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Mirzajani A.,University of Tehran | Hamidian A.H.,University of Tehran | Bagheri S.,Inland Waters Aquaculture Research Center | Karami M.,University of Tehran
Journal of the Marine Biological Association of the United Kingdom | Year: 2015

We studied the communities of the invasive Balanus improvisus and native Cerastoderma glaucum populations in the south-western Caspian Sea. The massive movement of live Bivalvia attached to Cirripedia colonies along the studied coastline strengthens the hypotheses asserting the possible negative effects of exotic species on endemic species. Different live stages of both animals including meroplankton and macro-invertebrates were considered in the analysis. Bivalvia larvae showed a downward trend in population, in contrast with an upward trend of Cirripedia larvae from 1996 to 2013. The abundance of C. glaucum decreased west to east along the sea shore in contrast with increasing biomass of B. improvisus. Both Bivalvia and Cirripedia larvae did not show any overlapping temporal abundance. The Cirripedia larvae showed its highest abundance in winter while the bloom of Bivalvia larvae occurred in April and May during 2004–2013. The biomass of B. improvisus reported in this study was higher than those reported for the northern parts and for the middle parts. Distribution patterns of both species were described based on temperature, salinity gradient and local nutrient content. A non-linear growth model of Bivalvia showed the short-term effects of Cirripedia on Bivalvia growth. The controversy between the effects of Cirripedia on the movement of two different Cardiidae (C. glaucum, which is affected by the presence of B. improvisus, and Adacna vitrea with no attached Cirripedia) highlights the contributing role of several other factors including ecosystem degradation. Copyright © Marine Biological Association of the United Kingdom 2015 Source


Valipour A.,Inland Waters Aquaculture Research Center | Shariatmadari F.,University of Tehran | Abedian A.,University of Tehran | Seyfabadi S.J.,University of Tehran | Zahmatkesh A.,Mirza Koochak khan Higher Education Center for Fisheries Science and Technology
Iranian Journal of Fisheries Sciences | Year: 2011

The influence of five pure diets of isonitrogenous and isoenergic with different ratios of Clupeidae fish oil (F) and soybean oil (S) on growth, molting and survival of narrow-clawed crayfish, Astacus leptodactylus, was evaluated during an 8-weeks trial. As soybean oil replaced with fish oil in each treatment, gently. Test diets were inclusive F0/S100, F30/S70, F50/S50, F70/S30 and F100/S0 fish oil per soybean oil percent. The test organism housed in fiber-glass tanks of 100 l capacity with flowing water and aeration in tanks are supplied. The test followed a Randomized complete design. Each treatment organized with 6 replicates and totally 30 rearing tanks involved. At the end of the trial, the crayfish offered diet containing Clupeidae fish oil (rich in n-3 fatty acids) showed the lowest food conversion ratio and highest weight gain performance as well as molting and survival rates. In contrast, the diet containing soybean oil (rich in fatty acids n-6) contributed least to growth and other indices. Statistical test showed the differences between this two formulated diets were significant (P<0.05). Results indicated that n-3 series of fatty acids are required in the diet of A. leptodactylus. Source


Valipour A.,Inland Waters Aquaculture Research Center | Ozorio R.O.A.,University of Porto | Shariatmadari F.,University of Tehran | Abedian A.,University of Tehran | And 2 more authors.
Journal of Applied Aquaculture | Year: 2012

The influence of dietary lipid level was evaluated on growth, survival, and molting of yearling narrow clawed crayfish, Astacus leptodactylus. Yearling crayfish were fed five isonitrogenous diets (35% protein), formulated to contain 4%, 7%, 10%, 13%, or 16% lipid. Crayfish (10.1 ± 1.6 g) were reared for 56 days in 60-L fiberglass tanks at 23 ± 1.7 °C, with flow-through water and continuous aeration. At the end of the trial, crayfish fed 13% lipid had the highest weight gain and specific growth rate, significantly different from crayfish fed 4% and 7% lipid (p < 0.05). Crayfish fed 13% lipid had a significantly higher survival rate (86.7%) than the animals fed 4% lipid (71%) (p < 0.05). Molting was not affected by lipid level (p > 0.05). We recommend 13% dietary lipid level for optimum growth and survival of Astacus leptodactylus in intensive cultivation. © Iranian Fisheries Research Organization. Source


Kaymaram F.,Iranian Fisheries Research Organization | Abdolmaleki S.,Inland Waters Aquaculture Research Center | Khedmati K.,Inland Waters Aquaculture Research Center
Iranian Journal of Fisheries Sciences | Year: 2012

This paper aimed to investigate the fishery and biological characteristics of anchovy Kilka in Iranian waters of the Caspian Sea from 2005-2007, including length and age structure, Von Bertalanffy growth parameters, length and age at first capture, condition factor, sex ratio, natural and fishing mortality. The examination of catch data approved that Kilka population in the Caspian Sea have been declined a few years ago following entrance jellyfish Ctenophora Mnemiopsis leidyi. The greatest destruction of anchovy kilka catch was occurred while the catch of anchovy from 4250 tonnes in 2005 reached to 924 tonnes in 2007. The results showed that K value and L∞ calculated 0.375/year, 131.7mm, respectively. The instantaneous coefficient of natural mortality was estimated 0.49/year. The instantaneous coefficient of fishing mortality and total mortality was 0.51 /year and 1/year, respectively. The Exploitation rate was calculated as 0.51. The length and age ranges restricted comparison to last decade and sharply decreased recruitment. In the past few years, the main reasons of disintegrates among anchovy Kilka stocks in the Caspian Sea were synchronized overfishing competitive anchovy Kilka with M. leidyi. Source

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