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Characteristics of selected bioaccumulative substances and their impact on fish health
2016
Walczak Marek | Reichert Michał
The aim of this article was to evaluate the influence and effects of chosen bioaccumulative substances i.e. heavy metals, pesticides, and polychlorinated biphenyls (PCBs) on fish, as well as provide information on time trends and potential threat to human health. Chemical substances which pollute water may affect living organisms in two ways. First of all, large amounts of chemical substances may cause sudden death of a significant part of the population of farmed fish, without symptoms (i.e. during breakdown of factories or industrial sewage leaks). However, more frequently, chemical substances accumulate in tissues of living organisms affecting them chronically. Heavy metals, pesticides, and polychlorinated biphenyls are persistent substances with a long-lasting biodegradation process. In a water environment they usually accumulate in sediments, which makes them resistant to biodegradation processes induced by, e.g., the UV light. These substances enter the fish through direct consumption of contaminated water or by contact with skin and gills. Symptoms of intoxication with heavy metals, pesticides, and PCBs may vary and depend on the concentration and bioavailability of these substances, physicochemical parameters of water, and the fish itself.
Mostrar más [+] Menos [-]Identification of histamine in fish and fish products in Poland during 2014–2018
2021
Pawul-Gruba Marzena | Osek Jacek
Histamine is one of the most important and toxic biogenic amines which may be present in food and may cause food poisoning in humans when contained at a high level. It is produced during bacterial decarboxylation of histidine in fish muscles. The aim of the study was to investigate the presence of histamine in fish and fish products available in Poland during 2014–2018.
Mostrar más [+] Menos [-]Identification of bacterial pathogens and determination of their antibacterial resistance profiles in some cultured fish in Turkey
2016
Türe Mustafa | Alp Hüseyin
Introduction: In the present study, some of the commercial fish farms located in the Black Sea region of Turkey, were screened for bacteria between 2012 and 2014.
Mostrar más [+] Menos [-]Antibiotic susceptibility of mycobacteria isolated from ornamental fish
2022
Guz Leszek | Puk Krzysztof
Nontuberculous mycobacteria (NTM) are increasingly recognised as causative agents of opportunistic infections in humans for which effective treatment is challenging. There is very little information on the prevalence of NTM drug resistance in Poland. This study was aimed to evaluate the susceptibility to antibiotics of NTM, originally isolated from diseased ornamental fish.
Mostrar más [+] Menos [-]Acute exposure to hyperosmotic conditions reduces sperm activation by urine in the yellowtail tetra Astyanax altiparanae, a freshwater teleost fish
2020
Nathalia Alcântara Rocha | Gabriel Marra Schade | Álvaro de Miranda Alves | Claudia de Souza Silva | Jacqueline Megumi Nakirimoto | Liura Sanchez Lauri | Lucca Gobatto Campos | Marcelo Galvão dos Santos | Nicole Nascimento Mesquita | Rachel Sordi Relvas | Rafaella Fernandes Carnevale | Se Yoon Oh | Victoria Portela Diniz Gaia | Vivian Renata Kida | Eneiva Carla Carvalho Celeghini | Mayra Elena Ortiz D´'Ávila Assumpção | José Augusto Senhorini | Hatus de Oliveira Siqueira | Nivaldo Ferreira Nascimento | Luciano Andrade Silva | Talita Maria Lázaro | José Antonio Visintin | Paulo Sérgio Monzani | George Shigueki Yasui
In freshwater fish with external fertilization, sperm sampling can be contaminated with urine, which triggers motility and gives rise to decreased fertilization success. The maintenance of freshwater fish in hyperosmotic conditions may reduce urine production and improve sperm quality. Thus, the aim of this work was to verify if acute exposure to various NaCl concentrations improves sperm quality in the yellowtail tetra Astyanax altiparanae. Spermiation was induced using a single dose of carp pituitary gland (5 mg kg-1) and the males were maintained at various NaCl concentrations: NaCl 0.00% (control), NaCl 0.45% (hypoosmotic), NaCl 0.9% (isosmotic) and NaCl 1.0% (hyperosmotic) for 6 h at 26 °C. Sperm was collected and verified for activation by urine and motility traits. At 0.00%, 0.45%, and 0.90%, the sperm was motile just after sampling, indicating activation by urine. Surprisingly, at hyperosmotic conditions, no activation was observed. Other sperm and motility parameters did not show any statistical differences, including sperm viability (P = 0.7083), concentration (P = 0.9030), total motility (P = 0.6149), VCL (curvilinear velocity; P = 0.1216), VAP (average path velocity; P = 0.1231) and VSL (straight-line velocity; P = 0.1340). Our results indicate that acute maintenance at hyperosmotic conditions eliminates sperm activation by urine and maintains sperm quality. Such a new procedure is interesting for both basic and applied sciences, including reproductive practice in fish.
Mostrar más [+] Menos [-]Effect of seasonal variations on performance and parasitic infestation of cultured fish in Fayoum governorate
2010
H. H. Emeash | M. A. El-Bably | Asmaa N. Mohamed
A field study was carried out in a fish farm to study the effect of seasonal variations during the production period on performance and parasitic infestation of cultured fish. Water samples were obtained to determine the Physio-chemical investigation of water in the examined farm to estimate temperature, dissolved oxygen, PH, ammonia, nitrite, nitrate, salinity, total alkalinity and total hardness. Fish samples were obtained for parasitological examination to detect external parasitic infestation.The results referred that an elevation of water temperature during summer months leading to slight increase of PH of water, while dissolved oxygen values decreased from 6.8±0.15 to 6.0±1.5 throughout the study period. The mean values of ammonia, nitrite and nitrate reach the maximum in July and August months (0.71±0.18, 0.20±0.07 and 3.1±0.07 mg/l respectively). In addition there was a slightly increase of the total alkalinity and total hardness at beginning of the study (37.8±3.0 and 147.0±5.0mg/l respectively) reached the maximum levels in the summer months (44.4±2.8 and 182.8±6.0 mg/l respectively). It can be noticed that the most prevalent ectoparasitic affecting cultured Tilapia are Trichodina,Monogenia and Epistylis. It can be noticed that, the average initial body weight of examined fish was 6.8±2.3 gm and reached 218.0±3.8 gm. at the end of experiment (210 days) with an average of daily weight gain 1.01 ±0.07 gm. From the aforementioned results, it can be concluded that special attention to Physio-chemical parameters of water fish ponds and regular inspection of fish parasitic infestation particularly during summer months obtained a good fish performance as well as high body weight gain and high survival percentage.
Mostrar más [+] Menos [-]Potential use of allicin (garlic, Allium sativum Linn, essential oil) against fish pathogenic bacteria and its safety for monosex Nile tilapia (Oreochromis niloticus)
2010
M. M. A. Hussein | W. H. Hassan
A study was conducted to investigate the antibacterial activities of allicin, one of the major essential oils of garlic, against some fish pathogenic bacteria as well as the toxic effect of allicin on monosex Nile tilapia (Oreochromis niloticus). Allicin 10% v/v solution in dimethyl sulfoxide (DMSO) was used in this study. The bacterial species investigated were Aeromonas hydrophila, A. caviae, A. sobria, A. veronii, and Streptococcus iniae. The minimum inhibitory concentrations (MICs) of allicin in DMSO against Aeromonas hydrophila was found to be 125 μg/mL, while ranged between 250–500 μg/mL for each of A. caviae, A. sobria, A. veronii. Interestingly, the MIC for Streptococcus iniae was 63 μg/mL. On contrary, allicin exists no bactericidal activity against any of the investigated bacteria. Allicin had high toxic effect on tilapia fingerlings while adult tilapia could tolerate it.
Mostrar más [+] Menos [-]Influence of water quality on fish productivity
2010
M. A. El Bably | H. H. Emeash | Asmaa N. Mohamed | Nahla R.
The physical, chemical and bacteriological parameters of water in fish ponds were investigated with a view to optimize the conditions for fish productivity by using three private fish farms with different water supplies. Water and fish samples were collected equally from each pond over a period of 17 months. Water temp., Dissolved oxygen (DO), pH, Ammonia, Nitrite, Nitrate, and bacterial count were determined. The average values of bacterial, parasitic, survival and growth rates of fish were also assessed. Results revealed that pond water in farm (III) had the highest averages of temperature nitrite, nitrate 31.8±1.5, 8.18± 0.9, 0.41 ± 0.06 , 3.79 ± 0.6 resp., with the least content of DO 3.6 ± 0.7 followed by farm (II),which had also the highest mean values of NH3 - N, total coliform and fecal coliforms were 3.15±0.65, 59.0 & 18.5 followed by ponds of farm (III), while, the lowest averages of estimated parameters were recorded in farm (I).Correspondingly, fish samples of farm (III) showed the highest level of total bacterial, coliform, fecal coliform count and parasitic infestation; were 42.5±5.4, 29.6±3.6 , 11.3±3.1 and 31.15% respectively, followed by fish of farm(II) 29.75±3.5, 11.5±3.3, 7.4±1.1 and 10.8 % respectively, Meanwhile, fish in farm (I) showed the lowest value of both bacterial contents with no parasitic infestation which explain the highest percentages of daily weight gain & survival rates 35.2±4.4 gm. & 97.0 ±1.6 % respectively. Throughout study period compared with those in farms (III & II) respectively, resulting from poor water quality & parasitic infestation which acts as stressors affecting fish health and productivity. Therefore, fish productivity can be enhanced if the water quality in the ponds were maintained at optimum levels.
Mostrar más [+] Menos [-]Detection of residues of some heavy metals in fish fillets in Egyptian markets
2010
R. H. Abdel-Dayem | H. M. Soltan | N. M. Marzouk
Fifteen samples of fish fillets were collected from different Egyptian markets to detect the residues of some heavy metals in them. The average weights of fish fillets samples were 250g. The samples were separately packed in polyethylene bag and sent to the laboratory for preparation and analysis. All equipment surfaces and utensils which used in this study were thoroughly cleaned with detergent, rinsed with water, dried and then rinsed with 2-propanol solution. The samples were stored at –2C prior to analysis. The mean levels of lead and cadmium in fish fillets collected from the Egyptian markets were 1.51 0.34 and 0.60 0.0.25 mg/kg; respectively. The concentration of lead in fish muscle were less than the permissible heavy metal limit in fish meat (2.0 mg kg) as stated by the World Health Organization, also these results were in line with the corresponding EU regulations. However the level of cadmium concentration was over than the heavy metal limits in fish meat (0.5 mg/kg) for the World Health Organization.
Mostrar más [+] Menos [-]Bacteriological status of fish marketed in Beni-Suef City
2010
F. A. Khalafalla | Fatma H. M. Ali | Abdel-Rahim H. A. Hassan
This study was carried out to evaluate the bacteriological status of fresh Tilapia nilotica, fresh Clarias lazera, frozen Mackerel and smoked Herring fish marketed in Beni-Suef City. The collected samples were examined for total bacterial count, coli form (MPN), faecal coli forms (MPN), E. coli (MPN), Staphylococcus aureus count, total proteolytic count, total lipolytic count, Aeromonas count and Pseudomonas count, as well as the isolation of E. coli, Staphylococcus aureus, Aeromonas hydrophila, Pseudomonas aeruginosa, Yersinia enterocolitica and Listeria monocytogenes. Most of the examined samples were within the permissible limits recommended by EOS and ICMSF, few samples of fresh Clarias lazera exceeded the recommended limits. The economic importance and public health significance of the isolated organisms were discussed.
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