Time filter

Source Type

Bandpei M.A.A.,Universiti Sains Malaysia | Mashhor M.,Universiti Sains Malaysia | Abdolmaleki S.,Inland Water Aquaculture Research Center | El-Sayed A.-F.M.,Alexandria University
Cybium | Year: 2010

The population dynamics of Caspian Kutum, Rutilus frisii kutum (Kamensky, 1901), sampled from commercial beach seine catches from the southern Caspian Sea (Iran), was investigated. A random sample of 1360 fish, representing a wide range of fish size (20 to 58 cm FL), was collected from early October 2006 to middle of April 2007. Length-frequency analyses and FiSAT software were used to study the population dynamics. The values of the von Bertalanffy growth function fit to size-at-age data were: L ∞ = 59.85 cm fork length (FL), K = 0.27 yr -1, C = 0.25, WP (winter point) =0.40. Using the seasonalized length converted catch curve, the instantaneous total mortality coefficient Z was estimated as 1.28 yr -1. The instantaneous natural mortality coefficient M was 0.46 yr -1, while the instantaneous fishing mortality coefficient F was 0.82 yr -1, giving the current exploitation rate E= 0.64.The mean length at first capture L c estimated from the analysis of probability of capture of each length class was 36.8 cm FL. The maximum exploitation rate E max predicted from the relative yield per recruit analysis was 0.76, while the current exploitation rate E is less than E max. This indicates that Caspian Kutum is moderately exploited in the southern Caspian Sea. Source

Jafarzadeh E.,Islamic Azad University at Lahijan | Khara H.,Islamic Azad University at Lahijan | Ahmadnezhad M.,Inland Water Aquaculture Research Center
Comparative Clinical Pathology | Year: 2015

The present study was carried out to evaluate the effects of synbiotic (Biomin IMBO) on haematological (white blood cell (WBC) and red blood cell (RBC) counts, haemoglobin (Hb) concentration, haematocrit (Hct), mean corpuscular haemoglobin (MCH), mean corpuscular volume (MCV) and mean corpuscular haemoglobin concentration (MCHC)) and immunological (immunoglobulin (IgM) and lysozyme activity) components of Russian sturgeon, Acipenser guldenstadti. Five experimental treatments and one control group with three replicates were considered. In treatment groups, fish were fed with diet containing 1 (T1), 1.5 (T2), 2 (T3), 2.5 (T4) and 3 (T5) g synbiotic/kg diet. In control group, fish were fed without supplement of synbiotic. Blood sampling for haematological and immunological studies was done at days 20, 40 and 60 after the beginning of the experiment. Based on our results, synbiotic supplement had no significant effects on values Hb, Htc, MCV and MCHC compared to control group (P > 0.05). Also, in all experimental treatments, these parameters did not considerable changes during the course of the experiment (P > 0.05). The effect of synbiotic supplement on MCH was not significant (P > 0.05); however, this value was higher in synbiotic supplement treatments compared to control group. MCH had no significant changes during the period of the experiment in all experimental groups (P > 0.05). In all synbiotic treatments, the values of WBC count, neutrophils, monocytes and eosinophils were higher than control group (P < 0.05). Only, lymphocytes in synbiotic supplement treatments were lower compared to control group (P < 0.05). Also, WBC count showed a decreasing trend during the period of the experiment in all synbiotic supplement groups (P < 0.05). Synbiotic supplement increased RBCs compared to control group; however, this was not significant (P > 0.05). The values of RBCs in T4 and T5 showed an increasing change over the course of the experiment (P < 0.05). The immunological components, i.e. IgM concentration and lysozyme activity, were found to be higher in synbiotic supplement treatments compared to control group (P < 0.05). These parameters had no significant changes over the course of the experiment (P > 0.05). © 2015, Springer-Verlag London. Source

Fazli H.,Caspian Sea Ecology Research Center | Daryanabard G.R.,Caspian Sea Ecology Research Center | Abdolmaleki S.,Inland Water Aquaculture Research Center | Bandani G.A.,Inland Water Stocks Research Center
Journal of Applied Ichthyology | Year: 2013

Recent changes in the Caspian ecosystem have caused changes in the absolute and relative abundance of the commercially important golden grey mullet (Liza aurata) in Iranian waters. In order to adjust for these changes a more rigorous management of this fishery resource is required. The present study examines the biomass of golden grey mullet during 1991-2010. Estimates of fMSY, yield-per-recruit and spawning biomass-per-recruit are presented for various harvesting strategies of Fmax, F0.1, F35%, and a method is proposed for estimating acceptable biological catch (ABC) that accounts for large differences in the quality and quantity of information and available data. Biomass estimates of golden grey mullet, derived from a biomass-based cohort analysis, increased from 13 527 tonnes in 1991-1992 to 20 100 t in 2000-2001, and declined to the lowest level (11 000 t) in 2007-2008. In 2009-2010, the total biomass was estimated to be 14 400 t. The ABC was estimated at 2200 t in 2010. Golden grey mullet is vulnerable to environmental factors, which should be considered in the stock assessment and management of the fish. © 2012 Blackwell Verlag GmbH. Source

Ahmadnezhad M.,Inland Water Aquaculture Research Center | Oryan S.,Kharazmi University | Sahafi H.H.,Iranian Fisheries Research Organization | Khara H.,Islamic Azad University at Lahijan
Turkish Journal of Fisheries and Aquatic Sciences | Year: 2013

To assess changes of gonad development and sex steroids hormones of R. frisii kutum, broodfish were captured during spawning season 2010 (March-April) and induced intramuscularly with following hormone treatments: single injections of 1 μg kg-1 b.w. LHRH-A2, combination of LHRH-A2 with two dopamine antagonists as follows: 1 μg kg -1 b.w. LHRH-A2 + 5 mg kg-1 b.w. PIM, 1 μg kg-1 b.w. LHRH-A2 + 2.5 mg kg-1 b.w. chlorpromazine, 1 μg kg-1 b.w. LHRH-A2 + 5 mg kg-1 b.w. PIM + 2.5 mg kg-1 b.w. chlorpromazine, single injections of 5 mg kg-1 b.w. PIM and 2.5 mg kg-1 b.w. chlorpromazine, carp pitatury extract (CPE), saline solution (NaCl 0.7%) and control group (without injection) were used, respectively. The number of ovulated fish was different in each treatment. Ovaries were more progressed in ovulated rather than non-ovulated fish. Also, sex hormones such as testosterone (T) and estradiol (E2) were changed in different hormonal treatments. In ovulated fish, histological analysis revealed six stages in ovaries, while ovaries in non-ovulated ones were developed only in fourth stage. © Published by Central Fisheries Research Institute (CFRI) Trabzon, Turkey. Source

Khara H.,Islamic Azad University at Lahijan | Maghsoodloo E.,Islamic Azad University at Lahijan | Ahmadnezhad M.,Inland Water Aquaculture Research Center | Yalghi S.,Inland Aquatics Stocks Research Center | Rahbar M.,Islamic Azad University at Lahijan
Comparative Clinical Pathology | Year: 2014

The aim of this study was to measure sex steroid levels before and after induction of ovulation using luteinizing hormone-releasing hormone analog (LH-RH-A)2 in female Persian sturgeons. A total of ten females were induced by LH-RH-A2 hormone. Seven females were ovulated successfully, and rest of breeders did not respond to hormonal treatment (non-ovulated fish). The serum cortisol (C), testosterone (T), oestradiol-17b (E2), progesterone (P4), testosterone (T), FSH, and LH concentrations were measured by radioimmunoassay. In ovulated and non-ovulated females, C and P4 levels tended to increase after LH-RH-A2 injection. Serum E2 levels in ovulated and non-ovulated females decreased dramatically after LH-RH-A2 injection. Following hormonal treatment, T levels increased slightly in ovulated and non-ovulated females, but values were not statistically different. An increase was observed in FSH levels of ovulated fish, but this trend was not observed in non-ovulated females. The data clearly illustrated that induction of ovulation in female Persian sturgeons using LH-RH-A2 led to change in steroid hormones. Also, the rise in C levels may indicate an interaction between corticosteroids and gamete maturation in Persian sturgeon. © 2013 Springer-Verlag London. Source

Discover hidden collaborations