Journal of Fisheries
Year:2010 | Volume:63 | Issue:1|Papers Count:8

Silver carp fillets were used to prepare three types of fish fingers (Slice, Mince and Surimi). Fish fingers were battered, breed and fried in frying machine for 3 minuets at+180oC. Organoleptic factors including texture, taste, odor, color and general acceptability were measured.Results showed that color and flavor of surimi fish fingers were better than those of other types of fish fingers in this study. The texture of slices and surimi fish fingers were better than that of fish fingers produced from mince.General acceptability assessments showed that surimi fish fingers have significant acceptability compared to other types of fish fingers. Thus, the use of surimi from silver carp flesh for fish finger production is recommended.

In this study, oocyte polarization index used as an indicator to determine physiological status of immature, premature and mature Caspian Roach, Rutilus frisii kutum Kamensky, 1901.For sampling, 100 oocyte were selected randomly from immature, premature and mature fishes. Then oocytes were fixed and cuted in animal-vegetal pole axis. After cuting, oocytes were stained by hematoxylin-eosin.. According to nucleus localization, oocyte polarization index were determined in all oocytes.Premature and mature oocytes were fertilized by sperm of male fish, then fertilization percentage was caculated. Nucleus localization in immature fishes was centeral, medidatorial in premature fish and in mature fishes was in marginal (near to micropyle). It was a difference between (P<0.01) fertilization percentage in premature fish (61 ± 3 % in average) and mature fish (93 ± 2 % in average). This study demonsrated that; oocyte polarization index can be used as a good indicator for proper broodstock selection in Caspian Roach.

The aim of present study was to screen rainbow trout broodstock population of Kelardasht reproduction and rearing center, with emphasis on presence and non-presence of microsatellite markers associated with body weight. For this purpose, 92 samples of caudal fin tissue from Kelardasht rainbow trout broodstock population were obtained and genomic DNA of these samples were extracted. Three microsatellite loci include omyRGT1TUF (linkage group 5), omyRGT4TUF (linkage group Oi) and omyRGT14TUF (linkage group N) were amplified using the polymerase chain reaction (PCR) with their specific primers. This study showed that presence of these microsatellite markers in this broodstock population were 92.4%, 78.8% and 96.97% and the number of polymorph for those were 6, 4 and 6 respectively. In 25% of high weight broodstocks there was significant relationship between presence of omyRGT4TUF (p<0.05) and complete association between omyRGT14TUF with body weight in females as well as complete association between omyRGT1TUF and omyRGT14TUF with body weight in males.

In the present study LHRHa2 was tested along with Metoclopramide and Chlorpromazine on 52 pieces of Abramis brama orientalis in May 2008. In order to identify the optimum doses which were proved to be (1, 2, 3, 4 mg/kg) for LHRHa, (5, 10, 15, 20 mg/kg) for Metoclopramide and (2, 5, 10, 12 mg/kg) for Chlorpromazine. The treatment sample fish were classified into five categories, and then the injected solvents were prepared. The procedures of the study included injection operations into the muscles and cupping was in the form of sagittarius hemal. After that, GTH II was conducted on the basis of RIA. The findings proved that all the compositions in a stimulating process resulted in an increase in the ration of GTH II and at P<0.05 resulted in meaningful differences in optimum dose. LHRHa2 (3 mg/kg) led to 0.554 IU/L, Metoclopramide (5 mg/kg) caused 0.618 IU/L and also Chlorpromazine (10 mg/kg) resulted in 0.522 IU/L increase in the ratio of GTH II.

An experiment was carried out to determine the stress response of common carp, Cyprinus carpio L., to a 3-h net confinement and a subsequent recovery period of 22 hours. Blood was collected to determine plasma cortisol, glucose, lactate, FFA, chloride, haematocrit and haemoglobin levels. The results showed that the plasma cortisol level was 85- fold higher than in the unstressed control at one hour post-stress and quickly returned to normal after 4 h recovery. Glucose value was increased after 20 minutes but returned to basal levels after 22 h recovery. Lactate levels were increased after 5 minutes confinement and then returned to a normal level after 1 hour net confinement. Free fatty acids were not elevated until 3h of confinement and quickly returned to basal level in 1 h recovery. However, confinement had no effect on chloride, haematocrit and haemoglobin levels. The results show that net confinement can induce primary (cortisol elevation) and secondary stress responses (glucose, lactate and free fatty acid elevations) in common carp.These results show that common carp respond to net confinement stress in a similar manner to other teleost species.

In this study, serum concentrations of sex steroid hormones (testosterone, 17b-estradiol (E2) and progesterone) of Vimba vimba and Alburnus chalcoides during spawning phase in Valiabad River (Tonekabon, northern Iran) were studied by radioimmunoassay (RIA). Testosterone levels in gravid vimba and shemaya were 20.3±9.9 and 6.08±1.64 ngml-1 respectively, but in ripe females, its concentration was significantly lower (P<0.05). In both species E2 concentrations were at high levels during spawning phase and in shemaya its levels in gravid and ripe fish were 90.85±6.4 and 112±6.4 ng/ml (P<0.05).Progesterone levels remained lower than 1 ng/ml in both species with non-significant difference between two groups. Based on the result, Caspian vimba and shemaya may be multiple spawner with protracted spawning period.

This study is aimed to investigate the effect of spawning on hydrolytic and oxidative rancidity development in fish fillet (pre-and post-spawned cultured common carp). Thus cultured common carp prepare at two different gonadal stages at two different times of the year (pre- and post-spawned fish in 11 June and 18 August 2007, respectively) was studied during frozen storage (-18oC, up to 6 months).Oxidative and hydrolytic analyses were performed in frozen fillet at months 0, 1, 3 and 6. Pre-spawned samples showed a higher second lipid oxidation index (Thiobarbituric acid index) than its post-spawned counterparts during frozen storage. Pre-spawned common carp showed a lower (p<0.05) hydrolysis development (FFA) than its counterpart from post-spawned. Conjugated diene increased during storage in pre-spawned samples significantly (P<0.05) but in post-spawned fillets did not show any significant difference. Results of fluorescence assessment proved to be lower (p<0.05) in fillets from Pre-spawned samples than its in fillets from Post-spawned samples. Fluorescence formation in pre-spawned samples did not show any significant differences during frozen storage. Heme iron measurements decreased in post-spawned fillets insignificantly (P>0.05), but in pre-spawned samples did not show a clear trend during frozen storage. According to some indices of lipid quality (such as TBA and CD measurements), pre-spawned common carp fillets showed a higher variation during frozen storage.