[Thyroid hormones changes in reproduction season of brownbanded bamboo shark [Chiloscyllium punctatum] from the Persian Gulf]

Background: Brownbanded Bamboo sharks [Chiloscyllium punctatum] is one of the cartilaginous fish that lives in the Persian Gulf

Objectives: The purpose of the present study is to study the effects of thyroid hormone on reproductive system of this specious

Methods: In this investigation, 36 individual of Brownbanded Bamboo sharks [Chiloscyllium punctatum] in both autumn [before reproduction] and spring [period of reproduction] seasons were caught from Dervish's Creek located at the northern of Persian Gulf. After weighing, biometry, sex determination and the numbering of sharks, [the sex is determined through clasper which is observed in male and not in female], ELISA was used to measure serum thyroid hormone concentrations

Results: The results showed that T3 and T4 hormones were increased dramatically in the reproductive season compared with the non-breeding season [p<0.05]. On the other hand, by classifying the sharks into different groups, we found that the levels of thyroid hormone were higher in the blood of larger sharks compared with the smaller ones [p<0.05]

Conclusions: It is probable that T4 hormone levels will increase dramatically for the development of eggs in the female shark

[Assessment of liver pathological alterations in yellowfin seabream [Achantopagrus latus] and Abu mullet [Liza abu] in Musa creek in response to petrochemical pullutants]

Musa creek, suitable place for spawning of many fish species and other organisms, is one of the most important and voluble ecosystems in the west of Iran that received so many attentions due to existents of various industries around this part of Persian Gulf. Previous studies confirmed that marine fish have collected high amounts of pollutants in this area which could be lead to sever tissue changes in these fish. In the present study, pathological alterations of liver is used for evaluating of contaminants effects on two fish species including of yellowfin seabream and abu mullet in Musa creek. In this study, 50 yellowfin seabreams and 50 abu mullets were collected from five sampling sites in Mussa creek including: 1. Petrochemical, 2. Gaafari, 3. Magidieh, 4. Ghazaleh and 5. Zangi. The samples were taken from the liver after fish dissection and were fixed in bouin's solution. The liver samples were then studied based on the routine histological methods. The pathological changes in the liver included vacuolation of hepatocytes, nuclear hypertrophy, focal necrosis, dilation of sinusoid and diss spaces. The amount of histopathological alteration index [HAI] for liver of both species was significantly higher at the Petrochemical station than other sites [p<0.05]. The least amount of HAI was related to Zangi station. The results of present study showed that the alternations of liver tissue structure in Achantopagrus latus and Liza abu caused by the Musa creek contamination and there is close relation between amounts of this alterations and the environmental pollution

Pituitary primary cell culture of Common carp [Cyprinus Carpio] and evaluation of its secretion effect on endocrine activity of incubated ovarian follicles

In this study, five carp pituitary glands were collected and dispersed enzymatically and mechanically. Then, the cells were cultivated as monolayer in MEM [minimum essential medium Eagle]. The culture media were collected after 72 h and frozen at -20°C. Carp ovarian follicles also were separated mechanically and incubated in BSS [basic salt solution] Cortland medium in 24-well microplates for 48 h at 20°C. Then, they were divided into two groups: control group which were incubated in BSS medium and experimental group which subdivided into three subgroups according to treatment with different concentration of collected pituitary secretion [50, 100 and 200 micro 1/ml]. Follicles culture media were collected 24 h later and were analyzed for 17-beta-oestradiol [E[2]] and 17-alpha-hydroxy progesterone [P[4]] content by radioimmunoassay [RIA]. The results showed that adding low concentration [50 micro 1/ml] of collected pituitary secretion [CPS] increased steroid hormones [E[2] and P[4]] secretion of incubated ovarian follicles significantly [P<0.05] but the high concentration of CPS [200 micro 1/ml] significantly decreased the secretion of E[2] and P[4] [P<0.05]. Collected pituitary secretion at the concentration of 100 micro 1/ml had no significant effect on steroid hormones [P>0.05]