INTERNATIONAL JOURNAL OF AQUATIC BIOLOGY
Year:2017 | Volume:5 | Issue:5 |Papers Count:8

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 differentspecies of fish. Since evaluating the cytotoxicity of any nutritional supplement is one of therequirements for optimizing the dose for a specified time, we conducted this study to investigate theeffects of oral administration of ZnO-NPs on oxidative stress and certain biochemical biomarkers incommon carp, Cyprinus carpio, as an experimental model. For this purpose, ZnO-NPs were orallyadministered to fish for 21 days at 0 (control), 5, 10 and 15 mg kg-1 feed. Administration of ZnONPs (15 mg kg-1) significantly enhanced aspartate aminotransferase (AST), and lactate dehydrogenase (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 mgkg-1 ZnO-NPs caused a significant increase in ALT and catalase (CAT) activities andmalondialdehyde (MDA) levels in liver, AST and CAT activities and MDA levels in kidney. ZnONPsdecreased the liver ALP activity. Administration of 5 mg kg-1 ZnO-NPs significantly increasedthe cellular total antioxidant (TA) levels in various tissues. Therefore, we suggest that oraladministration of 10 and 15 mg kg-1 ZnO NPs caused cytotoxicity and alterations in oxidativebiomarkers, but 5 mg ZnO-NPs per kg feed had no side effects on oxidative stress and biochemicalbiomarkers 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 (108species) with Ghotonga>Holmari ≥ Bhereki beels; richness of Chlorophyta and of Cosmarium>Staurastrum>Euastrum in particular. The monthly richness and community similarities affirmedheterogeneity 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 whileChlorophyta>Bacillariophyta recorded importance in Holmari and Ghotonga beels. Cyanophytashowed sub-dominance and Dinophyta>Euglenophyta showed low densities in the three beels.Phytoplankton richness and abundance followed oscillating monthly variations; ANOVA registeredinsignificant richness variations amongst beels. The results are characterized certain monthly andannual variations but mean values depicted high species diversity, low dominance and highequitability. Individual and cumulative influence (vide CCA) yielded limited insight on the role ofseventeen 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 ectoandendoparasites. A total of 158 specimens (58.31%) out of 331 grey mullets, and 61 (35.88%) outof 170 Caspian gobies, were found to be infected.1453 parasites belonging to 5 species were foundconsisting of Trichodina reticulata, unknown protozoan, nematode larvae (in golden grey mullet) anda cestode, Eustrongylides excisus larvae (in Caspian goby). The occurrence of unknown protozoanand nematode larvae in C. aurata and cestode larvae in N. caspius are reported for the first time inIran. Seasonal variations, the effects of host length, weight and localities on parasite prevalence andmean intensity have been examined during present investigation.

Regeneration ability is known for several Actinopterygii or ray-finned fishes. In order toassess the universality of regenerative potencies in this group of fishes, we have examined for thefirst time, caudal fin regeneration in tooth-carp, Aphanius dispar (Rüppell, 1829). The caudal fin isused because of its accessibility, simple structure and fast regeneration. The results revealed theregeneration ability in caudal fin of A. dispar. The initiation of the regenerative outgrowth wasdiffering in three examined water temperatures. It is started approximately 5 days post amputation (5dpa) at room temperature, and 2 dpa at 25oС and 28oС. Our finding indicates that water temperaturemore than 25oС promotes procedure in caudal fin regeneration of A. dispar. By considering the highregeneration ability in A. dispar, and also the relatively short life span of the members of the genusAphanius, 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 seagrassspecies Halophila beccarii to Valaichchenai Lagoon, 26.5 km north of Batticaloa Lagoon, where itwas previously recorded, along with the presence of two other species, Halophila ovalis and Haloduleuninervis. While the species composition the seagrass habitat of Valaichchenai Lagoon might changein the near future due to the impact of climate change, multiple threats already exist at these newlydiscovered seagrass habitats, including multiday fishing vessel movements, the collection of shellson the seagrass beds, and solid waste dumping into the lagoon. Decline of seagrass abundance inValaichchenai Lagoon would negatively impact the food security and income generation of fishers.Therefore, a well-established legislative framework and systematic long-term monitoring of seagrassin Valaichchenai Lagoon are essential in order to develop seagrass conservation plans beforepopulations decline significantly or become locally extinct.

Alosa caspia (Eichwald, 1838) belongs to clupeidae family, is considered as one of themain fish in the southern coast of the Caspian Sea. The aim of the present study was to evaluate thehelminthic parasite infections in abdominal cavity of A. caspia from southeastern part of the CaspianSea. In this regard, 30 fish were caught from Bandar-Torkaman and transferred alive to theparasitological laboratory. Then parasites specimens were fixed and transferred to the NationalMuseum 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 isolatedfrom 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 pyloriccaeca, intestine and stomach of 93.33% of the fish specimens. Anisakis simplex is found in abdominalcavity of 33.33 % of the studied fish. Intensity of A. simplex and P. ventricosa was calculated as8.4±5.31 and 91.4±21.46, respectively. Based on the statistical analysis, there were no significantdifferences in total parasites burden, parasite prevalence and parasite intensity between male andfemale of the studied fish (P>0.05).

Regarding to the high content of polyunsaturated fatty acids in fish tissues, improving thefish antioxidant status seems to be necessary and may be associated with beneficial effects on fishhealth. The present study aimed to investigate the effects of dietary vitamin C supplementation (20mg/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 changedsignificantly 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 thecontrol group. In conclusion, dietary vitamin C supplementation appears to be able to protect carperythrocytes against oxidative stress by decreasing lipid peroxidation.

Marine environments are continuously being threatened by a large number of pollutantsincluding heavy metals and organophosphorous pesticides from anthropogenic sources. Thesecompounds can cause a serious environmental problem. The present study aimed: (1) to measuresensitivity of acetylcholinesterase (AChE) activity to in vivo exposure to the organophosphorouschlorpyriphos-ethyl (CPF) and to the heavy metals cadmium (Cd) and copper (Cu) and (2) to use thehistopathological lesions as tissue biomarkers for biomonitoring of different contaminations. Theresults 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 differentpatterns in response to Cd, Cu and Cu+Cd mixture exposure. The transfer of treated crabs to the cleansea water allowed to recover totally or partially the lost activity depending on selected tissues andcontaminant exposure (metals or organophosphorous compounds). Histopathological biomarkers inC. maenas exposed to different contaminants showed the presence of different lesions which alteredthe digestive gland after 7 days of contamination.