bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical And Pathological Investigation Of Psychrobacter Immobilis Infection In Rainbow Trour (Oncorhynchus Mykiss, Walbaum)
Authors: Hisar Olcay , Yanik Telat , Hisar Sükriye Aras
Published: February 2021

The pathogenicity of Psychrobacter immobilis, isolated from naturally infected rainbow trout Oncorhynchus mykiss, was investigated. In experimentally-infected trout, no mortality was recorded during 35 days but the following external and internal symptoms were observed. Externally, skin was darkened, gills were pale and swimming was abnormal. Internally, there were dilatations of the vascular structures on cross-sections of the liver; vascular congestion, inflammatory mononuclear cell infiltration and degeneration in the gills; interstitial inflammatory mononuclear cell infiltration and free bleeding in patches of the posterior kidney; vascular con- gestion and free bleeding in the spleen; degeneration, atrophy, polymorphonuclear leukocyte infiltration and liquefaction necrosis in muscle fibers; edema, inflammatory mononuclear cell infil- tration and basophilic degeneration among muscle fibers of the heart; and congestion in vascu- lar structures on cross-sections of the brain tissue. It is suggested that P. immobilis is an oppor- tunist pathogen that causes secondary infections.
Ammonia Nitrogen Excretion Rate - An Index For Evaluating Protein Quality Of Three Feed Fishes For The Black Sea Turbot
Authors: Yigit Murat , Koshio Shunsuke , Aral Orhan , Karaali Burcu , Karayücel Sedat
Published: February 2021

Total ammonia nitrogen excretion rates were measured in young Black Sea turbot (74.79 g avg wt) reared in brackish water (17 ppt salinity) at 11±0.3°C. Duplicate groups of turbot were fed a fixed quantity of teleosts, either anchovy (Engraulis encrasicolus), goby (Gobius sp.) or whiting (Merlangius merlangus). Feeds were offered to the turbot as wet feed. Cumulative ammonia-N excretion over a 6-hour period was significantly lower (p<0.05) in fish fed goby (3.64±0.27 mg- N/100 g fish) and whiting (3.83±0.13 mg-N/100 g fish) than that in fish fed anchovy (4.48±0.06 mg-N/100 g fish). The ammonia-N excretion rate in all groups peaked two hours after feeding, but the peak value in the group fed anchovy was significantly higher (p<0.05) than in the other two groups. No differences were observed among diets in samples taken 3, 4, 5 and 6 hours after feeding. Significantly lower excretion levels in the goby and whiting groups could be relat- ed to the protein quality of these species which may be higher than that of the anchovy for tur- bot nutrition.
Natural Spawning And Rearing Of Mangrove Red Snapper, Lutjanus Agentimaculatus, Larvae In Captivity
Authors: Leu Ming-Yih , Chen I-Hui , Fang Lee-Shing
Published: February 2021

Mangrove red snapper (Lutjanus argentimaculatus, Forsskål) spawned naturally in captivity, without the use of hormones or other treatments, from May 21 to September 15, 1999. Each female laid an average 2,350,000 eggs. Larvae were reared in 4-ton circular fiberglass tanks. They were first fed S-type rotifers (Brachionus rotundiformis). Later, Artemia nauplii and cope- pods were added to the diet. They were weaned onto an artificial diet. Metamorphosis began at 18 days when the larvae reached 10.5 mm total length and was complete by day 30 when lar- vae were 17.2 mm. From day 26, large larvae (over 25 mm) cannibalized their smaller siblings. Abnormalities were observed in 4.9% of the individuals. At 50 days, the larvae rearing trial pro- duced juveniles of 49 mm average total length with a survival of 10.8-32.3%.
Effect Of Animal And Plant Protein Diets On Growth And Fecundity In Ornamental Fish, Betta Splendens (Regan)
Authors: James Raja , Sampath Kunchitham
Published: February 2021

The effects of different levels of animal and plant protein (10%, 15%, 25%, 35% and 45%) on growth and fecundity in Siamese fighting fish, Betta splendens, were tested over a period of 154 days. Fish fed 35% animal or plant protein had the highest mean body wet weight, growth rate, gonad weight and fecundity than any other tested level. Animal protein induced gonad develop- ment earlier than plant protein. Female B. splendens fed the 35% animal protein diet had a 79% higher gonad weight (87 mg wet weight) than those fed the diet with the same level of plant pro- tein (49 mg wet weight). Spawning trials showed that 35% animal or plant protein diets produced the highest number of eggs and the highest hatching rate compared to the other diets; hence, 35% animal or plant protein is considered the optimum level for B. splendens. Females fed the 35% animal protein diet laid 1044 eggs in three spawnings in contrast to 846 eggs produced by fish fed the 35% plant protein diet. The necessity of incorporating an optimum level of animal protein in the diet for maximum reproductive performance in B. splendens is discussed.
Supplementation Of An Isolated Fish Gut Bacterium, Bacillus Circulans, In Formulated Diets For Rohu, Labeo Rohita, Fingerlings
Authors: Ghosh Koushik , Sen Sukanta Kumar , Ray Arun Kumar
Published: February 2021

An extracellular protease producing bacteria Bacillus circulans (Lr 1.1) was isolated from the gut of rohu, Labeo rohita, fingerlings, and used as a supplement in five diets for rohu fingerlings. The effect of the supplement on the growth performance and feed utilization efficiency of the rohu was evaluated. Rohu fingerlings (avg wt 0.83±0.02 g) were fed diets supplemented with 1.5 x 104 (diet D2), 1.5 x 105 (diet D3), 1.5 x 106 (diet D4), 1.5 x 107 (diet D5) or 1.5 x 108 (diet D6) B. circulans cells per 100 g feed for 60 days at 3% of the body weight in triplicate treatments. The control diet (diet D1) was not supplemented with the bacteria. Diet D3 resulted in signifi- cantly better growth, a lower feed conversion ratio and a higher protein efficiency ratio than the other experimental diets. Intestinal α-amylase activity did not differ significantly beyond the low- est inclusion level (diet D2), whereas protease activity increased significantly with diets D2 and D3. Apparent dry matter and protein digestibility did not significantly correlate. However, lipid digestibility decreased with the increasing level of B. circulans.
Food Competition In Small Groups Of Juvenile Gilthead Sea Bream (Sparus Aurata)
Authors: Goldan Oded , Popper Dan , Karplus IIan
Published: February 2021

Four groups of single-size and four groups of mixed-size gilthead sea bream (Sparus aurata) were raised in small observation cells for 16 days. Each group consisted of four individually marked juveniles. Agonistic behavior, motor activity and feeding behavior were monitored on days 1, 4, 10 and 16. At the end of the study, the weight gain was measured. Aggressive interactions occurred almost exclusively during feeding. A linear dominance hierarchy stabilized sooner in the mixed groups than in the single-size groups. Rank in the hierarchy had a profound effect on the behav- ior and growth of all group members. The dominant fish in each group carried out more aggres- sive acts and bit at food particles more often than the other group members. The dominant fish also had the highest relative specific growth rate. Direct competition for food is probably the major social mechanism regulating growth in small groups of juveniles of this species when food is lim- ited and defendable. The relevance of these findings for the commercial culture of this species is discussed.
Thermal And Hormonal Feminization Of All Male YY Nile Tilapia, Oreochromis Niloticus L.
Authors: Karayücel Ismihan , Penman David , Karayücel Sedat , McAndrew Brendan
Published: February 2021

Hormonal and thermal sex reversal of YY male Oreochromis niloticus were compared. While similar percentages of females (34% and 32%, respectively) were produced, a significantly high- er percent of intersex individuals (18.5%) was produced in the heat (36oC) treatment than in the group treated with diethylstilbestrol (DES; 1.6%). The heat-treated groups had 62.6% survival, compared to 97.0% and 97.3% in the control and DES-treated groups, respectively. Our results demonstrate that a high temperature treatment can be an alternative to hormonal sex-reversal treatments for YY male O. niloticus. Although the low survival and high occurrence of intersex individuals may limit its use, it can be used to produce large numbers of YY male broodstock in countries where hormone use is illegal and/or consumer reaction to hormonally-treated fish is negative.
Genetic Variation In Strains Of Discus (Symphyodon Aequifaciata) Using RAPD PCR
Authors: Degani Gad
Published: February 2021

The DNA of five strains of discus (Symphyodon aequifaciata) were compared by random ampli- fied polymorphic DNA (RAPD PCR) using seven primers. Only two primers (ZG4 and ZG8) were suitable. Using primer ZG8, the red turquoise strain had five bands common to at least one fish of another strain and two bands common to all the fish in the red turquoise strain. Panda turquoise had one band in common with at least one fish of another strain and seven bands common to all panda turquoise. For royal red, these figures were five and one and for common brown they were three and one. Within the strains, the level of band-sharing was 0.83 in the red turquoise strain, 0.13 in the panda turquoise, 0.83 in the royal red and 0.75 in the common brown. Specific bands were found only with primer ZG8 in the common brown and panda turquoise strains. Using primer ZG4, very low variation was found between the royal red, cobalt blue and red turquoise strains. With both primers, the highest genetic variation was between the common brown strain and the others (0.33-0.83).
Cryopreservation Of Rainbow Trout (Oncorhynchus Mykiss) Semen
Authors: Tekin Necmettin , Secer Selçuk , Akcay Ergun , Bozkurt Yusuf
Published: February 2021

Rainbow trout semen was diluted in one of three extenders (1:3 v/v) containing egg yolk (7-10%) and 10% DMSO as cryoprotectants. The diluted semen was packaged in 0.5 ml straws and frozen in liquid nitrogen (LN2) vapor. For thawing, the straws were immersed in a water bath for 30 sec at 30°C. The best post-thaw motility and fertilization results, 56.67±5.77% and 80.5±16.01% respectively, were obtained when a glucose based extender was used.
Feeding Frequency And Feed Intake In The African Catfish Clarias Gariepinus (Burchell 1822)
Authors: Pantazis Panagiotis A. , Neofitou Christos N.
Published: February 2021

Triplicate groups of subadult catfish (Clarias gariepinus; 102.18±30.48 g) were fed a purified diet to satiation twice or three times a day during the daylight hours for 26 days. Fish fed twice a day consumed 1.42±0.49% of their body weight per day. Those fed three times a day consumed 1.27±0.27%. The fish fed twice a day exhibited better growth and food conversion. Despite the use of purified diets, performance indices for the group fed twice per day were good, compared to previously reported data. The specific growth rate was 1.24±0.08%, the weight gain was 38.51±2.96% and the food conversion ratio was 0.72±0.13.
Defining Energy And Protein Requirements Of Gilthead Seabream (Sparus Aurata) To Optimize Feeds And Feeding Regimes
Authors: Lupatsch Ingrid , Kissil George Wm. , Sklan David
Published: February 2021

Energy and protein requirements of growing fish can be quantified as the sum of the amounts of energy and protein retained as growth plus the amounts simultaneously lost from the body. The requirement for dietary gross energy and protein can be calculated using the respective effi- ciencies of utilization. Growth of gilthead seabream as a function of body weight and tempera- ture was predicted by the equation: y = 0.024 x BW0.514 x exp0.060T (where y = daily weight gain in g/fish, BW = body weight in g and T = temperature in °C). The gain was determined in fish ranging 1-470 g. The energy content of the fish depended on fish weight and rose from 4.7 to 11.0 kJ/g body mass as the fish grew whereas the protein content was constant at 176 mg/g regardless of fish weight. The efficiencies of utilization of digestible energy (DE) and digestible protein (DP) for maintenance and growth were determined by feeding the fish at increasing feed- ing levels from zero to the maximum voluntary feed intake. The daily requirement of DE for main- tenance was dependent on temperature and determined as (16.6kJ x exp0.055T)/BW in kg0.82. The maintenance requirement for DP was independent of temperature and equaled 0.62g/ BW in kg0.70. The relationship between DE intake and energy gain was linear, constant at kDEg = 0.67 and independent of feed intake and temperature. Efficiency of protein utilization for growth var- ied between 0.33 and 0.80 depending on the DP/DE ratio in the diet. The optimal protein uti- lization for protein deposition was estimated at kDPg = 0.47. Using these values allows optimiza- tion of feeding for seabream culture.
Replacing Fish Meal In Rainbow Trout (Oncorhynchus MyKiss) Diets
Authors: Yanil Telat , Dabrowski Konrad , Bai Sungchul C.
Published: February 2021

The effects of Ohio State University (OSU) meal (a mixture of blood meal, meat and bone meal, poultry by-products and feather meal), as partial or total replacement of fish meal was investi- gated. Thirty-two fish tanks, each containing 30 rainbow trout (initial mean weight 1.93 g), were fed one of 10 diets (the control had only two replicates) containing a different quantity of OSU meal for 14 weeks. The trout fed the diets containing 20% or 40% OSU meal grew similarly to the trout fed the fish meal based diet. Total replacement of the fish meal caused a significant reduction in growth (p<0.05) only at the 47% protein level and not at the 36%. The results of this study suggest that diets containing up to 75% OSU meal and 25% fish meal are sufficient for good growth in rainbow trout fry.
Effects Of Hydrogen Peroxide, Cold Storage And Descapsulation On The Hatching Success Of Artemia Cysts
Authors: Saygı Yasemin-Basbug
Published: February 2021

The effects of hydrogen peroxide, cold storage and decapsulation on diapause in partheno- genetic Artemia cysts from the Izmir Çamalti saltern were tested. To test the effect of hydrogen peroxide, cyst samples were incubated for 5 min in a 2% or 5% H2O2 solution. In the cold stor- age experiments, the cysts were divided into three groups. One group was stored in saturated saline, the second in a vacuum and the third in air for 15 days or one month. Decapsulation was tested after a 2-hour prehydration period. The hatching rate of the control group after 24 h in cysts harvested in November was 0, while in cysts harvested in March it was 19.2%. All the treatments for diapause deactivation resulted in increased hatching during the first 24 h but the final hatch- ing rates (at 72 h) of all treated groups were similar to or slightly lower than that of the control.
Hatchery And Growth Performance of Two Trout Pure Breeds, Salvelinus Alpinus And Salmo Trutta Fario, And Their Hybrid
Authors: Aras-Hisar Sukriye , Yanik Telat , Hisar Olcay
Published: February 2021

An allelic cross between Salmo trutta fario and Salvelinus alpinus was carried out under con- trolled hatchery conditions. Survival to the eyed stage was significantly lower for the hybrid than for both purebreds. There were significant differences in survival in the eyed and yolk sac stages and from fertilization to the first feeding (p<0.05) between the hybrid and the purebreds, while the differences between the purebreds were not significant (p>0.05). The hybrid did not display heterosis with respect to any hatchery property. During the first 45 days of nursing, there were significant differences between the purebreds and the hybrid in terms of weight gain, survival, feed conversion ratio and specific growth rate (p<0.05) with no significant differences between the purebreds (p>0.05). The hybrid was slightly heterotic (+1.69) with respect to survival how- ever no heterosis was observed in any other property to the first feeding stage.
Mariculture in Israel
Authors: Gordin Hillel
Published: February 2021

Israel is a long narrow country occupying 180 km of the eastern shore of the Mediterranean and 12 km of the shore of the Gulf of Aqaba/Eilat, Red Sea. More than half of the country, the southern half, is desert and receives less than 200 mm of rain annually. Therefore, the country suffers from a chronic shortage of fresh water and it is not surprising that governmental agencies encourage the development of food production systems using sea water. Governmental activities began in the early 1970s with the establish- ment of the National Center for Mariculture (NCM) in Eilat, as part of the Israel Oceanographic and Limnological Research Institution (IOLR).
Changes In Blood Ion Levels And Mortality Rates In Different Sized Rainbow Trout (Oncorhychus Mykiss) Following Direct Transfer To Sea Water
Authors: Türker Ali , Ergün Sebahattin , Yigit Murat
Published: February 2021

Plasma ion values and mortality rates were compared for 450 rainbow trout (Oncorhynchus mykiss) of three sizes following direct transfer from fresh water to Black Sea water of about 18 ppt. In fish of 14.29±0.30 g, plasma Na+, Cl- and K+ levels significantly (p<0.05) rose above ini- tial values five days after the transfer and peaked at 178.6±5.66, 153.9±0.14 and 1.14±0.04 mM/l, respectively. In 20.45±0.48 g fish, these values also rose significantly, reaching 172.4±4.24, 151.8±6.65 and 0.98±0.04 mM/l by day 5. In fish of 29.91±0.99 g, however, plasma Na+ and Cl- concentrations peaked 19 days after transfer, reaching only 165.5±6.43 and 142.9±8.34 mM/l, while plasma K+ reached its highest concentration of 1.02±0.06 mM/l on day 12, All three concentrations dropped to near initial values on day 26. In all groups, the plasma Ca2+ level rose significantly (p<0.05) above the initial value five days after transfer and then declined while the plasma P5+ concentration dropped on day 5, reaching a minimum on day 12 and recovering the initial level on day 26. The lowest mortality (8.0±1.89%) was recorded in the 30 g group, followed by 19.3±0.94% and 24.7±0.94% in the 20 g and 14 g groups. The failure of the smallest fish to adapt after direct transfer to sea water was likely due to excessively high plasma Na+ and Cl- concentrations and tissue dehydration, indicating that fish of 30 g best adapt to a seawater environment of 18 ppt.
Effects Of Dichlorvos And Characterization Of Microsomal Nadph-Cytochrome P450 And NADH-ferricyanide Reductase In Rainbow Trout (Oncorhynchus Mykiss) Liver
Authors: Özen Tevfik , Korkmaz Halil
Published: February 2021

The kinetics of oxidation of rainbow trout (Oncorhynchus mykiss) NADPH-cytochrome P450 reductase (NCPR) by cytochrome-c and NADH-ferricyanide reductase (NFR) by K3Fe(CN)6 were studied. NCPR and NFR activities from liver microsomes of rainbow trout (Oncorhynchus mykiss) had a specific activity of 0.0246 and 0.0350 nmoles/min/mg protein, respectively. The maximal rate of NCPR reaction was found at cytochrome-c concentrations above 2.1 mM and in the presence of cyt c. Vmax and Km were 0.0083 nmoles/min/mg and 1.14 mM. The maximal rate of NFR reaction was at K3Fe(CN)6 concentrations higher than 2.0 mM and in the presence of K3Fe(CN)6. Vmax and Km values were 1.04 nmoles/min/mg and 0.352 mM, respectively. The inhi- bition by dichlorvos (DDVP) on NCPR and NFR activity was not exhibited over the range 1.0-5.0 mM DDVP.
Carbohydrases In The Alimentary Canal And Associated Organs Of The African Snakehead, Parachanna Africans (Osteichthyes: Channidae)
Authors: Kori-Siakpere Ovie
Published: February 2021

Standard qualitative and quantitative methods were employed to determine the presence and activity of digestive carbohydrases in different regions of the alimentary canal and associated organs of the African snakehead, Parachanna africans. Qualitatively, amylase, maltase, sucrase, and lactase were present in the stomach, pyloric ceca, anterior and posterior intestine, liver and spleen. No carbohydrases were found in the esophagus whereas cellulase was com- pletely absent throughout the canal and organs. Quantitatively, a relatively large amount of lac- tase and maltase was found throughout the canal and organs (except the esophagus) while sucrase was active in varying degrees in all the canal regions and associated organs (except the esophagus).
Effect Of Anesthetics On Stress And The Innate Immune System Of Gilthead Seabream (Sparus Surata)
Authors: Ron Tetsuzan Benny , Bressler Keren
Published: February 2021

Anesthesia may depress the immune system in mammals and fish. In the present work, two anesthetics used in aquaculture, clove oil (0.445 mM) and benzocaine (0.225 mM), were tested to observe their effects on the stress response and innate immune system activity of gilthead seabream (Sparus aurata L.). Results showed that both anesthetics induced increased blood glucose and serum cortisol levels. In addition, benzocaine depressed lysozyme activity, produc- tion of reactive oxygen species and pinocytosis activity. These were not depressed by clove oil, suggesting that clove oil is a safer anesthetic for seabream as it does not cause immunode- pression in anesthetized fish.
A Preliminary Study On The Effects Of Salinity On Egg Development Of European Squid (Loligo Vulgaris Lamarck, 1798)
Authors: Sen Halil
Published: February 2021

The effects of salinity on the development and incubation of European squid (Loligo vulgaris, Lamarck, 1798) eggs were investigated from December 2001 to March 2002. The egg capsules were incubated in 37‰, 34‰, 31‰, 28‰, and 0‰ salinity without any acclimation process. Mean temperature was 12±2.0°C. Illumination was maintained at 1.5 lux at the water surface. Full embryonic development and hatching were observed after 64-76 and 66-76 days at 37‰ and 34‰ salinity, respectively. Hatching rates were estimated as 88.5% at 37‰ and 60% at 34‰. In salinity below 34‰, the eggs died at very early stages. Average dorsal mantle lengths of the new hatchlings were 2.53±0.08 mm at 37‰ and 2.48±0.11 mm at 34‰.
Amino Acid Profiles In The Midgut, Ovary, Developing Eggs And Zoes Of The Mud Crab, Scylla Serrata
Authors: Peñaflorida Veronica Dy
Published: February 2021

Culture of the mud crab, Scylla serrata, is beset by low and inconsistent survival of larvae in spite of the high fecundity of crab breeders. The nutrition of the embryo and pre-feeding zoea depends on what is stored in the egg. The protein and free amino acid contents of the midgut gland, ovary, eggs, pre-feeding zoea, live food and a maintenance diet for broodstock were analyzed by HPLC. The maintenance diet had lower arginine, histidine, methionine, threonine and tryptophan than the ovary and egg. The midgut had higher phenylalanine and valine and lower leucine, methionine and tryptophan than the ovary. Amino acid profiles in the ovary, egg and zoea showed that methionine was highest in the ovary and leucine was highest in the zoea. Low val- ues were observed for isoleucine and valine in ovary, arginine in egg, methionine and pheny- lalanine in zoea. When live foods were compared to zoea, histidine in Brachionus, leucine and tryptophan in Artemia, and arginine, leucine and valine in Acartia were low. Essential free amino acids in fertilized eggs were 2.5 times higher than in unfertilized eggs. Arginine, histidine, lysine, methionine, tyrosine and threonine decreased with egg embryogenesis, suggesting that these are the major free amino acids utilized as the egg develops. Information on egg and zoea amino acids can be used to predict viable crab eggs while information on amino acid profiles in the ovary, egg and zoea can be used to develop broodstock diets. Identification of limiting amino acids in live foods can be used to develop larvae diets.
Reproductive Biology Of The Shi Drum (Umbrina Cirrosa) In Captivity And Induction Of Spawning Using Gnrha
Authors: Mylonas Constantinos C. , Kyriakou Yiannos , Sigelaki Irini , Georgiou Georgios , Stephanou Daphne , Divanach Pascal
Published: February 2021

The reproductive biology of the shi drum (Umbrina cirrosa) in culture was histologically exam- ined and sperm quality was monitored during an entire reproductive period. Already in April, the ovary contained oocytes in all stages of maturation, from primary oocytes to full vitellogenesis, as expected from a group-synchronous multiple-batch spawning fish. Vitellogenesis of the first batch of oocytes occurred very rapidly and their mean diameter (500 μm) did not increase sig- nificantly (p>0.05) as the reproductive period proceeded. The spermiation index peaked in May- June, but fish never produced copious amounts of milt upon abdominal pressure. The sperma- tozoa motility percentage remained unchanged throughout the spawning season (80%) and a significant percentage (40%) maintained viability after overnight storage at 4°C. Sperm density and motility duration increased during the reproductive period and varied 13-26 x109 spermato- zoa/ml and 26-40 s, respectively. Spontaneous spawning was not observed during the two-year study. Injection of post-vitellogenic females with an agonist of gonadotropin-releasing hormone (GnRHa) was successful in inducing a single spawning after two days, with fertilization, hatch- ing and 4-day larval survival rates of 65%, 42-76% and 46-80%, respectively. The results under- line the failure of female shi drum in culture to undergo final oocyte maturation and, although GnRHa injection was effective in inducing spawning of viable eggs, multiple treatments did not induce multiple spawns, as was expected from fish with multiple-batch group-synchronous ovar- ian biology.
Combined Effects Of Temperature And Salinity On Egg Hatching Rate And Incubation Time Of Penaeus Semisulcatus (Decapoda: Penaeidae)
Authors: Aktas M. , Eroldogan O.T. , Kumluo M.
Published: February 2021

This study was undertaken to determine the combined effects of temperature and salinity on the incubation time and hatching rate of Penaeus semisulcatus eggs in controlled laboratory conditions. Fertilized eggs, from a female caught in nature and spawned in our laboratory, were stocked in 2-l round bottom glass flasks and received one of nine temperature (24, 28 and 32°C) and salinity (30, 35 and 40 ppt) combinations. The eggs hatched in all treatments. The hatching rate increased as salinity increased and was highest at 24°C. In terms of hatching rate, the best combinations in descending order were 24°C at 40 ppt, 32°C at 40 ppt and 28°C at 40 ppt. However, the incubation time was longer at 24°C (17.5 h) than at 28°C (14.5 h) or 32°C (11.5 h).
Total Aromatic Amino Acid Requirement Of The Indian Major Carp, Cirrhinus Mrigala (Hamilton-Buchanan)
Authors: Benakappa S. , Varghese T.J.
Published: February 2021

Quantification of the essential amino acid requirements of a species is required for formulating optimal diets for cultivated fish. In this study, crystalline L-phenylalanine was used to determine the quantitative phenylalanine requirement of juvenile Cirrhinus mrigala. Test diets (40% crude protein) contained vitamin-free casein and gelatin supplemented with crystalline L-amino acids to provide an amino acid profile similar to C. mrigala muscle protein except for phenylalanine. Diets containing six graded levels of L-phenylalanine (0.80, 1.10,1.40, 1.70, 2.00 and 2.30%) and a fixed level of tyrosine (0.52%) were formulated and fed to triplicate groups of C. mrigala juveniles twice a day at a rate of 10% of the fish body weight per day for 56 days. The optimum dietary requirement for phenylalanine, estimated by breakpoint regression analysis, was 1.75% of the diet (4.38% of the dietary protein) or 2.27% of the total aromatic amino acid (5.68% of the dietary protein). Beyond the optimum level, phenylalanine significantly depressed growth. The best feed efficiency, specific growth rate and survival were obtained with the diet containing close to the optimum level of aromatic amino acid.
Effects Of Alum On The Quality Of Aquaculture Effluents In Settling Ponds
Authors: Rowan Martha , Gross Amit , Boyd Claude E.
Published: February 2021

The effectiveness of alum (aluminum sulfate) in reducing the concentrations of potential pollu- tants in pond effluents was investigated in catfish production ponds. Application of alum at 50 mg/l to water remaining in ponds immediately after seining for harvest did not generally result in significantly greater removal of nutrients and solids than did settling alone, although removal rates of some variables were initially higher in the alum treated ponds. Within four hours of sein- ing in both alum treated and untreated ponds, there was removal of more than 85% of total sus- pended solids, 75% of total phosphorus, 72% of turbidity, and more than 40% of biochemical oxygen demand and chemical oxygen demand. Concentrations of soluble reactive phosphorus decreased after 48 h, but total ammonia nitrogen was not removed. Alum may be more effective in improving water quality in settling ponds if it is applied after the initial sedimentation has occurred.
Effect Of Feeding Frequency On Consumption, Growth, And Efficiency In Juvenile Tilapia (Oreochromis Niloticus)
Authors: Riche Marty , Oetker Michael , Haley David I. , Smith Tiffany , Garling Donald L.
Published: February 2021

Triplicate groups of juvenile Oreochromis niloticus (34.4 g) were fed a commercial diet once, twice, three, or five times a day for 29 days. Consumption, growth, and feed utilization were eval- uated. No significant differences in growth, feed efficiency, or protein utilization were detected among the fish fed two, three, or five times daily, but all were significantly better than in fish fed only once. Fish fed three meals had significantly higher gross energy and lipid and lower crude protein contents than fish in the other treatments (p<0.05). Energy retention in fish fed three times daily (84.7%) was significantly higher than in fish fed five times (49.4%). Feeding juvenile tilapia nutrient dense pelleted feeds obviates the need for frequent feedings.
Effect Of Feed Type On Growth And Fertility In Ornamental Fish, Xiphophorus Helleri
Authors: James Raja , Sampath Kunchitham
Published: February 2021

The effects of feed type on feed intake and conversion, ovary weight, and fertility were studied in red swordtail, Xiphophorus helleri, for 235 days. Five groups of 30-day-old juveniles (0.05±0.001g; 16.84±1.59 mm) were fed Artemia, earthworms, liver, pelleted feed, or a mixed diet. Mean body length and weight were higher in fish that consumed the mixed diet or Artemia than in those that consumed the other diets. Pelleted feed produced the highest feeding rate but the poorest conversion rate. Fish fed pelleted feed consumed 143 mg/g/day, which was con- verted into 13 mg/g/day flesh. Those fed the Artemia, earthworm, liver, or mixed diets consumed 46, 56, 89, and 84 mg/g/day, repectively, which were converted into 16, 18, 21, and 24 mg/g/day, respectively. The conversion rate dropped after parturition, possibly due to allocation of a major portion of the feed energy to development of gonads and young. Irrespective of feed type, gonads appeared on day 42. On day 84, the gonad weight of fish fed earthworms was 16 mg (wet weight), significantly (p<0.01) increasing to 25 mg in fish fed Artemia, 31 mg in fish fed liver, 86 mg for pellets, and 145 mg for the mixed diet. A similar trend was noted in the gonadosomatic index. Females fed the mixed diet, Artemia, and liver released 753, 612, and 509 fry in four breeding cycles while those fed earthworms and pellets bred only three times, releasing 315 and 155 fry, respectively.
Effects Of Androstenedione, A Phytoandrogen, On Growth And Body Composition In The African Catfish Clarias Gariepinus
Authors: Turan Funda , Akyurt Ihsan
Published: February 2021

The present study investigated the effects of a phytoandrogen, androstenedione, on growth, body composition, and survival in African catfish, Clarias gariepinus. Three concentrations (25, 50, and 75 mg/kg feed) were administered for 120 days. Survival of treated groups did not sig- nificantly differ from the control and ranged 94.44-97.78%. A significantly higher weight gain was obtained in the 50 and 75 mg/kg diets. The fish fed these diets also had significantly better food conversion and protein efficiency ratios. Apparent net protein utilization was better in treated groups than in the control. The protein and lipid contents of the carcass of treated fish were sig- nificantly higher than in the control, with the highest contents in the 50 mg/kg treatment. The highest ash content was in the 25 mg/kg treatment. In overall parameters, 50 mg androstene- dione per kg diet was the optimal concentration.
Potential Of Poultry By-Product Meal As A Substitute For Fishmeal In Diets For Black Sea Turbot Scophthlmus Maeoticus: Growth And Nutrient Utilization In Winter
Authors: Türker Ali , Yigit Murat , Ergün Sebahattin , Karaali Burcu , Erteken Adnan
Published: February 2021

The use of poultry by-product meal as an alternate dietary protein for Black Sea turbot Scophthalmus maeoticus (initial avg wt 18 g) in winter was evaluated. Triplicate groups of 15 fish were fed one of five isoenergetic (gross energy 20.5±0.21 kJ/g) and isonitrogenous (protein con- tent 55±0.35%) diets with 25%, 50%, 75%, or 100% of the fishmeal protein replaced by poultry by-product protein. White fishmeal was the sole protein source in the control diet. There was no significant (p<0.05) reduction in growth performance of the turbot fed the 25% replacement diet compared to the control diet (100% fishmeal). At the replacement levels of 50%, 75%, and 100%, however, there was a severe decrease in feed intake, growth performance, feed utiliza- tion, protein efficiency ratio, and apparent net protein utilization. Results indicate that up to 25% of the fishmeal protein can be replaced by poultry by-product meal with no negative effects in fish performance at temperatures ranging 6-8°C.
Effect Of Stimulants On Feeding Response, Feeding Behavior, And Growth Of Fry Of Sea Bass, Lates Calcarifer (Bloch, 1790)
Authors: Singh Ravendra Kumar , Vartak Vivek , Balange Amjad
Published: February 2021

The influence of four stimulants (glycine, proline, L-lysine, and Bombay duck fishmeal) on the feeding behavior of sea bass fry was studied. The substances were added at a level of 1% of the weight of moist pellets made from purified diets. Feeding responses were observed in glass tanks containing one or two fish.The fishmeal had significantly greater stimulating effect on the feeding behavior than the chemical substances. Feeding responses were significantly different when there were two fish in the tank. Inclusion of fishmeal at a 10% level (compared to 1%, 5%, 7.5%) produced the greatest ingestion response (50%). Compared to 7.5%, inclusion at 10% produced a significantly higher weight gain (0.54±0.03 g), FCR (1.79), and PER (1.20). The pre- sent investigation revealed that Bombay duck meal is a better natural fish feed stimulant than the tested chemicals.
Effect Of Photoperiod On Plasma Thyroxine Hormone Level Of Mirror Carp (Cyprinus Carpio) Raised At A Low Water Temperature In A Controlled Environment
Authors: Hisar Sükriye Aras , Kirim Birsen , Bektas Serdar , Altinkaynak Konca , Hisar Olcay , Yanik Telat
Published: February 2021

The objective of this study was to examine the effects of various lighting regimes on the plasma thyroxin hormone (T4) level of mirror carp (Cyprinus carpio). The carp were kept at the low tem- perature of 9°C to eliminate any influence of water temperature on feed intake, growth, and the hormone level. Treatments were 8 h light:16 h dark, 12 h light:12 h dark, and 16 h light:8 h dark. Plasma thyroxin levels were measured every four weeks for 12 weeks. The levels were signifi- cantly higher (p<0.05) in the groups exposed to 8 or 12 h light than in the group exposed to 16 h. The T4 levels significantly dropped with time in all photoperiods.
Effects Of Pre-weaning Feeding Frequency On Growth, Survival, And Deformation Of Senegalese Sole, Solea Senegalensis (Kaup, 1858)
Authors: Engrola Sofia , Conceição Luis E.C. , Gavaia Paulo J. , Cancela M. Leonor , Dinis Maria T.
Published: February 2021

Despite much interest in the production of Senegalese sole (Solea senegalensis) in southern Europe, weaning of this species onto artificial diets is problematic and varying results are obtained. The aim of this study was to test two feeding frequencies during a 13-day pre-wean- ing period and assess their impact on the growth and survival of Senegalese sole. Postlarvae were fed Artemia metanauplii with a peristaltic pump every hour for 12 hours per day or twice daily (morning and late afternoon). Both groups were suddenly weaned onto a commercial diet for an additional 30 days. At the end of the experiment, the relative growth rate and final dry weight were significantly higher and the survival significantly lower in the 12-hour treatment than in the twice-daily treatment. The feeding frequency had no effect on condition factor. The inci- dence of deformities was about 80% in both treatments.
Embryonic and larval development of striped sea bream (Lithognathus mormyrus L 1758)
Authors: Firat Kursat , Saka Sahin , Kamaci H. Okan
Published: February 2021

Development of the embryonic and yolk-sac larvae of striped sea bream (Lithognathus mormyrus) was investigated. The average egg and oil globule diameters were 0.71±0.1286 mm and 0.18±0.1344 mm, respectively. The morula, gastrula, and neurula stages, somite formation, and hatching occurred 2:10, 5:15, 8:45, 9:45, and 21:15 hours after fertilization. The total length, yolk- sac volume, oil globule volume, digestive tube length, otolith diameter, head length, eye diameter, preanal and postanal lengths of newly hatched larvae were 1.74±0.03 mm, 0.12±0.008 mm3, 0.003±0.0002 mm3, 0.47±0.02 mm, 54±8 μm, 299±11 μm, 157±8 μm, 911±0.3 μm, and 827±0.03 μm. When the mouth opened 40 h after hatching, these measurements were 2.87±0.014 mm, 0.003±0.001 mm3, 0.001±0.0001 mm3, 0.61±0.015 mm, 134±8 μm, 376±10 μm, 221±13 μm, 1.02±0.03 mm, and 1.84±0.03 mm. During the first 18 hours, the larvae reached 84% of its final total length, the yolk sac was 65% absorbed, and the oil globule was 62% absorbed. Statistical analysis showed negative allometry for the relationships between total length and yolk-sac volume (r2 = 0.88) and total length and oil globule volume (r2 = 0.76), and positive allometry for the relation- ship between total length and digestive tube length (r2 = 0.89).
Effect of temperature on embryonic development in sharpsnout seabream (Diplodus puntazzo) eggs
Authors: Firat Kursat , Saka Sahin , Özden Osman
Published: February 2021

Embryonic development of sharpsnout seabream (Diplodus puntazzo) was studied at eleven water temperatures (two degree intervals from 12 to 32°C). Embryos successfully developed at temperatures of 16-28°C. Cells did not divide at the temperature extremes of 12 and 32°C. Total mortality was observed by the 128 cleavage stage at 14°C and all eggs were dead by the time the embryos extended 2/3 of the internal circumference of the egg at 30°C. There was an inverse relationship between incubation temperature and the rate of embryonic development.
Prevalence and intensity of Hexamita salmonis in rainbow trout farms in the southeastern Black Sea and their relationship to environmental factors
Authors: Ogut Hamdi , Akyol Abdurrezzak
Published: February 2021

An acute rise of unexplained mortalities (reaching 84,000 fish at one farm in 2002, 32%) was observed at a rainbow trout (Oncorhynchus mykiss) farm on the southeastern Black Sea coast from January to June for at least the last four years. Three rainbow trout farms on the same river system were surveyed for eight months to determine the occurrence and spread of the suspect- ed causative agent, Hexamita salmonis. We found that this protozoan was endemic to the trout farms from December through late August. The main determinants of the incidence and intensi- ty were water temperature (non-linear regression, r 2 = 0.77) and oxygen and nitrate levels (ANOVA, r2 = 0.83). The mean intensity of the parasite gradually decreased while prevalence gradually increased from February to April at the farm with the highest values. There was no weight loss in infected fish compared to uninfected fish (p = 0.4). The downstream farm had a higher level of parasitic intensity than the upstream farm during the high risk season. Hexamitiasis was the main cause of the high mortality in May and June when water tempera- tures were around 6-13oC. Prophylactic measures should be taken in systems where this para- site is endemic. This is the first report of hexamitiasis from Turkey.
Screening of desert plants for use against bacterial pathogens in fish
Authors: Abutbul S. , Golan-Goldhirsh A. , Barazani O. , Ofir R. , Zilberg D.
Published: February 2021

The antibacterial activity of aqueous extracts of 104 desert plant species was studied on the fol- lowing fish bacterial pathogens: Aeromonas hydrophila, Photobacterium damselae subspecies piscicida, Streptococcus iniae, and Vibrio alginolyticus. Seventeen plant species had antibacte- rial activity, as identified by disk diffusion assay. The pathogen P. damselae was sensitive to all 17 active extracts except Peganum harmala and a high inhibitory effect (14-19.5 mm) was pro- duced by Anchusa strigosa, Hammada scoparia, Achillea fragrantissima, Pulicaria crispa and Loranthus acaciae. The pathogens A. hydrophila and V. alginolyticus were inhibited by H. sco- paria, L. acaciae, and P. harmala (7-20.5 mm). The pathogen S. iniae was inhibited by Ochradenus baccatus and Reseda stenostachya (10.5 mm). The benefits of using desert plants as an alternative to conventional antibiotics are discussed.
Effects of photoperiod on growth and feed utilization of juvenile Black Sea turbot (Psetta maeotica)
Authors: Türker Ali
Published: February 2021

A study was conducted to determine the effect of different photoperiods on the growth and sur- vival of juveniles of the Black Sea turbot (Psetta maeotica). Juvenile turbot (32.17±0.1 g) were reared under one of three experimental photoperiod regimes: natural, continuous light, or extended light (18 h light:6 h dark). The turbot were held in sea water (18 ppt) at 15-24°C from May 27 to July 29, 2004. The maximum growth rate, feed efficiency, and specific growth rate were recorded in the fish exposed to the extended light period (p<0.05). Continuous light may have acted as an irritant, inducing stress, suppressing growth, and reducing feed intake.
EFFECTS OF MOLTING ON THE GROWTH OF PRIMARY CULTURED MUSCLE CELLS FROM MACROBRACHIUM NIPPONENSE AND PENAEUS VANNAMEI
Authors: Sun Ru-Yong , Liu Yi-Chen , Nu Dong-Hong , Wang An-Li , Wang Wei-Na
Published: February 2021

This study examined the effects of molting stage on the growth of primary-cultured cells from the shrimps Macrobrachium nipponense and Penaeus vannamei. Muscle cells in different molting stages were cultured in L-15 medium, supplemented with 1g/l glucose,1g/l MgCl2,1 g/l CaCl2,100 IU/ml penicillin, and 100 μg/ml streptomycin. Results showed that cells cultured in the early postmolt stage grew best. They had an unfolding cell shape, a compact monolayer, a high rate of coverage, and the highest RNA:DNA ratio. Differences among early postmolt, premolt, and intermolt cells were significant (p<0.05).
Effect of restricted feeding regimes on compensatory weight gain and body tissue in fry of the Indian major carpHamilton, 1822)
Authors: Singh Ravendra Kumar , Balange Amjad
Published: February 2021

An 8-week experiment was conducted to examine the effect of restricted feeding on compen- satory weight gain and body tissue changes in fry of the Indian major carp, Cirrhinus mrigala. During the period of feed restriction, the control group was fed to satiation twice a day while feed for the three other groups was completely withheld for 1, 2, or 4 weeks. During the subsequent re-alimentation period, all groups were fed to satiation. At the end of the experiment, fish deprived of feed for two weeks had a significantly (p<0.05) higher body weight (5.40±0.20 g) and lower FCR (3.40±0.20) than the control group (4.55±0.10 g and 6.75±0.02, respectively). At the end of the experiment, there were no significant differences in dry matter, protein, lipid, or ash contents among groups, except that fish deprived of feed for four weeks had a significantly (p<0.05) lower protein content than fish in the other treatments.
Effects of flow velocity on growth of juvenile cobia
Authors: Yu Shyi-Liang , Ueng Ping-Sheng
Published: February 2021

The objective of this study was to investigate the growth rate and feed conversion ratio (FCR) of juvenile cobia, Rachycentron canadum, in different flow velocities. In experiment A, fifteen groups of fish with an initial mean weight of 14.35 g were reared for 28 days in one of five flow velocities: 0, 5, 10, 15, and 20 cm/s. In experiment B, fifteen groups of fish with an initial mean weight of 30 g were reared for 21 days in the same velocities as in experiment A. In experiment C, fish weighing an average 77 g were raised for 21 days in 0, 10, 20, 30, and 40 cm/s. The opti- mal velocities in terms of growth rate were 10 cm/s for fish of 10-30 g (experiment A), 20 cm/s for fish of 30-60 g (experiment B), and 23 cm/s for fish of 60-200 g (experiment C); the optimal velocity increased as the fish weight increased. FCR and specific growth rate (SGR) also signif- icantly (p<0.05) corresponded to the flow velocity for the different sized juveniles with the opti- mal FCR and weight gains occurring at 10-23 cm/s. FCR rapidly increased when the velocity exceeded 35 cm/s, regarded as the maximum flow velocity for fish growth.
Mycobacteriosis in European sea bass, l., cultured in Turkey
Authors: Korun Jale , Olgac Vakur , Akgun-Dar Kadriye , Colorni Angelo , Diamant Ariel
Published: February 2021

A case of mycobacteriosis in European sea bass (Dicentrarchus labrax L.) cultured in Turkey is described. Diseased fish were characterized by lethargy, lingering passively at the water sur- face, pale gills, and exophthalmia. Internally, grayish-white nodules were observed in the liver, spleen, and kidney. In one individual, a granulomatous mass of renal origin protruded into the abdominal cavity. The principal histological feature was the occurrence of characteristic granu- lomas with associated acid-fast, rod-shaped bacteria. This is the first confirmed case of fish mycobacteriosis in Turkey.
Growth and survival rates of bearded horse mussel (Modiolus barbatus Linne, 1758) in Mersin Bay (Turkey)
Authors: Lok A. , Acarli S. , Serdar S. , Koss A. , Goulletquer P.
Published: February 2021

The growth and survival rates of four size classes (10, 15, 20, and 25 mm) of bearded horse mussels (Modiolus barbatus) grown in net bags in Mersin Bay, Izmir, were assessed from May 2001 to May 2002. Temperature ranged 14-23°C, average chlorophyll a was 3.34±0.35 μg/l, average total particulate matter 12.43±0.68 mg/l, and average particulate organic carbon 210.23±18.00 μg/l. Shell lengths increased 23.05, 19.76, 19.40, and 12.09 mm in the four class- es (from small to large) and live weights increased 13.21, 10.46, 10.06, and 4.96 g, respective- ly. Survival rates ranged from 25% in the smallest size class to 87.5% in the 20 mm class (p<0.05). Mussels grew significantly fastest in the smallest size class (p<0.05).