Age- and Sex-Specific Bioaccumulation of Selected Metals in Freshwater Mussel (Unio elangatulus eucirrus Bourguignat, 1860) Populating from Keban Dam Lake (Elazig, Turkey).

In aquatic life, environmental chemicals are accumulated by mussels due to their sentinel nature and filter-feeding characteristics. Herein, the present study focused on assessing the concentrations of Cu, Zn, Mg, Mn, Fe, Cd, Pb, Ca, K, and Na levels in freshwater mussels (Unio elangatulus eucirrus) depending on sex and age. For all trace metals, some important differences of bioaccumulations were determined depending on ages and sex. In details, the results indicated that an important age-related accumulation of Mg, Cd, Ca, and K was in females and all trace elements, except Cu, Mg, and K levels in males (p < 0.05). No statistical differences were determined in mean concentrations of Cu, Zn, Mg, and Na. There are statistical differences in Mg, Mn, Fe, and Ca levels between females and males in four aged mussels (p < 0.05). Lead levels were under detectable limits. Overall, metal levels and their toxicity in freshwater mussels should be closely monitored for health of the environment, animals, and humans, since mussels and fish species fed on them are consumed highly in the research region and around.

Sperm quality and oxidative stress in chub Squalius orientalis and Padanian barbel Barbus plebejus (Teleostei: Cyprinidae) after in vitro exposure to low doses of bisphenol A.

In an aquatic environment, the presence of Bisphenol A (BPA) adversely affects reproduction, biology, behavior, gonads, and early larval development of fish due to being endocrine-disrupting compound. In addition, the detected concentration of BPA in water bodies is reported to be higher than 0.41 µg/L. As an alternative tool, sperm cells are used in toxicological assays for the reliable and practical assessment. For these reasons, we examined the effects of in vitro exposure of BPA on sperm quality of chub Squalius oriantalis and Padanian barbel Barbus plebejus. Spermatozoa were exposed to lower concentrations (0, 0.5, 1.25, 2.5, and 5 µg/L) of BPA for 2 h. The enzymatic activities [glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD)] and lipid peroxidation (MDA) were evaluated in spermatozoa. The results demonstrated that BPA exposure significantly decreased activities of SOD and GSH-Px but increased CAT activity and lipid peroxidation (MDA). Compared to control, the percentage and duration of sperm motility significantly decreased. Overall, spermatozoa clearly showed the sensitivity to lower concentrations of BPA.

Glyphosate disrupts sperm quality and induced DNA damage of rainbow trout (Oncorhynchus mykiss) sperm.

As a widespread pollutant, glyphosate (GLY) adversely affects the aquatic environment and can impair the reproductive ability and functions of fish. The purpose of the current study was to assess in vitro effect of GLY on rainbow trout (Oncorhynchus mykiss) sperm cells. The sperm cells were exposed to different GLY concentrations (2.5, 5, 10 mg/L). Sperm motility parameters were analyzed with computer assisted sperm analysis. DNA fragmentation (%) was measured by the comet assay using fluorescence microscopy. With increased GLY concentration, sperm motility and duration decreased after exposure. DNA fragmentation (% DNA in tail) in sperm cells was higher in treatments containing GLY than control (p < 0.05). Consequently, sperm cells are sensitive to low doses of GLY, and this can negatively affect natural populations.

Improvement of sperm motility of Oncorhynchus mykiss and Salvelinus fontinalis by L-tryptophan.

Experiments were designed to test the influence of L-tryptophan supplementation of the extender on the sperm motility parameters and bacterial flora of brook trout (Salvelinus fontinalis) and rainbow trout (Oncorhynchus mykiss). The extender containing 0.3 M glucose in 10% Dimethyl sulfoxide (DMSO) was supplemented with 0, 0.5, 1, 2, and 4 mM L-tryptophan. Sperm samples stored for up to 12 days at 4°C for brook trout were motile while motility was not observed after six days of storage for rainbow trout. Diluted sperm samples were spread-plated onto Plate Count Agar (PCA) (Total Bacteria Count), Rose Bengal Agar (RBC) (Yeast-Mold Count), Violet Red Bile Dextrose (VRBD) (Enterobacteriaceae count) and Mannitol Salt Agar (MSA) (Micrococcus/Staphylococcus count) and counts were performed in duplicate and sampling occurred on day 0, 2, 4, 6, and 12 of cold storage. L-tryptophan supplementation of the extender yielded a positive effect, significantly prolonging sperm motility in S. fontinalis and O. mykiss compared to the control group (p < 0.05). The ideal results were obtained above a concentration of 0.5 mM for both species. Total bacteria count in fresh sperm (undiluted samples) was not detectable and not detected in sperm samples treated with different L-tryptophan concentrations. Yeast-mold, Enterobacteriaceae and Micrococcus/Staphylococcus were not detected from fresh and treated sperm brook trout and rainbow trout. On the basis of the results, L-tryptophan-based extender is useful for maintaining sperm quality in short-term storage. L-tryptophan had a negative effect on the bacterial flora. The results of the current study encourages further studies related to long-term storage and reproduction management. Abbreviations: DMSO: dimethyl sulfoxide; PCA: plate count agar; RBC: rose Bengal agar; VRBD: violet red bile dextrose; MSA: mannitol salt agar; SCA: sperm class analyzer; CFU: colony-forming unit.

Malathion-induced spermatozoal oxidative damage and alterations in sperm quality of endangered trout Salmo coruhensis.

The use of pesticides has been increased along with increasing the farming activities and has caused environmental impacts deleteriously. In particular, non-target organisms including fish can be affected by toxic effects of pesticides. Therefore, the impacts of malathion (MTN) on oxidative stress and sperm quality were investigated in vitro. The MTN concentrations used on this study were 0 (control), 75, 100, and 125 µg/L. Lipid peroxidation (MDA), non-enzymatic (GSH), and enzymatic (SOD, GSH-Px, and CAT) activities in spermatozoa were examined for determination of oxidative stress status. Our findings showed that motility rate and period of sperm cells significantly decreased with exposure to MTN. Biochemical assays revealed that CAT activity and levels of MDA, GSH increased in spermatozoa based on concentration while activity of GSH-Px and SOD decreased. Consequently, spermatozoa were highly sensitive to MTN exposure. MTN has disruptive effects on sperm quality and caused to oxidative stress in spermatozoa.

Effect of Cobalt on Sperm Motility in an Endangered Trout Species, Salmo coruhensis.

Experiments were designed to examine the in vitro effect of cobalt on sperm motility of the endangered trout species (Salmo coruhensis). Sperm samples were diluted in an immobilizing solution, and activated in a motility-activation solution that was supplemented with cobalt at concentrations of 1, 10, 100 and 1000 mg/L. The percentage of motile sperm and duration of motility were determined. Cobalt concentrations of 1-100 mg/L had a positive effect on the percentage of motile sperm and duration of motility compared to the control group, while a concentration of 1000 mg/L resulted in decreases in these parameters (p < 0.05). The percentages of motile sperm at cobalt concentrations of 0, 1, 10, 100 and 1000 mg/L were 83.33% ± 0.25%, 88.33% ± 0.34%, 89.00% ± 0.57%, 90.00% ± 0.87% and 42.50% ± 0.45%, respectively; and the time durations over which the sperm remained motile were 72.00 ± 0.63, 74.83 ± 0.28, 77.40 ± 0.47, 81.14 ± 0.78, and 50.25 ± 0.67 s, respectively. This study has shown that sperm motility and duration were significantly enhanced (p < 0.05) at cobalt concentrations of 1, 10 and 100 mg/L, relative to controls, and significantly decreased at 1000 mg/L.

CRYOPRESERVATION OF GOLDFISH (Carassius auratus) SPERMATOZOA: EFFECTS OF EXTENDER SUPPLEMENTED WITH TAURINE ON SPERM MOTILITY AND DNA DAMAGE.

BACKGROUND: Amino acids, present in seminal plasma at high concentration, protect spermatozoa against cell damage during cryopreservation. OBJECTIVE: Experiments were designed to analyze the effect of semen extender supplemented with taurine on post-thawed sperm motility and duration, as well as DNA damage. MATERIALS AND METHODS: Extenders were supplemented with 1, 2 or 4 mM taurine. Semen samples were diluted at the ratio of 1:9 with the extenders. Diluted samples were aspirated into 0.25 ml French straws and 0.1 ml pellets. DNA damage was assessed with the comet assay after cryopreservation. RESULTS: The percentage and duration of sperm motility were significantly increased by taurine. Additionally, sperm motility and the motility period in pellets were higher than in straws. The best concentration of taurine was 4 mM, and the highest post-thaw motility rate (72.50 ± 3.54 %) and duration (17.50 ± 0.71 s) were obtained from the extender with 4 mM in pellets. DNA damage was decreased after taurine supplementation. CONCLUSION: Pellets could be used for goldfish sperm cryopreservation. The addition of 4 mM taurine increases the post-thaw motility and decreases DNA damage on goldfish semen.

The in vitro effect of cypermethrin on quality and oxidative stress indices of rainbow trout Oncorhynchus mykiss spermatozoa.

There is limited information on the scientific literature about the effect of in vitro exposure of fish sperm to pesticides. In vitro effect of cypermethrin on sperm quality and oxidative stress has not yet been fully investigated. Therefore, the effects of cypermethrin, a type II pyrethroid insecticide, on quality and oxidative stress of spermatozoa were examined in vitro. To explore the potential in vitro toxicity of cypermethrin, fish spermatozoa were incubated with different concentrations of cypermethrin (1.025, 2.05 and 4.1 µg/l) for 2 h. The motility rate and duration of sperm were determined after exposure to cypermethrin. Reduced glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) in spermatozoa were analyzed for determination of oxidant and antioxidant balance. Our results indicated that spermatozoa motility and duration significantly decreased with exposure to cypermethrin. Additionally, activity of GSH-Px (P<0.05) and MDA and GSH levels increased in a concentration-dependent manner while CAT activity decreased (P<0.05). Consequently, the oxidant and antioxidant status and sperm quality were affected by quantitative changes and different concentrations of cypermethrin.

The in vitro effect of Lambda-cyhalothrin on quality and antioxidant responses of rainbow trout Oncorhynchus mykiss spermatozoa.

There is little information in the scientific literature about effect of in vitro exposure of fish spermatozoa to pesticides. In vitro effect of Lambda-cyhalothrin (LCT) on sperm quality and oxidative stress has not been fully explored yet. The effects of LCT, which is a synthetic pyrethroid insecticide, on quality and oxidative stress of spermatozoa were investigated in vitro due to extensively use to control a wide range of insect pests in agriculture, public health, and homes and gardens. To explore the potential in vitro toxicity of LCT, fish spermatozoa were incubated with different concentrations of LCT (0.6, 1.2 and 2.4 µg/L) for 2h. Reduced glutathione (GSH), glutathione peroxidase (GSH-Px), catalase (CAT) and malondialdehyde (MDA) in spermatozoa were analyzed for determination of oxidant and antioxidant balance. Our results indicated that the percentage and duration of sperm motility significantly decreased with exposure to LCT. Activity of GSH-Px and MDA (P<0.05) and GSH levels (P<0.05) increased in a concentration-dependent manner while CAT activity decreased (P<0.05). In conclusion, the oxidant and antioxidant status and sperm quality were affected by increasing concentrations of LCT.

Effect of semen extender supplementation with cysteine on postthaw sperm quality, DNA damage, and fertilizing ability in the common carp (Cyprinus carpio).

Amino acids have an important biological role for prevention of cell damage during cryopreservation. The objective of this study is to determine the effects of cysteine on postthaw sperm motility, duration of sperm motility, DNA damage, and fertility in the common carp (Cyprinus carpio). Sperm collected from 10 individuals was cryopreserved in extenders containing different cysteine concentrations (2.5, 5, 10, and 20 mM). Semen samples diluted at the ratio of 1:9 by the extenders were subjected to cryopreservation. After dilution, the semen was aspirated into 0.25-mL straws; the straws were placed on the tray, frozen in nitrogen vapor, and plunged into liquid nitrogen. DNA damage was evaluated by comet assay after cryopreservation. Our results indicated that an increase in the concentration of cysteine caused a significant increase in the motility rate and duration of sperm in the common carp (C carpio; P < 0.05). Comparing all concentrations of cysteine, the best concentration of cysteine was 20 mM. Higher postthaw motility (76.00 ± 1.00%) and fertilization (97.00 ± 1.73%) rates were obtained with the extender at the concentration of 20 mM. Supplementation of the extender with cysteine was increased the fertilization and hatching rate and decreased DNA damage. Consequently, cysteine affected the motility, fertilization, and DNA damage positively, and extenders could be supplemented with cysteine.

Cryopreservation of rainbow trout Oncorhynchus mykiss spermatozoa: effects of extender supplemented with different antioxidants on sperm motility, velocity and fertility.

In present study, it was examined whether addition of different antioxidants to the cryopreservation extenders had an effect on semen post-thaw fertility and motility in rainbow trout (Oncorhynchus mykiss) and also it was investigated the sperm characteristics post-thaw sperm characteristics and fertility. The collected semen was pooled to minimize individual variation. Each pooled ejaculate was split into 12 equal aliquots and diluted with base extenders supplemented with the antioxidants, and a base extender with no additives (control). The pooled semen samples diluted at the ratio of 1:10 by the extenders were subjected to cryopreservation. Antioxidants were separately added to the extenders (one per experimental group): catalase (250 U/l), superoxide dismutase (250 U/l), peroxidase (250 U/l), oxidized glutathione (1.5 mmol/l), reduced glutathione (1.5 mmol/l), L-methionine (1.5 mmol/l), uric acid (0.25 mmol/l), L-ascorbic acid (0.5 mmol/l), α-tocopherol (2.0 mmol/l), ß-carotene (0.5 mmol/l) and carnitine (0.5 mmol/l). After dilution the semen was aspirated into 0.25 ml straws, the straws were placed on the tray, frozen for 10 min, and plunged into liquid nitrogen. Our results indicated that the post-thaw motility rate increased in extenders supplemented with uric acid, L-methionine, SOD, L-carnitine, α-tocopherol and L-reduced glutathione (p<0.05). The motility duration of frozen thawed semen increased in extenders supplemented with uric acid, L-methionine, SOD, α-tocopherol and L-reduced glutathione (p<0.05). Fertilization rate and hatching rate of frozen-thawed semen was not affected by the tested antioxidants. Consequently, the tested antioxidants affected the motility parameters and cryopreservation extenders could be supplement with antioxidants. This study suggested usage of antioxidants in the cryopreservation of rainbow trout.

Determination of bioaccumulation of heavy metals and selenium in tissues of brown trout Salmo trutta macrostigma (Duméril, 1858) from Munzur Stream, Tunceli, Turkey.

The objective of the present work was to determine the bioaccumulation of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), uranium (U) and selenium (Se) in gill, liver, and muscle tissues of the fresh water fish Salmo trutta macrostigma (Duméril, 1858) in Munzur Stream, Tunceli, Turkey. The highest concentrations of U (1.83 µg kg(-1)), Pb (119.84 µg kg(-1)) and Se (1.31 µg kg(-1)) were recorded in the gills of S. t. macrostigma. Concentrations of As (46.27 µg kg(-1)), Cd (109.19 µg kg(-1)), Hg (16.40 µg kg(-1)), Cu (18.19 µg kg(-1)) were recorded at highest levels in the liver. The results showed that there were significant differences in concentrations of As, Cd, Cu, Pb, Se, U and Hg in gill, liver and muscle tissue (p < 0.05). Heavy metals were within the edible parts of the investigated fish were in the permissible safety levels for human uses.