bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Wound Healing In African Catfish, Clarias Gariepinus, Fed Diets Supplemented With Ascorbic Acid
Authors: Erazo-Pagador Gregoria , Din Mohd Shariff
Published: February 2021

Wound healing in African catfish, Clarias gariepinus, fed diets supplemented with ascorbic acid was studied under laboratory conditions. Fish weighing approximately 80-110 g were stocked in 500 l aquaria in a static water system and fed one of five test diets containing different levels of microencapsulated ascorbic acid (0, 0.06, 0.10, 0.30 and 0.70 g AsA/100 g feed). After two weeks, all experimental fish were wounded by making a 1 x 1 cm dorso-lateral incision above the lateral line of the fish. Wounded tissues were sampled for histopathological analysis 4, 8, 24, 48 and 96 hours, 6, 8, 10, 12 and 14 days after making the incision. There were significant differences in weight gain, specific growth rate (SGR) and feed conversion ratio among the dietary treatments. Weight gain and SGR of fish fed the ascorbic acid free diet were lower than those of fish fed diets supplemented with ascorbic acid. The wound healing response showed a direct correlation to ascorbate level in the diet. Fibroblasts were present at 96 h irrespective of the ascorbic acid level. As 14 days, fish fed no ascorbic acid had some regeneration of muscle tissues, whereas fish fed diets containing supplemental ascorbic acid had a normal epidermis, dermis and muscle structure. There was no mortality during the experimental period, and fish fed ascorbic acid free diets did not exhibit any deficiency signs. Results of this study indicate that about 0.10-0.70 g AsA/100 g feed is needed for wound repair in African catfish.
Epitopes Of Tilapia Red Blood Cells. I. Species-Specific Antibodies For The Control Of Tilapia Breeding Stocks
Authors: Timan Bracha , Shirak Andrey , Segal Ruth , Machnes Ziv , Avtalion Ramy R.
Published: February 2021

Specific antisera against red blood cells of some tilapia species were obtained by reciprocal inter- specific and intergeneric immunizations. The antisera were used to confirm co-dominant expres- sion of epitopes in F1 interspecific hybrids and to identify the parental origin of three red tilapia strains. The antisera in all hybrids (Oreochromis niloticus x O. mossambicus, O. aureus x O. horno- rum, O. niloticus x S. galilaeus and O. niloticus x O. aureus) were positive to both parental strains. However, while all F1 hybrids of O. mossambicus x O. hornorum were positive to anti-O. mossambi- cus antiserum, only 50% were positive to anti-O. hornorum antiserum. In most cases, these results point to co-dominant expression of the species-specific epitopes in hybrids.

In addition, the triple parental origins of the Philippine red tilapia (positive for O. aureus, O. mossambicus and O. niloticus epitopes) and of mossambicus red tilapia (positive for O. hornorum, O. mossambicus and O. niloticus epitopes) were assessed. The O. niloticus red tilapia, described as a purebred red variant of O. niloticus, was positive for both anti-O. niloticus and anti-O. aureus antibodies, with a significantly more intense reaction to the latter. A possible genetic basis of this last finding is discussed.
Aquaculture In Turkey
Authors: Memis Devrim , Demir Nilsun , Eroldogan Orhan Tufan , Kucuk Semra
Published: February 2021

Marine and freshwater aquaculture in Turkey have grown substantially. The first trout farm was established in the 1960s and the first marine cage farm for sea bream and sea bass in 1985. From the beginning of the 1970s to 1999 the number of licensed fish farms increased from two to 1,444. Since 1995, the number of cage farms has grown to 57 and production reached 4,100 tons in 1999. Total aquaculture production grew from 3,075 tons in 1986 to 63,000 tons in 1999. Production is dominated by inland production, mainly of trout (Oncorhynchus mykiss), which supplies 60% of the total.

From 1995 to 1999, marine production increased from 8,494 tons to 25,230 tons. The major contributors are sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax). Because of the rel- atively high temperatures in the Black Sea, Atlantic salmon (Salmo salar), cultured from the late 1980s to 1997, is no longer grown; only rainbow trout (O. mykiss) in floating net cages is produced.

Because of the growing demand caused by increased population and export, aquaculture pro- duction and consumption in Turkey are expected to grow. New fish and shellfish species, mainly marine, are being developed. The bureaucracy involved in licensing fish farms, especially in marine environments, is complicated, time-consuming, and suffers from a lack of technical knowl- edge and insufficient exchange of know-how and cooperation concerning new developments.

• Corresponding author. Present address: Istanbul Universitesi, Su Ürünleri Fakültesi, 34470 Laleli, Istanbul, Turkey; e-mail: mdevrim@istanbul.edu.tr
Early Development And Growth Of Arctic Charr (Salvelinus Alpinus) And Rainbow Trout (Oncorhynchus Mykiss) At A Low Water Temperature
Authors: Yanik Telat , Hisar Sükriye Aras , Bölükbasi Canan
Published: February 2021

Hatchery traits and growth of eggs and fry of rainbow trout, Oncorhynchus mykiss, and arctic charr, Salvelinus alpinus, were tested in fresh water of a low temperature. There were significant differences (p<0.05) between the survival rates from fertilization through the eyed stage and the first exogenous feeding. No significant differences were observed between species with regard to feed conversion or survival of fry at the end of the 154-day trial, but weight gain and specific growth rate differed significantly (p<0.05). These results suggest that the arctic charr could be considered an alternative to rainbow trout, particularly in coldwater farms.
Influences Of Dietary Protein Deficiency On Amino Acid And Fatty Acid Composition In Tilapia, Oreochromis Niloticus, Fingerlings
Authors: Ogunji Johnny O. , Wirth Manfred
Published: February 2021

The influence of dietary protein deficiency on the amino acid and fatty acid compositions of tilapia (Oreochromis niloticus) fingerlings was studied. Two experimental diets (0.81% and 33.32% protein, dry matter) were prepared. The protein content of fish fed diet 1 (0.81% pro- tein) decreased from 57.14% to 49.18% in eight weeks. Fish fed diet 2 (33.32% protein) had higher protein and amino acid contents. The lipid content of fish fed diet 1 was higher than that of fish fed diet 2, suggesting that carbohydrates transformed into lipids. The levels of fatty acids 16:0 and 18:2 n-6 in fish fed diet 1 remained nearly unchanged and did not reflect the diet, demonstrating that fatty acids in diet 1 may not have been incorporated into the triglycerides of the tissues. Possible impairment of lipid secretion from the liver, caused by depletion of protein in the blood lipoprotein, may have affected the transport of lipids to the muscles. A dietary pro- tein deficiency results not only in a deficiency of essential amino acids in the body but also affects transport and storage of lipids within the fish.
Microflora On The Skin Of European Eel (Anguilla Anguilla L., 1758) Sampled From Creek Yuvarlakçay, Turkey
Authors: Sahin Nurettin , Ugur Aysel , Yılmaz Fevzi
Published: February 2021

Bacterial skin microflora of eel obtained from Mugla (Turkey) province were studied. The aero- bic bacteria associated with skin and slime were estimated using the dilution plate technique. The dominant bacterial species were Pseudomonas spp. (17.23%), Acinetobacter baumannii (15.51%) and Stenotrophomonas maltophilia (12.05%). A lower frequency of Gram-positive bacteria (18.93%) was found in samples.
Dietary Threonine Requirement Of Indian Major Carp, Cirrhinus Mrigala (Hamilton), Juveniles
Authors: Benakappa S. , Varghese T.J.
Published: February 2021

A growth study was conducted to determine the dietary threonine requirement of juveniles of the Indian major carp (Cirrhinus mrigala) known as “mrigal”. Diets containing casein and gelatin as sources of intact proteins were supplemented with crystalline amino acids to obtain a crude pro- tein content of 40%. Six diets with different levels of threonine (1.0, 1.3, 1.5, 1.7, 1.9 and 2.1%) were fed to triplicate groups of mrigal juveniles twice a day for 56 days. The dietary threonine requirement, estimated by break-point analysis, was 1.66% of the dry diet (4.15% of the dietary protein). The highest growth and specific growth rate were recorded in fish fed the diet contain- ing 1.7% threonine.
Growth And Survival Of Penaeus Merguiensis Postlarvae At Different Salinities
Authors: Zacharia Sherly , Kakati V.S.
Published: February 2021

The growth and survival of postlarval Penaeus merguiensis were examined to optimize condi- tions and improve farm production. Postlarvae were subjected to one of four salinities (5-35 ppt) for a period of 28 days. Results indicated maximum survival at 25 ppt while the best growth rate was obtained at 15 ppt. The highest performance index was obtained at 15 ppt. Hence, 15 ppt was found to be the optimum salinity for the production of P. merguiensis postlarvae. The fast growth rate and good tolerance of P. merguiensis larvae to a wide range of salinity in captivity indicate that P. merguiensis is a promising candidate for aquaculture.
Spat Settlement And Growth On A Long-line Culture System Of The Mussel, Mytilus Galloprovincialis, In The Southern Black Sea
Authors: Karayücel Sedat , Erdem Muammer , Uyan Orhan , Saygun Serkan , Karayücel Ismihan
Published: February 2021

Spat settlement and growth at the depths of 3 and 7 m in a long-line mussel system in the south- ern Black Sea were determined in two seasons. The first spat collectors were hung in July 1997, the second in January 1998. Temperature, salinity, seston, particulate organic matter and chloro- phyll-a were measured monthly. Depth had no significant effect on any of these parameters (p>0.05). There was a significant positive correlation between particulate organic matter and chlorophyll-a (p<0.05) at both depths. On the first collectors, most of the spat settled from October to January and on the second most settled in April-May 1998. The mean shell length, height, width and weight of the mussels from the first collectors were 32.11±0.68, 18.32, 11.76±0.35 mm and 3.40±0.22 g, respectively. Spat collectors were most efficient in February and March when heavy spat settlement occurred and predation and fouling were minimal. Growth performance of seeds was high due to the favorable environment. Recommendations for spat collection and cultivation are given.
Milt Production Of Sea Bass Lates Calcarifer Bloch Administered An Analogue Of Luteinizing Hormone-Releasing Hormone And 17α-Methyltestosterone
Authors: Hilomen-Garcia G.V. , Baldevarona R.B. , Lacanilao F.
Published: February 2021

The milt production responses of sexually mature sea bass Lates calcarifer to (D-Ala6, Pro9-N- ethylamide) luteinizing hormone-releasing hormone (LHRHa) and 17α-methyltestosterone injec- tions were examined.

At 24 h after injection of a low dose of LHRHa (20 μg/kg BW), the sperm count decreased significantly compared to saline-treated fish, but it returned to pre-treatment levels 48 h after injection, suggesting a possible hydration of the milt. Other milt parameters (milt volume, sper- matocrit, sperm production) in LHRHa-treated fish did not vary from their controls at 24 or 48 h after injection but the overall pattern suggested a reduction in milt viscosity. Total expressible milt and spermatozoa collected over the 48-h experiment was approximately three-fold higher in LHRHa-injected fish than in saline-injected fish, indicating a stimulation of spermatozoa produc- tion, not merely milt dilution due to hydration.

In a second experiment, sperm count and spermatocrit were significantly lower than those of saline-injected fish at 17 and 48 h after a single injection of a high dose of LHRHa (80 μg/kg BW). A methyltestosterone injection combined with the LHRHa injection also resulted in a significant- ly lower sperm count, but the spermatocrit remained comparable to the control group, suggest- ing a suppression of the LHRHa-induced milt hydration response.

Results demonstrate that LHRHa stimulates milt hydration and spermatozoa production in milting sea bass and that a simultaneous methyltestosterone injection partially suppresses this response.
Growth, Feed Utilization And Carcass Composition In Rainbow Trout Fed Diets With A Similar Digestible Energy Content And Different Carbohydrate Levels
Authors: Tekinay Ahmet Adem , Davies Simon John , Güner Yusuf
Published: February 2021

Three diets including 13.2%, 22% or 30.5% carbohydrates as extruded wheat meal were fed to rainbow trout, Oncorhynchus mykiss (initial weight 34.8 g), for twelve weeks to investigate their influence on growth, protein and energy utilization and carcass composition. Daily feeding rates were 1.76, 2.05 or 2.17 g feed per 100 g body weight for the three diets, respectively, so as to reach a daily allowance of about 35.5 kJ digestible energy per 100 g body weight. No significant differences (p>0.05) in final mean weight or specific growth rate were observed between the treatments. Feed efficiency was negatively correlated to the dietary carbohydrate level. Utilized digestible protein and energy per kg growth were 365, 348, 358 g and 15.4, 15.9, 17.0 MJ, respectively, for the three diets. Apparent net protein and energy utilization of the groups fed a medium or high carbohydrate level were higher than those of the low carbohydrate group. Analysis of fish carcasses at the end of the trial revealed no significant (p>0.05) variations attrib- utable to the carbohydrate level.
Prediction Of Carcass Quality Traits Of Common Carp By X-Ray Computerized Tomography
Authors: Hancz C. , Romvári R. , Petrási Z. , Horn P.
Published: February 2021

X-ray computerized tomography (CT) and chemical analysis were used to determine the fat and protein contents in the fillet of table-sized mirror carps. Serial CT scans were taken along the body from the operculum to the beginning of the caudal fin. After scanning, the anesthetized fish were immediately processed; slaughter value and fillet yield were determined before taking sam- ples for chemical analysis. Independent variables of prediction equations were produced from the CT density values, which ranged from -90 to 160 on the Hounsfield scale. Based on the data derived from the CT scanning, areas (cm2) of muscle and fat tissue were identified. Fat deposi- tion was highest in the dorsal fin region. The muscle area varied according to the body shape and seems to be inadequate for predicting the slaughter value of common carp. The fat and pro- tein contents of the fillet, when predicted from scanning only the dorsal region, were as accurate as when predicted from scanning the whole body and were R2 = 0.88 and 0.86, respectively.
Epidemiological Description of A New Viral Disease Afflicting Cultured Cyprinus Carpio In Israel
Authors: Perelberg Ayana , Smirnov Margarita , Hutoran Marina , Diamant Ariel , Bejerano Yitzhak , Kotler Moshe
Published: February 2021

Since spring 1998, a new disease causing high mortality has afflicted cultured ornamental and common carps (Cyprinus carpio) in Israel. The clinical signs of the disease are fatigue, gasping movements in shallow water, gill necrosis, sunken eyes, pale patches on the skin and increased mucus secretion. The disease was experimentally transmitted to koi and common carp of various ages by injection with affected tissue filtrates, cohabitation trials and exposure to the isolated viral agent. Immersion of healthy fish in tanks containing 2.7x104 plaqueformingunits(PFU) per l or intraperitoneal injection (0.2 ml) of a viral inoculum of 1000 PFU/ml were sufficient to induce the terminal disease in over 80% of the fish. Here we report that the disease is restrict- ed to C. carpio, that young fish of 2.5 g and 6 g are more sensitive to the virus than adults (230 g) and that the virus remains active in the water for at least four hours.
The Influence of Multiple Meals On The Gastric Evacuation Rate In Rainbow Trout (Oncorhynchus Mykiss)
Authors: Tekinary Ahmet Adem , Güner Yusuf , Akbas IIhan , Baysal Hüsnü
Published: February 2021

Rainbow trout, Oncorhynchus mykiss (mean weight 70.8±1.0 g SEM) raised in the Sea of Marmara (Turkey), were used for a preliminary gastric evacuation study. After being starved 72 hours, three groups of 110 fish, each, were fed ad libitum once, twice or three times in a single day. Ten fish from each group were withdrawn and killed in an anesthetic solution during each sampling at 0, 3, 6, 9, 12, 15, 18, 21, 24, 27 and 30 hours following the last feeding. Gastric material was removed from the fish and dried for gastric evacuation modelling. Gompertz and logistic models (with fixed asymptotes) best explained the data. The gastric emptying rate of the trout offered a single meal (Group A) was faster than those fed two (Group B) or three (Group C) meals while the emptying patterns of Groups B and C were similar to each other. The time required to evacuate 95% of the gastric material from the first meal was estimated as 54.3, 68.0 and 67.8 h for Groups A, B and C, respectively, according to the Gompertz equations (with a fixed asymptote).
Effects Of Meal Frequency On Growth And Reproduction In The Ornamental Red Swordtail, Xiphophorus Helleri
Authors: James Raja , Sampath Kunchitham
Published: February 2021

Experiments were performed to investigate the influence of meal frequency on growth, gonad weight and fertility in an ornamental fish, the red swordtail Xiphophorus helleri. Five groups of uniform-sized 30-day juveniles (0.04±0.01 g, 13.10±0.61 mm) were fed either one meal in 3 days (1/3), one meal in 2 days (1/2), one meal a day (1/1), two meals a day (2/1) or three meals a day (3/1) for 210 days. Group 3/1 had the highest mean body weight throughout the experiment, fol- lowed successively by groups 2/1, 1/1, 1/2 and 1/3. The growth rate was higher in all groups before breeding began and drastically declined afterwards; the significant reduction might have been due to the diversion of assimilated food energy to fry production. The gonad weight and gonadosomatic index (GSI) increased with the increase in meal frequency and as the rearing period progressed. Fish in groups 1/1, 2/1 and 3/1 began to develop gonads on day 42 and reached the breeding stage on day 70; fish in 1/2 and 1/3 began to develop gonads on days 70 and 98 and reached the breeding stage on days 98 and 112, respectively. The increase in meal frequency significantly reduced the interbrood interval and fertility. Fish in group 3/1 produced the highest number of fry (704). Those in groups 2/1, 1/1, 1/2 and 1/3 released 450, 372, 70 and 8 fry, respectively. Groups 3/1, 2/1, 1/1, 1/2 and 1/3 bred four, three, three, two and one times, respectively. Based on the present study, three meals a day is optimum for X. helleri growth and reproduction in a culture system.
Growth And Production In Long-Line Cultivated Mediterranean Mussel (Mytilus Galloprovincialis) In Sinop, Black Sea
Authors: Karayücel Sedat , Karayücel Ismihan , Erdem Muammer , Saygun Serkan , Uyan Orhan
Published: February 2021

One-year rope-grown mussels (Mytilus galloprovincialis Lam.) with a mean length of 37.6±0.52 mm and live weight of 5.02±0.28 g were collected from fish farm mooring ropes and cultured in cotton or nylon socks in a long-line system in Sinop, Black Sea. The growth of the mussels, water temperature, salinity, chlorophyll a, seston and particulate organic matter were monitored from July 1997 for eleven months. Shell length and live weight were high from May to October when the temperature was 13oC-25oC. Growth decreased during late autumn and winter due to the low temperature and food availability. A significant and positive relationship was found between particulate organic matter, shell growth and live weight. At the end of the experiment, shell length reached 59.89±0.93 mm in the cotton socks and 57.81±0.88 mm in the nylon socks, while live weight reached 19.42±0.91 g in the cotton socks and 16.89±0.76 g in the nylon. Harvestable production was lower in the cotton (4.1 kg/m) than in the nylon socks (8.7 kg/m). Meat yield was high during spring and early summer and significantly and positively correlated with chlorophyll a, particulate organic matter and seston. In the light of these results, recom- mendations for mussel culture in the long-line system are given.
Marine Recirculating Systems In Israel-Performance, Production Cost Analysis And Rationale For Desert Conditions
Authors: Mozes Noam , Eshchar Micha , Conjieski Daniel , Fediuk Michael , Ashkenazy Arik , Milanez Fernando
Published: February 2021

A semi-commercial 100 m3 marine recirculating system (RAS) was designed, based on the results of a 5 m3 experimental system. The system was stocked with gilthead seabream (Sparus aurata). After 200 days, the fish in the semi-commercial system had a similar weight (about 330 g) and density (78 kg/m3) and identical survival (99%) and FCR (1.8) as similar fish grown in a flow-through system (FAS). Annual production in the RAS was calculated as 90 kg/m3. Seawater consumption was 3.5-4 m3 per kg fish produced, resulting in an average water exchange rate of 80% of the system volume per day. While this is relatively high compared to freshwater RAS, the marine RAS required only 10% of the sea water consumed in an FAS. Since sea water is an inexpensive input, water consumption was a minor component of the total production costs in the RAS (approximately 6%). The economical analysis for a theoretical 500 ton/y farm showed that the main capital investment components would be the rearing volume (fish tanks) and the biofiltration unit, representing over 60% of the total investment. The highest production costs would be feed, fingerlings and return on the investment, in that order, representing over 50% of the production costs. CO2 stripping may limit further intensification because the limited surface area of the tank limits the number of paddlewheels that can be used. Also, the DO/TAN ratio may be a factor limiting achievement of a higher nitrification rate and reduction of the biofilter size. Based on the results of this study, a 100 ton/y pilot plant is currently being designed as a model farm.
Clearance Rates Of Suspended Particulate Organic Carbon By Nile Tilapia With A Dual Pattern Of Filter Feeding
Authors: Turker Hakan
Published: February 2021

The filter-feeding activity of Nile tilapia, Oreochromis niloticus L., was observed during a 24-h feeding cycle for five consecutive days. The feeding activity was high from afternoon to midnight, with a peak after dusk, and lowest from midnight to morning. The clearance rate of cyanobacte- ria dominated water was estimated during the low morning and high evening feeding periods. The tilapia cleared 34 mg C/l suspended particulate organic carbon in 4.5 h during the reduced morning period (beginning 07:00) and 45 mg C/l in 1 h during the peak evening period (begin- ning 20:30). Clearance rates of the cyanobacterial water were 13.4±1.2 l/kg fish/h in the morn- ing and 66±3.6 l/kg fish/h in the evening.
Effects Of Land-Based Trout Farms On The Benthis Macroinvertebrate Community In A Turkish Brook
Authors: Kırkagaç Mine Uzbliek , Pulatsü Serap , Köksal Gülten
Published: February 2021

Benthic macroinvertebrates and physico-chemical parameters were surveyed at the source of the Karasu Brook in Bozüyük, Bilecik Province, Turkey, and at the inlets and outlets of five rainbow trout farms that use the brook water and discharge effluents into it. The dissolved oxygen, pH, ammonia-nitrogen, nitrite-nitrogen, nitrate-nitrogen and total phosphorus in the farm effluents were within effluent standards for trout farming in different countries. The macroinvertebrate community in the brook consisted of Mollusca, Gastropoda (Physidae, Limnaedae, Planorbidae, Neritidae), Bivalvia (Spharidae), Annelidae, Oligochaeta (Tubificidae), Hirudinea (Glos- siphonidae, Erpobdellidae), Arthropoda, Insecta (Chironomidae, Ephemerellidae) and Crustacea (Gammaridae, Asellidae). Tubificidae and Chironomidae were generally observed in all sampling stations; the highest abundance was in the inlets and outlets of the two farms nearest the source. The most common measures of biodiversity, i.e., richness, Simpson’s index, Shannon-Wiener index and evenness, were used during the year-long study.
Economic Evaluation Of Multiple Research Innovations On An Eel Farm
Authors: Din Gregory Yom , Zugman Zinaida , Degani Gad
Published: February 2021

An approach for evaluating multiple innovations of an aquaculture farm is proposed, based on a model of induced innovations, supplemented with a bio-economic table for the calculation of pro- duction function. Data gathered from a model eel farm were used as an example. The proposed approach enables evaluating each innovation to determine which is the most profitable.
Successful Replacement Of Fishmeal By Plant Proteins In Diets For The Gilthead Seabream, Sparus Aurata L.
Authors: Kissil George Wm. , Lupatsch Ingrid
Published: February 2021

Soy protein concentrate, wheat gluten, and corn gluten meal were evaluated in combination and as sole dietary protein sources in diets for gilthead seabream. A growth trial and digestibility determinations demonstrated the effectiveness of these plant proteins as alternatives to fish- meal. Digestibility trials indicated superior protein digestibility for soy protein (92%), wheat gluten (96%), and corn gluten (90%) in comparison with fishmeal (86%), while energy digestibility was higher than fishmeal (84%) only in wheat gluten (91%; it was 75% for soy protein and 72% for corn gluten). For the growth trial, eight isonitrogenous and isoenergetic (as-fed basis) diets were formulated with differences in the protein sources. Growth in the range of 40-130 g was superi- or to the fishmeal control with the diet containing wheat gluten but inferior in the diets containing soy protein concentrate or corn gluten meal. Diets that replaced 25-100% of the fishmeal with a mixture containing equal portions of all three plant proteins outperformed the control with a 9- 16% greater weight gain and 4-10% lower feed conversion ratio. The use of soy protein or corn gluten as the sole protein source in diets for seabream is not recommended but their use in com- bination with wheat gluten can provide a partial or complete alternative to fishmeal. However, the cost of supplemental arginine made replacement economic at only the lowest replacement level (25%). An in-depth evaluation of the need for this amino acid in the protein mixture could signif- icantly affect the feasibility of using higher replacement levels.
Dietary Histidine Requirement Of Fingerling Indian Major Carp, Labeo Rohita (Hamilton)
Authors: Abidi Shabihul Fatma , Khan Mukhtar A.
Published: February 2021

A 6-week growth trial was conducted to assess the dietary histidine requirement of fingerling Indian major carp, Labeo rohita (3.50±0.04 cm; 0.40±0.02 g) by using amino acid test diets (40% crude protein; 4.28 kcal/g) containing casein, gelatin, and L-crystalline amino acids. Diets with graded levels of histidine (0.25, 0.50, 0.75, 1.00, 1.25, and 1.50% of the diet) were fed to tripli- cate groups of fingerlings at 5% of their body weight divided into two feedings (07:00 and 17:30). Live weight gain, specific growth rate, protein efficiency ratio, and feed conversion ratio were sig- nificantly (p<0.05) affected by dietary histidine concentration. Weight gain and conversion effi- ciencies were best at 0.75% dietary histidine. Whole body protein content was highest and mois- ture and fat were lowest in the 0.75% dietary histidine treatment while whole body ash was the same at all treatment levels. Second-degree polynomial regression analysis of the live weight gain and feed conversion ratio resulted in more accurate histidine requirement estimates of 0.90 and 0.82% of the dry diet, respectively, corresponding to 2.25 and 2.05% of the dietary protein. It is recommended that dietary histidine be included at a level of 0.82% of the feed, correspond- ing to 2.05% of the dietary protein, for optimal growth in L. rohita fingerlings.
Spawning And Larvae Production Of Common Pandora, Pagellus Erythrinus L.
Authors: Güner Yusuf , Özden Osman , Altunok Muhammet , Koru Ediz , Kızak Volkan
Published: February 2021

Spawning of the common pandora (Pagellus erythrinus L.) in captivity was studied at ambient temperature (21.2±1.2°C) during the breeding season in 1998. Broodstock were cultivated in net fishpens and spawned in large fiberglass tanks (10 m diameter) between June and July. Approximately 33.2 million eggs were collected from 30 mature 4-7 year old females, 97% of which were buoyant healthy eggs with diameters ranging 753-801 μm. The eggs were incubat- ed at 19, 21, or 23°C and development and morphological changes were observed until day 50. The best hatching rate (88.9%) was obtained at 19°C. Swim bladder inflation occurred 8-20 days after hatching. The average survival at day 50, at an initial density of 40 larvae/l, was 3.2%. Exogenous feeding began on day 3. Larvae were first fed rotifers, Brachionus plicatilis, and later Artemia nauplii. Larvae completed yolk absorption 78 hours after hatching. A green water envi- ronment was maintained by introducing cultured microalgae (Nannochloropsis oculata and Tetraselmis suecica). Larvae (13.3 mm) transformed into juveniles (18.71 mm) 29-37 days after hatching.
In Vitro Melatonin Rhythm Reveals A Clocked Pineal In The European Sea Bass, Dicentrarchus Labrax
Authors: Ron Benny
Published: February 2021

The melatonin-generating system of the European sea bass, Dicentrarchus labrax, was studied in vitro using a perfusion tissue culture methodology. The examined properties included photic entrainment in the pineal gland, and circadian rhythmicity in alternating dark and light, in contin- uous darkness, and in continuous light. Pineal glands were removed from adult fish and placed in a perfusion tissue culture at a constant temperature of 24°C. Melatonin discharge into the cul- ture medium was measured using radioimmunoassay. Melatonin concentrations during a pho- toperiod of 12h light:12h dark were low during the light periods and high during the dark. The melatonin discharge was inhibited by continuous light but strong and rhythmic in continuous dark with a circadian period (Tau) of about 24 h (n = 10). The results demonstrate that the European sea bass pineal gland is photosensitive, with ability to be entrained, and contains an internal cir- cadian oscillator that regulates melatonin production.
Effect of freezing techniques, extenders and cryoprotectants on the fertilization rate of frozen rainbow trout (Oncorhynchus mykiss) sperm
Authors: Bozkurt Yusuf , Akcay Ergun , Tekin Necmettin , Secer Selçuk
Published: February 2021

Rainbow trout (Oncorhynchus mykiss) sperm was frozen in liquid nitrogen in straws or as pellets on dry ice and stored in liquid nitrogen until artificial insemination. Sperm was diluted with one of three extenders containing 15% DMSO or 15% DMA as a cryoprotectant at a ratio of one part sperm to two parts extender. The straws were thawed in a water bath while the frozen pellets were thawed in their own extenders at 30oC for 30 s. For both freezing methods, the best fertil- ization results were obtained with extender III containing 15% DMSO, 52.3% (56.3% of the con- trol) for sperm frozen in straws and 48.4% (52.4% of the control) for sperm frozen as pellets. The interaction between extender and cryoprotectant was statistically significant (p<0.05).
Growth, Behavior, And Mating Of Pharaoh Cuttlefish (Sepia Pharaonis Ehrenberg) In Captivity
Authors: Anil M.K. , Andrews Joseph , Unnikrishnan C.
Published: February 2021

The pharaoh cuttlefish (Sepia pharaonis) was successfully reared from egg to an average size of 168 mm mantle length and 521 g in 210 days, using simple biological filtration systems. The period of egg incubation was 15 days at a temperature of 27-31 ̊C. Hatchlings were reared at a stocking density of one animal per liter during the first month; density was reduced as growth proceeded. Food items consisted of live mysids, Artemia salina, juvenile fishes, and prawns. Juveniles were gradually acquainted with dead food items such as caridian prawns and small fishes. The present study shows that the pharaoh cuttlefish can be reared in captivity with a sur- vival rate of 41%, using live feeds during the first 50 days. Future commercial scale culture of this species depends on development of artificial feeds and high density culture systems.
Effect of restricted feeding regimes on compensatory weight gain and body tissue composition in Cirrhinus mrigala (Hamilton) fry.
Authors: Singh Ravendra Kumar , Balange Amjad K. , Vartak Vivek R.
Published: February 2021

An experiment was conducted to examine the effect of restricted feeding on compensatory weight gain and body tissue composition in Cirrhinus mrigala fry. The control group was fed to satiation twice a day throughout the 8-week experiment. Feed for the other three groups was restricted for one, two, or four weeks. When reinstated, feed was given to satiation. Fish deprived of feed for two weeks had significantly (p<0.05) higher body weight (5.40±0.20 g) and lower FCR (3.40±0.20) than those of the control (4.55±0.10 g and 6.75±0.02, respectively). At the end of the re-alimentation period, there were no significant differences in dry matter, protein, lipid, or ash contents except that protein content in fish deprived of feed for four weeks was significant- ly (p<0.05) lower than in fish of other treatments.
Effects of natural and synthetic pigments in diets on flesh coloration and growth of rainbow trout (Oncorhynchus mykiss W.)
Authors: Diler Ibrahim , Hossu Belgin , Dilek Kamil , Emre Yilmaz , Sevgili Huseyin
Published: February 2021

The desired pink to red color of rainbow trout flesh (Oncorhynchus mykiss W.) can be obtained by adding carotenoids to the fish diet. This study was conducted to determine the effects on growth and color retention of natural pigments (30 ppm red pepper meal, 60 ppm red pepper meal, 30 ppm shrimp by-products meal, 60 ppm shrimp by-products meal), synthetic carotenoids (30 ppm astaxanthin, 60 ppm astaxanthin), and a control group (no added pigment). Duplicates of each of the seven treatments were reared for three months. The best specific growth rates were obtained with 30 ppm astaxanthin (0.83%) and 60 ppm red pepper meal (0.84%); the low- est was in the control (0.54%). The lowest food conversion ratio was obtained with 30 ppm astax- anthin (1.38) and highest in the control (2.23; p<0.05). Visual coloration values ranged from 14.46±0.23 in the 30 ppm astaxanthin group to 11.55±0.25 in the control. Retention coefficients ranged from 6.63 in the 30 ppm astaxanthin group to 1.79 in the 60 ppm shrimp by-products meal (p<0.05). Tristimulus chromometer a values ranged from 0.87±0.47 in the control to 6.96±0.47 in the 60 ppm astaxanthin treatment, b values from 10.94±0.27 in the control to 12.90±0.27 in the 60 ppm red pepper meal treatment, and L values from 46.81±0.50 in the 60 ppm astaxanthin group to 54.57±0.26 in the control (p<0.05).
Effects of feeding raw soybean meal to fry of indian major carp, Catla catla, on growth, survival, and protein digestibility
Authors: Patnaik Deepak , Sahu Narottam Parasad , Chaudhari Aparna
Published: February 2021

Effect of feeding raw soybean meal on growth, nutrient utilization, and amylase and protease activity of Indian major carp (Catla catla) fry was studied in a 70-day feeding trial. Five isocaloric (1568 kJ/100 g diet) and isonitrogenous (45 g crude protein/100 g diet) semi-purified diets had varying levels of soybean meal (0, 5, 10, 20 or 30%). Ninety C. catla fry (0.94±0.02 g) were dis- tributed into the five treatment groups with three replicates of each treatment. The weight gain, SGR, and PER of groups receiving diets with soybean meal were significantly (p<0.05) lower than in the control group that contained no soybean meal. Trypsin inhibitor units in the diets neg- atively correlated with weight gain (r = -0.7557), protein digestibility (r = -0.9541), trypsin (r = -0.9087) and protease activity (r = -0.8596), and positively correlated with carbohydrate digestibility (r = 0.8140) and amylase activity (r = 0.7802). An increase of trypsin inhibitor units resulted in increased hypertrophy of pancreatic, kidney, and liver tissues. Inclusion of as little as 5% soybean meal depressed the growth rate. Hence, although the soybean diets did not result in mortality, inclusion of raw soybean meal in the diet of C. catla fry should be discouraged.
Evaluation of organic tilapia culture in periphyton-based ponds
Authors: Milstein Ana , Joseph Dan , Peretz Yaacob , Harpaz Sheenan
Published: February 2021

The introduction of hard surfaces in the water column to induce the growth of biofilms and peri- phyton on these surfaces is a method used to increase natural productivity of the water body and food for cultured aquatic organisms. In periphyton-based systems in Africa and Asia, substrate introduction and consequent periphyton development positively affected water quality and pro- duction of the target species. In Israel, this technology is being evaluated in the culture of organ- ically produced tilapia. Among other restrictions imposed by organic standards, fish stocking densities must be low and only organic feeds and manures must be supplied. Organic pelleted feeds cost twice as much as regular aquaculture feeds. Since feed constitutes the major pro- duction expense, economic viability is hampered by using costly organic feeds. An experiment was performed at the Dor Aquaculture Station to explore methods of improving natural food pro- duction for tilapia and reducing added feeds. Submerged plastic surfaces equivalent to 40% of the pond surface area were immersed in polyculture ponds containing 85% hybrid tilapia (Oreochromis niloticus x O. aureus), together with a reduction of 40% of the amount of pelleted feed. The treatment improved nitrification and saved 40% of the feed costs, with only a 10% reduction in the tilapia growth rate and yield. These results indicate that periphyton-based aqua- culture is an appropriate technology for reducing production costs and allowing economically viable organic tilapia production.
Nitrogen excretion patterns and postprandial ammonia profiles in Black Sea turbot under Controlled conditions
Authors: Yigit Murat , Erdem Muammer , Aral Orhan , Karaali Burcu
Published: February 2021

Measurements of the rate of nitrogenous excretion were carried out in two batches of young Black Sea turbot (small 42 g, large 72 g) at 12±1°C under natural light conditions (10 h light:14 h dark and 13 h light:11 h dark, respectively). The ammonia nitrogen excretion rates of fish starved for 48 hours were 0.20±0.05 mg-N for the small fish and 0.18±0.09 mg-N/100g fish/h for the large. Fish were then fed a pellet diet containing 8.3% nitrogen at average rations of 0.67% and 0.59% of the body weight, respectively, for four days. On the fourth day, ammonia nitrogen excretion rates were evaluated. In both batches, the rates were 2-3 times higher immediately after feeding than in the starved fish, reaching a peak 3-6 hours after feeding and declining after- wards. For the small and large fish, respectively, 21% and 20% of the consumed nitrogen was excreted as ammonia nitrogen, 6% and 7% as urea nitrogen, and 8% and 4% as feces nitrogen within 24 hours after feeding.
Authentication of fish species using a simple PCR-RFLP method
Authors: Hisar Oicay , Erdogan Orhan , Aksakal Ecrument , Hisar Sükriye Aras
Published: February 2021

A polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was developed as a tool to prevent commercial frauds in fish products. The PCR was used to ampli- fy the cytochrome b gene, part of the mitochondrial genome. The PCR products were digested with different restriction endonucleases (AluI, HaeIII, HinfI, Hsp92, Taql) to identify five fish species - Mugil cephalus, Pomatomus saltator, Belone belone, Merlangius merlangus, and Oncorhynchus mykiss. None of the tested enzymes, alone, was able to distinguish between the five fish species, but by combining the results of two digestions, all five species could be differ- entiated. Thus, this method can be used to expose fraudulent substitutions with less valuable fish.
Moisture, protein, and amino acid contents of three freshwater zooplankton used as feed for aquacultured larvae and postlarvae
Authors: Ovie Solomon I. , Ovie Stella O.
Published: February 2021

The moisture content, crude protein level, and amino acid profile of three freshwater zooplank- ton (Moina micrura, Diaphanosoma excisum, Brachionus calyciflorus) commonly used for rear- ing fish larvae were analyzed using standard methods. The moisture contents and crude protein levels were similar, as follows: M. micrura 89% and 52.4%, D. excisum 89.3% and 57.3%, and B. calyciflorus 91.6% and 50.3%, respectively. The samples contained 17 amino acids: nine essential and eight non-essential amino acids. The dominant essential amino acids (per 16 g N) in M. micrura were lysine (10.73 g), arginine (8.17 g), leucine (8.0 g), and histidine (5.09 g); in D. excisum, lysine (9.95 g), leucine (8.0 g), valine (6.23 g), and arginine (4.78 g), and in B. caly- ciflorus, leucine (8.95 g), lysine (8.64 g), arginine (6.37 g), phenylalanine (5.20 g), and valine (4.83 g). In all three species, glutamine and aspartic acid dominated the non-essential amino acid profile, and methionine was the essential amino acid in the smallest concentration. Differences among amino acid profiles were insignificant (p>0.05).
Preliminary study of settlement of flat oyster spat (Ostreaedulis L.) on oyster and mussel shell collectors
Authors: Lok Aynur , Acarli Sefa
Published: February 2021

Oyster recruitment was monitored in Karantina Island near Izmir, Turkey, from May to October 1999. The aim of the study was to determine the recruitment pattern for six months and the most suitable time to collect oyster spat from nature. Oyster and mussel shells were used as sub- strates in spat collectors. Five groups of each type of collector were deployed from May to August. The recruitment levels were highest in the groups deployed on June 16, with 4069 and 1575 oyster spats collected on the oyster and mussel shell collectors, respectively. Spat recruit- ment varied considerably between collector types as well as between the outsides and insides of shells (p<0.05). Spats larger than 10 mm were found on the second or third sampling date in each group for both oyster and mussel shell collectors. Barnacles (Balanus sp.) settled on both collector types in high numbers throughout the study. Data suggest that maximum recruitment in this area is most likely to occur on both collector types between May and mid-June.
Prevalence and pathology of ectoparasites of Mediterranean sea bream and sea bass reared under different environmental and aquaculture conditions
Authors: Vagianou S. , Athanassopoulou F. , Ragias V. , Di Cave D. , Leontides L. , Golomazou E.
Published: February 2021

Sea bream, Sparus aurata L., and sea bass, Dicentrarchus labrax L., were sampled from an off- shore cage farm in eastern Greece, an inshore cage fish farm in southern Greece, and a lagoon in northern Greece. The prevalence and intensity of Metazoan parasites and factors associated with the prevalence were investigated. In Farm 1 (eastern Greece), ectoparasite prevalence in sea bream and sea bass was 61.5% and 76.9% for Monogenea, none for Isopoda, and 0 and 23% for Copepoda. In Farm 2 the prevalence was 13.3% and 26.3% for Monogenea, 13.7% and 20% for Isopoda, and 0 and 13.6% for Copepoda. In the lagoon, the prevalence of ectoparasites was 100% and 21.9% for Monogenea and Copepoda, respectively. The lagoon had the highest prevalence of parasites among the studied ecosystems, however, the variety did not significant- ly affect the health of the infected fish. In Sparidae, gill lesions were due to monogeneans while skin and eye lesions were due to larvae of the isopod Ceratothoa oestroides that caused severe pathology. Furnestinia echeneis and Diplectanum aequans were host specific to sea bream and sea bass, respectively, and persisted in all aquaculture systems. Lernanthropus kroyeri was host specific and detected only in sea bass from the cage farms.
Growth enhancement and survival of Macrobrachium rosenbergii larvae fed Artemia nauplii enriched with cod liver oil and/or Lactobacillus
Authors: Babitha Rani A.M. , Reddy A.K. , Sahu N.P.
Published: February 2021

A 60-day experiment was conducted to study the single and combined effects of feeding Artemia nauplii enriched with an emulsion containing cod liver oil and/or a probiotic bacteria (Lactobacillus sporogenes) on the growth and survival of Macrobrachium rosenbergii larvae. Artemia enriched with the emulsion (with and without probiotic enrichment) and tissue of M. rosenbergii fed such Artemia had significantly higher (p<0.05) HUFA (20:5 n-3, 22:6 n-3) con- tents than unenriched Artemia or Artemia enriched with the probiotic only. The first postlarvae appeared 7-8 days earlier and 95% of the postlarvae 11-12 days earlier in the emulsion-enriched groups than in the control or probiotic-only groups. Growth in the probiotic-only group did not sig- nificantly differ (p>0.05) from the control. Feeding probiotic-treated Artemia reduced pathogenic bacteria (Vibrio sp. and Pseudomonas sp.) in the gut microflora. The highest survival was recorded in the group fed Artemia nauplii enriched with both the probiotic bacteria and the cod liver oil emulsion.
Effects of partial replacement of fishmeal with isolated soy protein on digestibility and growth performance in sterlet (Acipenser ruthenus)
Authors: Ustaoglu S. , Renner B.
Published: February 2021

Fishmeal was partially replaced by isolated soy protein in diets for sterlet (Acipenser ruthenus) juveniles at an amount at which one-half or one-third of the protein was supplied by soy. Nutrient digestibility, growth, and whole body composition were determined after 79 days. Protein digestibility was significantly higher in the diet in which half the protein derived from isolated soy protein (84.9%) than in the diet in which one-third of the protein derived from soy (82.6%). Otherwise, digestibility, growth, feed efficiency, and whole body composition did not differ between the two diets.
Efficacy and toxicity of orally administrated anti-coccidial drug treatment on Enteromyxum leei infections in sharpsnout seabream (Diplodus puntazzo C.)
Authors: Golomazou E. , Athanassopoulou F. , Karagouni E. , Vagianou S. , Tsantilas H.
Published: February 2021

Three drugs effective against myxosporeans and commonly used to treat spore-forming para- sites were tested in sharpsnout sea bream (Diplodus puntazzo) infected by Enteromyxum leei. Two medicated diets were applied, one containing salinomycin and amprolium and the second containing fumagillin. Compared to untreated fish, both treatments resulted in significant reduc- tions in prevalence, intensity of all developmental myxosporean stages, and mortality. The effect was more prominent with the salinomycin and amprolium combination, where the significant reductions in intensity, prevalence, and mortality were unaccompanied by any histopathological evidence of toxic side effects or growth reduction. Sporoblasts and mature spores with distorted structures were observed in both drug treatments, but were more prevalent in the salinomycin and amprolium treatment than in the fumagillin treatment, indicating direct effectiveness on the parasite. Salinomycin with amprolium is a promising treatment for myxosporean infections in intensively cultured warmwater fish, leading to parasite elimination.