Effects of oxytetracycline residues in Thai Koi (Anabas testudineus Bloch) collected from Sylhet, Bangladesh

The present study was conducted to determine the levels of oxytetracycline residues in Thai Koi (Anabas testudineus Bloch) collected from some local fish markets of Sylhet Sadar Upazilla, Bangladesh during March to August, 2016. For the purpose of the study, 24 fresh Thai Koi fish samples were randomly collected from four (4) local markets of Sylhet Sadar Upazilla. Concentration of oxytetracycline residues in collected fish samples were determined by High Performance Liquid Chromatography (HPLC) at the Food Toxicology Laboratory of Institute of Food Science and Technology, Bangladesh Council of Scientific and Industrial Research, Dhaka. The results showed that 9 (37.50%) samples with detectable amount of oxytetracycline residues (mean = 42.30±3.00 ppb) were found in Thai Koi. Oxytetracycline residues level below detection limit was also reported in 15 (62.50%) samples of Thai Koi during this study. The detected residues of oxytetracycline in this fish sample did not exceed the maximum residue limit (MRL) 100 ppb recommended by the European Commission. Though residue level of oxytetracycline is lower than the MRL but long term exposure could be hazardous for human health. For that reason, control of antibiotic usage in aquaculture, regular residue monitoring, legislations and regulations for the use of antimicrobials in aquaculture and food safety education are utmost things in this regard

Assessment of heavy metals concentration in water and Tengra fish (Mystus vittatus) of Surma River in Sylhet region of Bangladesh

The study was carried out to assess the concentration of heavy metals in water and Tengra fish (Mystus vittatus) of the Surma River, the largest water basin ecosystem covering the north-eastern parts of Bangladesh. Water and Tengra fish (M. vittatus) samples were collected from a total of six sampling stations in which three sampling stations were in Sylhet district and the rest three were in Sunamganj district. Samples were collected from February 2017 to June 2017 on a monthly basis. Water and Tengra fish (M. vittatus) samples were analyzed for the detection of heavy metals viz., lead (Pb), chromium (Cr) and cadmium (Cd) concentrations. Atomic absorption spectrophotometry was used for the detection of heavy metals after digestion of the samples. Pb and Cr were detected from both water and Tengra fish (M. vittatus) samples collected from all the six sampling stations of Sylhet and Sunamganj district. But, Cd was not found both in water and Tengra fish (M. vittatus) during the study period. This study concluded that the detected concentrations of metals (Pb and Cr) in the studied Tengra fish (M. vittatus) muscles were accepted by the international legislation limits and are safe for human consumption. But in water, Pb is the only metal that potentially poses the ecological risk to the water body as it exceeds the acceptance level recommended by World Health Organization (WHO). Consequently, close monitoring of metals pollution of the Surma River is recommended with a view to minimizing the health risk of the population that depend on the river for their water and fish supply

Effects of aflatoxin contaminated feed on the fingerlings of tilapia (Oreochromis niloticus Linnaeus, 1758)

Aflatoxin contamination, particularly common in cultured fishes in Asian countries, are considered unsafe both for fish and human health. However, the presence of aflatoxin in cultured fish feed and their effect are still under estimated in Bangladesh. The present study aimed to assess the effects of aflatoxin on growth performance and residues in tilapia (Oreochromis niloticus) fingerlings. Fish feed were treated with several concentration of aflatoxin as 0 ppb (T0, control), 25 ppb (T1), 50 ppb (T2) and 100 ppb (T3) and fed the tilapia fingerlings (n=10) in individual glass aquaria (24×12×12 inch, 105-litre capacity) conditions for 12 weeks. Comparatively higher body length (cm) and weight gain (g) were observed in treatment T0 (1.68 and 4.98) and T1 (1.60 and 5.48) than those of treatment T2 (1.31 and 4.06) and T3 (1.20 and 3.10), respectively. The specific growth rate (SGR) were almost similar in treatment T0 (52%), T1 (51%) and T2 (52%) whereas declined significantly (p<0.05) in T3 (39%). Higher survival rate was also demonstrated in treatment T0 (90%) and T1 (90%) whereas significantly decreased in treatment T2 (60%) and T3 (40%). The residue of aflatoxin was not detected in T0 and T1. On the contrary, the residual effect in tilapia fingerling was evident in T2 and T3 treatment. The findings of the present study revealed that aflatoxin contaminated feed is harmful for the growth performance and survival of O. niloticus fingerlings. Further study is necessary to safeguard the aquaculture production as well as to produce healthy food for human consumption

Screening of organochlorine insecticides (DDT and heptachlor) in dry fish available in Bangladesh

The concentrations of organochlorine insecticides DDT and heptachlorwere investigated to estimate the current status of insecticidesused in dry fish. The most popular dry fish– ribbon fish (Chhuri),shrimp (Chingri) and bombay duck (Loittya) were selected for thisstudy and these dry fishes were collected from different markets ofDhaka and Chittagong. The range of DDT used in all the samples was3.038 ppb to 874.966 ppb. The range of DDT in ribbon fish 131.611 ppb to 149.430 ppb, in shrimp 3.038 ppb to 318.206 ppb and in bombayduck 61.918 ppb to 874.966 ppb was found. The range of heptachlorused in all the samples was 0.682 ppb to 5.464 ppb. The range ofheptachlor in ribbon fish 1.710 ppb to 2.306 ppb, in shrimp 0.682 ppbto 3.806 ppb and in bombay duck 1.762 ppb to 5.464 ppb was found.The heptachlor was not found in ribbon fish (CTG-2), shrimp (DHK-2and CTG-1) and bombay duck (DHK-1). The concentration of heptachlorin dry fish compare to DDT was found too much less

Organochlorine insecticides (DDT and heptachlor) in dry fish: Traditional washing and cooking effect on dietary intake

The concentrations of organochlorine insecticides (DDT and heptachlor) were investigated to estimate the effect of various washing and boiling/cooking to elucidate the concentration level we intake actually. For this study five most popular dry fish samples namely bombay duck (loittya), ribbon fish (chhuri), shrimp (chingri), chinese pomfret (rupchanda) and Indian salmon (lakhua) were analyzed. The highest concentrations of DDT and heptachlor were found 737.238 ppb (Indian salmon, normal) and 44.806 ppb (shrimp, normal) respectively; after boiling treatment a big amount was washed out and remained only 135.516 ppb and 16.868 ppb respectively. Boiling treatment was found more effective than the others

Cooking

washing and cooking effect on dietary intak