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1.
The effect of removing heavy metal ions (copper, zinc, lead, and cadmium) with a polymeric heavy metal absorbent (PHMA) on metamorphosis of Penueus chinensis Osbeck was investigated. There was a significant ( P < 0.05) reduction in metamorphosis of protozoea to mysis at concentrations more than 31.0 μg/L copper, 38.3 μg/L zinc, 32.5 μg/L lead, and 30.3 μg/L cadmium, in the absence of PHMA. At concentrations more than 61.0 μg /L copper, 68.3 μg/L zinc, 62.5 μg/L lead, and 60.3 μg/L cadmium there was a significant ( P < 0.01) interaction between the absence and the presence of PHMA for metamorphosis of mysis to postlarvae. At concentrations of 12.3 μg/L copper, 45.8 μg/L zinc, 106.2 μg/L lead, and 200.2 μg/L cadmium, the metamorphosis of protozoea to mysis was blocked, but it was 51.4% in the presence of PHMA. At concentrations of 252.3 μg/L copper, 335.8 μ/L zinc, 806.2 μg/L lead and 300.2 μg/L cadmium, the metamorphosis of mysis to postlarvae was stopped, but it was 51.0% in the presence of PHMA. The toxicity of copper, zinc, lead, and cadmium to P. chinensis was reduced with PHMA.  相似文献   

2.
A 15-day study was conducted to evaluate the effect of enrichment of Artemia metanauplii with four different emulsions, including: (A) Easy-DHA Selco; (B) Easy-DHA Selco + L-lysine (4 g/L); (C) Easy-DHA Selco + DL-methionine (4 g/L); and (D) Easy-DHA Selco + L-lysine (2 g/L) + DL-methionine (2 g/L) on growth and stress resistance of white leg shrimp Litopenaeus vannamei larvae (from Mysis I to postlarvae12). It is noticed that shrimp PL in group B had the highest wet (36.1 ± 3.1 mg) and dry (1116.7 ± 60.0 µg) weights as well as stress resistance to fresh water (64.0 ± 5.5%).  相似文献   

3.
The present study investigated the effectiveness of biochar as a water quality control agent and an alternative carbon source in a tilapia-based biofloc technology (BFT) system. Water quality parameters were measured following standard procedures (APHA, 1998) and fish physiological indices were measured using designated ELISA kits. Data was analyzed using repeated measures ANOVA and one-way ANOVA. Two biochar treatments were employed i.e. B; only biochar, GB; biochar + glucose, while for the control (G) only glucose was added. Tilapia fingerlings were cultured for approximately 10 weeks with no water exchange. Significant reduction (p < 0.05) in dissolved oxygen (DO) level was observed in group G (5.99 ± 0.10 mg/L) compared to B (6.66 ± 0.12 mg/L) and GB (6.53 ± 0.56 mg/L). Notably, concentrations of total suspended solids (TSS) were signficantly lower in the biochar treatments (B and GB) compared to the control (G). Additionally, alkalinity was significantly higher in G (156.47 ± 5.17 mg/L) compared to B (137.92 ± 3.83 mg/L) and GB (146.44 ± 3.87 mg/L). Levels of NO3- and total nitrogen (TN) were significantly higher in group B compared to G and GB. Also, significant difference was observed in PO43- levels between B (30.81 ± 2.28 mg/L) and GB (22.70 ± 1.84 mg/L). The dynamics of the water quality parameters revealed that heterotrophic assimilation and nitrification were active in maintaining the water quality. Overall, the result showed no significant differences (p > 0.05) in all the fish growth parameters. Urea nitrogen measured in the fish was significantly lower in B (3.85 ± 0.32 mmol/L) compared to G (5.40 ± 0.39 mmol/L) and GB (5.53 ± 0.39 mmol/L). Generally, there were no notable detrimental effects of biochar application on fish growth and physiological performance.  相似文献   

4.
用盐酸对苯二胺法对青海省148只绵羊进行了血清铜蓝蛋白酶活性测定。结果为:小尾寒羊,(18.660±0.905)IU/L;新疆细毛羊,(10.024±0.359)IU/L;青海半细毛羊,(48.380±1.152)IU/L;海南藏羊,(58.090±0.864)IU/L;欧拉羊,(45.440±1.342)IU/L。同时,在公、母组间进行比较,小尾寒羊母羊的血液铜蓝蛋白酶的活性极显著的高于公羊(P<0.01)。  相似文献   

5.
ABSTRACT

The effect of photoperiod (24L:00D, 12L:12D, and 00L:24D) and temperature (22 ± 1°C and 28 ± 1°C) on performance of Clarias gariepinus larvae was tested. Larvae weighing 3.2 ± 0.24 mg were cultured in aquaria at a stocking density of 20 fish L?1 and fed twice a day on catfish starter diet (40% CP) at 10 % BW day?1. Highest mean weight gain (31.00 mg), SGR (7.56% day?1), and survival (83%) were achieved at photoperiod and temperature combination of 00L:24D and 28 ± 1°C. Percent survival of larvae differed significantly (p < .05) among treatments with optimal survival of (83%) in treatment combination of 28 ± 1°C and 00L:24D, while lowest survival (40%) in treatment combination of 22 ± 1°C and 24L:00D.  相似文献   

6.
The toxicity of hydrogen peroxide (H2O2) to fingerling (80-160 mm total length) walleye, Stizostedion vitreum, was evaluated. Walleye were exposed in a 1 hour static bath to 50, 75, 100, 200, 225, 250, 400, and 600 ppm (µL/L) active ingredient (H2O2) in five experiments. Three to six replicates of each concentration were used in each experiment, with 25 fish per replicate. After resuming flow, concentrations of H2O2 in the tanks declined by 23.8% every hour, reaching 0 ppm (µL/L) about 3.5 hours after treatment. Mortalities, as well as dissolved oxygen, temperature, and H2O2 concentrations were monitored at 1, 12, 24, 48, 72, and 96 hours. Dissolved oxygen concentrations increased 0.25-1.16 ppm (µL/L) 1 hour after the addition of H2O2, because of the dissociation of H2O2 (2H2O2→2H2O + O2). The LC50 following a single 1-hour exposure ranged from 145.1 ppm (µL/L) at 12 hours to 142.8 ppm (µL/L) at 96 hours, which indicates that the toxic effect is mainly from initial contact. The toxicity threshold for walleye is about 50 ppm (µL/L) (1.3% mortality at 96 hours following 1 hour exposure). Other studies indicate that rainbow trout, Oncorhynchus mykiss, tolerate up to 250 ppm (µL/L) for 1 hour, but fingerling walleye should not be exposed to more than 50 ppm (µL/L) for the same exposure interval.  相似文献   

7.
Molecular and otolith analyses were conducted for 173 settlement-stage larvae of emperor fishes (family Lethrinidae) collected by light traps at Ishigaki Island, southern Japan, in July and August (summer season), to (1) present diagnostic DNA markers for identification of lethrinid species and (2) compare the size and age at settlement of each species. PCR–RFLP and direct nucleotide sequencing analyses identified 8 species. Size (standard length, SL) at settlement differed significantly between species; Lethrinus ornatus (mean SL ± SD, 12.8 ± 1.5 mm), L. obsoletus (14.2 ± 0.8 mm) and L. harak (15.8 ± 1.6 mm) settled at a smaller size than L. atkinsoni (17.0 ± 1.3 mm), L. genivittatus (17.3 ± 1.0 mm), L. olivaceus (18.1 ± 0.6 mm), L. nebulosus (18.6 ± 4.2 mm), and L. sp.2 reported by Lo Galbo et al. (J Mol Evol 54:754–762, 2002) (21.7 ± 1.4 mm). Age at settlement tends to increase with settlement size; L. obsoletus (mean age ± SD, 25.6 ± 1.2 days), L. atkinsoni (26.1 ± 2.1 days) and L. ornatus (26.3 ± 2.9 days) were younger at settlement than L. nebulosus (28.4 ± 2.1 days), L. harak (29.2 ± 1.7 days), L. olivaceus (29.5 ± 1.0 days), L. genivittatus (30.5 ± 1.7 days) and L. sp.2 (31.0 ± 2.0 days). Although our study showed interspecific variation in body size and age at settlement among 8 lethrinid species, further seasonal replication is necessary to clarify the general patterns.  相似文献   

8.
Long‐day photoperiods are considered as an effective managerial tool in manipulating of reproduction and somatic growth in a number of fish species. In this study, the effects of three different artificial photoperiods on the gonadal development and somatic growth of rainbow trout (Oncorhynchus mykiss L.) were investigated. Two years‐old immature female rainbow trout (279.94 ±2.25 g) were exposed to three artificial photoperiod regimes of 24L:0D, 18L:6D and 6L:18D and natural light (NL) regime for 5 months. The highest gonadosomatic indices were recorded in NL and 6L:18D groups while the rates were significantly lower in fish maintained under 18L:6D and 24L:0D photoperiods (P < 0.05). Mean oocyte diameters in fish exposed to 24L:0D and also to 18L:6D were significantly lower than the 6L:18D and NL groups. Photoperiods with 24L:0D and 18L:6D regimes resulted in significantly higher mean final weights and specific growth rates (SGR) than NL regime. The highest mean final weight (635.45 ± 16.19 g) and SGR (1.03 ± 0.04% day?1) were obtained under 24L:0D photoperiod. Fish exposed to 24L:0D and 18L:6D showed the highest condition factor as 1.44 ± 0.01 and 1.44 ± 0.02 respectively, when compared with the NL (1.27 ± 0.01) and 6L:18D (1.34 ± 0.02) groups. Basically, the results suggested that continuous artificial lightning can be used as an influential factor in delaying gonadal development and enhancing somatic growth in rainbow trout during gonadal growth phase.  相似文献   

9.
The study was conducted to evaluate the effect of dietary lipid levels on growth, liver oxidative stress, and serum metabolites of juvenile hybrid snakehead (Channa argus × Channa maculata). Five isonitrogenous (crude protein 420 g kg?1) practical diets containing 58, 87, 115, 144, and 173 g kg?1 crude lipid (named L58, L87, L115, L144, and L173, respectively) were fed to triplicate groups of 30 fish (mean initial weight 24 g) for 8 weeks. The results showed that the final body weight (58.68–78.81 g), specific growth rate (1.41–1.75 % day?1), and protein efficiency ratio (1.66–2.64) increased significantly with the increasing dietary lipid levels. Liver lipid contents (71.65–101.80 g kg?1) and crude lipid (52.10–83.63 g kg?1) of whole body increased with increasing dietary lipid levels and reached the highest values in fish of L173. Fish of L173 showed lower alkaline phosphatase (23.81 King Unit gprot?1) and catalase activities (4.44 U mgprot?1) but higher malondialdehyde content (0.69 nmol mgprot?1) in liver than the other groups. Higher alanine transaminase activity (8.20 U L?1), aspartate transaminase activity (63.65 U L?1), and triglyceride (0.29 mmol L?1) in serum were observed in fish of L173 compared to the other treatments. Fish of L144 showed higher superoxide dismutase activity and glutathione peroxidase activities in liver than that of fish fed diet L58. Fish fed diet L58 showed lower total cholesterol (3.61 mmol L?1), high-density lipoprotein cholesterol (1.39 mmol L?1), and low-density lipoprotein cholesterol (0.46 mmol L?1) in serum. These results suggested that juvenile snakehead (Channa argus × Channa maculata) achieved good growth performance with dietary lipid level 173 g kg?1. Diet with 143 g kg?1 lipid was more conductive to liver health. The appropriate dietary lipid supplementation needs to be determined in further studies.  相似文献   

10.
研究了超低温冷冻保存(-196℃)对俄罗斯鲟(Acipenser gueldenstaedti)精浆和精子中总三磷酸腺苷酶(AT-Pase)、琥珀酸脱氢酶(SDH)、乳酸脱氢酶(LDH)、肌酸激酶(CK)等酶活性的影响,并分别测定了冷冻前后俄罗斯鲟精浆和精子中酶的活性。结果显示,经过超低温冷冻保存后,俄罗斯鲟精子活力下降,精子内各酶活性均显著降低,添加冷冻保护液组精子中总ATPase、SDH、LDH和CK的活性分别从(198.47±14.43)U/mL、(30.00±2.65)U/mL、(6 982.29±24.32)U/L和(1.94±0.05)U/mL下降至(110.19±2.32)U/mL、(16.33±2.08)U/mL、(5 122.93±195.07)U/L和(1.49±0.14)U/mL。未添加抗冻剂组则分别下降至(2.25±0.33)U/mL、(11.67±0.58)U/mL、(4 488.04±78.33)U/L和(1.16±0.02)U/mL;精浆中酶的活性均显著升高,添加冷冻保护液组精浆总ATPase、SDH、LDH和CK活性分别从(12.70±0.57)U/mL、(7.50±0.71)U/mL、(2017.26±116.81)U/L和(2.93±0.59)U/mL升高至(92.49±5.18)U/mL、(13.33±0.58)U/mL、(3 688.97±172.67)U/L和(4.39±0.24)U/mL,未添加抗冻剂组则分别上升至(200.27±12.97)U/mL、(24.67±3.06)U/mL、(6 124.40±329.14)U/L和(5.20±0.16)U/mL。结果表明,超低温冷冻对俄罗斯鲟精浆和精子中酶活性及精子活力均有较大影响。  相似文献   

11.
This study was undertaken to determine the effects of dietary lipid levels on growth and nutrient utilization, and carbon (C), nitrogen (N) and phosphorus (P) balances in juvenile turbot (Psetta maxima) in brackish water. Four isonitrogenous diets (50 % protein) differing in dietary lipid levels from 10 to 19 by 3 % increments (named 10L, 13L, 16L and 19L, respectively) were fed to four replicate groups of fish with an initial weight of 54.4 ± 0.2 g for 9 weeks. Significantly better growth and feed conversion ratio were observed in fish fed 13L than those fed 16L and 19L. The whole body, fillet, viscera and liver dry matter and lipid levels were increased as dietary lipid was increased. Liver protein levels were lower in 16L and 19L than 10L. There was an ascending pattern in the whole-body C levels and C/N ratios with the increase in dietary lipids. No significant effect of dietary lipids on either protein efficiency ratio or N and P retentions was detected. Dietary lipids led to an increase in C losses to the environment. Overall, high dietary lipids when introduced at an adequate protein level did reduce growth and feed utilization without a protein-sparing effect and resulted in higher C losses in juvenile turbot reared, and a dietary lipid level of about 13 % seemed to be optimum.  相似文献   

12.
Due to the wide use of glyphosate (GLY) in soybean cultivation, their residues in the environment may affect non-target organisms such as fish, developing toxic effects. Despite GLY being widely used in Brazil, there are few studies comparing the effects of commercial formulations in native freshwater fish species. Silver catfish (Rhamdia quelen) were exposed to three different commercial formulations of GLY 48 % (Orium®, Original® and Biocarb®) at 0.0, 2.5 and 5.0 mg/L for 96 h. The effects in thiobarbituric acid-reactive substances (TBARS), catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST) and histological alterations were analysed in the liver, whereas alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were studied in the plasma. In the liver, TBARS levels increased and CAT decreased in all treatments and herbicides tested in comparison with the control group. The SOD increased at 2.5 mg/L of Orium®, Original® and 5.0 mg/L Orium® and Biocarb®, whereas GST increased at 2.5 mg/L Orium® and decreased at 2.5 mg/L Biocarb® when compared to the control group. The main histopathological alterations in hepatic tissue were vacuolisation, leucocyte infiltration, degeneration of cytoplasm and melanomacrophage in all GLY treatments. The ALT decreased after exposure to 2.5 mg/L of Biocarb® and AST increased at 2.5 mg/L of Orium®, Original® and 5.0 mg/L of Biocarb® in comparison with the control group. In summary, the oxidative damage generated by GLY may have caused the increased formation of free radicals that led to the histological alterations observed in hepatocytes.  相似文献   

13.
Calanoid copepods, including species of the genus Acartia, are commonly used as larval diets for marine finfish. This study aimed to determine the separate effects of water temperature (18, 22, 24, 28° ± 0.5°C) and photoperiod (24L:0D; 18L:6D; 12L:12D; 8L:18D; 0L:24D) on Acartia grani egg production (EP), hatching rate (EHR) and population growth. Egg production rate was not affected by the two abiotic parameters. A. grani eggs incubated at T24°C and T28°C were the first to achieve 50% hatching rate (23–25 hr), with significant differences at the end of the experiment (48 hr) between T28°C treatment (EHR 88 ± 5%) and T18°C treatment (EHR 65 ± 2%). However, different temperature regimes did not affect final number of individuals in population growth experiment. Still, when eggs were excluded from data, population at lower temperatures (18°C) was mainly composed by the nauplii stage (72%), while at higher temperatures (24°C and 28°C) more than 60% of the population was composed by copepodites and adults. A. grani subjected to long‐day photoperiods had significantly lower EHR (16.7% at 24L:0D; 20.8% at 18L:6D) than at short‐day photoperiods (52.6% at 6L:18D; 50.0% at 0L:24D). In population growth experiment, eggs were the most common life stage after 12‐day culture. Lowest population number was found at constant light conditions (665.0 ± 197.1), suggesting higher metabolic rates and depletion of energy reserves in long‐day conditions. This study expanded knowledge on the biological response of A. grani to separate temperature and photoperiod regimes, and provided ground to improve the culture of this potential life feed species for hatcheries.  相似文献   

14.
Androgen immersion protocols have been unsuccessful in consistently producing all-male tilapia at a high enough ratio for them to be commercially viable. This study explored the use of ultrasound to improve on the results of previous immersion studies. Variables tested include two hormones (trenbolone acetate-TBA and 17α-methyldihydrotestoterone-MDHT) at two concentrations (100 and 250 μg/L) and with or without ultrasound (cavitation level). All hormone treatments with ultrasound and non-ultrasound resulted in significantly higher masculinization than the appropriate controls ( P < 0.05). Among pairs of treatments of the same hormone at the same dose, all ultrasound treatments resulted in significantly higher number of males compared with non-ultrasound treatments with the exception of MDHT 250 μg/L ( P 0.05). Comparing across all ultrasound treatments, TBA 250 μg/L with ultrasound had higher masculinization than all the other ultrasound treatments ( P 0.05). Comparing across all non-ultrasound treatments, TBA 250 μg/L had higher ( P 0.05) masculinization than MDHT 100 μg/L and TBA 100 μg/L with non-ultrasound. Two of the three replicates of TBA 250 μg/L ultrasound treatment resulted in 100% males and the highest mean percentage (98%) of males. This study thus demonstrated the potential of a short-term immersion protocol using ultrasound to more predictably produce all-male, commercially viable tilapia seed.  相似文献   

15.
凡纳滨对虾养殖塘主要有机污染指标相关性分析   总被引：1，自引：0，他引：1  
2009年4—9月期间,对上海市奉贤区某凡纳滨对虾(Litopenaeus vannamei)养殖场池塘两个养殖周期中总有机碳(TOC)、高锰酸盐指数(CODMn)、和五日生化需氧量(BOD5)进行分析检测。结果显示:试验的两个周期中(4—7月、7—9月),14个池塘BOD5分别为(8.62±3.08)mg/L和(10.47±3.87)mg/L,CODMn为(13.09±3.98)mg/L和(16.16±6.07)mg/L,TOC为(17.60±5.91)mg/L和(20.32±6.07)mg/L。TOC/CODMn分别为(1.35±0.22)和(1.32±0.30);TOC/BOD5为2.10±0.44和2.08±0.63;BOD5/CODMn为0.66±0.13和0.65±0.11。TOC、CODMn和BOD5两两之间呈显著线性正相关,第一个养殖周期中:BOD5=0.4174TOC+1.2777,r=0.8022;CODMn=0.5616TOC+3.2091,r=0.8342;BOD5=0.6264CODMn+0.4209,r=0.8106。第二个养殖周期中:BOD5=0.4764TOC+0.7902,r=0.7480;CODMn=0.7941TOC+0.0237,r=0.7962;BOD5=0.568CODMn+1.2912,r=0.8920。结果表明,利用建立的TOC、CODMn和BOD5之间的相关方程,可进行各指标之间的相互换算,从而与不同的水质标准或其他相关研究进行对比,为凡纳滨对虾养殖池塘的水质管理和健康养殖提供指导。  相似文献   

16.
ABSTRACT

Litopenaeus vannamei postlarvae were exposed to 0, 6, 13, and 19 mg/L total ammonia nitrogen (TAN) treatments. After 45 days, shrimp weight and length were lowest under TAN concentrations of 13 and 19 mg/L (P ≤ 0.05). Maximum weight gain was observed in control and 6 mg/L treatments. Mortality was highest (80.55 ± 4.80%) under 19 mg/L reared in 35 ppt salinity. Average intermolt periods of PLs exposed to 0, 6, 13, and 19 mg/L TAN were 11.5 ± 0.7, 10.8 ± 1.3, 9.4 ± 1.0, and 8.7 ± 0.6 days under 35 ppt and 11.1 ± 0.5, 10.7 ± 0.6, 10.1 ± 0.5, and 9.5 ± 0.2 days under 45 ppt salinity. Although TAN increased postlarvae molting frequency, its negative effects on the shrimp growth and survival of PLs was directly linked to its concentration and exposure duration. Higher salinity reduces the effects of ammonia and increases the survival.  相似文献   

17.
Three isonitrogenous (320 g kg?1 crude protein, casein and gelatine) semi‐purified diets with 80 (L8), 130 (L13) and 180 (L18) g kg?1 lipid (sunflower oil at increasing levels and cod liver oil fixed at 50 g kg?1) at three digestible energy levels (12 096, 13 986 and 15 876 kJ kg?1 dry weight) and were tested, in triplicate, on rohu fingerlings (3.2 ± 0.08 g) at two different temperatures (21 and 32 °C). Fish were fed to apparent satiation, twice daily, at 09.00 and 15.00 h, 7 days a week for 56 days. Maximum growth was obtained at a lipid level of 80 g kg?1 (L8) at 21 °C (439.37%) and 130 g kg?1 (L13) at 32 °C (481.8%). In general growth rate was higher at 32 °C than at 21 °C at all lipid levels. Tissue monounsaturated fatty acid (MUFA) contents decreased with increasing lipid level at 32 °C, but the reverse occurred at 21 °C. At 21 °C, Polyunsaturated fatty acid (PUFA) level increased significantly (P > 0.05) over initial values, but was affected insignificantly by dietary lipid level. At 32 °C, fish fed diet L13 had more n‐3 fatty acid (FA) in liver and muscle than the other two dietary groups while at 21 °C, both liver and muscle FA profiles exhibited significant change (P > 0.05) in n‐3 and n‐6 FA content which corresponded to variation in percent addition of dietary lipid. However, n‐3/n‐6 ratio was higher for fish fed diet L13 at 32 °C and diet L8 at 21 °C and may be correlated with fish growth.  相似文献   

18.
This study evaluated whether anesthesia with essential oil (EO) of Lippia alba (300 mg L?1 for 4 min) prior to electronarcosis (128 V m?1 × 300 Hz for 5 s) or hypothermia (ice/water slurry) could delay fish spoilage during chilled storage of whole fish. Silver catfish (Rhamdia quelen) were subjected to two different pre-stunning treatments (water or anesthesia with EO of L. alba) followed by two different stunning procedures (hypothermia or electrical stunning), yielding four groups (n = 32/group): water (control) + hypothermia, water (control) + electrical stunning, EO of L. alba + hypothermia, and EO of L. alba + electrical stunning. After stunning, fish were slaughtered by percussion and stored in ice. Preslaughter anesthesia with the EO of L. alba extended fish shelf life by delaying the loss of freshness (nucleotide degradation), growth of Enterobacteriaceae, and fish deterioration (sensory evaluation). Such preservative effect was most remarkable for fish that were subsequently submitted to electrical stunning, as they had the lowest demerit scores and greatest shelf life in the sensory evaluation. Our results showed that preslaughter anesthesia with EO of L. alba followed by electrical stunning can delay the loss of freshness and extend fish shelf life during chilled storage.  相似文献   

19.
Vinclozolin (VZ) is a pesticide that acts as an anti-androgen to impair reproduction in mammals. However, VZ-induced disruption of reproduction is largely unknown in fish. In the present study, we have established a combination exposure in which adult goldfish were exposed to VZ (30 and 100 μg/L), anti-androgen flutamide (Flu, 300 μg/L), and androgen testosterone (T, 1 μg/L) to better understand effects of VZ on reproductive endocrine system. mRNA levels of kisspeptin (kiss-1 and kiss-2) and its receptor (gpr54), salmon gonadotropin-releasing hormone (gnrh3) and androgen receptor (ar) in the mid-brain, and luteinizing hormone receptor (lhr) in the testis were analyzed and compared with those of control following 10 days of exposure. kiss-1 mRNA level was increased in goldfish exposed to 100 µg/L VZ and to Flu, while kiss-2 mRNA level was increased following exposure to Flu and to combinations of 30 µg/L VZ with Flu, 100 µg/L VZ with T, and Flu with T. gpr54 mRNA level was increased in goldfish exposed to Flu and to combination of 30 µg/L VZ with Flu and 100 µg/L VZ with T. gnrh3 mRNA level was increased in goldfish exposed to 100 µg/L VZ, to Flu, and to combinations of 30 µg/L VZ with Flu, 100 µg/L VZ with T, and Flu with T. The mid-brain ar mRNA level was increased in goldfish exposed to Flu and to combinations of 30 µg/L VZ with Flu, 100 µg/L VZ with T, and Flu with T. Testicular lhr mRNA level was increased in goldfish exposed to Flu and to combination of 30 µg/L VZ with Flu. These results suggest that VZ and Flu are capable of interfering with kisspeptin and GnRH systems to alter pituitary and testicular horonal functions in adult goldfish and the brain ar mediates VZ-induced disruption of androgen production.  相似文献   

20.
The effects of a range of different sublethal salinities were assessed on physiological processes and growth performance in the freshwater ‘tra’ catfish (Pangasianodon hypophthalmus) juveniles over an 8-week experiment. Fish were distributed randomly among 6 salinity treatments [2, 6, 10, 14 and 18 g/L of salinity and a control (0 g/L)] with a subsequent 13-day period of acclimation. Low salinity conditions from 2 to 10 g/L provided optimal conditions with high survival and good growth performance, while 0 g/L and salinities >14 g/L gave poorer survival rates (p < 0.05). Salinity levels from freshwater to 10 g/L did not have any negative effects on fish weight gain, daily weight gain, or specific growth rate. Food conversion ratio, however, was lowest in the control treatment (p < 0.05) and highest at the maximum salinities tested (18 g/L treatment). Cortisol levels were elevated in the 14 and 18 g/L treatments after 6 h and reached a peak after 24-h exposure, and this also led to increases in plasma glucose concentration. After 14 days, surviving fish in all treatments appeared to have acclimated to their respective conditions with cortisol levels remaining under 5 ng/mL with glucose concentrations stable. Tra catfish do not appear to be efficient osmoregulators when salinity levels exceed 10 g/L, and at raised salinity levels, growth performance is compromised. In general, results of this study confirm that providing culture environments in the Mekong River Basin do not exceed 10 g/L salinity and that cultured tra catfish can continue to perform well.  相似文献   

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