jaefr-blog

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Both color and morphological abnormalities on two different flatfish species [Dicologlossa cuneata (Moreau, 1881) and Scophthalmus maeoticus (Pallas, 1814)] have been recorded from Turkish seas. Abnormal flatfish species, Dicologlossa cuneata (Moreau, 1881), wedge sole, was sampled from two different localities in Aegean sea. First wedge sole from Izmir bay (Aegean sea) had three different colour abnormalities (ambicoloration; albinism and xanthochroism) on eyed and blind sides of their body. Other abnormal wedge sole specimen from Ekincik cove (Aegean sea) had ambicoloration on blind side of the body. Second abnormal flatfish species Scophthalmus maeoticus (Pallas, 1814), Black sea turbot, was caught from the Black sea coast of Istanbul and the specimen had totally ambicolored (blind side of the body was colored as like as eyed side) and morphological abnormalities (a fleshy piece-hook-above the head).

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Technical measures in order to decrease interactions between dolphins and fishermen: pingers

Almost all marine mammal species are in interaction with fishing activities and this interaction frequently results with the death of marine mammals in gillnet fisheries. This situation which results with the death of thousands of harbor porpoise (Phocoena phocoena) and bottlenose dolphin (Tursiops truncatus) is defined as by-catch ( non-target catch) in gillnet fisheries and in this way it is legalized at least partially. These inreactions between fisheries and dolphins cause ecologic and social concerns, while that means much more economic losses from the perspective of fishermen. In most of studies which aim to determine necessary measures to reduce by-catch of dolphins, gillnet fisheries is taken as basis and dolphin deterrent devices called pingers are used. In this subject many studies have been carried out in world, while only a few in Black Sea. However, it is still difficult to make an assessment for effectiveness of pingers. 

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Determinants of Hypertension Among Patients in Bale Zone, Southeast Ethiopia: A Case Control Study

Hypertension is a chronic disease in which blood flows through arteries at higher than normal pressures. Normal blood pressure (BP) for adults is defined as a systolic pressure below 120 mmHg and a diastolic pressure below 80 mmHg [1,2]. From the types of Hypertension, primary Hypertension, ‘silence killer’, is by far the most common type [3,4] that cause of Cardio alcohol (CVDs) and premature deaths worldwide with an estimated 1.56 billion in adult’s patients, in 2025 [5]. Determinants of Hypertension can be Lnfluenced by a number of factors, including adopting a healthy lifestyle [6,7], like due to urbanization, that accounts for the rising of prevalence of Hypertension at large [8]. Primary prevention provides an attractive opportunity to interrupt and the continuing costly cycle of managing Hypertension and its complications [9,10].

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Motility evaluation and cryopreservation of fish sperm exposed by water-borne and food-borne boron

Boron (B) is required for organisms as an essential nutrient, whereas could be toxic in definite doses. In this study, for the first time, the effects of water-borne and food-borne B on fish sperm motility were initially determined and these sperm samples were cryopreserved in liquid nitrogen aiming to reveal how the quality of these samples are affected by cryopreservation. 12 mature male goldfish (Carassius auratus) individuals for each treatment performed in triplicate for 45 days were used in the study. Fish were fed with diets containing 1 mg, 5 mg and 10 mg of B per kg feed for foodborne experiments. In waterborne experiments, fish were kept in aquariums containing 1 mg/L, 10 mg/L and 20 mg/L of B. In both fresh and cryopreserved samples, the motility durations (s) and percentages of the sperm samples, vitality of spermatozoa (%) were determined. In the fresh samples, percentages of sperm motility and viability in the both B treatments decreased compared to the control, while increasing B concentration. After cryopreservation, the sperm samples in 5 mg of B per kg feed treatment has shown higher duration of sperm motility. Therefore, it is shown that feed-borne B could improve sperm resistance to cold shock.

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Effect of dietary betaine supplementation on some productive traits of rainbow trout (oncorhynchus mykiss w.) Cultivated in recirculation system

The aim of the study was to determine the effect of the dietary betaine supplementation on the survival rate, weight gain and feed conversion ratio of rainbow trout (Oncorhynchus mykiss W.), cultivated in recirculation system. The fish were fed with extruded pellets “Aqua UNI“, with size 2 mm. Betaine in amount of 1% and 3% was added in the feed of the rainbow trout from the experimental groups EG1 and EG2 respectively, the control group (CG) received no betaine supplementation of the diet. In regards to the survival of the fish from different groups no discrepancies were observed. The average individual gain of the rainbow trout was as follows: CG-70.23 ± 1.42 g, EG1 -71.93 ± 1.33 g and EG2 -73.91 ± 1.30 g, the differences were significant (P<0.01). The best feed conversion ration had the rainbow trout from EG2 - 1.04 ± 0.01% and it was lower than that of the groups EG1 and CG by 1.07 ± 0.01% and 1.13 ± 0.02% respectively, the differences were significant (P<0.01). The economic conversion ratio of fish production in the groups, receiving 1% and 3% dietary betaine supplementation was identical 3.47, that is lower than these ones of the fish from control group by 4.32%.

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Determination of heavy metal contents in water, sediments and fish tissues of tinca tinca in kovada lake, turkey

The present study was carried out to detect the levels of heavy metals in water, sediment and tissues of tench (Tinca tinca) in Kovada Lake, Turkey. Water, sediment and fish samples were collected from September 2012 to February 2013 at different three sites. DORM 3, DOLT 4 and HISS 1 reference material showed good accuracy. As a result of analysis in water, all of the metals except Pb were determined in water. Fe was the highest and Cd was the lowest in water. Kovada Lake's water was classified as category I according to the standards Ministry of Forestry and Water Management. All of the metals were determined in sediment and fish tissues, and Fe was the highest and Cd was the lowest in sediment. The highest metal levels were found in liver compared with gill and muscle. No significant relationships were determined between metal levels in fish with fish weight and lenght. The metal levels which were detected in fish tissues was compared with acceptable levels for fish tissues given by World Health Organization, European Commission and Turkish Standart Institute. This study shows that a potential danger may occur in the future depending on the agricultural development

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Modification of the oreochromis spp. Aquaculture production environment using greenhouses

The aim of this study was to determine the effect of greenhouse culture conditions on water quality variables that are important for tilapia aquaculture. Six experimental ponds, three in open atmosphere and three under greenhouses were set up. Each pond was further subdivided by hapas to make 12 experimental units of which half were stocked with Oreochromis niloticus and the other Oreochromis macrochir. Water was sampled fortnightly from each pond for chemical and physical quality assessment. Water temperature, conductivity, turbidity, total dissolved solids, dissolved oxygen and pH, were determined in-situ over a period of 24 hours. The following chemical variables were also analysed: biological oxygen demand, chemical oxygen demand, alkalinity, chlorides, chlorophyll a, nitrates, total phosphorus, reactive phosphorus, total suspended solids and ammonia. Water temperatures, chlorophyll a and reactive phosphorus concentrations were significantly higher in the greenhouse ponds than in the open ponds. Otherwise, the concentrations of all the other chemical water variables were not significantly different between greenhouse and open ponds both before, and after the rainfall season. This study revealed that modification of the culture conditions for tilapia production, greatly influenced physical water variables important for fish growth, but had little effect on the chemical variables.

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Seasonal distribution patterns of marine cladocerans in the surface waters of gulluk bay

In this study, seasonal abundances and distribution of Cladocera species were investigated in Gulluk Bay, Mugla. Sampling operations were performed in four stations during April-October 2017. Zooplankton samples were taken horizontally by WP2 UNESCO plankton net with 200 micrometer mesh size. Five Cladocera species which are P. avirostris, P. tergestina, E. spinifera, P. polyphemoides, P. intermedius were determined in the study area. Other zooplankton groups in the samples were copepods, appendicularians, chaetognaths and meroplankton. P. polyphemoides was found in all sampling months except July. Maximum mean abundance of P. polyphemoides was observed 317 ind./m³ in April. P. avirostris showed maximum abundances in May and June but these values were not very high. P. intermedius was found in September and October in the samples. P. tergestina was dominant Cladocera species in May, June, July, August and September. Maximum abundance of E. spinifera was determined in June (mean 105 ind./m3 ).

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Influence of feeding administration of brood-stock on breeding performance of common carp

The aim of the experiment was to determine the effects of three types of formulated feed containing varying levels of protein, lipid on breeding performance of common carp (Cyprinus carpio). C. carpio was reared for 120 days under three dietary treatments (T1 to T3) with varying crude protein levels and crude lipid levels. Experimental diets T1, T2 and T3 were formulated from locally available feed ingredients having crude protein percentage of 23.56 ± 0.23, 28.60 ± 0.10 and 18.04 ± 0.32; crude lipid percentage of 9.50 ± 0.22, 11.06 ± 0.38 and 8.34 ± 0.19 respectively. Effect of the three diets was studied in terms of gonadosomatic index (GSI), fecundity, fertilization rate, hatching rate and deformity of fry. Fishes reared under Treatment 2 showed the highest gonadosomatic index (32.08 ± 7.24%), fecundity (355963.33 ± 77142), fertilization rate (84.00 ± 6.89%), hatching rate (87.33 ± 12.45) and lowest rate of larval deformity (11.56 ± 3.56%). Brood stock management of Treatment 2 showed significantly better results (P<0.05) in respect of gonadosomatic index, fecundity, fertilization rate, hatching rate and larval deformity among three selected hatcheries. Hence, it can be concluded that 28.60 ± 0.10% protein and 11.06 ± 0.38% lipid is adequate for better breeding performance of common carp (Cyprinus carpio).

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A novel trout pond inlet structure

Water inlet structures to rearing units at fish hatcheries are used to maintain continuous water flow, prevent the introduction of undesirable organisms and organic debris, and deter escapement by the fish being reared. This paper describes a novel pond water inlet structure that not only kept the water flowing unimpeded, but required considerably less labor to maintain than other designs. This relatively simple aluminum structure consisted of a collar for attachment to the inflow pipe and a terminal splashplate. The splashplate was perpendicular to the inflow pipe during normal operations to both prevent fish from jumping into the inflow pipe and aerate the incoming water. The splashplate was designed to swivel upward to allow for the efficient removal of any debris, such as branches or leaves. Use of the inlet structure consistently increased incoming dissolved oxygen levels, which were as low as 4.75 mg/L, to over 9.0 mg/L. Increased efficiencies during hatchery operations can be realized by using this inexpensive and relatively easy-to-construct inlet structure.

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Effect of sorting sieves on the survival and growth performance of catfish (clarias gariepinus) in tarpaulin ponds

Sorting sieves were introduced into the hatchery management of Clarias gariepinus fry in Lagos State to improve on the survival rate and growth performance of catfish . gariepinus from fry to juvenile stage. The trials were set up in six farms across the State. Two hatching troughs served as Treatment 1 (T1) and Treatment 2 (T2) in each farm. T1 utilized sorting sieves while T2 used hand manual sorting. Broodstocks of 1500 ± 10.52 g were used for breeding. Fertilized eggs were shared weight for weight between T1 and T2 and normal management procedures were followed. Sorting of fish were done on the 14th, 21st, 28th, 42nd, 56th and 70th day after hatching. The percentage hatching was high, 78.33 ± 4.08% and 76.92 ± 3.19% in T1 and T2 respectively but not significant (P ˃ 0.05). 70.76 ± 6.70% (T1) and 60.69 ± 7.52% (T2) fry survived to fingerling stage in the 6th week. Survival rate from fingerlings to juveniles at the 10th week significantly (P ˂ 0.05) reduced to 62.33 ± 12.73% (T1) and 40.55 ± 8.44% (T2) respectively. At harvest (10th week), there were more numbers of small (4 – 6 cm) and large (8 – 12 cm) sizes of juveniles in T2 than T1 whereas numbers of medium (6 – 8 cm) size juveniles in T1 almost doubled that of T2 at a significant level (P ˂ 0.05). Economic analysis of the trial gave Marginal Rate of Return (MRR) of N5.50k in favour of T1. It was concluded that introduction of sorting sieves to catfish hatchery will reduce drudgery in fry sorting while increasing percentage survival and profitability at the same time.

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Forecasting nile tilapia weight production units in temperate zones using an anfis and linear regression models

This paper proposes two models to estimate individual net weight of the Nile Tilapia (Oreochromis Niloticus), in an experimental intensive production unit located in the temperate zone of the state of Durango, Mexico. As a first approach, it is proposed a model based on the neuro-fuzzy ANFIS system (Adaptative Neuro-Fuzzy Inference System) model, which is used for training phase data size and individual weight obtained from a sampling process during a production period of six months, considering as input variable the precaudal length (centimeters) and as output variable the weight (grams). Different configurations are tested in the antecedent and consequent parameters of the ANFIS network to determine the best fit in the model. The first four months were used to collect data for training, and the remaining two months for validation. As a second approach, a linear regression model using data in the same way (first four months to make the model adjustment and the remaining months to verify the predictive capabilities) is also proposed. The results show that the ANFIS model has greater predictive power, since the error in the forecast inside and outside of the sample is below than the error obtained with the linear regression model.

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The changes in the molecular weight profiles and biochemical compositions of potential feed ingredients for sustainable aquaculture

The objective of study was to evaluate the differences in the molecular weight profiles and the biochemical compositions of potential feed ingredients such as fish meal (FM), Artemia nauplii (ArtN), Artemia metanauplii (ArtMn), copepod meal (CopM), dry Daphnia sp. (dryD), Daphnia magna (freshD) and Tubifex. The lowest and highest ash (ArtN 5.84±0.05%, 45.18±1.17% dryD) lipid (dryD 4.71±0.06%, ArtN 30.19±0.65%) and protein contents (45.45±3.90% freshD, 66.74±0.2% CopM) were detected (p<0.05). The highest palmitic acid and oleic acid levels were  found in dryD and ArtMn, respectively. Except for freshD, the linoleic acid levels were relatively  low. Linolenic acid level was just found Tubifex and dryD. The highest docosahexaenoic acid  and eicosapentaenoic acid levels were observed in fish meal and copepod meal, respectively. The  highest and lowest levels of feed ingredients used were determined in 2532>= Da and 2532-13000 Da, respectively. The highest molecular weight profile belongs to 67000<=Da was observed in Tubifex. In conclusion, accorded to their nutritional levels of tested ingredients can make important contributions to microdiet formulations. Considering this molecular weight profiles data results cautioned that the use of all feed ingredients except for Tubifex in microdiet formulations may cause the high leaching ratios containing 2532>= Da molecular weight.