Serum biochemical characteristics of Carassius auratus (L) following short-term formalin or NaCl treatment

Goldfish Carassius auratus were subjected to either formalin (250 ppm) or NaCl (10 ppt), over a 0.5-h period followed by 24-h freshwater exposure. Serum biochemistry was monitored before exposure (0), immediately after (0.5) plus 3 and 24 h after exposure. Results showed that both formalin and NaCl treatments caused rapid increase in cortisol with a peak at 3 h, which did not recover until 24 h. Likewise, glucose showed similar patterns, however, returned to initial levels at 24 h after exposure. Formalin caused significant decrease in sodium and chloride levels which returned to initial levels at 24 h after exposure. Both formalin and NaCl caused calcium and total protein elevation at 3 and 24 h after exposure. Albumin and globulin levels were significantly affected by formalin and NaCl at 3 and 24 h after exposure. It is suggested that formalin and NaCl at the therapeutic concentrations cause rapid stress in goldfish which is eliminated after 24 h in freshwater. In addition, formalin causes slightly osmotic disturbance which is eliminated after 24 h recovery in freshwater. Both formalin and NaCl cause serum calcium and protein alteration after a while, which lasts until, at least, 24 h. More studies are needed to explain underlying mechanisms. Formalin and NaCl treatment, although advantageous in ecto-parasite removal, are stressful in goldfish, which should be considered if they are going to be used. Since formalin causes osmotic disturbance and more stress response, NaCl treatment is suggested as an alternative

Anesthesia of juvenile Persian sturgeon, Acipenser persicus; Borodin 1897, by peppermint, Mentha piperita, extract – Anesthetic efficacy, stress response and behavior

Anesthesia in large animals such as sturgeons is unavoidable, so in this regard it is important to choice a best anesthetic with lowest side effects in fish.in the present study anesthetic efficacy of mentha, Mentha pipertia, extract was studied in Persian sturgeon, Acipenser persicus, to find if it is a suitable anesthetic for this species. In this regard, the fish were subjected to 300, 500, 750 and 1000 mg L-1 mentha extract, or 150 mg L-1 clove oil, and behavioral response, stress indices, induction and recovery time were recorded. According to the results, the fish exposed to mentha extract showed more severe exciting movements than those exposed to clove oil. No histopathological effects were recorded in gills and kidneys of the fish after anesthesia with both mentha extract and clove oil. Exposure to either 150 mg L-1 clove oil or 750 mg L-1 mentha extract for 3 min resulted in the fish serum cortisol change. Result showed a significant increase in serum cortisol at 6 hrs after anesthesia in both mentioned anesthetic. However, in the fish anesthetized by clove oil, serum cortisol level returned to the pre anesthesia value, at 24 hrs post anesthesia. In the fish anesthetized by mentha extract, a further significant increase in serum cortisol level was observed at 24 hrs after anesthesia. However, it returned to the pre anesthesia level at 72 hrs after anesthesia. At all sampling time, serum cortisol levels of the fish anesthetized by mentha extract were significantly higher than those anesthetized by clove oil. Totally it is concluded that, in Persian sturgeon, use of mentha extract as anesthetic results higher stress compared to clove oil, in the other word, it can be used as a good anesthetic agent but clove oil is better

Effects of pre-sampling fasting on serum characteristics of common carp (Cyprinus carpio L.)

Common carp, Cyprinus carpio (L.) were blood-sampled after 0, 2, 6, 12, 24, 48 and 72 h fasting to find serum baseline levels. There was a significant difference in serum glucose, lactate, triglyceride and total protein but not cholesterol, albumin and calcium levels among the treatments. Glucose levels increased with fasting tine and reached to a peak after 6 h. Then, the glucose level decreased to the lowest level after 12 h. Changes of glucose and lactate had reverse trends, as lactate levels decreased with fasting time and reached to the dip point at 6 h and, thereafter, the levels increased to peak point at 12 h.  Serum glucose and lactate levels showed stable values during 24-72 h of fasting, compared with the values measured at 0 h. Triglyceride levels showed an increasing trend parallel to that of the fasting period and reached to a peak point after 6 h. The levels reached 0 h values at 24 h and showed further decrement at 48 and 72h. Total protein showed elevation while fasting progressed and reached the peak point at 6 h and remained stable during 24-48 h fasting; However, it decreased after 72 h fasting. According to the results, cholesterol, calcium and albumin baseline levels were not affected by 0-72 h fasting. Glucose and lactate baseline could be determined after 24-72 h fasting. Total protein baseline could be determined after 24-48 h fasting. Triglyceride levels are significantly affected by fasting period which should be taken into account when it is measured. Possible mechanisms involving in common carp serum fluctuation over 0-72 h fasting period are discussed

Effects of safflower (Carthamus tinctorius) extract on serum antibacterial activity of rainbow trout (Oncorhynchus mykiss) against Aeromonas hydrophila, Streptococcus iniae and Yersinia ruckeri

In the present study, the effects of safflower (Carthamus tinctorius) extract on serum antibacterial activity of rainbow trout (Oncorhynchus mykiss) against Aeromonas hydrophila, Streptococcus iniae and Yersinia ruckeri was studied. In this regard, 450 fish with average weight of 100±10 g were stocked into fifteen fiberglass tanks. This experiment consisted of 3 treatment groups (received 50, 100 and 200 mg/kg BW safflower extract via IP injection), one positive control group (just received normal saline) and one negative control group (with no injection). Blood samples were taken at the 3th, 7th and 10th days after the injections, and antibacterial activity of serum were determined in vitro using CFU method. The results showed that safflower extract injection had no significant effects on serum anti-bacterial activity against A. hydrophyla and Y. rukeri during 10 days post injection. However, in the fish receiving 100 mg/kg safflower extract, serum bactericidal activity against S. iniae was significantly higher than the other groups. This study demonstrated that safflower extract at the doses of 50-200 mg/kg via IP injection did not cause significant changes in serum antibacterial activity against A. hydrophila and Y. ruckeri, but injection of 100 mg/kg extract led to an increase in the serum antibacterial activity against S. iniae, in rainbow trout

Determination of mancozeb toxicity and biochemical effects in common carp (Cyprinus carpio)

The aim of this study was to investigate mancozeb toxicity and its effects on physiological characteristics of common carp. Fish were reared for one week to acclimatize with the experimental conditions. For 96h-LC50 determination, the fish were stocked in 16 aquaria at the density of 10 fish per aquarium. The aquaria were exposed to 8 mancozeb concentrations (two aquaria per concentration) for 96 h (0, 0.94, 1.87, 3.75, 7.50, 15, 30 and 60 mg/L). 96h-LC50 was calculated based on the fish mortality, being 8.03 (4.95-13.2) mg/L. For sub-acute test, the fish were exposed to 0 (control), 1.6, 2.4 and 3.2 mg/L mancozeb (20, 30 and 40% of the 96h-LC50) for one week. Blood samples were taken from each treatment for determination of plasma glucose, total protein, albumin, globulin, calcium, alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Mancozeb exposure led to increase in glucose and AST, and decrease in plasma proteins and ALT. In conclusion, mancozeb exposure causes stress response, health problem and tissue damage in common carp

Plasma 17beta-estradiol and alkali-labile phosphoprotein levels in male and female Tench (Tinca tinca) in the Anzali and Amirkolayeh wetlands

Environmental pollutants are potentiate to disturb biological processes such as metabolism, growth and reproduction of aquatic organisms. These compounds are able to cause gonadal abnormalities, biased sex ratios and alteration in reproductive physiology in fish. The aim of this study was to examine plasma 17β-estradiol (E2) and alkali-labile phosphoprotein (ALP) levels in male and female Tench (Tinca tinca) from a polluted (the Anzali Wetland) and a non-polluted environments (the Amirkolayeh Wetland). Samples were collected over the maturation season of Tench between May and June 2017. The results revealed significant difference in mean ALP and E2 between genders in the polluted environment. However, the mean plasma ALP concentrations in male Tench of the polluted environment (39.46±1.02 µg/ml) was 45% of the average recorded in female (86.18±2.25 µg/ml) and was two times higher than the amount measured in males in the non-polluted environment (18.68±0.35 µg/ml). High concentrations of E2, were detected in the male samples from the Anzali Wetland. Mean plasma E2 concentrations for male in the Anzali Wetland was almost two times higher than male in the Amirkolayeh Wetland. The results indicate that the reproductive physiology of Tench was affected by contaminants found in the Anzali Wetland, a highly polluted area

Effects of dietary olive leaf extract on intestinal immune-related gene expressions in common carp, Cyprinus carpio

This study aimed to investigate the effects of dietary olive leaf extract (OLE) on intestinal immune-related genes expression of tumor necrosis factor alpha (TNFa), interleukin 1 beta (IL1b), lysozyme (LYS), and mucin2 (MUC2). For this purpose, common carp (~15 g) were fed with 0 (control), 0.1 (OLE-0.1), 0.5 (OLE-0.5) and 1 (OLE-1) % OLE diets for eight weeks. The fish were sampled after one and eight weeks to study intestinal TNFa, IL1b, LYS, and MUC2 gene expressions. The results showed that dietary OLE administration significantly up-regulated intestinal TNFa gene expression after one (all OLE-treated groups) and eight (OLE-0.5) weeks. Moreover, OLE-0.1 and OLE-1 groups showed up-regulated intestinal IL1b expression, after one week, all the OLE-treated fish had significantly higher intestinal IL1b expression, after eight weeks. OLE had no significant effects on LYS gene expression after one week, but OLE-0.1 and OLE-0.5 had significantly higher gene expressions after eight weeks. OLE-0.1 and OLE-1 had significantly lower MUC2 gene expression after one week, but all OLE-treated fish had significantly higher MUC2 gene expression after eight weeks. In conclusion, dietary 0.1-0.5% OLE supplementation is suitable to support common carp intestinal health

Efficacy of fish oil- and linseed oil-enriched Artemia nauplii on growth performance and stress resistance of tiger barb larvae (Puntius tetrazona)

Fish oil is the important fat source in fish nutrition. High demand for fish oil and low global supply arise a need of alternative oils in fish culture. Plant oils are a good candidate in this case. The aim of the present study was to compare the efficacy of fish oil and linseed oil on growth and stress resistance of tiger barb (Puntius tetrazona) larvae. Artemia nauplii were enriched by 2.5, 5 and 7.5 of each oil. The enriched nauplii were offered to larvae for 14 d. thereafter, fish were fed non-enriched nauplii for another 14 d. At the end of the trial, larvae were subjected to osmotic stress and their survival was recorded. There was no significant difference in final weight, SGR and weight gain among the treatments at day 14. However, oil type and oil levels significantly affected these parameters after 28 d. Fish of 2.5-LO and 5-FO groups showed the best and worst performance, respectively. There was no significant difference in survival rate among the treatments, after 14 and 28 d; however, oil type significantly affected survival of the larvae after osmotic stress. Survival of larvae fed on linseed oil-enriched nauplii was significantly higher than that of those fed on fish oil-enriched nauplii. Linseed oil showed significantly better results in growth performance and stress resistance compared to fish oil. It is concluded that linseed oil is more suitable than fish oil for Artemia enrichment to feed tiger barb larvae. The potential reasons for the better performance of larvae fed on linseed oil-enriched Artemia were discussed

Nano-liposome of thyme essential oil promotes growth performance, antioxidant and immune responses to aeromonad septicemia in Nile tilapia, Oreochromis niloticus, fingerlings

Nano-encapsulation protects essential oils and increases their efficiency, compared to bulk forms. Hence in the present study, four diets (328 g/kg crude protein and 4402 kcal/kg gross energy) containing 0 (CTL), 25 mg/kg (25TV), 50 mg/kg (50TV), and 100 mg/kg (100TV) thyme, Thymus vulgaris, essential oil nano-liposomes (TV-NP) were offered to Nile tilapia fingerlings (initial weight of 4.27 ± 0.05 g) at water temperature of 26.46 ± 0.43°C, followed by intraperitoneal infection by Aeromonas hydrophila. Three hundred and sixty healthy fish were stocked in 12 tanks (60 L), 30 fish per tank, with daily water renewal rate of 40%. Each diet was offered to three tanks for 70 days. The fish were sampled at the end of feeding period and 12 h after the bacterial challenge. Compared to CTL, 50TV and 100TV treatments exhibited significant elevations in growth rate (14-17%; P<0.001), intestinal activities of amylase (9-19%; P=0.004), lipase (13-26%; P<0.001), protease (20-23%; P=0.001), and post-challenge survival (26-27%; P=0.001). Plasma lysozyme (14-15% P<0.001) and complement (5.1-5.4%; P=0.004) activities significantly increased in 25TV and 50TV, but decreased (lysozyme: 19%, complement 5.9%) in 100TV before the challenge; however, all TV-NP treatments showed similar lysozyme and complement activities after the challenge that were higher than CTL. 50TV and 100TV treatments also showed a decrease in lipid peroxidation (23-26%; P<0.001) and highest glutathione peroxidase activity (17-18%; P=0.001) and pre-challenge superoxide dismutase (21%; P=0.046) and catalase (15-17%; P=0.001) activities. Expression of tumor necrosis factor-alpha (11-fold, P<0.001), inerleukin-1 beta (5-fold, P<0.001), and transforming growth factor-beta (31-fold; P=0.001) in head kidney significantly increased in 100TV before the challenge. After the challenge, the transcripts of the cytokines significantly increased in all treatments and the highest expressions were observed in 50TV and 100TV treatments (62-148-fold). In conclusion, dietary 50-100 mg/kg TV-NP can be considered as a new feed additive in tilapia culture, as it improves growth rate, antioxidant capacity, and disease resistance in the fish