Effect of different dietary protein levels on reproductive performance of paradise fish Macropodus opercularis

In this study, the effect of different protein levels, on paradise fish growth and reproduction were investigated. Thus, number of one thousand paradise fish (0.5 ± 0.01 g) were collected from hatchery bred brooders and divided into six group, each group was offered one of six experimental diet comprising different protein levels (25%, 30%, 35%, 40%, 45% and 50%). After six month feeding period, the highest weight gain (5.96± 0.17), the highest weight gain percentage (90.8 ± 0.31) were submitted in the group fed 40% protein. Moreover, the highest feed conversion ratio (0.9 ± 0.3) as well as daily growth was observed in this group. In the reproduction, the highest eggs released by the group fed with diet containing 45% protein. The GSI and the egg diameter and larval length were highest in 45% protein group. The group of 25% and 30% the reproduction efficiency was the lowest. Protein increment up to 50% had no effect on reproduction performance. No differences were seen in biochemical composition and amino acid profile of the ovaries between groups

Induction of population triploid-interploid in rainbow trout (Oncorhynchus mikiss) using by indirect

Induced polyploidy is a suitable tool for producing sterile fish which made commercial benefits in the aquaculture industry. This study carried out in order to produce triploid-interploid population via mating tetraploid female with diploid male rainbow trout. Heat shock was used for making tetraploid population and the best temperature and induction time were examined. Result showed that highest mortality from 1 day after fertilization to emerging were in groups 6 of embryos (40.1%) and the lowest were in groups 3 (33 %). Flowcytometry results showed that some fish were polyploidy. Comparative analyze of genome levels in tetraploid fish to control fish (diploid) and hen as standard indicator, confirmed tetraploid fishes in this study. In conclusion we can state that heat shock induction for 7 minutes at 65 hour –degree after fertilization in 28ºC is optimum temperature for inducting tetraploid rainbow trout

Investigation of chromosome and ploidy levels of rainbow trout produced from imported eyed eggs

Rainbow trout is the main cultural species of coldwater fishes in iran. Often, aquaculturists intend to breeding in order to production of lines with higher growth rate potential and disease resistant. Nevertheless in the country, no trout breeding programs, has been performed yet and most of the farms focused on the cultivation of the first (unbred) race. While European countries progressed in trout breeding techniques and production lines with higher growth through genetic manipulation (chromosomal number and type changes of fish) and/or selection and their fish products derived from this technology, including eyed eggs and so on have sold to other regions of the world (eg: Iran). In this study, some biological parameters including survival, growth, feed conversion ratio (FCR.) and chromosomal number of two juvenile groups from imported( group 1) and native(group 2) eyed fish eggs were compared. For chromosomal investigation, blood smear test and flow cytometry were performed. sults showed a significant difference (P≤5%) in growth rate of native fishes and French group Native fish feed conversion ratio (0.9) was significantly difference (P≤5%) from that of French fishes (1.15). Chromosomal analysis showed no difference in chromosome number in treatments and two fish groups were 2n chromosome. Based on the results, the fishes of group 1 had faster grow potential and gain weight in less time than that of group 2 and this has been achieved to go through the process of selection and feminization without any change in number of ploidy. Whereas the ability of native fishes in food efficiency ( lower FCR.) was better. However, the reduction of rearing period is the benefit and preference of cultivation of imported or origionally foreign

Production of monosex female population of rainbow trout by use of 17-B estradiol as direct method

In many species of finfish, females exhibit higher growth rates than males and achieve larger sizes. In addition, in some species, males mature before reaching marketable size. Therefore, there is great interest from the fish farmers to produce all-female stocks. In this project tried to reversing the sex of rainbow trout larvae by 17 estradiol and direct method, further more finding the optimum dose of this natural estrogen for endocrine sex reversion of Rainbow trout (O. mykiss). Four experimental treatments were designed with doses of 10, 20, 30 and 40 mg/kgf. Trout which treated with 40 mg/kgf yielded 96% female and greatest growth

Estimation of hormone residuals (B-Estradiole) in rainbow trout

Residual level of 17- Beta Stradiol and progesterone hormones in rainbow trout fish plasma were measured during different period using RIA method. Blood sampling from abdominal aorta were taken from 70 individual of female fishes (100±11 g) which had been exposed to hormone at 0.5, 1,2,4,8,12,24 and 168 h (7 groups) compared with control group which was not exposed to this hormone. Results showed that plasma hormones measurement in different fish groups after exposing had significant differences (P<0.01) and the highest and lowest 17-Beta Stradiol hormone residue were observed in fishes that exposed 0.5h and 168h to hormone respectively (121±9 ng. ml^-1 and 3±0.9 ng. ml^-1) but there is no any differences between fishes exposed 168h to hormone and control group. Also the highest progesterone hormone level were measured in fishes 0.5 an 1h exposed and the lowest one was in fishes 168 h exposed. The range of progesterone hormone were between 0.3 to 1.1 ng .ml^-1 and significant increasing of this hormone levels were obtained in fishes exposed to hormone 4 to 24h (P<0.01). As consequence these hormone can not residue in fishes for a long time and maximum after one week the levels back to the normal

The production of all-female in rainbow trout (Oncorhynchus mykiss) using indirect feminization

The sex reversal technique in fish is widespread in many countries. The development of these techniques is desirable because rainbow trout males reach their gonad maturity earlier compared to the females. Rainbow trout alevins were treated with 17α-methyltestosterone incorporated in the diet (0.5. 1.5, 3, 6 and 10 mg/kg) for 60 days from the beginning of first feeding. Sex was determined at 180 and 680 dpf by sampling fish (n = 20) from each group and examining gross gonadal morphology under a dissecting microscope. Also sex reversal ratio and growth performance were determined in hormone-treated groups. These sex reversed functional males were reared for brood stock until they attained sexual maturity. At the end of experiment, normal rainbow trout eggs were fertilized with the sperms taken from sex reversed males for producing all-female populations. Examination of the results showed that 17α- methyltestosterone was effective in all treatment. The highest sex reversal ratio with 100% was observed in group treated with 0.5, 1.5 and 3 mg/kg 17α- methyltestosterone. The highest live weight ratios were observed in groups fed with 6, 0.5 17α-methyltestosterone and control group. Female progeny produced from the sex reversed males were 100 % in all males that sired offspring. All female trout stocks produced by this method have advantage in rainbow trout culture since the fish is not meant for direct human consumption and is used to generate brood stock, therefore, difference of growth parameters do not influence the success

Genetic improvement of rainbow trout in Iran

Inthisstudy, Iranian and French male and female Oncorhynchus mykiss broodstocks were invided into two groups 50 and 24 respectivelyin Research center of genetic and breeding of coldwater fishers, Yasouj,Iran and the genetic structure of them was investigated using 6 microsatellite markers. Along with broodstock maturation, fertilization 1:1(female:male) were randomly assigned and occurred in25 of12Iranian andFrench treatment respectively. Reproductive parameters were recordedfor the whole family.Average number of observed alleles in Iranian and French stocks was 6.68 and 6.83, respectively.Average number of effective alleles in Iranian and French stocks was 3.13 and 3.45 respectively.Fixation index Fstwas calculated based on allelic frequency between two stocks was 0.058 with significant difference between 2 stocks. Eyed percentage for french broodstock calaulated zero and deleted. Fertilization rate(100-0), the eyed percentage (98-0), The hatch rate(98- 0),the averagefecundity4114.708, the average eggs size 4.88 mm, Survivalinthe first three months 19-73% calculated for Iranian broodstocks. Considering the quality of eggs and larvaeat different stages and selection between the different family and the within family remained 10 treatments and are keptas future broodstocks. Therelationship between fecundity-egg size, fecundity-weight, fecundity-length, egg sizeweightwas performed using regression. The results showed that Fecundity wasinfluenced more byweight and productivelength. The research is beginning to IDthe broodstockin our country