nutritional value (gross biochemical composition and fatty acid profile) of I. galbana Parke is, to a large extent, determined by the temperature at which it is grown and the harvest time.
Cryopreservation of Pike Perch Sperm in Hatchery Conditions
Authors: Bokor Zoltan , Horvath Akos , Horvath Laszio , Urbany Bela
Published: February 2021

Experiments were carried out on pike perch (Sander lucioperca L.) to find a method for stripping sperm without contamination by urine, to determine sperm concentration, and to fertilize large batches of eggs with cryopreserved sperm. Induced spawning technology for pike perch, an important predator fish species in Hungarian and central-eastern European pond aquaculture, has been developed only recently. Sperm cryopreservation can be an important tool for several reasons including the simplification of hatchery work and long-term preservation of genomes of males with high genetic value. In the present study, sperm was stripped without urine contami- nation, improving sperm quality, and large amounts of eggs were fertilized using 0.25 ml sperm, resulting in hatching percentages of 55±3% for 30-g batches of eggs and 87% for a 50-g batch.
Immunization of Rainbow Trout (Oncorhynchus mykiss) against Lactococcus garvieae Using Vaccine Mixtures
Authors: Kubilay A. , Altun S. , Ulukoy S. , Ekici S. , Diler O.
Published: February 2021

The effectiveness of vaccine mixtures against lactococcosis was tested in rainbow trout (Oncorhynchus mykiss). The M1 strain of Lactococcus garvieae, isolated from a recent outbreak of lactococcosis at a rainbow trout farm in Turkey, was used in a trial comparing five immuniza- tion treatments: (a) formalin inactivated bacterin (vaccine), (b) the above bacterin together with Freund’s Incomplete Adjuvant (FIA), (c) the bacterin combined with β-glucan, (d) β-glucan only, and (e) phosphate buffered saline-PBS (control). Fish were given intrapritoneal injections and challenged by exposure to the bacteria 30, 75, or 125 days after vaccination. In fish exposed to the bacteria 30 days after injection, the relative percent survival (RPS) was 88.89% in the group that received only bacterin and 100% in the group that received the bacterin combined with FIA. Immunity remained high in the bacterin+FIA group, as the RPS in this group remained 100% in fish challenged at 75 days, significantly higher than in all other groups. In fish exposed to the bacteria 125 days after vaccination, the RPS was 54.55% in fish vaccinated with the bacterin only and 84.84% in fish vaccinated with bacterin+FIA. In the group that received only β-glucan, immunity did not improve after vaccination. Micro-agglutination tests of serums showed that immunized fish produced antibodies at high titers within 30 days. In short, the formalin-inacti- vated M1 strain provided longer lasting protection against Lactococcus garvieae in rainbow trout when combined with FIA than when administered alone or with β-glucan.
Impact of planting season on growth and survival of the carpet shell clam (Tapes clecussatus, Linnaeus 1758)
Authors: Serdar S. , Lok A.
Published: February 2021

The growth and survival of juvenile carpet shell clams, Tapes decussatus, planted in autumn (October-April) and spring (April-October) in Sufa Lagoon near Izmir, Turkey, were compared. Clams of 20.39±0.24 mm were sown in October (Group I) and clams of 20.43±0.23 mm were sown in April (Group II). Seedlings were sown in plastic boxes at a density of 160 clam/m2. Temperature ranged 8-32oC, salinity 38-43‰, and chlorophyll a 4.04-30.93 μg/l. In six months, the clams in Group I reached 23.16 mm while the clams in Group II reached 24.02 mm (p<0.05). Survival was 80% in Group I and 77.5% in Group II (p>0.05).
Isolation, characterization, and sequencing of nodavirus in sturgeon (Acipenser gueldestaedi L.) reared in freshwater facilities
Authors: Xylouri Eftychia , Kotzamanis Yannis R. , Athanassopoulou Fotini , Dong Li , Pappas Loanis S. , Argyrokastritis Alexandros , Fragkiadaki Eirini
Published: February 2021

The study demonstrates the presence of a nodavirus that affected sturgeon in fresh water, caus- ing disease with neurological signs. The virus was isolated and inoculated onto SSN-1 (striped snakehead, Channa striatus) cell cultures where cytopathic effects (CPE) of the virus included vacuolation of the cells and degeneration of the monolayer. A 255 bp amplicon from nucleic acid preparations of brain tissue from infected sturgeon was detected by PCR (RT-PCR and nested- PCR) and compared with corresponding amino acid sequences of other infected species. The sequences from the sturgeon were similar to those of sea bass, red spotted grouper, and European eel, supporting the hypothesis that the virus originated in marine fish and was hori- zontally transmitted to freshwater sturgeon.
Amino Acid Composition of Heterobranchus longifilis Fry, Fingerlings, and Broodstock
Authors: Ovie Stella O. , Ovie Solomon
Published: February 2021

The whole-body amino acid composition of fry, fingerlings, and brood fish of Heterobranchus longifilis was determined using a Technicon Sequential Multisample Auto-Analyser, equipped with a pen recorder for drawing chromatograms. The fish samples consisted of nine essential amino acids (arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threo- nine, valine) and eight nonessential amino acids (alanine, aspartic acid, cystine, glutamic acid, glycine, proline, serine, tyrosine). There were no significant differences among the three stages and all are closely related to those of other fish species.
The Effect of Stocking Density on Yield, Growth, and Feed Efficiency of Himri Barbel (Barbus luteus) Nursed in Cages
Authors: Gokcek C. Kaya , Akyurt Ihsan
Published: February 2021

Himri barbel (Barbus luteus Heckel, 1843) fingerlings (mean wt 15.73 g) were stocked at 40, 60, 80, or 100 fish per cage in 1-m3 cages suspended in a reservoir lake to determine total yield, growth rate, and feed efficiency after seven months. Total yields increased as the stocking den- sity increased and were 3.59, 4.80, 6.32, and 7.91 kg per cage, respectively. The highest mean fish weight was obtained in the lowest stocking density. Neither the food conversion ratio nor the mortality rate was affected by stocking density.
Immunogenic and Antigenic Profiles of Nine Lactococcus garvieae Strains from Different Rainbow Trout Farms
Authors: Altun S. , Adiloglu A.K. , Kubllay A. , Diler O. , Delibas N. , Sutcu R.
Published: February 2021

The aims of this study were to determine differences with respect to immunogenic potency in the antigenic profiles of nine Lactococcus garvieae strains from Turkey, Spain, and England, to develop a bacterin, and to examine the immunological response of rainbow trout to the bacterin. The strains had identical Western blot patterns with 30, 37, 40, 46, 52, and 66 kDA mw protein bands. After culturing the bacteria, proteins were separated by SDS-PAGE and transferred to Immobilon membranes. The membranes were incubated with hyperimmune rabbit sera obtained by immunizing a rabbit against L. garvieae. One group of 50 fish was immunized with formalin- killed bacterin prepared from the most immunogenic strain of L. garvieae. A second group of 50 fish served as an unimmunized control. Four weeks after vaccination, both groups were chal- lenged intraperitoneally with a homologous strain. The protection rate of the bacterin was judged by the relative percent survival (RPS) of the groups. A significantly high level of protection was achieved in the vaccinated group (88.8% RPS).
Occurrence and Distribution of Actinomycetes in Marine Environs and their Antagonistic Activity against Bacteria that is Pathogenic to Shrimps
Authors: Sahu Maloy zkumar , Murugan M. , Sivakumar K. , Thangaradjou T. , Kannan L.
Published: February 2021

The mean population density of actinomycetes in water samples from eight stations off Little Andaman Island in India ranged from 0.29 x 103 CFU/ml at station 2 (Naval Area) to 0.45 x 103 CFU/ml at station 4 (Chandra Nallah). Density in sediment samples ranged from 1.21 x 103 CFU/g at station 2 (Naval area) to 3.29 x 103 CFU/g at station 6 (Buttler Bay). Forty-one strains were isolated and tested for their antagonistic activity against Vibrio alginolytics, V. harveyi, and V. parahaemolyticus, bacteria that are highly pathogenic to shrimps. Over 60% of the strains (26) exhibited varying degrees of antagonistic activity. Among them, six showed good activity and were tentatively identified as Streptomyces xantholiticus, S. aureofasciclus, S. galtieri, S. vastus, S. galbus, and S. rimosus. Results suggest that actinomycetes from the marine environment can be used as bio-control agents in shrimp culture systems to control diseases caused by bacteri- al pathogens.
Pituitary Collection from Gibel Carp Carassius gibelio (Bloch 1782) in Lake Pamvotis (Greece): Prospects for Use in Carp Reproduction
Authors: Perdikaris Costas , Levavi-Sivan Berta , Chantzaropoulos Athanasios , Nathanailides Cosmas , Gouva Evangelia , Paschos Ioannis
Published: February 2021

Gibel carp (Carassius gibelio Bloch, 1782) is regarded as a pest species in most aquatic ecosys- tems where it occurs and eradication methods have not been very promising. However, because of the close taxonomical proximity between gibel carp and cultured cyprinids, the pituitary of gibel carps could be exploited for hormonal induction of artificial propagation in aquaculture. Thirty-two mature female gibel carps were electrofished in Lake Pamvotis (northwest Greece) in March 2005 and their pituitaries were collected and processed. The carp luteinizing hormone (cLH) levels in 20 pituitaries were assayed and found to correlate with total body weight, total length, dry pituitary weight, and gonadosomatic index. The cLH levels were in the same range as cLH levels in pituitaries of common carp (Cyprinus carpio Linnaeus, 1758) used in Israeli hatcheries for artificial propagation. Hence, it may be possible to use gibel carp pituitaries for hormonal induction in cyprinids, with total weight of the gibel carp as a field criterion for select- ing pituitary donors.
Isolation of Putative Probionts from the Intestines of Indian Major Carps
Authors: Ghosh Shubhadeep , Sinha Archana , Sahu Chittaranjan
Published: February 2021

Probiotic strains were isolated from the intestines of 28 Indian major carps (Labeo rohita, Catla catla, Cirrhinus mrigala) cultured in sewage-fed ponds. Intestinal microflora were isolated, count- ed, and identified, and their in vitro antibacterial properties were determined. The double layer method revealed that four strains (SG1, SG2, SG3, SG4) elicited antagonism against the pathogen Pseudomonas fluorescens. Using cross streak and parallel streak methods, SG4 max- imally inhibited the fish pathogens Pseudomonas fluorescens, Aeromonas hydrophila, and Edwardsiella tarda. Therefore, SG4 was chosen for further study as a probiont. SG4 was non- pathogenic to C. mrigala fingerlings, and adhered well to stainless steel, high density polyethyl- ene, and glass plate substrates. Biochemical tests showed that SG4 was endospore-forming, aer- obic, motile, rod-shaped Bacillus subtilis. However, since in vitro experiments can only give an indication of in vivo success, future research should include large-scale in vivo experiments.
Genetic Diversity of Gilthead Seabream (Sparus aurata) Broodstocks as Determined by RAPD-PCR
Authors: Bilgen Guldehen , Akhan Suleyman , Arabaci Muhammed , Oguz Ismall
Published: February 2021

The objective of this study was to determine the genetic diversity in gilthead seabream brood- stocks from two hatcheries on the northern Aegean Coast of Turkey by RAPD-PCR. Forty primers were tested for each broodstock. Twenty-five produced scorable RAPD bands in stock from the Seferihisar hatchery and 28 in stock from the Aliaga hatchery. Nineteen revealed pat- terns with scorable amplified primers in both broodstocks. Depending on primer, the number of bands varied 3-16, ranging in size from 438 to 2520 base pairs (bp). The average genetic simi- larity within stocks was 0.466 for the Seferihisar stock and 0.617 for the Aliaga. The average genetic similarity between the two broodstocks was 0.420, lower than the values within the broodstocks, and the genetic distance between the two broodstocks was 0.245.
Canola Meal as an Alternative Protein Source in Diets for Fry of Tilapia (Oreochromis niloticus)
Authors: Yigit Nalan Ozgur , Olmez Murtaza
Published: February 2021

Canola meal was used to replace fishmeal protein in diets for fry of tilapia (Oreochromis niloticus L. 1758) at rates of 0 (control), 10%, 20%, 30%, 40%, and 50%. The diets contained approximately 30% crude protein and 3000 kcal/kg digestible energy. The fry were fed 90 days and the growth, feed conversion ratio, protein efficiency ratio, hepatosomatic index, reno- somatic index, and body composition were determined. The final weight (5.12 g) and feed intake (7.99 g) of fry fed the 10% diet did not significantly differ from those of the control. Weight gains declined beyond this replace- ment level, probably because of increased levels of antinutritional factors, particularly glucosinolates. Whole body percentages for moisture, crude lipid, crude protein, and ash were unaffected by the dietary treatment. Re- sults indicate that protein from canola meal can replace up to 10% of protein from fishmeal in diets for tilapia fry.
Color Enhancement in the Ornamental Dwarf Cichlid Microgeophagus ramirezi by Addition of Plant Carotenoids to the Fish Diet
Authors: Harpaz Sheenan , Padowicz Daniel
Published: February 2021

The present research examined the effects of adding carotenoids from oleoresin paprika to fish feeds for ornamental dwarf cichlid, Microgeophagus ramirezi. The growth rate, survival, carotenoid accumulation level, and color intensity were evaluated. Post larvae and near-adult (three months old) fish were tested to determine when carotenoids are better assimilated. The addition of carotenoids had no effect on the growth rate or survival in either life stage, however, they had a clear effect on color enhancement. After 45 days, near-adult fish that consumed carotenoid-supplemented diets at 60, 120, or 240 mg/kg had significantly higher levels of carotenoids (72.19±4.55, 84.81±5.29, and 86.55±4.50 μg/g dry matter, respectively) than con- trol fish (33.69±1.06 μg/g), with no significant differences between treatments. After 75 days, post larvae that consumed 240 mg/kg carotenoids accumulated significantly more carotenoids in their body (59.34±3.93 μg/g dry matter) than fish that consumed only 60 mg/kg carotenoids (40.53±2.37 μg/g dry matter) or no supplemental carotenoids (29.18 μg/g dry matter). Visual examination revealed a strong correlation between level of pigment accumulation and color appearance in the fish. Results indicate that addition of 60 mg oleoresin paprika per kg diet is sufficient to obtain good coloration in M. ramirezi.
The Effects of Different Sized Granules and Particle Composition on Growth of Rainbow Trout (Oncorhynchus mykiss)
Authors: Sonmez Adem Yavuz , Hisar Sükriye Aras , Hisar Olcay , Yanik Telat , Aras M. Sıtkı
Published: February 2021

Three feeding regimes were tested to determine their effects on growth, survival, and feed conversion in rainbow trout alevins for 60 days. In the first regime, the alevins were fed a starter feed consisting of 800 micron parti- cles for the first 15-day period. For the following 15-day period, the alevins were given a starter feed consisting of 1200 micron particles. For the final two 15-day periods, the alevins were given feeds consisting of 1500 micron and 2 mm particles, respectively. In the second regime, feed particles in the four periods were 1200 micron, 1500 micron, 2 mm, and 3 mm granules, respectively. In the third regime, feeds contained 1500 micron, 2 mm, 3 mm, and 4 mm granules. During the first two 15-day periods, no significant dif- ferences in growth parameters were detected (p>0.05). In the second two 15-day periods, there were significant differences in final live weight, growth, and feed conversion rates between groups (p<0.05). Growth was lowest in the group fed the first regime. There were no significant differ- ences between groups in survival rate (p>0.05).
Partial Substitution of Fishmeal by Meat and Bone Meal, Soybean Meal, and Squid Concentrate in Feeds for the Prawn, Artemesia longinaris: Effect on Digestive Proteinases
Authors: Gimenez Analia Veronica Fernandez , Diaz Ana Cristina , Velurtas Susana Maria , Fenucci Jorge L.
Published: February 2021

The effect of alternative protein sources on proteinase activity in the midgut gland of Artemesia longinaris was studied. Three isoproteic feeds were compared: a basal diet containing 48% fishmeal and 17% soybean meal (diet 1), the basal diet containing meat and bone meal as partial replace- ment of the fishmeal (diet 2), the basal diet containing additional soybean meal and a squid protein concentrate as partial replacement of the fishmeal (diet 3). Midgut gland extracts from the three treatments and wild prawns (control) were assayed to quantify proteinase activity. Specific inhibitors were used to identify proteinase classes by SDS-PAGE. Specific proteolytic activity was highest in the wild prawns and in prawns fed diet 2. Trypsin ac-tivity was higher in prawns fed the diets (1.9-2.6 absorbance/min/mg) than in wild prawns (0.6 absorbance/min/mg). Chymotrypsin activity was high- est in prawns fed diet 2. Proteinase activity in samples on azocasein was inhibited by soybean trypsin inhibitor and Nα-p-tosyl-L-lysine chloromethyl ketone. Electrophoresis revealed at least six different bands with zones having caseinolytic activity in prawns fed the diets as compared to wild prawns, including four trypsins (16.6, 18.2, 21.9, and 25.1 kDa) and one chymotrypsin (53.7 kDa). Our findings indicate that proteolytic activity in A. longinaris adapts to the quality of the dietary protein and that fishmeal can partially be replaced by additional soybean meal in combination with squid protein concentrate.
Fatty Acid Profile of Spirulina platensis Used as a Food Supplement
Authors: Diraman Harun , Koru Edis , Dibeklioglu Hamdi
Published: February 2021

The commercially produced multicellular microalgae, Spirulina platensis, is widely consumed by humans in the Aegean area of Turkey as a food addi- tive or a whole food. The fatty acid profiles of six commercial tablets pro- duced from S. platensis in Turkey and one from China were determined. The samples contained 33.68-66.75% saturated fatty acids (SFA) and 28.20-47.78% polyunsaturated fatty acids (n-3 and n-6 PUFA). Spirulina platensis is a rich source of gamma linolenic acid (GLA), which accounted for 4.07-22.51% of the fatty acids. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were found in only two samples where they accounted for 1.79 and 7.70%, and 2.28 and 2.88%, respectively. There was a significant (p<0.05) variation among samples in total SFA, monosat- urated fatty acids (MUFA), PUFA, GLA, total unsaturated fatty acids (UFA), and ratio of n-3 to n-6 PUFA. The S. platensis samples from Turkey were classified by fatty acid profile using two multivariate statistical methods, Principal Component Analysis and Hierarchical Cluster Analysis. Clustering produced defined groups according to production site.
Surveillance of Emerging Fish Viral Pathogens in Some Southeast Asian Countries
Authors: Lio-Po Gilda , Amar Edgar , Peña Leobert de la , Orozco Zenith Gaye , Faisan Joseph , Suarnaba Vonie , Tubo Delia Belle
Published: February 2021

Preventing the transboundary movement of fish viral pathogens in a global environment requires active surveillance. This study examined the presence of three emerging viral pathogens among koi, common, grass, and silver carp in Cambodia, Lao PDR, Myanmar, Philippines, and Vietnam. The stud- ied viruses included koi herpesvirus (KHV), spring viremia of carp virus (SVCV), and grass carp reovirus (GCRV). Detection methods consisted of virus isolation by cell culture, infection assay in naive fish, polymerase chain reaction (PCR), and reverse-transcriptase PCR (RT-PCR). Tissues were collected and pooled from 193 fish samples in Dec. 2004 to Feb. 2005, 406 in Sep. 2005 to Feb. 2006, and 1302 in Oct. 2006 to Feb. 2007. For cell cul- ture, tissue filtrates were prepared from pooled spleens, kidneys, livers, and gills and inoculated onto koi fin (KF-1), grass carp kidney (GCK), and fat head minnow (FHM) cells. For infection assay, tissue filtrates were injected intraperitoneally to healthy, naive common carp. No virus was detected after three cell culture passages and the infection bioassays. One-step and nest- ed-step PCR was used to detect KHV in gills of fish samples. One-step and semi-nested RT-PCR was used to detect SVCV and GCRV in the spleens, kidneys, and livers of fish samples. Samples from all three years from all five countries yielded negative results for all three viruses, indicating that KHV, SVCV, and GCRV were not present in these five countries during the period of the study although KHV outbreaks had been detected in Indonesia, Taiwan, Japan, Thailand, China, and Malaysia.
Bacteria in Rainbow Trout (Oncorhynchus mykiss) in the Southern Black Sea Region of Turkey - A Survey
Authors: Kayis Sevki , Capkin Erol , Altinok IIhan
Published: February 2021

Thirty-two freshwater rainbow trout (Oncorhynchus mykiss) farms, two rain- bow trout marine cages, and one research station in the Black Sea region of Turkey were surveyed for bacterial pathogens and diseases in 2006- 2008. Forty bacterial isolates were phenotypically identified in 558 fish. Yersiniosis, furunculosis, vibriosis, motile Aeromonas septicemia, bacterial cold water disease, and Pseudomonas infection were recorded. Infections caused by Yersinia ruckeri, A. hydrophila, and A. salmonicida occurred most frequently, but one or two outbreaks of P. putida, Flavobacterium psy- chrophilum, and P. luteola infection were also recorded. Most of the bacte- ria were isolated in spring and summer rather than fall and winter. Susceptibility to antibiotics was fairly consistent regardless of geographic area or year of isolation. Fifty percent or more of the bacteria were resistant to ampicillin, cephalothin, erythromycin, neomycin, sulfamethoxazole, tetra- cycline, and O/129. The most effective antibiotics were oxolinic acid and flo- refenicol.
Optimal Dose of Total Residual Oxidants for Hybrid Tilapia (Oreochromis mossambicus x O. niloticus) and Whiteleg Shrimp (Litopenaeus vannamei) in Ozone-Treated Sea Water
Authors: Lee Hung-Tsai , Lee Hung-Jen , Wang Jih-Temg , Leu Ming-Yih , Meng Pei-Jie
Published: February 2021

The purpose of this study was to use total residual oxidants (TRO) as an indicator for determining the optimal ozone dosage needed to control water quality and thereby enhance survival of cultivated aquatic organisms. When the TRO concentration was maintained at 0.16 mg/l for two hours, the total bacteria plate count dropped from 7.7 x 103 CFU/ml in the untreated sea water to less than 10 CFU/ml in the ozone-treated sea water. The TRO con- centration in the ozone-treated water was well below the 96-h LC50 for hybrid tilapia (Oreochromis mossambicus x O. niloticus) and whiteleg shrimp (Litopenaeus vannamei) determined in this study. Hence, adjust- ment of the ozone concentration in aquacultural sea water is a viable option that simultaneously kills the majority of harmful bacteria in the water and enhances survival of cultivated aquatic organisms.
Evaluation of Feed Stimulants in Diets for Sea Bream (Sparus aurata)
Authors: Chatzifotis Stavros , Arias Marta Vazquez , Papadakis Ioannis E. , Divanach Pascal
Published: February 2021

Six isoprotein and isolipidic diets were formulated to investigate the effect of dietary additives on growth and feed efficiency of sea bream (Sparus aura- ta) fry fed a fishmeal-based diet for 80 days. The additives (protorsan, hydrolyzed fish protein, squid meal, krill meal, and betaine + inosine-5’- monophosphate) were added to the diets at the expense of fishmeal. The specific growth rates of the fish ranged from 2.17-2.18% per day for the pro- torsan and control groups to 2.42% per day for the group fed the squid addi- tive. Significant differences (p<0.05) in final body weight and specific growth rate were detected only between the protorsan and control groups and the squid additive group. The feed conversion ratio ranged from 1.04 in the group fed hydrolyzed fish protein group to 1.24 in the group fed krill with no statistically significant differences (p>0.05) between treatments. The feed stimulating action of taurine was tested by observation. Pellets coated in a taurine solution were more actively consumed than control pellets during the morning feeding but consumption did not differ during the afternoon feeding.
Effects of Seminal Plasma Composition on Sperm Motility in Mirror Carp (Cyprinus carpio)
Authors: Bozkurt Yusuf , Ogretmen Faith , Secer Faik Sertel , Ercin Ugur
Published: February 2021

This research provides data concerning the biochemical (ionic and organic) composition of sperm of the mirror carp (Cyprinus carpio) and its relation- ship to spermatozoa motility. Seminal plasma contained 67.12±1.06 mM/l Na+, 105.1±2.24 mM/l K+, 7.85±0.67 mg/dl Ca2+, 2.61±0.11 mEq/l Mg2+, 0.14±0.002 g/dl total protein, 10.3±1.01 mg/dl triglyceride, 6.83±0.72 mg/dl cholesterol, and 54.72±3.49 mg/dl urea. A positive relationship (p<0.05) was determined between Na+ and motility (r = 0.522). On the other hand, Ca2+, K+, and Mg2+ ions negatively correlated (p>0.05) with motility (r = -0.565, r = -0.160, and r = -0.184, respectively). Spermatozoa motility correlated negatively (p>0.05) with protein (r = -0.233), triglyceride (r = -0.348), and urea (r = -0.331) but positively with cholesterol (r = 0.012). This information will help to develop cryopreservation procedures, to meet species-specific extender requirements, and to optimize artificial fertilization procedures in mirror carp.