bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation Of Plant Proteins As Partial Replacement For Animal Proteins In Diets For Penaeus Indicus And P. Merguiensis Juveniles
Authors: Peñaflorida Veronica D.
Published: February 2021

The growth rate and survival of two white shrimps, Penaeus indicus and P. merguiensis, fed diets in which fishmeal was partially replaced with plant protein sources were investigated in three trials. In trial 1 with P. indicus, soybean, yeast and leaf meals of kangkong, papaya and Cassia tora L. were screened as partial substitutes for fishmeal. The total biomass of shrimp fed 20% yeast (20yeast) was highest but not significantly different than that of shrimp fed 10yeast and 10papaya. Survival was highest with 20yeast, 10papaya and 10yeast . Shrimp fed Cassia tora L. had the highest weight gain and SGR but their survival was similar to those fed poor performing diets. In trial 2 with P. merguiensis, the ingredients were modified by decreas- ing fishmeal and increasing the yeast and soybean substitution. The biomass of the shrimp fed 10yeast was similar to that of the shrimp fed 20yeast and 26soybean, the weight gain and SGR were similar to shrimp fed 20yeast while survival was highest but not different from 20yeast and 26soybean. In trial 3 with P. indicus, weight gain and SGR were best with 20yeast and 34soy- bean. However, biomass and survival did not differ among replacement levels.

The performance of the white shrimp varied with different levels of yeast and soybean meal incorporation. The response of P. indicus was best with 20yeast (15% by weight) or 34soybean meal (34% by weight) while that of P. merguiensis was with 10yeast (7% by weight), 20yeast (15% by weight) or 26soybean meal (26% by weight). Partial replacement of fishmeal with yeast or soybean meal would result in lower feed costs but the use of these feeds needs further refine- ment since survival was low in all treatments. Rearing techniques, such as increasing the feed- ing frequency, simulating deep pond conditions or using adequate substrates, should be refined.
Distribution Of Different Forms Of Copper In Freshwater Pond Soils Of Orissa, India
Authors: Adhikari S.
Published: February 2021

The distribution of native copper fractions in freshwater pond soils of Orissa and their relation- ship to important soil properties were studied. Total Cu and diethylene triamine penta acetic acid (DTPA) extractable Cu ranged 7.0-24.0 and 2.0-4.9 mg/kg soil, respectively, with mean values of 12.7 and 3.1 mg/kg. The amounts of exchangeable, weakly adsorbed, moderately adsorbed, strongly adsorbed and organic matter associated Cu ranged 1.7-2.6%, 3.5-6.0%, 3.3-6.6%, 0.7-2.2% and 0.8-7.2% of the total Cu, respectively. Cu occluded or bound by car- bonates or other acid-soluble mineral fractions was 1.5-6.1% of the total Cu. Most of the Cu (58-91%) was in the residual fraction. All the chemical fractions of Cu significantly correlated with each other and with the organic carbon status of the soils.
Fertilization Of Freshwater Fish Ponds With Cobalt And Its Adsorption And Desorption In The Pond Sediment
Authors: Adhikari S. , Ayyappan S.
Published: February 2021

The use of cobalt as a micro-nutrient fertilizer in the culture of the freshwater Labeo rohita was evaluated in terms of primary productivity, Chlorophyll a production, plankton volume and fish growth. Three cobalt doses (5, 10 and 15 kg CoCl2/ha) were tested. In the 5 and 10 kg CoCl2/ha treatments, primary productivity, Chlorophyll a production, plankton volume and growth of Labeo rohita increased (p<0.05). The highest increment was obtained in the 10 kg CoCl2/ha treatment. The adsorption and desorption of the cobalt in the pond sediment fit the Langmuir isotherm. The highest adsorption and desorption values were found in pond sediments from the Dhenkanal area, due to its higher clay content, total Mn content and pH, indicating that sediments with a higher capacity to adsorb cobalt also have a higher capacity to desorb cobalt.
Production Of Androgenetic Nile Tilapia, Oreochromis Niloticus L.: Optimization Of Heat Shock Duration And Application Time To Induce Diploidy
Authors: Karayücel Sedat , Karayücel Ismihan , Penman David , McAndrew Brendan
Published: February 2021

Diploid androgenetic Nile tilapia, Oreochromis niloticus, were produced using 5 min UV irradia- tion at 150 μW/cm and heat shock at 42.5oC for 3:30 min applied 25 min after fertilization. The survival rates to morula, pigmentation, hatching and yolk sac resorption stages were 42.84±4.73%, 10.69±2.24%, 2.03±0.60% and 0.07±0.07% (relative to controls), respectively. A significant female, but not male, effect on the survival was confirmed. Multilocus DNA finger- printing produced by hypervariable 33.15 DNA probe verified the all-paternal inheritance in the androgens. The sex ratio of the androgenetic tilapia was not significantly different from the expected ratio of 1:0 (male:female), indicating that O. niloticus has a monofactorial sex-deter- mining mechanism with female homogamety and male heterogamety. This study confirmed that the YY genotype is viable and fertile in O. niloticus.
Growth And Yield Of Asian Catfish Clarias Macrocephalus (Gunther) Fed Different Growth-Out Diets
Authors: Coniza Eliseo B. , Catacutan Mae R. , Tan-Fermin Josefa D.
Published: February 2021

Juveniles of the Asian catfish Clarias macrocephalus (3.6±0.17 g; 78.0±0.09 mm) were fed one of four diets: a laboratory-formulated diet of 18.9% (Diet 1) or 34.2% (Diet 2) protein, a com- mercial feed pellet of 28.9% protein (Diet 3) or a diet of 80% blanched chicken entrails and 20% rice bran (31.7% protein; Diet 4). After 120 days of culture, catfish fed Diet 2 grew significantly better (p<0.05) than the other groups, reaching 108.9 g and 232.8 mm (daily weight gain 0.88 g; specific growth rate 2.9%), with a condition factor of 0.86 and production of 18.2 kg per 25 m2 pen. Feed conversion with Diets 2 and 3 (2.5 and 2.3, respectively) was better than with Diets 1 and 4 (3.4 and 5.0). Survival (68-81%) did not differ significantly among treatments (p>0.05). Catfish fed Diet 2 had the highest apparent lipid retention (131.7%). The protein efficiency ratio was lowest (1.3) in Diet 2, but did not differ significantly from Diets 1 and 3. Catfish fed Diet 4 were fatty and had a lower crude protein content. Results suggest that C. macrocephalus fed 34.2% crude protein have a significantly higher weight and total yield. Further, a taste test showed that odor, flavor and appearance did not differ amongst the diets.
Growth And Feed Consumption Of Young Rainbow Trout (Oncorhynchus Mykiss) Exposed To Different Photoperiods
Authors: Ergün Sebahattin , Yigit Murat , Türker Ali
Published: February 2021

A feeding experiment was carried out in a brackish water (18 ppt) flow-through system to deter- mine the effects of different photoperiods (light hours/dark hours; L/D) on feed intake and growth performance of young rainbow trout (Oncorhynchus mykiss). Duplicate groups of fish (35.32 g avg body wt) were exposed to a natural photoperiod, a long photoperiod (16L/8D) or a continu- ous photoperiod (24L/0D) for 60 days and fed to satiation twice a day. The growth rate, daily feed intake and feeding rate in the natural photoperiod were significantly lower (p<0.05) than in the long and continuous photoperiod groups. Growth was highest in the continuous photoperiod, but did not significantly differ from the long photoperiod. The feed conversion ratio, feed efficiency and gross efficiency in the long and continuous photoperiods were slightly better (about 5-7%) but did not significantly differ (p>0.05) from the natural photoperiod. Survival was not significantly (p>0.05) affected by the treatment. For better growth and a lower food conversion rate, the long photoperiod is recommended for young rainbow trout.
The Gut Contents Of Grass Carp, Ctenopharyngodon Idella, Drug Nursing In An Earthen Pond
Authors: Kirkagaç Mine Uzbilek
Published: February 2021

Grass carp fry (0.04±0.01 g avg wt; 1.48±0.03 cm total length) were stocked into an earthen pond in June. Every week for twelve weeks, fifteen fish were sacrificed and the content of their guts was examined. At the first week, animal material represented 74% of the gut contents. From the second week onwards, plant material was higher (mean value 79%). In the seventh week, when grass carp reached 4.83±0.09 cm, filamentous algae were replaced by macrophyte frag- ments. Besides the macrophytes, animal material such as the rotifers Monostyla and Lecane and the cladoceran Bosmina were found and the proportion of animal material in the gut varied 11-26%.
Carbon Dioxide Removal Rate By Aeration Devices In Marine Fish Tanks
Authors: Eshchar Micha , Mozes Noam , Fediuk Michael
Published: February 2021

A procedure for measuring the transfer coefficient KLa for the removal rate of carbon dioxide by aeration devices in fish tanks was developed in the National Center for Mariculture in Eilat, Israel. The KLa for a paddlewheel and a submerged aerator were calculated, following experi- ments in which the aeration devices were used simultaneously for both carbon dioxide stripping and oxygenation. The paddlewheel was more efficient, with a transfer rate up to 1,200 g CO2 per hour and a stripping efficiency of 1.2 kg CO2 per kWh. In intensive sea bream culture, the cal- culated maximum feed load that a single paddlewheel aerator can support is 43.6 kg feed per day with an energy requirement of about 1.0 kWh per kg fish produced.
Inheritance Of The White-Red (Kohaku) Color Complex In Ornamental (Koi) Carp (Cyprinus Caprio L.)
Authors: Gomelsky Boris , Cherfas Nina , Hulata Gideon , Dasqupta Siddhartha
Published: February 2021

Color variability was investigated in three normal (amphimictic) and three meiotic gynogenetic progenies obtained from white-red (kohaku, according to Japanese classification) koi parents. All the amphimictic and gynogenetic progenies consisted of three color types – white, white-red and red. The ratio of colors depended on the relative coverage by red patches in the kohaku parents. The lowest percentage of red fish and highest proportion of white fish were recorded in progeny obtained from kohaku parents with relatively weak development of the red color. The percent coverage by red patches was measured in a sample of thirty or sixty white-red fish from each amphimictic progeny and the distribution of color classes within the sample was determined. The distribution of the sample, together with the white:white-red:red ratio in the total progeny, was used to estimate the color class distribution in the entire progeny (including the solid white and solid red individuals). In two of the amphimictic progenies, the fish clearly divided into two groups: non-red (solid white and white-red) and solid red fish. Appearance of these groups might be explained by the existence of some major color-determining gene(s), which determine(s) the background color (either white or red) of the individual fish. It is also suggested that the devel- opment of red patches in fish with a white body background is controlled by many genes with alleles that either maintain the white color or induce the appearance of red patches.
Effects of Chloramine-T And CuSO4 On Enzyme Activity Of Glucose 6-Phosphate Dehydrogenase From Rainbow Trout (Oncorhynchus Myskiss) Erythrocytes In Vitro An In Vivo
Authors: Çiltas Abdulkadir , Erdogan Orhan , Hisar Olcay , Çiftçi Mehmet
Published: February 2021

Traditional treatments of parasitic and bacterial diseases are based on chemotherapeutic com- pounds such as chloramine-T and CuSO4. Although many compounds are used in fish treat- ments, their undesirable effects are not known. In this study, glucose 6-phosphate dehydroge- nase (G6PD) was purified from rainbow trout (Oncorhynchus mykiss) erythrocytes by hemolysate preparation, ammonium sulfate precipitation and 2’, 5’-ADP Sepharose 4B affinity gel chromatography in a single day. The enzyme, with a specific activity of 14.51 EU/mg protein, was purified 906.8-fold with a yield of 70.38%. To check the purity of the enzyme, SDS poly- acrylamide gel electrophoresis was performed, which showed a single band. The effects of chlo- ramine-T and copper sulfate (CuSO4) on the G6PD were investigated in vitro. Chloramine-T and CuSO4 had inhibitory effects on the enzyme. I50 values of the chemotherapeutic compounds were determined by plotting percent activity and Ki values, and types of inhibition were deter- mined for each compound by means of Lineweaver-Burk graphs. In vivo studies showed that G6PD in rainbow trout erythrocytes was significantly inhibited by CuSO4 in one hour but not inhibited by chloramine-T.
Influence Of Brackish Water On Survival And Growth Of The Juvenile White Grouper, Epinephelus aeneus
Authors: Ron Benny , Peduel Adi
Published: February 2021

The natural habitat of the white grouper, Epinephelus aeneus, is the Mediterranean Sea, which has a salinity of approximately 35 ppt. As fish species vary in their tolerance of environmental conditions, potential production in specific conditions must be determined empirically. The growth, survival and cortisol level of 1.7 g grouper juveniles grown in diluted sea water (4 ppt) or brackish water (4 ppt) from the Tsofar well in the Arava (southeastern Negev, Israel) was com- pared to the growth of similar fish in sea water (43 ppt). Survival in all treatments was 100%. During the first ten days, the fish grown in brackish water grew significantly less (p<0.01) than the fish grown in full-strength or diluted sea water. There were no significant differences between the treatments during the second growth period or in the final weight (approximately 9 g). Total cortisol concentrations ranged 2.7-4.5 ng/l and did not significantly differ between treatments. Results indicate that the white grouper can flourish in water with salinity as low as 4 ppt and that there are no detrimental chemical factors in the brackish water from the Tsofar well.
Key Factors Influencing Juvenile Quality In Mariculture: A Review
Authors: Koven William
Published: February 2021

Environmental (temperature, salinity) and nutritional (DHA, EPA, ArA, vitamin A, phospholipids, iodine) factors during larvae rearing largely dictate the successful transformation of larvae to juveniles during metamorphosis which, in turn, determines juvenile quality. Studies on Atlantic halibut, turbot and Japanese flounder report higher metamorphic success, in terms of pigmen- tation, eye migration and general development, when copepods, rather than enriched Artemia, were fed to larvae. Copepods have higher levels of vitamin A, which is required for the synthe- sis of rhodopsin in the retina, a critical visual pigment in the rods necessary for vision at low light intensities. Deficient rhodopsin affects neural transmission from the retina via the central nervous system that triggers pituitary production of melanophore stimulating hormone leading to reduced melanin synthesis and pigmentation deficiency. DHA, an abundant PUFA in copepods, is also vital to vision as it provides the membrane fluidity necessary for rhodopsin to function when stim- ulated by light. The essential fatty acids EPA and ArA are more involved in eicosanoid synthe- sis. These highly potent metabolites are thought to regulate the mechanisms involved in the release of melanophore stimulating hormone and pigmentation. Thyroid hormones play a major role in regulating many developmental processes that occur during metamorphosis. Immersing different age marine fish larvae into various concentrations of thyroid hormone has been shown to synchronize and shorten the duration of metamorphosis in a dose dependent manner in species such as grouper. However, the effect of this immersion on survival varied with the type of thyroid hormone, dose and timing of application. In some species, such as the European seabass (Dicentrarchus labrax), females grow up to 40% faster than males. However, when this species is intensively cultured, masculinization can result in a 70-90% male population. A num- ber of studies have shown that manipulating temperature and salinity during larviculture can result in higher quality juveniles, i.e., a higher percent of faster growing females.
Parental Effects On Sex Ratios In Progeny Of The European Sea Bass (Dicentrarchus Labrax)
Authors: Gorshkov S. , Meiri I. , Rosenfeld H. , Ben-Atia S. , Lutzki S. , Peduel A. , Ron B. , Skvortzov A. , Gorshkova G. , Tandler A.
Published: February 2021

In European sea bass (Dicentrarchus labrax), females grow 20-50% faster than males. Therefore, they are more in demand than males for commercial farming, generating much inter- est in the development of female monosex populations. Whereas most current research focus- es on the influence of temperature on sex determination, the present experiments aimed at studying parental effects on sex ratios in progeny. The study analyzed progeny resulting from a diallel crossing (2 x 2 type or a complete bi-factorial mating design), reflecting both maternal and paternal genetic relatedness among progeny. The proportion of females varied significantly among families (20.7-68.2%). There were significant maternal and paternal effects on the pro- portion of females among the progeny. The effect of the parental interaction on the sex ratio in the progeny was also significant. Parents had a significant effect on total length and body weight. Sexual growth dimorphism, in favor of females, was evident in all the full-sib families and varied significantly between families. Among offspring at 9-9.5 months (68.9±23.7 g), females were 26.6% heavier than males. It is concluded that in addition to temperature manipulation in sea bass, as proposed in earlier studies, selection of parents will probably result in an improved ratio of female to male progeny.
Effect Of Dietary Olive Pomace Oil And L-Carnitine On Growth And Chemical Composition Of African Catfish, Clarias Gariepinus (Burchell, 1822)
Authors: Yilmaz Erdal , Naz Mehmet , Akyurt Ihsan
Published: February 2021

The effects of dietary olive pomace oil and L-carnitine on growth performance, body indices and chemical composition of African catfish, Clarias gariepinus, were investigated. A 3x2 factorial design was used by offering diets having three different energy/protein ratios and supplemental L-carnitine at either 0 or 2000 mg/kg diet. Ten juvenile African catfish (12 g/fish) were stocked into 80-l glass aquaria and fed an experimental diet for seven weeks. The L-carnitine supple- mentation did not affect body indices. However, growth and chemical composition were influ- enced by both dietary lipid and L-carnitine. The increase in muscle lipid was greater than in the liver for all treatments. Fish fed the high energy diet (9% olive pomace oil) had a low appetite and feed intake, while fish fed the low energy diet (3% olive pomace oil) and supplemental L- carnitine had better feed intake and growth. On the other hand, fish fed the high energy diet (9% olive pomace oil) with or without L-carnitine had better feed conversion.
Live And Inert Foods For Postlarvae Of The Giant Freshwater Prawn Macrobrachium Rosenbergii
Authors: Belsare S.G. , Indulkar S.T.
Published: February 2021

Five live or inert food organisms (adult Artemia, Moina, Tubifex worms, clam meat, poultry egg custard) were evaluated as feed for postlarvae of Macrobrachium rosenbergii. The postlarvae (avg 5.2±0.22 mg, 7.2±0.38 mm) were reared in plastic pools (0.9 m diameter x 0.6 m) contain- ing 100 l fresh water, stocked at one postlarva per liter for 30 days, with five replicates of each treatment. There were significant differences (p<005) in final weight gains of the postlarvae (62.94-88.86 mg), final length gains (16.45-20.71 mm) and survival (69.67-92.33%). The live Moina were superior to the other foods with a significantly higher weight gain (1708.92±54.03%), length gain (287.70±4.76%) and specific growth rate (9.45±0.1%/d). The higher protein (66.16%) and n-3 HUFA (10.20%) levels in Moina may explain these results.
Effects Of Fresh And Sea Water On Growth, Estradiol-17β Concentration And Ovarian Development In Juvenile Tilapia
Authors: Altun Tülay , Sarıhan Ercan , Kayrın Levent , Doran Figen
Published: February 2021

The effects of fresh water and sea water on growth, estradiol-17β levels, ovarian and oocyte development of Oreochromis niloticus, O. aureus and Tilapia zilli were determined. Sea water affected growth positively (p<0.05) but estradiol-17β concentrations in fish reared in sea water did not reach the levels in fish reared in fresh water. Ovarian stages developed differently in sea and fresh water. Ovulation occurred only when the fish were grown in fresh water whereas mature and atretic oocytes were seen simultaneously in all species when grown in sea water. There were no statistically significant differences in oocyte diameter between the groups grown in fresh and sea water (p>0.05).
Digestibility Of Nutrients And Energy In Diets For The African Catfish Clarias Gariepinus (Burchell 1822)
Authors: Pantazis Panagiotis A. , Neofitou Christis N.
Published: February 2021

A purified diet, the raw material zein, and two diets composed of complex foodstuffs (fishmeal, soy, wheat) were tested for eight months in the African catfish Clarias gariepinus (Burchell 1822) to determine the in vivo Apparent Digestibility Coefficients (ADC) for dry matter, crude protein, lipid, carbohydrates, ash, energy, and amino acids. Feces were collected by sedimentation and digestibility coefficients were calculated using chromium oxide as an external indicator. Average ADCs ranged 54-96%. The ADC of crude protein (80-90%) was similar to previously recorded ADCs. Ash digestibility (54-89%) varied significantly between diets, probably as the result of the reduced bioavailability of minerals and trace elements in the constituent raw materials. ADC for individual amino acids ranged 82-99%. Zein, as an experimental feed ingredient, had an accept- able ADC for both gross nutrients and amino acids. When the nutrient level in the test ingredi- ent differed greatly from that in the reference diet, calculation of ADC was based on relative nutri- ent contributions. Results are discussed in relation to the nature of the dietary ingredients and their suitability for related experimental nutritional work.
Effects Of Fish Density On Spread Of Infectious Hematopoietic Necrosis Virus (IHNV) In Rainbow Trout, Oncorhynchus Mykiss
Authors: Ogut H. , Reno P.W.
Published: February 2021

Rainbow trout (Oncorhynchus mykiss) were held at one of seven densities (8, 4, 0.63, 0.31, 0.16, 0.08 or 0.012 fish per liter) and challenged to the infectious hematopoietic necrosis virus (IHNV) by cohabitation with a single presumably infected donor fish. The trout were exposed to the IHNV-infected fish for 11 days to determine the effect of density on occurrence, spread and prevalence of the disease. The host density and IHNV prevalence were positively associated (r2 = 0.89, regression analysis) with no occurrence of the virus at the two lowest densities (0.08 and 0.012 fish/l). Host density, therefore, is a key factor in determining the incidence and magnitude of IHNV infection.
Enteric Red Mouth Disease In Cultured Rainbow Trout (Oncorhynchus Mykiss) On The Black Sea Coast Of Turkey
Authors: Karatas Süheyla , Candan Akin , Demircan Didem
Published: February 2021

Although Yersinia ruckeri, the etiological agent of the enteric red mouth disease (ERM), has been isolated from freshwater fish in several countries, there are few reports of its presence in cultured sea and brackish water fish. The aim of this study was to isolate and identify the etio- logical agent of disease outbreaks that occurred in rainbow trout cage farms on the Black Sea coast of Turkey in 2002. Clinical observation, biochemical, API 20 NE, and agglutination tests allowed the diagnosis of ERM caused by Y. ruckeri, which was successfully treated with med- icated feed (oxytetracycline at 75 mg per kg body weight per day for 10 days).
Fertility Problems In The Second Generation Of A Four-Species Tilapia Cross
Authors: Hulata Gideon , Cnaani Avner , Slossman Tatiana , Gall Graham A.E.
Published: February 2021

Reproductive problems were encountered in attempting to produce the second generation of a four-way cross of tilapia from interspecific F1 hybrids. The cross (Oreochromis mossambicus x O. aureus) x (Sarotherodon galilaeus x O. niloticus) successfully bred for one generation, how- ever, not even a single batch of progeny was obtained in the subsequent generation. It was con- cluded that the complex genetic structure of this cross caused the fertility problem. Any similar breeding programs that are based on multi-species crosses should take into consideration that reproductive problems may occur.
Masculinization Of Genetic Females Of The Common Carp (Cyprinus Carpio L.) By Dietary Administration Of An Aromatase Inhibitor
Authors: Tzchori Itai , Zak Tatyana , Sachs Ofer
Published: February 2021

In the present study, we demonstrated the ability of Fadrozole, an aromatase inhibitor, to induce sex inversion of genetically female common carp fry during the critical sex differentiation period. Thirty-day-old female fingerlings with a mean initial weight of 4.0 g (experiment I) and 3.5 g (experiment II) were fed a diet containing Fadrozole for 36 or 50 days, respectively. Not a single male was found in the control groups of both experiments. In experiment I, Fadrozole at 200 mg/kg feed resulted in 58.6% males, while fish receiving 17α-methyltestosterone at 50 or 100 mg/kg feed resulted in only 5-10% males. In experiment II, the efficiency of Fadrozole was dose- dependent; the lower dose of 100 mg/kg caused masculinization in 86% of the treated fry while the higher doses of 200 and 400 mg/kg feed increased the percentage of males to 97%. These results confirm the importance of aromatization during the labile period in common carp since low aromatase activity during this period, regardless of genotype, resulted in masculinization.
Alteration Of Renal Tissue In Nile Tilapia, Oreochromis Niloticus, After Transfer To Saline Water
Authors: Benli A.C. Karasu , Yildiz H. Yavuzcan
Published: February 2021

Changes in renal tissues and plasma osmolality were investigated in Nile tilapia (Oreochromis niloticus) 72 hours after transfer from fresh water to 9 or 18 ppt salinity. Exposure to high salin- ity was associated with cell infiltration into renal tissue. Plasma osmolality increased with increasing salinity but the hematocrit remained unchanged.
Use Of Nitrification Inhibitors To Increase Efficiency Of Nitrogenous Fertilizers In Aquaculture
Authors: Thakur Amrita , Banerjee Abira , Chattopadhyay G.N.
Published: February 2021

High doses of nitrogenous fertilizers are often applied in fishponds but only a small part of the added nitrogen is utilized for improving primary productivity and, thereby, fish yields. A large por- tion of the nitrogen is lost from the pond environment through various mechanisms, especially nitrification. In the present investigation, we studied the effects of three nitrification inhibitors: (a) neem (Azadirachta indica) extract, (b) karanj (Pongamia glabra) extract, and (c) sodium azide (NaN3), on the transformation of applied nitrogen in simulated fishpond conditions. The study revealed that nitrification inhibitors considerably retard the rate of nitrification from the ammoni- um form of nitrogen (NH4+), resulting in a higher amount of nitrogen in the soil and water. The increased nitrogen concentration significantly increased gross primary production and, hence, improved the efficiency of the added nitrogen.
Correlation Between Biochemical And Spermatological Parameters In Rainbow Trout (Oncorhynchus Mykiss) Semen
Authors: Secer Selçuk , Tekin Necmettin , Bozkurt Yusuf , Bukan Neslihan , Akcay Ergun
Published: February 2021

Levels of biochemical parameters in seminal plasma and physical parameters of rainbow trout (Oncorhynchus mykiss) semen were determined and compared. Seminal plasma contained 80.51±31.48 mmol/l Na+, 46.21±12.58 mmol/l K+, 4.65±1.57 mg/dl Ca2+, 3.48±1.18 mEq/l Mg2+, 112.5±25.93 mmol/l Cl-, 1.33±0.76 mg/dl glucose, 0.15±0.09 g/dl protein, 2.55±2.47 mg/dl cho- lesterol, 8.0±2.84 mg/dl triglyceride, and 31.65±40.78 mg/dl urea. Semen volume was 19.9±21.43 ml, spermatozoa motility 60.0±30.09%, duration of spermatozoa movement 174.0±1.82 s, spermatozoa concentration 1.52±0.70 x 109/ml, total spermatozoa number 44.25±64.59 x 109, and pH 6.7±0.25.

There were significant positive correlations between semen volume and Na+ (r = 0.667, p<0.05), total spermatozoa number and semen volume (r = 0.977, p<0.01), total spermatozoa number and spermatozoa concentration (r = 0.652, p<0.05), Na+ and Cl- (r = 0.733, p<0.05), Na+ and triglyceride (r = 0.632, p<0.05), K+ and protein (r = 0.728, p<0.05), and Ca2+ and protein (r = 0.685, p<0.05). Significant negative correlations were found between Cl- and glucose (r = - 1.00, p<0.05), and triglyceride and urea (r = -0.716, p<0.05). Consequently, although there were no definite correlations between biochemical and spermatological parameters, it was observed that a higher Na+ content has a positive effect on semen volume.
Use Of Glucan From Saccharomyces Cerevisiae As An Immunostimulant In Carp: Impact On Hematology, Phagocyte Function, And Infection With Aeromonas Hydrophila
Authors: Selvaraj V. , Sampath K. , Sekar V.
Published: February 2021

Glucan was extracted from yeast (Saccharomyces cerevisiae) and subjected to chemical analy- ses. Thin layer chromatography (TLC) revealed that glucan is primarily composed of glucose units and contains 97.2% glucose. Infrared spectrum showed a major band at 883/cm, suggest- ing that glucan is linked to β-glycosidic. Intraperitoneal administration of different doses of glu- can enhanced the survival rate of carp (Cyprinus carpio) infected by Aeromonas hydrophila. When a concentration above 500 μg glucan per fish was administered, survival relative to the uninfected control was 100%. The total leukocyte count and neutrophil and monocyte popula- tions increased after administration of the glucan. The maximum effect occurred on day 6 after injection. Macrophages of compound-administrated test animals significantly increased produc- tion of superoxide anions, efficiently killing the bacterial pathogen. This study showed that glu- can can be effective in inducing non-specific cellular defense mechanism in carp.
Effect Of Bacterial Load In Feeds On Intestinal Microflora Of Seabream (Sparus Surata) Larvae And Juveniles
Authors: Savaş Sevgi , Kubilay Aysegul , Basmaz Nevin
Published: February 2021

Aerobic bacterial flora in the intestines of seabream (Sparus aurata) larvae and juveniles, in diets they were fed (rotifers, brine shrimp, artificial diet), and in their rearing water were analyzed. Fish fed live feeds had a higher bacterial count than the fish fed the artificial diet. In rotifers, the total bacteria count was 8.7 x 106 and Pseudomonas dominated the flora (60.2%). In larvae fed rotifers, the bacteria count was 9.8 x 102, with Pseudomonas (48.4%) and Vibrio (28.3%) domi- nating. In brine shrimp, the bacterial count was 1.7-3.5 x 107 cfu/g and Vibrio (73.7-81.3%) was more prevalent than Pseudomonas (10.2-15.5%). In larvae fed brine shrimp, the bacterial count was 5.3 x 104-1.8 x 105 and Vibrio (61.2-70.1%) dominated. The count for the artificial feed was 1.2 x 104 with Pseudomonas slightly dominating while for juveniles fed artificial feed the count was 2.3 x 104, with Vibrio slightly dominating. Bacterial microflora in the rearing water ranged from 1.3 x 102 to 3.2 x 103 cfu/ml. The study showed that the microflora of fish feeds quantita- tively and qualitatively affect the intestinal microflora of seabream larvae and juveniles.
Management induced changes in food selection, growthandsurvivalofkoicarp,Cyprinuscarpiovar.koi l.,Intropicalponds
Authors: Jha Prithwiraj , Barat Sudip
Published: February 2021

The effects of different management regimes on the feeding habits and food selection of koi carp (Cyprinus carpio var. koi L.) larvae were examined. Weight gain, fish deformities, and survival were compared in an 11-week growth trial conducted in tropical ponds maintained according to four culture regimes: (1) live food system; (2) poultry manure treated system; (3) cow dung treat- ed system; and (4) a control. The Ivlev’s Electivity Index showed that koi larvae avoided phyto- plankton and preferred cladocerans, an important source of natural food in all the regimes. In the poultry and cow manured ponds, the larvae were negatively elective towards copepods although they were more abundant than cladocerans. Weight gain and survival was significantly higher in the live-feed system (p<0.05) than in the other systems. Fish deformities were significantly high- er (p<0.05) in the control.
Effects of dietary fish oil, soy-acid oil, and yellow grease on growth and hepatic lipidosis of hybrid tilapia fry
Authors: Genc Ercument , Yilmaz Erdal , Akyurt Ihsan
Published: February 2021

The objective of this study was to compare the effects of dietary lipids on growth and liver histopathology of hybrid tilapia, Oreochromis niloticus x O. aureus, fry (6.0 g). Fish were fed one of six diets containing 8.4% fish oil (control), 8.4% soy-acid oil, 8.4% yellow grease, 5.6% yellow grease plus 2.8% soy-acid oil, 2.8% yellow grease plus 4.6% soy-acid oil, or 4.2% soy-acid oil plus 4.2% yellow grease for 60 days. Growth was similar in all groups and retarded in compari- son to earlier studies. Lipid accumulation as well as microvesicular (foamy degeneration) and macrovesicular degeneration in the liver were histopathologically detected.
Use of geographic information system (GIS) to select fish cage farming sites in Surmene Bay, Black Sea
Authors: Guneroglu Abdulaziz , Kose Ercan , Eruz Coskun , Basar Ersan , Erkebay Sebnem
Published: February 2021

Attempts to develop open sea fish farming projects in the Black Sea have often failed due to poor site selection. This problem can be solved by using the Geographic Information System (GIS) to collect, manipulate, query, display, and integrate various data sets. In this study, data sets were arranged together to analyze habitats and a site selection methodology was developed for the coastal region of Trabzon on the Surmene Bay. Data included temperature, salinity, and current velocity, collected during regular cruises of the KTU-R/V Denar-I research vessel. Shoreline data were digitized using regional maps and spatial relationships were examined using Boolean Algebra. Two interpolation methods (Kriging and Inverse Distance Weight) were used to form thematic maps and identify optimal sites for a rainbow trout cage farm. No significant differences were found between the results of the two methods. Temperature was the most influential fac- tor determining the final site position.
Effect of short-term preservation of mirror carp (Cyprinus carpio) semen on motility, fertilization, and hatching rates
Authors: Bozkurt Yusuf , Secer Selçuk
Published: February 2021

Mirror carp (Cyprinus carpio) semen was collected by hand stripping for short-term preservation. Two groups of pooled semen were diluted with one of two extenders; a control group was undi- luted. The three groups were stored at 4oC for 72 h. During preservation, spermatozoa motility (%) and duration of spermatozoa movement (s) were determined every 12 h. Following preser- vation, fertilization was carried out using the dry fertilization technique at 1 x 105 spermato- zoa/egg. The highest fertilization rates were 21±3.60% in May and 16.67±2.08% in June, both significantly higher than in the control. The highest hatching rates, 69.60±11.86% in May and 89.13±10.75% in June, did not significantly differ from the control.
The first pasteurellosis case in cultured sea bass (Dicentrarchus labrax l.) at low marine water temperatures in Turkey
Authors: Korun Jale , Timur Gulsen
Published: February 2021

The first observed pasteurellosis outbreak at a low marine water temperature (18-19oC) is here- by reported. The disease was identified in three sea bass farms in the Aegean near Bodrum, Turkey. Diseased fish, Dicentrarchus labrax (L.), were characterized by lethargy, loss of appetite, darkened skin color, exophthalmia, abdominal swelling, pale gills, and hemorrhages over the operculum and ventral part of the body. Some diseased fish had hemorrhages on the head and opaque eyes. There were whitish nodules in the liver, the spleen varied in size (0.5-4 mm), and both organs were pale. Morphological, physiological, and conventional biochemical tests were used to determine the phenotypic properties of pure cultures of isolated colonies in samples taken from internal organs. Mono-Pp agglutination kit and API 20E were used to con- firm the identified bacteria. The isolated strain was Photobacterium damselae subsp. piscicida. The sensitivity of the Aquarapid-Pp kit, which produced positive results in all diseased fish, was 0.91 and the specificity was 0.95. The principal histological changes were depletion of hemo- poietic tissue and multiple round small or large necrotic and lytic areas in the spleen, vacuole degeneration and diffuse hemorrhagie in the liver, and peritubular vacuole degeneration and tubular necrosis in the kidney. Treatment with flumequine in the feed at 50 mg/kg body weight/day for seven days controlled mortality.
Effect of salinity on gestation period, fry production, and growth performance of the sailfin molly (Poecilia latipinna lesueur) in captivity
Authors: vasagam K.P. Kumaraguru , Rajagopal S. , Balasubramanian T.
Published: February 2021

Breeding and growth trials were carried out with Poecilia latipinna in different salinities (0.5, 10, 15, 25, and 35‰) and effects on gestation period, fry production, and fry growth (75 days) were examined. Results showed that while P. latipinna successfully spawned in all salinities, there was a significant difference in fry production among treatments. The minimum gestation period was 28 days in all salinities except fresh water (0.5‰); the maximum fry production was obtained in 25‰. Fry growth was highest in 10‰ and significantly differed (p<0.05) from the rest of treat- ments in terms of weight gain, specific growth rate (SGR), and feed conversion ratio (FCR). Maximum SGR was 3.35% per day in 10‰ salinity. FCR ranged 4.28-5.67. The results suggest that the optimum salinities for breeding and rearing P. latipinna are around 25‰ and 10‰, respectively.
Atypical aeromonas infection in cultured sea bass in the Black Sea
Authors: Karatas Süheyla , Candan Akin , Demircan Didem
Published: February 2021

The Black Sea, an inland sea, has contributed about 70% to the total fish production of Turkey for many years. Because of its low salinity and appropriate water temperature, both freshwater and marine fish such as salmon, trout, and sea bass can be cultured in the Black Sea. The aim of this study was to identify the etiological agent of mortality that occurred in sea bass in the Black Sea during July 2002. Bacteria isolated from kidneys and livers of infected fish were iden- tified as Aeromonas salmonicida achromogenes according to morphological and biochemical characteristics, API 20NE results, and an agglutination test for A. salmonicida. The diseased fish had petechial hemorrhages on the bottom of the fins and lesions on the lateral and ventral sides of the body. Cumulative mortality was approximately 20%. This is the first report of A. salmoni- cida achromogenes associated with sea bass in Turkey.
Induction of ovulation and spawning in the Mediterranean red porgy, by controlled delivery and acute injection of GnRHa
Authors: Kokokiris L. , Canario A. , Mylonas C. , Pavlidis M. , Kentouri M. , Divanach P.
Published: February 2021

Gonadotropin-releasing hormone analogue (GnRHa) in the form of saline injections or sus- tained-release microspheres was used to induce oocyte maturation, ovulation, and spawning in captive red porgy (Pagrus pagrus). Individually tagged vitellogenic females (n = 9 or 10) were treated at the beginning of the spawning season (March) with 20 μg/kg body weight (bw) GnRHa-loaded microspheres, a single injection of 20 μg/kg bw dissolved in saline, or physio- logical saline (control). Females were placed in tanks (one tank per treatment) connected to overflow egg collectors and monitored for 11 days. In addition to the eggs collected from the tank overflow, eggs were stripped from the fish on a daily basis. Only one spawn was obtained from the control fish, probably from a single female, given the small relative fecundity (700 eggs/kg bw). On the contrary, treatment with a GnRHa injection produced two spawns (9 and 11 days after treatment) and 50% of the fish ovulated. Treatment with GnRHa microspheres induced seven spawns (3 and 6-11 days after treatment) and 100% of the females ovulated. Females did not spawn all the eggs ovulated on a particular day, evident from the significant number of eggs obtained by manual stripping. Egg quality did not significantly differ among treatments, whereas number of spawned eggs and total relative fecundity were significantly higher in fish treated with GnRHa microspheres (ANOVA, p<0.05). The results demonstrate the potential of GnRHa- loaded microspheres to induce spawning in red porgy, as a method of overcoming spawning fail- ures in commercial hatcheries.
Filtration and ingestion rates of the rotifer Brachionus plicatilis fed five species of microalgae at different cell densities
Authors: Savaş Sevgi , Güçlü Zekiye
Published: February 2021

The microalgae Tetraselmis suecica, Nannochloropsis oculata, Chlorella sp., Isochrysis gal- bana, and Dunaliella tertiolecta were used as food for the rotifer Brachionus plicatilis (L type) raised in laboratory conditions at 25±1oC and 25‰ salinity. Filtration and ingestion rates of the rotifer were determined to study the effects of different microalgae densities and feeding times on the feeding behavior of the starved B. plicatilis. The highest filtration (11.5 x 10-4 ml/ind/min) and ingestion (246.99 x 102 cells/ind/min) rates were obtained with N. oculata. The filtration rates dropped when the microalgae density rose beyond the optimum level, but ingestion rates varied with algae species. Feeding time significantly influenced these rates: after 60 min, both rates dropped.
Exotic species in global aquaculture - a review
Authors: Rothbard Shmuel , Shelton William L.
Published: February 2021

The culture of exotic fishes contributes about 17% to global food aquaculture production. Transplanted native species add substantially to the aquatic harvest of food and sport fishes in many countries. Some countries are very dependent on the cultivation of non-native species; yields of exotics exceed 25% of the total harvest in China, 60% of the freshwater harvest in the Philippines, and 50% of the production in Brazil. Aquatic food production in Israel is predomi- nately from introduced fishes. In the USA, transplanted species are economically important as food and sport fish and exotics are used in resource management as well as a major food source. Countries of origin for globally important fishes include China (endemic carps), USA (Atlantic salmon and rainbow trout), Europe (common carp), and Africa (tilapias). The aquacul- ture production of food fish will become increasingly vital as oceanic capture fisheries continue to stagnate. Exotic and transplanted fishes that are widespread today will represent a greater proportion of future aquaculture production because technology for their culture is already well known and can readily be applied, and because these species are more easily domesticated and genetically improved.
Effect of dietary Spirulina level on growth, fertility, coloration and leucocyte count in red swordtail, Xiphophorus helleri
Authors: James Raja , Sampath Kunchitham , Thangarathinam Ramasamy , Vasudevan Iyyadurai
Published: February 2021

Experiments were performed to investigate the influence of different levels of Spirulina (0, 1, 3, 5 and 8%) on feed consumption, growth, fertility, coloration, and leucocyte count in the orna- mental red swordtail, Xiphophorus helleri. Feed intake, specific growth rate (SGR), and mean body length and weight increased as levels of Spirulina increased. Fish fed 8% Spirulina per- formed better than those fed lower levels. The gonad weight and gonadosomatic index (GSI) increased with the Spirulina level and rearing period. Fish fed 8% Spirulina had four times heav- ier gonads than fish fed 0-3% Spirulina. Female X. helleri fed 8% Spirulina released 89 young, significantly higher (p<0.01) than those fed 5, 3, 1, or 0% Spirulina (79, 64, 49, and 41 young, respectively). The total carotenoid content in the fins, skin, and muscle increased with the Spirulina level and the maximum carotenoid content was obtained in fish fed 8% Spirulina. The maximum coloration was in the fins, followed by the skin and muscle in all treatments. Fish fed 8% Spirulina had more monocytes, neutrophils, and lymphocytes and fewer basophils and thrombocytes while control fish showed the opposite trend. The necessity of incorporating an optimum level of Spirulina (8%) in the diet for maximum growth, reproduction, and coloration in X. helleri is discussed.
Application of streptomyces as a probiotic in the laboratory culture of Penaeus monodon (Fabricius)
Authors: Das Surajit , Lyla P.S. , Ajmal Khan S.
Published: February 2021

Probiotic supplementation of live microorganisms in aquaculture aids in preventing disease, thereby increasing production and decreasing economic loss. In the present study, Streptomyces cells were incorporated in Penaeus monodon (Fabricius) laboratory culture for 25 days. Streptomyces was inoculated into the feed in different concentrations (0, 2.5, 5.0, 7.5, and 10.0 g/kg feed) on days 1, 10, and 20. Growth was monitored on days 5, 15, and 25. Experimental culture tanks provided with Streptomyces had better water quality parameters than the control tank. At the cell concentration of 10 g, the pH was 7.9, ammonia 0.00067 ppm, nitrate 0.00285 ppm, phosphate 0.00224 ppm, silicate 0.00836 ppm, total heterotrophic bacteria 3.279 x 105 CFU/ml, and total Vibrio 0.2 x 102 CFU/ml. Growth increased as the Streptomyces cell con- centration increased. At 10 g concentration, growth in length and weight was 15.79% and 57.97%, respectively, and the interval between molts was 12.5 days.
Marker-assisted breeding for viral disease resistance in Japanese flounder (Paralichthys olivaceus)
Authors: Ozaki Akiyuki , Okamoto Nobuaki , Sakamoto Takashi , Fuji Kanako , Kobayashi Kazunobu , Hasegawa Osamu
Published: February 2021

DNA marker technologies can be used for genetic improvement through selection of favorable traits such as disease resistance. These traits are generally modeled as being controlled by many genes of small additive effects, known as quantitative trait loci (QTL). Construction of a genetic linkage map based on DNA markers at a large number of sites in the fish genome is necessary to identify QTL controlling traits of disease resistance. By identifying markers associated with high per- formance QTL in different strains or species, it may be possible to improve the performance of such traits in other strains through intro- gression of the desired QTL. One of the goals of selective breeding programs is to integrate genetic marker information from pedigreed brood stock into successful management and culture. Such an approach, termed marker- assisted selection (MAS) and/or marker- assisted gene introgression (MAI), is expect- ed to increase genetic response by affecting efficiency and accuracy of selection.