Nassir Niamaimandi; Tooraj Valinassab; Reza Dehghani; Reza Daryanabard
Abstract
Abstract Biodiversity indices and abundance of demersal resources in Hormozgan waters (53 00E to 57 00E) was studied by bottom trawl survey during winter season, 2013. Sampling was done by R/V Ferdos 1. In this study, 89 stations within the 10-20 m, 20-30 m and 30-50 m depth layers were sampled and abundance ...
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Abstract Biodiversity indices and abundance of demersal resources in Hormozgan waters (53 00E to 57 00E) was studied by bottom trawl survey during winter season, 2013. Sampling was done by R/V Ferdos 1. In this study, 89 stations within the 10-20 m, 20-30 m and 30-50 m depth layers were sampled and abundance and species diversity of demersal fish communities at different depths were evaluated using various indices. In this study 99 taxa communities were identified including 88 fish species and 13 species or species groups that belonged to the other marine organisms such as crabs, sea cucumbers, sea snakes, jelly fish and corals. The value for the Shannon (H́) index for the entire investigated area (10-50 m depths) were 3.21, Simpson (D), 0.06, Pielou (J), 0.69, Margalef (R), 7.55 and Menhinick (IMen), were 0.16. The value indices in different depths of 10-20 m, 20-30 m and 30-50 m were identical. Based on the results of Shannon and Simpson indices, this area has a fair quality of population in number of species, however species richness indices indicated low species richness and due to high water temperature and salinity degree, this area is under stress.
Tooraj valinasab; Eassa Kamali; Reza Dehghani; Hojjatollah Fourooghifard
Abstract
Abstract The study of age and growth of aquatics is basic and necessary information for further fisheries management. By aging the fishes, we can estimate the population dynamics parameters such as growth and mortality rates. In this study the Otolithes ruber (Tiger toothed croaker) was selected as one ...
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Abstract The study of age and growth of aquatics is basic and necessary information for further fisheries management. By aging the fishes, we can estimate the population dynamics parameters such as growth and mortality rates. In this study the Otolithes ruber (Tiger toothed croaker) was selected as one of the most important and commercial species for aging from September 2008 to November 2009. During 15 months, a total of 540 specimens were collected and 238 sagitta otoliths were extracted and then were sectioned in laboratory using microtome cutter. The sectioned otoliths were aged by reading the increment rings. The overall Von-Bertalanffy growth equation was estimated as L(t)= 72(1-e -0.151(t+1.369)). The smallest fish was 18 cm total length and with an estimated age of 0.25 yrs; and the biggest size was 54 cm with the age of 8 yrs. The Length-weight relationship was found as W=0.0064 TL3.1268. The natural mortality of croaker was estimated 0.4604 per year.
Meysam Golzar; Tooraj Valinasab; Mehrdad Shirin Abadi; Mahmood Hafeziyeh
Volume 5, Issue 2 , December 2016, , Pages 25-33
Abstract
The various stages of embryonic growth pharaoh´s cuttlefish (Sepia pharaonis) reside in Oman until hatching was studied. Gregor tours and the eggs collected for further study of the propagation of Education, Research Center of the Earth - Chabahar Moved .once every 24 hours to get detailed information ...
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The various stages of embryonic growth pharaoh´s cuttlefish (Sepia pharaonis) reside in Oman until hatching was studied. Gregor tours and the eggs collected for further study of the propagation of Education, Research Center of the Earth - Chabahar Moved .once every 24 hours to get detailed information was sampling of from fertilized eggs. Egg size of 11±4 mm were selected because of the large size of cuttlefish eggs during incubation stages of embryonic development within the capsule is visible. The studies showed that the water temperature of 20±2°C hatching takes about 20±10 days. In this study results showed that the first cleavage was performed on the first day and the 15th day after the yolk sac has started to decrease. Tentacle is visible on day 14. Cuttlefish in all developmental stages of the embryonic development of a model to follow, but the temperature plays an important role in hatching time.
