Limit of drug residues in aquatic products (NY5071-2002)

Weimin, ZOU, lexian YANG, lan JIANG, Shuqin WU, Qi YI, Jianli WU

Distribution of drug resistant luminous bacteria in penaeid shrimp grow-out ponds

Distribution of luminous bacteria (LB) in penaeid shrimp grow-out pond water in semiintensive seawater farming system and their resistance to 15 antibacterials were investigated. Total viable counts and luminous bacterial counts in pond water ranged from 2.00xl03 to 1.35xl04/ml and l.OOxl01 to 8.00Xl02/ml, respectively. The percentage composition of LB in the total viable population increased significantly with period of culture. Five species of LB such as Vibrio fischeri, V. harveyi, V. orientalis, V. splendidus 1 and Photobacterium leiognathi were encountered. V. harveyi was the dominant species, constituting >80% of the total LB. Multiple antibiotic resistance was more common in these LB. Pond water isolates showed resistance to at least four antibacterial agents.

Determination of length-weight relationship of squid (Loligo duvauceli) found along Pakistan coast

Common squid (Loligo duvauceli) is caught as by-catch of shrimp trawlers in shallow coastal. waters off Pakistan. Size frequency data of squid for sexes combined collected from Karachi Fish Harbour were analyzed. The length-weight relationship of the form W = a.L b was determined and to mean length of squid sample measured compared with mean length derived from inverse equation was tested for any significant differences, none were observed and it was inferred that the equation W = 0.243xL 2.2424 describe the relationship.

Determination of length-weight relationship in Sepia pharaonis and test for sex specific variation

The parameters a and b of the length-weight relationship of Sepia pharaonis of the form of W=a.L was determined. Sex separated size fequency data collected from Karachi fish Harbour was analysed the length-weight equations, separable by male, female and sex combined. The apparent difference in paired values of exponents b1, b2 for any combination i.e. male versus female and male, female versus sex combined was tested for their significant difference. No significant difference was observed for any combination, this indicated no sex specific variation in length-weigh relationship of Sepia pharaonis.

A novel short neurotoxin, cobrotoxin c, from monocellate cobra (Naja kaouthia) venom: isolation and purification, primary and secondary structure determination, and tertiary structure modeling

A novel short neurotoxin, cobrotoxin c (CBT C) was isolated from the venom of monocellate cobra (Naja kaouthia) using a combination of ion-exchange chromatography and FPLC. Its primary structure was determined by Edman degradation. CBT C is composed of 61 amino acid residues. It differs from cobrotoxin b (CBT B) by only two amino acid substitutions, Thr/Ala11 and Arg/Thr56, which are not located on the functionally important regions by sequence similarity. However, the LD50 is 0.08 mg/g to mice, i.e. approximately five-fold higher than for CBT B. Strikingly, a structure-function relationship analysis suggests the existence of a functionally important domain on the outside of Loop III of CBT C. The functionally important basic residues on the outside of Loop III might have a pairwise interaction with alpha subunit, instead of gamma or delta subunits of the nicotinic acetylcholine receptor (nAChR). (C) 2002 Elsevier Science Inc. All rights reserved.

Determination of threshold current densities for different reactions of fishes using a pantostat

The threshold current densities required for first reaction, galvanotaxis and galvanonarcosis of fish depended upon species, length of the body, conductivity of water, nature of current and frequency of impulses. The threshold values and their ratios decreased with increase in length of fish. With rise in conductivity of water in the ratio of 1:4:13, these values increased in the ratio 1: 2:5. Impulse D. C was superior to continuous D. C and the threshold values of current densities for different reactions of fish decreased with rise in impulse frequency reaching minimum at an impulse frequency of 48/sec. Among Salmo irideus, ldus melanotus and Cyprinus carpio, the first one was affected earlier and required minimum current densities to exhibit the reactions, while the last one showed similar reactions only at higher current densities.

Determination of acute mercury toxicity to developing stages of Cyprinus carpio and Cirrhinus mrigala

Toxicity of inorganic mercury to different life history stages of fresh water fishes, Cyprinus carpio and Cirrhinus mrigala were demonstrated by static bioassays. 48 and 94% of egg hatching occurred in controls at 72 and 24h of experimentation in C. carpio and C. mrigala respectively. While fish eggs in water containing mercuric chloride showed delayed development as compared to the control. LC50, LC100 and safe concentrations of hatchling, fry and fingerling were calculated. Hatchling and fry were observed to be more susceptible as compared to fingerlings of C. carpio and C. mrigala.

Human immunodeficiency virus-1 genotypic drug resistance among volunteer blood donors in Yunnan, China

BACKGROUND: Drug resistance profiles of human immunodeficiency virus-1 (HIV-1) in treatment-naive infections have been reported in developed countries. However, little is known in developing countries, including China, especially in treatment-naive volunt

Milt quality determination of a critically endangered fish, olive barb (Puntius sarana, Ham.) in Bangladesh

The present study was aimed to evaluate the characteristics of the olive barb sperm. Milt was collected fortnightly from 49 male fish (mean weight 90.8 g and length 18.64 cm) from April to July in 2008. In the olive barb ejaculated milt, volume (µl/g), motility (%), duration of motility (s), concentration (x 10 super(10)/ml) and pH values were found to be 6.06±0.32, 88.27±0.71, 171.41±7.41, 5.16±0.05 and 7.75±0.04, respectively. Milt volume was significantly (P<0.05) correlated with sperm concentration. Milt volume, sperm concentration, motility and duration of motility significantly varied (P<0.05) during spawning season.

The survey on determination of malathion biomarker with genotoxicity and ecophysiological reactions in the Caspian roach (Rutilus rutilus caspicus)

In the present study possibility of Malathion biomarker with Genotoxicity and Ecophysiological reactions were determined in Caspian Roach (Rutilus rutilus caspicus). At fist LC50 value of Malathion, an organophosphate insecticide was determined. Then four groups of experimental fish (containing 30 fish in each group) were exposed to different concentrations of Malathion. e. 0, 0.01, 0.05 and 0/1 ppm respectively for 23 days and effects of Malathion on Hematological (RBC, WBC, Hb and Hct) and biochemical parameters (Glucose, triglyceride, urea, total protein and Albumin), some enzymes (SGPT, SGOT and ALP), Cortisol level, plasma cations (Na+ and K+) , histological changes (gill and liver) and finally DNA destruction were examined. Sampling was done in 3rd, 13th, 23rd days during exposure and also 30 days after recovery. Data analysis was done by SPSS (Ver.13) and graphs were drawn by Excel 2007. Results showed that WBC, RBC, Hb, Hct, some biochemical parameters and K+ of Mallation treatments were decreased significantly in compare to control group (P<0.05). Changes in enzyme were many different. No significant changes were observed in Na+ and cortisol levels (except in groups treated with 0.01 Mallation) (P>0.05). LC50 value of Malathion in Caspian Roach was 6.5 ppm. Histological examinations showed that Mallation cause tissue damages and there were more damages in longer times and in higher concentrations. Apoptotic cell and comet were observed as DNA destruction and they were more in treatments with higher Mallation concentrations for longer times.

Determination of bioaccumulation and microscopic survey of LAS pollutant effect on the liver, kidney and gill tissues of Rutilus frisii kutum in Caspian sea

Linear alkylbenzene sulfonate (LAS) are widely used in detergent industry. Due to contaminants entering the water, and the effects of their accumulation in fish, LAS, has a great importance in environmental pollution. In the present study, accumulation of LAS and its histological effects on gill tissue, liver and kidney of Caspian kutum (Rutilus frisii kutum) were studied. Caspian kutum is the most important and most valuable teleosts of the Caspian Sea. Due to releasing Caspian Kutum in rivers and Anzali Lagoon and unlimited entry of wastewater to the aquatic ecosystem, research on the impact of LAS on Caspian kutum is important. In the present study, fish exposed to sublethal concentrations of LAS (0.58, 1.16 and 2.32 mg/l) for 192 hours. Control treatments with three replicates at 0, 24, 48, 72, 96 and 192 hours were done. For assessments of the histological effects of LAS, tissue sections prepared and by using Hematoxylin - Eosin were stained, then the prepared sections, examined by light microscopy. For determination of the bio accumulation of LAS, the soxhlet extraction and solid phase extraction was performed to determine the amount of LAS using HPLC with fluorescence detector. According to results average of bioconcentration factor and LAS concentrations in fish had reached stable levels after approximately 72 h and thus represented steady state BCF values in this species. The value of steady-state bio-concentration factor of total LAS was 33.96 L.Kg- 1 and for each of the homologous C10-n-LAS, C11-n-LAS, C12-n-LAS and C13-n- LAS were 3.84, 6.15, 8.58 and 15.57 L.Kg-1 respectively. According to the results obtained in gills exposed to LAS, histopathological alteration include hypertrophy, lifting of lamella epithelium, edema, clubbing of lamellae hyperplasia, lamellar fusion and aneurysm were seen. In liver tissue exposed to three concentrations of LAS, congestion and dilation of sinusoids, irregular-shaped nuclei and degeneration in the hepatocyte, vacuolar degeneration and necrosis were observed. In kidney exposed to three concentrations of LAS, reduction of the interstitial haematopoietic tissue, degeneration in the epithelial cells of renal tubule, tubular degeneration, necrosis, shrinkage and luminal occlusion were observed. According to the results the most alteration due to exposure to LAS was seen in the gill tissue. None of the control samples showed histological effects of LAS.