The effect of different levels of betaine and tryptophan on growth and resistance to salinities in the Caspian ROACH was investigated. Fish (1.90±0.04 g body weight) were divided into 9 groups (4 treatments groups containing betaine (0.5 and 1), tryptophan (0.25 and 0.5), betaine and tryptophan mixtures (0.25- 0.5, 0.25, -1, 0.5- 0.5 and 0.5- 1), and control group). After recording the growth factors, the fish were exposed to salinities (12, 16 and 20 ppt) and clinical symptoms and mortality rate were recorded. No mortality occurred in 12 ppt salinity. At 16 ppt, the lowest mortality (16.66%) was recorded in the treatment containing 1% betaine and 0.5% tryptophan, while the highest mortalty (59.98%) occurred in the control group. At 20 ppt salinity, 100% mortality occurred within 6 hours in the control, while in the other treatments 100%-mortality occurred after 24 hours. Behavioral symptoms, such as jerky movements, ataxia, increased respiratory rate, were more prominent in higher salinities. Tryptophan did not reduce food consumption meaningfully.Increaesd food consumption as the result of betaine did not show significant effect on the fish growth rate.

In this research a number of five formulae for production of cold marinade from ROACH (Rutilus rutilus) were investigated. The samples were stored in a domestic refrigerator at 6±2°C for a period of sixty days. Then during these sixty days, and according to a time schedule, the samples were tested for changes in their organoleptic properties, pH, peroxide value, total volatile base and total count of bacteria. The results indicate that after two days the pH in all samples dropped to less than 4.1. On the other hand changes in peroxide value were between 1.1 and 6.6 milliequivalents/1000 g, whereas total volatile base for the samples was 4.5 mg/100g, not showing any change. The total count of bacteria for most of the samples was negative. According to the taste panel, two of the formulae scored a high degree of acceptance and the rest as medium for their organoleptic properties.

In this research five formula for production of fried marinade from ROACH (Rutilus rutilus caspius) were investigated. The samples were refrigerated at 6±2°C for sixty days. The refrigerated samples were tested at a scheduled interval for the changes in their organoleptic properties, pH, peroxide value, total volatile base and total count of bacteria. The results showed that after two days of the storage the pH of all the samples reached to less than 4.12 while the peroxide value ranged between 2.15 and 7.1 milli equivalents/Kg but the amount of total volatile base for the samples was 7.8 mg/100g and did not show any changes. The total count of bacteria for most of the samples was negative. According to the results of the taste panel two of the formula ranked as the best and two as medium for their organoleptic properties.

A research experiment was conducted to provide a protocol for seminatural propagation and rearing of ROACH up to release size. The attempt was made to combat the declining trend in the population size and catch of the fish in the Caspian Sea. The optimum temperature for spawning brood-stocks lasts from middle March to late April when the ambient temperature range is 12-17°C. During the four months research period, brood stocks were caught in the estuary of the Gorganrood in Golestan Province, north east Iran. The stocks were released into 2 hectare earthen ponds enriched with manure and fertilizers. Artificial spawning grounds made of pine branches were placed in the ponds. Ponds were stocked with 700 female breeders with an average weight of 150 grams and around 350 male breeders weighing 100 grams on average. Spawning and fertilization of eggs occurred in the ponds of which an estimated 80-90% eyed that were observed from the fifth day onwards. The starting of hatching was observed in the 6th day and yolk sac absorption was observed in day 4 to 6. The larvae were fed on natural zooplankton and artificial food. Assessment of 146 fries for ingested food indicated that the fries fed on Rotifer (Rotatoria sp. and Daphnia sp.) in the ponds. The length-weight relationship was not significantly different among the ponds and also specific growth rates (SGR) did not show any difference in the fries. The relative gut length in the fries were smaller than 1 (RLG<I) and fries with an average weight of 0.5 to 1 gram were released into their natural habitat.

This study was conducted to study of osteological structure of the Caspian ROACH (Rutilus rutilus caspicus). Five specimens of Caspian ROACH was purchased from local fishermen from the Turkmen Harbor. The cleared and stained specimens and their separated parts were scanned and photographed using an Epson v700 scanner equipped to glycerin bath. The bone structures were examined and described using a stereomicroscope Leica (MS5). Characteristics of the Caspian ROACH’s skeleton including cephalic, post-cranial, caudal regions were described in detail to provide the osteological feature of the Caspian ROACH.

Copper (Cu) and mercury (Hg) enter aquatic ecosystems from different sources threatening health of aquatic organisms such as fish. As such, in this investigation, determinaing, Cu and Hg toxic concentration in Caspian ROACH (Rutilus rutilus caspicus), was undertaken. Acute toxicity of Cu and Hg were determined in fish specimen under semi-static condition. Caspian ROACH fry (~1 g) were exposed to Cu or Hg at 6 concentrations (0.2, 0.27, 0.39, 0.47, 0.59 and 0.66 mg L-1 total Cu and 0.22, 0.26, 0.3, 0.37, 0.44 and 0.52 mg L-1 Hg). Control fish were exposed to water with no Cu or Hg. Mortality was recorded at 24-h-intervals for 96 h. Total Cu-LC50 values found to be 0.43 mg L-1 for 24 and 48 h and 0.42 mg L-1 for 72 and 96 h. The lowest observed effect concentration (LOEC) values for total Cu were 0.39 mg L-1 for 24 and 48 h, and 0.20 mg L-1 for 72 and 96 h. On the other hand, free-Cu-LC50 values found to be 0.22 mg L-1 for 24 and 48 h and 0.21 mg L-1 for 72 and 96 h. LOEC values for free Cu were 0.20 mg L-1 for 24 and 48 h, and 0.10 mg L-1 for 72 and 96 h.24-72 h LC50 values for Hg were 0.37 mg L-1, while 96 h LC50 found to be 0.33 mg L-1. Likewise, LOEC values for Hg were 0.26 mg L-1 for 24-72 h, and 0.22 mg L-1 for 96 h. The results showed LOEC values for Cu and Hg in Caspian ROACH were lower than these metal concentrations in Caspian Sea water, suggesting little risk of acute toxicity in the sea. Chronic toxicity test is suggested to illustrate the effect of current levels of contamination in Caspian ROACH.

This study was conducted to determine some biological characteristics of migration population of ROACH, Rutilus rutilus caspicus, including age, growth and reproduction in Gomishan wetland from early November 1999 to early December 2000. The sampling were carried out monthly but in the peak of spawning period (late February to mid April) it was done weekly. The sex ratio was found M:F = 1.17:1.00 without any significant difference (even at 10% level); but the results of the sex ratio for each seperate age group showed significant difference (p < 0.0.5). A significant correlation was determined between total length, body weight, scale radius and age (p<0.001). Based on back calculation, the maximum growth ratewere found in ages 1+ and 2+. Gonadosmatic index (OSI) was age-dependent; with two peaks of late February and early March for males and late March and early April for females. The eggs diameter was measured with a range from 0.9 mm to 1.45 mm and the absolute fecundity was related to age.

The histology of digestive tract of Caspian ROACH (Rutilus rutilus caspicus) were studied for 53 days from hatching to fingerling size at the natural habitat of the larval stage. Ages 1, 4, 10, 18, 28, 39 and 53 days after hatching (DAH) were selected for the histological studies. after sampling and fixation with 10 percent formalin the histological process were conduct. The newly hatched larvae showed a simple and undifferentiated digestive tube. The oral cavity was still closed. Tubular shape liver and primary swim bladder was other features of this stage. The larvae at 4 DAH had the mouth opened and a few goblet cells between stratified cells of pharynx and a small esophagus with stratified squamous epithelium were observed. The most important incident at 10 DAH was starting the exogenous feeding. The buds and goblet cells in boccopharingeal cavity were changed position deeper in epithelium. Fully absorption of yolk sac and final differentiation of esophagus happened until 28 DPH. The complete differentiate of pharyngeal teeth, deletion of microscopic observed yolk sac and twisting the intestine were other features until the end of the study. Intestine was the first and the pharyngeal teeth were the last region differentiated. Keeping endogenous feed long time after starting exogenous feed shows a good point in this fish to increase survival in lack of food conditions. The ontogeny features were discussed in this study showed that this organ differentiate same in this fish as other Ostariophisy fish although there are some Interspecies differences like what we saw in pharyngeal teeth.