Age and growth of Alburnus mossulensis (Cyprinidae) in Bibi-Sayyedan River of Isfahan Province

Population structure and growth of Mossul bleak, Alburnus mossulensis, a native species of cyprinids in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. For this purpose, 543 specimens (353 females, 159 males and 31 immature) were caught using seine net (5 mm mesh size) and a cast net. Age groups of males and females were 0+ to 5+. The most frequent age group was 2+ in both sexes. The sex ratio was 1M:2.2F (p0.05). The largest female was 16.80 cm in total length and 49.12 g in weight, while the largest male was 14.10 cm in total length and 28.19 g in body weight. The length-weight relationship was calculated as W = 0.0169L^3.0355 (r^2=0.95) for males, W=0.0061L^3.1751 (r^2=0.98) for females and W=0.0066L^3.139 (r^2=0.99) for all fish (males, females and immature). Regression coefficient (b) based on Pauly test, was significantly different from 3 in females, but not in males (p<0.05), indicating an isometric growth pattern in males and a positive allometric growth pattern in females and all fish

Reproductive biology of Mossul bleak (Alburnus mossulensis) in Bibi-Sayyedan River of Tigris basin in Iran

Reproductive characteristics of Mossul bleak, Alburnus mossulensis, a native species of Cyprinidae family in Bibi-Sayyedan River of Semirom, Isfahan, were investigated by monthly sampling during December 2010 to December 2011. Five hundred and fourty three specimens (256 females, 159 males and 31 immature) were caught by a sein net (5 mm mesh size). The collected sampeles were anesthesized in 1% clove oil solution and transported to the laboratory on ice and subjected to dissection and biometric measurments. Age of males and females ranged from 0+ to 5+ years. The sex ratio was 1M: 2.2F (p < 0.05). The females outnumbered the males in all age classes. The largest female was 16.8cm in total length and 49.12g in weight and the largest male was 14.1cm in total length and 28.19g in weight. The age and total length at first maturity of females and males were estimated as 1 year and 5.3cm total length, and 2 years and 4.4cm, respectively. The minimum, maximum, and avarge absolute fecundity were 2064, 10316, and 5505 ± 2686, respectively and also the relative fecundity was 203 ± 58 egg/g body weight. Macroscopic analysis of gonads and gonadostomatic index values suggested that spawning of A. mossulensis occurs from March to June with a peak in April. Thus, A. mosullensis is considered a group-synchronous type species with a capacity for multiple ovulations within a reproductive season (multiple spawner)

Short communication: Age and growth of king nase, Condrostoma regium (Cyprinidae), from Bibi-Sayyedan River of Semirom, Isfahan, Iran

Age determination is an important step in fisheries management. The cyprinid fish Chondrostoma regium (Heckel, 1843) is widely distributed in Tigris-Euphrates basin and the Mediterranean basins of southeastern Turkey and the northern Levant. In Iran, it is found in Karun and Karkheh Rivers, the Hoor-al-Azim Marsh and also in Zayandehrud River and Bushehr basin. This species is not found in other basins of Iran. However, there is little information about its habitat requirements. ... The aim of the present study was to investigate the length-weight relationship and age and growth of C. regium population in Bibi-Sayyedan River of Semirom, Isfahan as a tributary of Tigris basin in Iran

The sub-lethal effects of cadmium on some gill histopathology in the cultivated Sterlet (Acipenser ruthenus)

The sub-lethal effects of water-born Cadmium (Cd) on histopathological changes of gill tissues were investigated on Sterlet, Acipenser ruthenus. In this research, 60 fish (41.69 ± 0.95 g and 23.98 ± 0.14 cm) were randomly distributed in 4 experimental groups, each with 3 replicates. The fish were exposed to different concentrations of Cd for 21 days under semistatic experimental condition as: 0, 16, 32 and 64 µg/L Cd. At the end of the experiment, the gill tissues were fixed in Bouin's solution for histopathological studies. Qualitative and quantitative changes of the gill tissues were analyzed. Several qualitative changes including hyperplasia, hypertrophy of epithelial cells and epithelial edema as well as necrosis, rings and fusion of gill filaments and secondary lamellae were observed in all treated fish including control group. Quantitative analysis based on organ index (Iorg) showed significant increase in histopathological changes in the gill tissues coincided by elevation of Cd concentration in the water. However, there was no significant differences in the organ index between control and 16Cd group.The results of this study demonstrate severe histopathological changes in the gill tissues after exposing to sub-lethal concentration of water-born Cd under experimental condition. The results of this study might be used as a guildline for evaluation of histopahological changes being induced by heavy metals in natural or cultivated environment for sturgeon fish

Induced spermiation of rainbow trout, Oncorhynchus mykiss, using a GnRh analogue

In this study, the benefits of using the first Iranian made GnRHa[D-Ala6 des Gly10] mGnRH ethylamide, to induce spermiation in male rainbow trout, Oncorhynchus mykiss, were evaluated, In addition, its effect on acceleration and synchronization, quality and quantity of milt and the plasma Testosterone (T) fluctuations were examined. For these purposes, 40 non-spermiating male rainbow trouts were injected with a mammalian gonadotropin releasing hormone analog (GnRHa) preparations of 0 (control), 30, 40 and 80 μg/kg B.W. or vehicle (propylene glycol). Spermiation was very synchronous and accelerated in treated groups. Six days after first injection, the cumulative spermiation rates reached respectively 40, 49 and 79% in injected groups (i.e. 30 to 80 μg/kg B.W.) while none of the control fish was spermiated. GnRHa injections advanced spermiation and reduced the average time to spermiation from 16 3.67 days for control group to 14.3± 2.2, 9.2 ±0.75 and 6.6± 0.29 days for treated groups, respectively (p0.05). Circulating levels of testosterone (T) prior to the GnRHa treatment were relatively low in all groups. Treatment with GnRHa induced significant increase in plasma T after 12 h, increasing it to 43.43±5.82, 38.66±5.63, 39.72±5.07 ng/ml in groups 2 to 4, respectively, which were higher than T levels for control (i.e. 24.58±7.13 ng/ml) p<0.05. These levels remained high up until 48 h in treated groups; but after this time, T levels reduced to the basal levels of time 0, except in 4 which had received its second GnRHa injection at time 48

Effect of dietary wood betony, Stachys lavandulifolia extract on growth performance, haematological and biochemical parameters of common carp, Cyprinus carpio

A 6 week study was conducted to assess the effects of wood betony (WB), Stachys lavandulifolia extract on growth performance, hematological and biochemical parameters of common carp, Cyprinus carpio. Different levels of the WB extract (0, 2, 4 and 8 % weight per weight, W/W, 0WB, 2WB, 4WB and 8WB) in the diet were used. The results showed that final weight and weight gain were significantly improved by WB (p0.05). There were no significant differences in hemoglobin, hematocrit, mean erythrocytes of hemoglobin, mean erythrocyte volume, mean hemoglobin erythrocyte concentration and white blood cell (WBC) counts (p>0.05), while, red blood cells (RBC) counts showed significant declining trend by increasing the level of the plant extract from control to 8WB (p<0.05). Significant elevation in the levels of total protein, albumin and globulin and albumin/globulin ratio by increasing WB concentration in the diet were observed (p<0.05). Diet enriched by WB could decrease serum level of triglycerides and cholesterol in comparison with the control (p<0.05). Based on the results of this study, it could be concluded that feeding common carp with WB can improve growth and some immunity characteristics as well as lipid metabolism