INTERNATIONAL JOURNAL OF AQUATIC BIOLOGY
Year:2017 | Volume:5 | Issue:6 |Papers Count:8

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

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

White spot syndrome virus (WSSV) is a widespread and highly pathogenic virus; thatinfects shrimp, crayfish and other crustaceans. The objectives of the present study were to investigateWSSV implications on some crayfish tissues, within light and sever stages of infections. Severalparameters have been investigated including DNA integrity, oxidative stress, and histologicalchanges in gills, muscles and hepatopancreas cells, using several techniques such as comet assay, DNA fragmentation assay, oxidative stress biomarkers estimation and histopathologicalexamination. Specimens were divided into three groups according to the nested PCR results. GroupI included healthy specimens whose tissues were all negative two-step PCR; Group II involved lightlyinfected specimens with positive two-step PCR. Group III included heavily infected specimenswhose tissues were tested mostly positive one-step PCR. WSSV generates an increase in the differentparameters of DNA damage (P<0.05) with abnormal histological features and notable reduction(P<0.05) of the endogenous scavengers in the tested tissues of the infected crayfish in comparisonwith the normal healthy ones. Furthermore, gills were found to be the most affected organ followedby muscle and finally hepatopancreas. These outcomes additionally demonstrated that comet testcould profitably be utilized in genotoxicity evaluation protocols in aquatic invertebrates.

This study was carried out to investigate the genotoxic, and hematological and serumbiochemical 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 for30 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 tooxadiazon significantly decreased WBC, RBC, Hb, Hct as well as serum albumin, glucose, and totalprotein levels, while serum ALP was significantly increased in the exposed fish groups. Nosignificant differences were found in MCV, MCHC and MCH levels between oxadiazon treatmentsand control groups. In conclusion, this study shows that oxadiazon is highly toxic to C. carpio andcauses significant changes in hematological and biochemical parameters as well as indicates themutagenic potential of oxadiazon in the erythrocyte cells of this fish.

Anesthesia in large animals such as sturgeons is unavoidable, so in this regard it isimportant to choice a best anesthetic with lowest side effects in fish.in the present study anestheticefficacy of mentha, Mentha pipertia, extract was studied in Persian sturgeon, Acipenser persicus, tofind 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 menthaextract showed more severe exciting movements than those exposed to clove oil. Nohistopathological effects were recorded in gills and kidneys of the fish after anesthesia with bothmentha extract and clove oil. Exposure to either 150 mg L-1 clove oil or 750 mg L-1 mentha extractfor 3 min resulted in the fish serum cortisol change. Result showed a significant increase in serumcortisol at 6 hrs after anesthesia in both mentioned anesthetic. However, in the fish anesthetized byclove oil, serum cortisol level returned to the pre anesthesia value, at 24 hrs post anesthesia. In thefish anesthetized by mentha extract, a further significant increase in serum cortisol level was observedat 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 weresignificantly higher than those anesthetized by clove oil. Totally it is concluded that, in Persiansturgeon, use of mentha extract as anesthetic results higher stress compared to clove oil, in the otherword, 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 MazandaranProvince. The Alborz Dam has been built along the river to provide annual irrigation and floodprotection. This study aimed to identify and describe the prevalence and parasite intensity of someendemic 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 fishspecimens, including Alburnoides tabarestanensis, Capoeta razii and Squalius turcicus, wereexamined. A total of 13 parasite species, including Ichthyophthirius multifiliis, Trichodina gracilis, Myxobulus minutus, Dactylogyrus chalcalburni, D. vistulae, D. lenkorani, Gyrodactylusgobioninum, G. prostate, Paradiplozoon homoion, Allocreadium isoproum, Rhabdochona denudatai, Ligula intestinalis and Bothriocephalus acheilognathi, were isolated from the examined fishes. Theresults showed that host-parasite system in Alborz Dam is mainly influenced by the parasite’s faunaof Babol River. The only exception in this regard is the plerocercoids of L. intestinalis, one of themost common parasites in Alborz Dam and found in the abdominal cavity of all fish species. Theprevalence rate and the mean intensity of parasitic infection in this reservoir are far more than thosein 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 coastin 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 toSeptember 2015. Quantitative samples were taken with a horizontal Van-Dorn sampler and 20 mmmesh plankton net was used for additional qualitative sampling. Microscopic observation ofphytoplankton allowed identification of 208 species including 70 Bacillariophyta species, 58Chlorophyta species, 24 Charophyta species, 21 Euglenophyta species, 18 Cyanophytes species, 9Phyrrophyta species, 5 Ochrophyta species and 3 Cryptophyta species. The Shannon diversity indexvaried 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 totalphytoplankton. Aulacoseira granulata and Euglena gracilis were the most predominant species withrespectively 40.17% and 15.91% relative abundance. Regarding the horizontal pattern ofphytoplankton abundance, downstream stations have the greatest abundances. So, the results suggestthat downstream stations are richer in phytoplankton which structure differs from that in upperstations.