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The objectives of this experiment were to (i) determine the efficacy of essential oils of clove ( CO) and Lippia alba ( EOLA) to induce deep anaesthesia in juvenile specimens (49.0 ± 6.2 g body mass, 16.6 ± 0.8 cm; n = 8 per treatment) of meagre ( Argyrosomus regius); and (ii) study the feasibility of these substances, together with 2-phenoxyethanol (2- PHE), as potential sedatives [low concentration: (i) EOLA: 12 mg L−1; (ii) CO: 1 mg L−1; and (iii) 2- PHE: 33 mg·L −1; n = 8 per treatment] for live fish transport of this species. All test were performed at a constant temperature (18°C). Thus, the main primary stress indicator (plasma cortisol) and secondary factors (plasma metabolites) were evaluated. In addition, growth hormone ( GH) mRNA expression was also evaluated in the pituitary gland. The results indicated that EOLA is considered to be effective for deep anaesthesia when the concentration is close to 160 mg L−1, while CO produces the same effect when lower concentrations are added (40-50 mg L−1). Regarding sedative concentrations, a significant ~3-fold increase in plasma cortisol levels was detected in the EOLA group when compared to control specimens. In addition, glucose levels were not reduced and significantly increased (~1.6-fold) for 2- PHE in relation to the control fish. None of the anaesthetics promoted a significant difference for GH expression with respect to the control group, but a significant ~2-fold increase for 2- PHE treatment with respect to the EOLA exposition was found in this gene expression. Results show that none of the anaesthetics analysed, at least in the ranges of concentrations used in this study ( EOLA 12 mg L−1, CO 1 mg L−1, 2- PHE 33 mg L−1), are recommended for live fish transport, as shown by the absence of inhibition on the stress parameters assessed. [ABSTRACT FROM AUTHOR]

The article presents a study conducted to evaluate effects on the life of Hucho taimen fishes reared in coloured tanks. It mentions that study revealed little effects of colour tank on the growth of fishes, physiological effect was noticed but no effects on plasma glucose and lactate levels, Hucho taimen reared in yellow tanks provides favourable climate for food intake, difference in body colour has been noticed in black tank that can reduce conspicuousness and stress in fishes.

This study examined the effects of anesthesia on the hematological and biochemical parameters as well as the reproductive performance of wild female Persian sturgeon, Acipenser persicus, during controlled spawning. Fourteen mature females were divided into two groups: 'anesthetized' and 'non-anesthetized'. All activities including transportation, catheterizing and handling were performed with both groups: (i) under anesthesia (150 ppm clove oil), and (ii) without anesthesia. After 10 days storage and handling, blood samples were taken from all fish after anesthesia. No signifi- cant differences were found in the reproductive performance of either group. However, differences were found in the hematological parameters, with values being significantly higher in the non-anesthetized group, including neutrophils (34.36 ±6 .33% vs 23.63 ± 5.22%), monocytes (2.84 ± 1.70% vs 1.27 ± 0.64%), mean corpuscular volume (321.3 ± 39.40 pg vs 228.0 ± 24.46 pg) and mean corpuscular hemoglobin (106.9 ± 15.70 fl vs 76.50 ± 7.50 fl). Significantly lower values were found in the non-anesthetized group for lymphocytes (60.68 ± 7.25% vs 73.54 ± 4.80%), Hb (4.62 ± 0.74 mg dl-1 vs 6.28 ± 1.21 mg dl-1), Hct (13.86 ± 1.76% vs 18.84 ± 3.85%), red blood cell (0.43 ± 0.05 cell mm-3 vs 0.85 ± 0.13 9 106 cell mm-3) and white blood cell (22 403 ± 2240 cell mm-3 vs 35 318 ± 084 cell mm-3). The non-anesthetized fish had significantly higher cortisol levels compared to the anesthetized group (62.33 ± 8.85 ng ml-1 vs 46.12 ± 8.07 ng ml-1). There was no difference in plasma glucose levels between groups. It is concluded that the use of clove oil as an anesthetic is suitable for handling of wild female Persian sturgeon in controlled propagation programmes. However, further research is needed to determine a standardized protocol for the safe application of anesthesia for use in sturgeons in general. [ABSTRACT FROM AUTHOR]

The article presents a study which examines the hematological impact of fish transportation stress on the juvenile (1+) Atlantic sturgeon Acipenser oxyrinchus. The study is investigated by one-way analyses of variance (ANOVA), Duncan's multiple range tests, and post-hoc pairwise comparisons. Results show that transportation stress can affect the blood variables in A. oxyrinchus Mitchill L. juveniles.

This study verified the effects of CaSO4 on physiological responses of the tropical fish matrinxã Brycon amazonicus (200.2 ± 51.1 g) in water containing CaSO4 after a 4-h transportation at concentrations of: 0, 75, 150, and 300 mg L−1. Blood samples were collected prior to transportation (initial levels), immediately after packaging, at arrival, and 24 h and 96 h after transportation (recovery). Cortisol levels increased after packaging (118.2 ± 14.2 ng ml−1), and decreased slightly after transportation in water containing CaSO4 (106.8 ± 14.1), but remained higher than initial levels (21.0 ± 2.6 ng ml−1). Fish kept at 150 mg L−1 CaSO4 reached the pre-transportation levels at 24 h of recovery. Blood glucose increased after transportation in all treatments (8.2 ± 0.2 mmol L−1) and declined after full recovery to values below initial levels (4.8 ± 0.1 mmol L−1). Chloride levels did not change in CaSO4 treatments; serum sodium concentrations decreased after packaging and after transportation. Serum calcium levels did not differ among treatments, but decreased after packaging and increased at 96 h of recovery. Hematocrit and the number of red blood cells were higher in all treatments after packaging and arrival, except in fish exposed to 300 mg L−1 CaSO4. Mean corpuscular volume increased in 75 mg L−1 CaSO4, which reached the higher VCM after transportation. Hemoglobin levels increased only after transportation, regardless of calcium sulfate levels. Handling before transportation and transportation itself were both stressful to fish; calcium sulfate at concentrations tested in the present work had a moderate influence in the reduction of stress responses. [ABSTRACT FROM AUTHOR]

Tested was the efficiency of dietary metyrapone (MTP) in the inhibition of cortisol biosynthesis, as a tool to elucidate the effects of this hormone in the tropical fish pacu (Piaractus mesopotamicus H.) during air-exposure-induced stress. Moreover, MTP efficiency was shown to be affected by both the dose and time of administration and that a daily dose of 30 mg kg-1 body weight for 10 days reduced the levels of circulating cortisol in stressed fish. The tested method of MTP administration, including the concentration and the time of administration, efficiently regulated cortisol synthesis in a non-invasive manner. [ABSTRACT FROM AUTHOR]