علوم زیستی دریا
Sahar Ahmadvand; Solmaz Shirali; Nasrin Sakhaei; Babak Doustshenas
Abstract
The Unionidae family is the most abundant family among freshwater bivalves which belongs to the Unionida order. Considering the nutritional, economic and environmental importance of bivalve molluscs, as well as the lack of information related to freshwater mussels of the Unionida order, especially the ...
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The Unionidae family is the most abundant family among freshwater bivalves which belongs to the Unionida order. Considering the nutritional, economic and environmental importance of bivalve molluscs, as well as the lack of information related to freshwater mussels of the Unionida order, especially the species belonging to the Unionidae family, as well as their global risk and concidering the importance of the ovary and the testis as an important organ of reproduction and survival and since histological studies are the most accurate method in determining the stages of the gonadal cycle, this research was conducted with the aim of investigating the histology of oogenesis and spermatogenesis in Unio tigridis of the Karun River. Sampling was done seasonally. For this purpose, the studied species after catching in every season were transferred to the histological laboratory, then they were biometrically identified using valid identification books and keys. After dissection, small pieces of gonads were separated and after tissue passage, they were examined histologically and histometrically. The results of the histological studies of the gonads showed that this species is often heterosexual. The results of the histological studies of gonads showed that out of 41 oysters in this study, there was only one hermaphrodite, and testicular and ovarian tissue were simultaneously observed in the gonad tissue. The ovary was asynchronous type because, at any time, all types of follicles in different stages of development (oogonia, previtellogenic oocytes, vitellogenic oocytes) were visible in the ovaries. The highest rate of development and maturation of both male and female gonads was observed in spring. It seems that the main breeding time of Unio tigridis species in the Karun River in the study area is in spring.
علوم زیستی دریا
Shahla Hamid; Faedeh Amini; Solmaz Shirali; Kamal Ghanemi; Ahmad Shadi
Abstract
In this study, the amount of heavy metals (nickel, cadmium, lead, copper, mercury) in brown algae Sargassum sp., Padina sp. and Cystoseira sp., sediments and the amount of mercury in water were also measured. ampling was done during winter 2016 and summer 2017 at four stations from the shores of Bushehr.Analysis ...
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In this study, the amount of heavy metals (nickel, cadmium, lead, copper, mercury) in brown algae Sargassum sp., Padina sp. and Cystoseira sp., sediments and the amount of mercury in water were also measured. ampling was done during winter 2016 and summer 2017 at four stations from the shores of Bushehr.Analysis of heavy metals in sediments and algae after chemical digestion and preparation was investigated by Savanta model atomic absorption spectrophotometer. The order obtained from the concentration of heavy metals in Padina sp. cadmium > lead > nickel > copper > mercury, for Sargassum sp. as lead > copper > nickel > cadmium > mercury and for Cystoseira sp. It is in the form of copper > lead > nickel > cadmium > mercury, among which Padina sp algae had the highest accumulation of heavy metals. The order of concentration of metals in sediments was nickel > lead > copper > cadmium > mercury. All metals, except for lead metal, have a higher average in the summer season, and the average mercury metal in water was measured at 0.23 micrograms per gram of dry weight. Correlation results showed that the concentration of heavy metals (nickel, cadmium, lead, copper, and mercury) in macroalgae Padina sp, Sargassum sp, sp. Cystoseira and their adjacent sediments in the shores of Bushehr, two algae Sargassum sp. and sp. Cystoseira have a greater ability to accumulate heavy metals.Cystoseira have a greater ability to accumulate heavy metals. According to the obtained results, the concentration of heavy metal mercury in the waters of the shores of Bushehr city with its amount in the studied algae, it seems that Sargassum sp. It is a suitable material for biological monitoring of this metal in the study area.
علوم زیستی دریا
Somayeh Zangeneh; Solmaz Kakeshian; Solmaz Shirali; Ahmad Savari; Hossein Najafzadeh Varzi; Abdolali Movahedinia; Mohammad Zakeri
Abstract
The present study has performed to investigate the effects of different levels of soy and garlic phytoestrogens on ovarian structure in Yellowfin seabream (Acanthopagrus latus). A total of 105 Yellowfin seabream were divided in seven groups including a control group that were received standard ...
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The present study has performed to investigate the effects of different levels of soy and garlic phytoestrogens on ovarian structure in Yellowfin seabream (Acanthopagrus latus). A total of 105 Yellowfin seabream were divided in seven groups including a control group that were received standard food without any extract and six treatment groups that were received different doses of soy (2/5, 5 and 7/5%) and garlic (0/5, 1 and 2%) hydroalcoholic extract. Fish were fed daily at a rate of 3% of body weight twice for 14 days. Sampling was done in days of 0, 7, 10 and 14. In every time, a section of mid portion of gonad was cut for histological examination. The results showed that different doses of soy and garlic phytoestrogens have various effects on growth and development of gonad in Yellowfin seabream as a protandrous hermaphrodite fish, so that increase in dose and time of consumption of food containing garlic hydroalchoholic extract cause increase in number of vitellogenesis follicles and finally growth and development of ovary, while consumption of food containing soy hydroalcoholic extract cause observing of testis and immature ovaries containing previtellogenesis follicle and prevents gonad development from testis to ovary in protandrous hermaphrodite fish.