International Journal of Aquatic Biology
Volume:6 Issue: 3, Jun 2018

Red tail catfish, Phractocephalus hemioliopterus, in one of the popular ornamental fish. The present study is aimed to describe and visualizes the cardiovascular system of this species with corrosion cast study method. For this purpose, 10 red tail catfish with 580 gr average weight were obtained and were filled their blood vessels and heart with fluid artificial resin made on the basis of methylmetacrylate after anaesthetizing and euthanizing. For complete polymerization and hardening of the methylmetacrylate, the fish were further submersed for 12-24 hrs in water bath following by 24-48 hrs submersion in a 25% solution of KOH to full maceration. Based on the results we describe the cardiovascular system i.e. the afferent and efferent vessels of gill, different parts of the heart, ventral aorta, dorsal aorta, intestinal and gastric vessels, liver, anterior and posterior parts of the kidneys, spleen, portal and hepatic vein

Otter was irregularly observed on Gurney Drive coast in the northern part of Georgetown, Penang Island from June 2015 to March 2016. Authors examined relationship between the otters sighting date and time and the tide pattern. Otter was observed a total of five times on 27th June, 17th August, 6th December 2015, 14th March, and 16th March 2016. These otters were identified same species which was the smooth-coated otter, Lutrogale perspicillata, from the morphological characteristics. Swimming direction of the otters were characterized two patterns that the first was the otters swam from inner part to east coast in a cove of Gurney Drive coast and the second was the otters swam from the east coast to inner part of the cove. From this result, it was suggested that the otters swam to drive fish toward tide flow and the otters catch the fish efficiently.

In this study, potential effects of Pirimicarb and lead (Pb) were investigated on biochemical parameters in tissues of freshwater snails, Galba truncatula. During an 8-day experiment, snails were exposed to sub-lethal concentrations of Pirimicarb (0.5 and 1 mg/L) and/or lead acetate (0.1 and 0.2 mg/L). Biochemical analyses of tissues to Photometric method in snails indicate that snails treated with Pirimicarb, Pb, or both Pirimicarb and Pb increased malondialdehyde (MDA) and catalase (CAT) and decreased gamma-glutamyl transferase (GGT) levels, compared to the control group. Alanine transferase (ALT), lactate dehydrogenase (LDH), and alkaline phosphatase (ALP) activity were increased in combined treatments of Pirimicarb and Pb. Total antioxidant (TAO) level increased in snails exposed to both Pirimicarb and Pb, while it decreased in snails treated with either Pb or Pirimicarb. Cholesterol level increased in most experimental groups. Aspartate aminotransferase (AST) was showed no significant changes in groups treated with 0.1 and 0.2 mg/L of Pb compared to the control; however, AST enhanced in other treatments. In groups exposed to 0.5 and 1 mg/L of Pirimicarb, the inhibition of acetylcholinesterase (AChE) was not significant, although a significant reduction was found in AChE level in other treatments. The results indicated that cytotoxicity of Pirimicarb alone and in combination with Pb depended on their concentrations. Higher concentrations of Pb induced significant changes in some biochemical parameters. Moreover, increased Pb level in water intensifies toxic effects of Pirimicarb in snails. Pirimicarb or/and Pb, in sub-lethal concentrations, induced oxidative damages in soft tissue of snails. Finally, these data support the hypothesis that changes in biochemical parameters were induced by exposure to Pirimicarb or/and Pb.

This study was carried out to evaluate the combined effects of three stocking densities and two tank colors on growth, body composition and skin coloration of common carp (1.41±0.05 g). Fish with low (LD: 20 specimens/tank or 0.70 g/L), medium (MD: 40 specimens/tank or 1.41 g/L) and high (HD: 80 specimens/tank or 2.82 g/L) densities were reared in two tank colors (black and white) for 45 days. At the end of the experiment, density recorded 2.45 g/L and 7.00 g/L at low and high densities treatments, respectively. The final weight and specific growth rate of the fish at LD treatment were significantly higher than those of MD and HD treatments. The highest weight (4.90±0.44 g) and the lowest feed conversion ratio (1.21±0.13) were obtained for the LD fish treatment reared in the black tanks. Rearing density has a significant effect on the fish body total protein content, but the tank color had no effects on this factor. The fish body lipid content in the white tanks and high density was significantly higher than other treatments. Significant interactions between tank color and rearing density were observed for the fish body protein, fiber and dry matter. The fish skin color was considered by three factors: L*, a* and b*. The results showed that black color had a negative effect on the fish skin color indices. Brightness (L*) and yellowness (b*) values of the fish skin in the white tanks were higher than those of the black tanks. In the present study, tank color and rearing density significantly affected growth and feed performance of common carp, while no combined interaction was found between the two factors examined.

Effect of stocking densities on the growth, survival and production of bata, Labeo bata fry and fingerlings were tested in a primary nursery rearing system. The experiment was conducted for a period of 4 weeks in six earthen nursery ponds having an area of 0.032 ha each. Four-day-old fry stocked at 1.0 million/ha was designated as treatment-1 (T1), 1.5 million/ha as treatment-2 (T2) and 2.0 million/ ha as treatment-3 (T3). At stocking, all fry were of same age with a mean length and weight of 1.03±0.03 cm and 0.12±0.01 g, respectively. Fry in all the treatments were fed with Mega commercial fish feed. Physico-chemical parameters such as water temperature, transparency, dissolve oxygen, pH and total alkalinity in all the treatments were suitable ranges for fry and fingerling rearing. Plankton population (both phytoplankton and zooplankton) were found to be at optimum level for fish culture. Highest weight gain was observed in T1 (3.46±0.08) and lowest in T3 (1.98±0.03). Final length, final weight and survival of fingerlings also followed the same trends as weight gain. Fingerlings in T1 produced significantly higher specific growth rate (12.15±0.08) than T2 (11.31±0.03) and T2 (10.22±0.05). Feed conversion ratio was significantly lower in T1 (0.26±0.01) than T2 (0.42±0.02) and T3 (0.65±0.01). Significantly higher number of fingerlings was produced in T3 (1177700±4700) than T2 (963300±9900) and T1 (717850±7350), respectively. Despite of this, consistently higher net benefits were found from T1 than T2 and T3. Overall, highest growth (3.60±0.16 g), survival (71.79 ± 1.04%) and net benefits (TK. 127,087.00) of fingerlings were obtained at a density of 1.0 million hatchlings/ha. Therefore, out of three stocking densities, 1.0 million fry/ha appears to be most suitable stocking density for nursing and rearing of L. bata fry and fingerlings in primary nursing.

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.

The study was aimed to establish reference interval for some blood biochemical (sodium, potassium, calcium, and magnesium) and hematological (total count of white blood cells, neutrophils, lymphocytes, monocytes, and eosinophils) indices in both sexes of Alburnus chalcoides in response to its habitats with different physiochemical conditions and to seasonal variation. Fish samples were collected from its seasonal habitats, including river, estuary, and Caspian Sea. The mean concentration of sodium, potassium, calcium, and magnesium in plasma of fish were 134.69±13.61 (mmol/l), 3.26±0.83 (mmol/l), 11.65±1.82 (mg/dl) and 2.13±1.12 (mmol/l), respectively. These electrolytes demonstrated significant differences between the male and female as well as between the fish collected from different habitats. Total WBCs count was 6045.35±960.25 (per mm3) and the mean percentage of neutrophils, lymphocytes, monocytes and eosinophils were 26.55±3.37%, 67.74±3.72%, 3.04±0.70% and 0.98±0.04%, respectively. WBCs generally showed considerable differences between male and female. Furthermore, a higher percentage of monocytes, neutrophils and eosinophils were observed in the fish collected from river and estuary during spring and summer. The study demonstrated that differences in sex, habitat and seasonal variation cause variation in hematology and plasma chemistry reference intervals for wild population of A. chalcoides when migrating between its natural habitats.