International Journal of Aquatic Biology
Volume:5 Issue: 5, Oct 2017

If the dose and duration of zinc oxide nanoparticle (ZnO-NPs) supplementation optimize, low concentrations of Zn nanoparticles can replace conventional Zn sources in diets of different species of fish. Since evaluating the cytotoxicity of any nutritional supplement is one of the requirements for optimizing the dose for a specified time, we conducted this study to investigate the effects of oral administration of ZnO-NPs on oxidative stress and certain biochemical biomarkers in common carp, Cyprinus carpio, as an experimental model. For this purpose, ZnO-NPs were orally administered to fish for 21 days at 0 (control), 5, 10 and 15 mg kg-1 feed. Administration of ZnO-NPs (15 mg kg-1) significantly enhanced aspartate aminotransferase (AST), and lactate dehydro-genase (LDH) activities in liver, and alanine aminotransferase (ALT), alkaline phosphatase (ALP), and LDH activities in kidney. Dietary ZnO-NPs increased glucose-6-phosphate dehydrogenase (G6PDH) activity in liver of fish. The results indicated that administration of 10 mg kg-1 and 15 mg kg-1 ZnO-NPs caused a significant increase in ALT and catalase (CAT) activities and malondialdehyde (MDA) levels in liver, AST and CAT activities and MDA levels in kidney. ZnO-NPs decreased the liver ALP activity. Administration of 5 mg kg-1 ZnO-NPs significantly increased the cellular total antioxidant (TA) levels in various tissues. Therefore, we suggest that oral administration of 10 and 15 mg kg-1 ZnO NPs caused cytotoxicity and alterations in oxidative biomarkers, but 5 mg ZnO-NPs per kg feed had no side effects on oxidative stress and biochemical biomarkers in fish.

Phytoplankton of three floodplain lakes (beels) of the Majuli River Island of upper Assam, northeast India (NEI), sampled during September 2010–August 2012, revealed rich diversity (108 species) with Ghotonga > Holmari ≥ Bhereki beels; richness of Chlorophyta and of Cosmarium > Staurastrum > Euastrum in particular. The monthly richness and community similarities affirmed heterogeneity in phytoplankton composition. Phytoplankton comprised between 59.5±12.5, 57.1±12.3 and 48.6±13.5% of net plankton abundance of Bhereki, Holmari and Ghotonga beels, respectively. Bacillariophyta > Chlorophyta showed quantitative importance in Bhereki while Chlorophyta > Bacillariophyta recorded importance in Holmari and Ghotonga beels. Cyanophyta showed sub-dominance and Dinophyta > Euglenophyta showed low densities in the three beels. Phytoplankton richness and abundance followed oscillating monthly variations; ANOVA registered insignificant richness variations amongst beels. The results are characterized certain monthly and annual variations but mean values depicted high species diversity, low dominance and high equitability. Individual and cumulative influence (vide CCA) yielded limited insight on the role of seventeen abiotic factors on phytoplankton in Holmari and Bhereki beels.

This study was performed to investigate ecto-and endo-parasites of golden grey mullet, Chelon aurata (Risso, 1810) (N=331) and Caspian goby, Neogobius caspius (Eichwald, 1831) (N=170) from the southern Caspian Sea. The sampling was carried out for one year in three stations, including Chamkhaleh (St1), Kiashahr (St2) and Anzali (St3) coastal areas, Guilan Province, Iran. Biometric characteristics were recorded, sexes were determined and specimens examined for ecto- and endoparasites. A total of 158 specimens (58.31%) out of 331 grey mullets, and 61 (35.88%) out of 170 Caspian gobies, were found to be infected. 1453 parasites belonging to 5 species were found consisting of Trichodina reticulata, unknown protozoan, nematode larvae (in golden grey mullet) and a cestode, Eustrongylides excisus larvae (in Caspian goby). The occurrence of unknown protozoan and nematode larvae in C. aurata and cestode larvae in N. caspius are reported for the first time in Iran. Seasonal variations, the effects of host length, weight and localities on parasite prevalence and mean intensity have been examined during present investigation.

Regeneration ability is known for several Actinopterygii or ray-finned fishes. In order to assess the universality of regenerative potencies in this group of fishes, we have examined for the first time, caudal fin regeneration in tooth-carp, Aphanius dispar (Rüppell, 1829). The caudal fin is used because of its accessibility, simple structure and fast regeneration. The results revealed the regeneration ability in caudal fin of A. dispar. The initiation of the regenerative outgrowth was differing in three examined water temperatures. It is started approximately 5 days post amputation (5 dpa) at room temperature, and 2 dpa at 25°С and 28°С. Our finding indicates that water temperature more than 25°С promotes procedure in caudal fin regeneration of A. dispar. By considering the high regeneration ability in A. dispar, and also the relatively short life span of the members of the genus Aphanius, we concluded that these fishes could probably be used in regeneration researches. However, details of this mechanism in Aphanius need further examinations.

This study presents the first record of Halodule pinifolia on the eastern coast of Sri Lanka, approximately 310 km along the coastline from the previously recorded location (Kapparathota, Weligama). Further, this study describes the new locality of the nationally endangered seagrass species Halophila beccarii to Valaichchenai Lagoon, 26.5 km north of Batticaloa Lagoon, where it was previously recorded, along with the presence of two other species, Halophila ovalis and Halodule uninervis. While the species composition the seagrass habitat of Valaichchenai Lagoon might change in the near future due to the impact of climate change, multiple threats already exist at these newly discovered seagrass habitats, including multiday fishing vessel movements, the collection of shells on the seagrass beds, and solid waste dumping into the lagoon. Decline of seagrass abundance in Valaichchenai Lagoon would negatively impact the food security and income generation of fishers. Therefore, a well-established legislative framework and systematic long-term monitoring of seagrass in Valaichchenai Lagoon are essential in order to develop seagrass conservation plans before populations decline significantly or become locally extinct.

Alosa caspia (Eichwald, 1838) belongs to clupeidae family, is considered as one of the main fish in the southern coast of the Caspian Sea. The aim of the present study was to evaluate the helminthic parasite infections in abdominal cavity of A. caspia from southeastern part of the Caspian Sea. In this regard, 30 fish were caught from Bandar-Torkaman and transferred alive to the parasitological laboratory. Then parasites specimens were fixed and transferred to the National Museum of Parasitology, Faculty of Veterinary Medicine at University of Tehran for identification. A total of two parasite species including Anisakis simplex and Pronoprymna ventricosa were isolated from the fish. 100% of the fish were infected with at least one helminthic parasite species. Pronoprymna ventricosa has the highest infection prevalence rate and was isolated from pyloric caeca, intestine and stomach of 93.33% of the fish specimens. Anisakis simplex is found in abdominal cavity of 33.33 % of the studied fish. Intensity of A. simplex and P. ventricosa was calculated as 8.4±5.31 and 91.4±21.46, respectively. Based on the statistical analysis, there were no significant differences in total parasites burden, parasite prevalence and parasite intensity between male and female of the studied fish (P>0.05).

Regarding to the high content of polyunsaturated fatty acids in fish tissues, improving the fish antioxidant status seems to be necessary and may be associated with beneficial effects on fish health. The present study aimed to investigate the effects of dietary vitamin C supplementation (20 mg/kg body weight, 4 weeks) on some oxidative status biomarkers in RBC of common carp (Cyprinus carpio). The results showed that the activities of antioxidant enzymes including catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) were not changed significantly following dietary vitamin C supplementation in comparison to the control group. Moreover, dietary vitamin C supplementation for 28 days significantly lowered malondialdehyde (MDA) concentration in erythrocyte haemolysate by approximately 26% compared to that of the control group. In conclusion, dietary vitamin C supplementation appears to be able to protect carp erythrocytes against oxidative stress by decreasing lipid peroxidation.

Marine environments are continuously being threatened by a large number of pollutants including heavy metals and organophosphorous pesticides from anthropogenic sources. These compounds can cause a serious environmental problem. The present study aimed: (1) to measure sensitivity of acetylcholinesterase (AChE) activity to in vivo exposure to the organophosphorous chlorpyriphos-ethyl (CPF) and to the heavy metals cadmium (Cd) and copper (Cu) and (2) to use the histopathological lesions as tissue biomarkers for biomonitoring of different contaminations. The results clearly showed that the AChE activity in different tissues (digestive gland, muscle and eyes) of Carcinus maenas was relatively sensitive to the concentrations of CPF and tended to have different patterns in response to Cd, Cu and Cu mixture exposure. The transfer of treated crabs to the clean sea water allowed to recover totally or partially the lost activity depending on selected tissues and contaminant exposure (metals or organophosphorous compounds). Histopathological biomarkers in C. maenas exposed to different contaminants showed the presence of different lesions which altered the digestive gland after 7 days of contamination.