International Journal of Aquatic Biology
Volume:5 Issue: 6, Dec 2017

Shirazi thyme is an active phytobiotc contains phenolic compounds and flavonoids which have strong antioxidant properties. This study was conducted to investigate the potential protective effects of Shirazi thyme compared to that of vitamin E against cadmium toxicity. Common carp juveniles (34±3 g) were divided into four groups and fed by three different diets including commercial diet without any additive (for control and metal only group) and supplemented with either 1% ground Shirazi thyme or 100 mg/kg vitamin E. All treatments except the control were exposed to sublethal concentration of waterborne cadmium (1.5 mg/L free ion) for 15 d and liver, kidney and gill were sampled 3, 7, 10 and 15 days after the metal exposure. Results showed that treatment of the fish with cadmium for 15 days resulted in a significant reduction in glutathione reductase (GR), glutathione-S-transferase (GST) and catalase (CAT) and led to liver, kidney and gills dysfunction. On the other hand, the level of malondialdehyde (MDA) significantly increased during metal exposure. Supplementation of diets with Shirazi thyme and vitamin E led to a significant protection against metal exposure in different tissues. Moreover, Shirazi thyme was found to be as effective as vitamin E. The current finding can provide a useful reference for stress protective effects of thyme and its beneficial role in aquaculture.

The aim of the present study is to provide a basis for better knowledge of the surface architecture of the GBE of some hill-stream fishes. The skin of the hill- stream fishes, on the dorsal surface of the body just behind the head, is densely set with scales and composed of an epidermis and a dermis supported by a hypodermis. Noticeable differences exhibited in the patterns of microridges on epithelial cells, distribution of mucous cells and presence of tubercles on the general body epidermis of the hill-stream fishes may be considered as modifications relating to possible difference in the functional requirement at the different locations. The skin has long been recognized to protect the organisms from deleterious environmental impacts (physical, chemical, microbiological). It is also well-known to be crucial for the maintenance of temperature, electrolyte and fluid balance.

White spot syndrome virus (WSSV) is a widespread and highly pathogenic virus; that infects shrimp, crayfish and other crustaceans. The objectives of the present study were to investigate WSSV implications on some crayfish tissues, within light and sever stages of infections. Several parameters have been investigated including DNA integrity, oxidative stress, and histological changes in gills, muscles and hepatopancreas cells, using several techniques such as comet assay, DNA fragmentation assay, oxidative stress biomarkers estimation and histopathological examination. Specimens were divided into three groups according to the nested PCR results. Group I included healthy specimens whose tissues were all negative two-step PCR; Group II involved lightly infected specimens with positive two-step PCR. Group III included heavily infected specimens whose tissues were tested mostly positive one-step PCR. WSSV generates an increase in the different parameters of DNA damage (P

This study was carried out to investigate the genotoxic, and hematological and serum biochemical effects of a widely used herbicide, oxadiazon in common carp (Cyprinus carpio) fingerling. Fish were exposed to different concentrations (0, 1, 1.5 and 2 ppm) of the herbicide for 30 days. Blood samples were collected, then comet assay in circulating erythrocyte cells was applied. Erythrocytes cells of fish exposed to 1, 1.5 and 2 ppm of oxadiazon showed DNA damage (21.3%, 22.9%, and 28.4%, respectively) significantly higher than the control group. Moreover, exposure to oxadiazon significantly decreased WBC, RBC, Hb, Hct as well as serum albumin, glucose, and total protein levels, while serum ALP was significantly increased in the exposed fish groups. No significant differences were found in MCV, MCHC and MCH levels between oxadiazon treatments and control groups. In conclusion, this study shows that oxadiazon is highly toxic to C. carpio and causes significant changes in hematological and biochemical parameters as well as indicates the mutagenic potential of oxadiazon in the erythrocyte cells of this fish.

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.

The Babol River is one of the main rivers in the Southern Caspian Sea basin in Mazandaran Province. The Alborz Dam has been built along the river to provide annual irrigation and flood protection. This study aimed to identify and describe the prevalence and parasite intensity of some endemic fish species in Babol River and Alborz Dam and to compare their parasite communities. The field investigations were carried out from June 2016 to March 2017 and approximately, 546 fish specimens, including Alburnoides tabarestanensis, Capoeta razii and Squalius turcicus, were examined. A total of 13 parasite species, including Ichthyophthirius multifiliis, Trichodina gracilis, Myxobulus minutus, Dactylogyrus chalcalburni, D. vistulae, D. lenkorani, Gyrodactylus gobioninum, G. prostate, Paradiplozoon homoion, Allocreadium isoproum, Rhabdochona denudatai, Ligula intestinalis and Bothriocephalus acheilognathi, were isolated from the examined fishes. The results showed that host-parasite system in Alborz Dam is mainly influenced by the parasite’s fauna of Babol River. The only exception in this regard is the plerocercoids of L. intestinalis, one of the most common parasites in Alborz Dam and found in the abdominal cavity of all fish species. The prevalence rate and the mean intensity of parasitic infection in this reservoir are far more than those in Babol River. In addition this is the first report of Trichodina gracilis from the gills and skin of C. razii in Iran.

This study attempted to describe the length and weight frequency, and length-weight relationship in the black sea urchin, Stomopneustes variolaris, in Sri Lanka. The sampling sites Mount-Lavinia (n=43), Beruwala (n=99) and Tangalle (n=55) were selected from South-west coast in Sri Lanka. The shell length and body weight were measured separately for three sampling sites. The mean length and weight of S. variolaris were 5.55±1.04 cm, 101.40±57.76 g; 6.54±0.86 cm, 147.90±50.40 g, and 6.41±1.05 cm, 150.50±59.45 for Mount-Lavinia, Beruwala and Tangalle, respectively. In addition, the length-weight relationship of S. variolaris were W=0.9953*L2.6472, W=0.9651*L2.6536 and W=1.4665*L2.4637 for Mount-Lavinia, Beruwala and Tangalle, respectively.

This study aimed to assess the composition and structure of floating phytoplankton assemblage in Ouémé basin. Phytoplankton samples were collected monthly from October 2014 to September 2015. Quantitative samples were taken with a horizontal Van-Dorn sampler and 20 μm mesh plankton net was used for additional qualitative sampling. Microscopic observation of phytoplankton allowed identification of 208 species including 70 Bacillariophyta species, 58 Chlorophyta species, 24 Charophyta species, 21 Euglenophyta species, 18 Cyanophytes species, 9 Phyrrophyta species, 5 Ochrophyta species and 3 Cryptophyta species. The Shannon diversity index varied from 2.4 bit.ind-1 and 3.1 bit.ind-1 showing a relatively good diversification of the community. The population appears largely dominated by 14 species which represent 83.8% of the total phytoplankton. Aulacoseira granulata and Euglena gracilis were the most predominant species with respectively 40.17% and 15.91% relative abundance. Regarding the horizontal pattern of phytoplankton abundance, downstream stations have the greatest abundances. So, the results suggest that downstream stations are richer in phytoplankton which structure differs from that in upper stations.