نشریه علوم آبزی پروری ایران
سال یکم شماره 1 (بهار و تابستان 1392)

The effect of different levels of canola meal on growth indices¡ body composition and survival rate of white leg shrimp (average weight 1.63 ± 0.09 gr) was studied. The experiment was according to completely random design with five dietary treatments (0¡ 5¡ 15¡ 25 and 35 percent of canola meal) in triplicate groups. Four hundred and fifty shrimp were randomly distributed between 15 tanks of 300 L capacity (30 shrimp per tank). Shrimps were fed three times a day according to their body weight at a temperature of 31 ± 0.09 °C for 8 weeks. After 8 weeks of feeding¡ growth and nutritional indices such as weight gain (WG)¡ specific growth rate (SGR)¡ protein efficiency ratio (PER)¡ feed efficiency (FE)¡ average daily weight gain (ADG)¡ percent of body weight increase (BWI)¡ percent of protein production (PPV) survival rate¡ price index were measured. Results showed that replacing canola meal by fishmeal in the diet of white leg shrimp have not any negative impact on shrimp growth performances up to 25 percent. There is no significant differences were observed in body composition and survival rate between treatments. Results of this study showed that fish meal can be replaced by canola meal up to 25 % and reliable price index in the diet of juveniles shrimp.

Because of the direct contact of the fish with water that contain of fish excrete metabolite and chemical pollution;it is one of the most susceptible organs of fish. In this study variety of gill lesions of rainbow trout were studied in cold water fish farm. This study has been carried out on 30 samples from 2 farms of rainbow trout culture (2 of extensive culture farm) in Kohgiluyeh Boyer Ahmad province.After gross examination¡ for microscopic study¡ a 1×1×1 piece of gill was separated and immediately fixed in 10%neutral buffered formalin.Then processed routinely and embedded in paraffin and cut with microtom in thickness 5 μm¡ and stained with Hematoxylin – Eosin.Histopathological study revealed 27% edema and hyperemia. However other microscopic lesion including of hypertrophy (20%)¡ telangiectasia(10%)¡ inflammation of the basal membrane of secondary lamella(10%)¡ hyperplasia and fusion of secondary lamella(13%) and clubbing(10%) in some cases in the gill were also seen. In 17% of 30 specimens¡there were no lesions in gills.

This study was carried out to evaluate the effect of Probiotic (Bacillus spp) on feeding parameters and survival in Rainbow Trout (Oncorhynchus mykiss) larvae (176 mg) during 30 days. Rainbow Trout larvae were fed on Artemia parthenogenetica nauplii enriched at suspension of five probiotic bacillus at doses of 1×108¡ 2×108 and 3×108 (CFU/liter). The feeding level was 30 percent of total biomass per day. The daily ration was divided into four feeding portions. Feeding parameters were influenced by Probiotic bacilli-enriched artemia (P

Sparidentex hasta is benefitcailt and economical fish in Persian Gulf that has attracted more attention during this years and is a good candidate for marine aquaculture in coastal zone of Iran. It is understood that the optimal ratio of diet ingredients guarantee appropriate growth rates¡ condition and health of the fish. After adaptation in 2 weeks by a lipid-free diet¡ fish were fed for 8 weeks by experimental diets in 300 L tanks (n=36). The routine procedures of preparation of tissues were followed and the paraffin blocks were cut at 5 microns ¡ stained with H&E and studied under light microscope. In some unsuitable ratio¡ histopathological changes for example congestion¡ margination of nucleous and vaculation in hepatocyte were seen. Results showed for culture of Sparidentex hasta¡ with protein(47.7%) and energy (18.95%) was optimized for other liver histological parameters.

The feeding habits of Kutum¡ Rutilus frisii kutum (Kamensky 1901)¡ in the southern Caspian Sea (waters Mazandaran) were investigated by examining the stomach contents of fish collected monthly from the commercial and experiment catch from early October 2006 to September 2007. Their diet consisted different prey. Age determination¡ based on scale readings¡ showed that the population was composed of eight age- groups comprise to 1¡2¡3¡4¡5¡6¡7 and 8 years. The highest Index of Fullness (IOF) was occurred in October for female (av.±SD) 313.86±65.9and 350.75 ±103.7 for male. The minimum IOF obtained in March¡ 119.42±59.21 and 144.07± 85.04 percent for female and male¡ respectively which coincided to spawning period. The significant different was between IOF and sex (at the female and male) in various months (ANOVA¡ P

For evaluate the effect of Levamisole on intestinal bacterial flora in rainbow trout¡ 1500 (50 g) and 1125 (150 g) fry and adult fish¡ respectively cultured for 60 day. All fish were fed with different concentrations of levamisole (0 as control¡ 100¡ 250¡ 500 and 1000 mg/kg) in diet and every 15 days intestinal samples were taken for bacterial analysis. Results showed levamisole strongly colonized gram positive bacteria in the fry intestine but there was not seen any effect in adult rainbow trout intestinal flora. At the end of the trial adult fish had more diversity of bacterial flora in their intestine.

The snow trout (Schizothorax zarudnyi) is a valuable and commercial species belong to cyprinidae and native to Sistan basin. The present study evaluated the induce spawning in snow trout using synthetic hormones (ovaprim) in order to achieve biotechnic of artificial propagation. Wild broodstocks (females and males: 1375 ± 108.84¡ 632 ± 17.6 g respectively) selected from Chanimeh reservoirs (Sistan¡ Iran). The females treated with quadruplet injections (0.2¡ 0.5¡ 0.5 and 0.3 ml Ovaprim/kg B.W). The distance between first¡ second and third injections were 24 h and between third and fourth was 12h. The males were injected at the time of the second females’ injections (with 0.3 ml Ovaprim/kg B.W.) The results showed spawning rate and mean working fecundity were 83.3% and 39531±7802¡ respectively. The latency period (time between first injection and ovulation) was 60.15±12.05 h¡ incubation period was 120 to 140 h (depend on water temperature (14 to 18.5º C)). Relative fecundity¡ volume of dry egg (ml)¡ number of dry egg per each milliliter¡ conversion percentage of dry egg to eyed egg¡ conversion percentage of eyed egg to larvae and number of larvae from each female was 28410.61 ± 4796.26¡ 172.5 ± 25.09¡ 275¡ 88.97 ± 0.9¡ 81.93 ± 1.15 and 34120 ± 4526.84¡ respectively. Obtained Larvae after reaching a length of 8 to 10 mm¡ who had absorbed their yolk sac for about two-thirds were transferred to fertilized earthen ponds.