JOURNAL OF AQUACULTURE SCIENCES
Year:2016 | Volume:4 | Issue:5 |Papers Count:6

This study was conducted to determine the morphometric and meristic parameters of female Asp ´ male Kutum (Leuciscus aspius ♀ ´ Rutilus frisii ♂) hybrid and its comparison with the parents. Fish were produced from artificial reproduction of female Asp and male Kutum in April 2012. For this purpose, fifty-four fish were randomly caught and 16 morphometric characters and 6 meristic characters were evaluated for the samples and the desired parameters were compared between hybrid and parents according to available literatures. The results showed that mean total length, standard length and fork length in this fish were 22.80 ± 0.51, 18.55 ± 0.49 and 20.36 ± 0.46 cm, respectively. Also, mean of head length, head width, eye diameter, inter orbital distance, maximum body height, dorsal fin length, pectoral fin length, ventral fin length, anal fin length, caudal peduncle length, caudal peduncle height, dorsal-pectoral fin distance, dorsal-anal fin distance were measured as 4.46 ± 0.08, 2.11±0.05, 0.96 ± 0.02, 1.06 ± 0.0 3, 3.95 ± 0.12, 3.25 ± 0.08, 3.27 ± 0.09, 2.62 ± 0.08, 2.38 ± 0.06, 4.28 ± 0.08, 1.59 ± 0.06, 5.71 ± 0.14, 5.41 ± 0.16 cm, respectively. In this fish, mean number of scales on lateral line, scales above the lateral line, scales below the lateral line, branched rays of dorsal and anal fin, soft rays of dorsal fin and soft rays of anal fin were obtained as 60-68, 10, 5, 2, 9 and 10-11, respectively. Also, the most number of pharyngeal teeth was belonged to the formula 5.1-1.5 and 5.2-1.5, each with frequency 23.53 %. In general, results of the present study showed that this hybrid is not as same as with the parents in terms of morphometric parameters and especially meristic, and these are intermediate and even different characteristics.

The aim of the present study was to determine the effects of different levels of probiotic feed supplement (Primalac) on reproductive performance, survival of larvae as well as growth performance and feed utilization, body composition and survival rate of Golden Severum, (Heros severus) fry. The study was performed in a completely randomize design with 1 control group and 3 experimental groups include different level (1, 2.5 and 5 g per kg) of Primalac as probiotic. The study was performed in two separate phases: in first phased on spawners and their larvae and in second phase on performance and feed utilization, body composition of fry. Treatments repeated in triplicates with stocking density of 40 fish per experimental unit. In first phase, spawners were fed on primalac before the first spawning till 5 spawning cycle and reproductive performance parameters were measured. In second phase, fry were fed on experimental diets for 60 days and sampled for determination of above mentioned parameters. The results showed that Primalac significantly increased reproductive performance parameters include fertilization rate, absolute fecundity, hatching rate as well as survival of larvae (P<0.05). Also, feeding fish with 2.5 or 5 g kg-1 primalac remarkably improved growth parameters (Final weight, weight gain, length increase, SGR) (P<0.05). Furthermore, feed conversion ratio as well as PER were improved in primalac fed fish (P< 0.05). Also, primalac increased total protein, albumin, globulin and total glucose if fry body (P<0.05). The results of the present study, revealed that primalac is a suitable probiotic to be used for spawners as well as in hatecheries to improve growth performance and FCR of Golden Severum. Biochemical parameters also showed that primalac improved physiological status of fry.

In this study, The effect of green algae (Scenedesmus quadricauda), manure (cattle+poultry, 1: 1 ratio in weight), vegetable (spinach+parsely+coriander, 1: 1: 1 ratio in weight), manure+soil, vegetable+soil, and algae+soil were examined on culture of freshwater cladocerans, Daphnia magna. The experiment was carried out as completely randomized design with three replications under laboratory conditions. Results showed that the maximum population density (1513.9±627.1 individuals/L) (mean±SE) in algae treatment and maximum specific growth rate (SGR) (0.25±0.03 /day) and minimum doubling time (Dt) (3±0.7days) were obtained when D. magna fed on algae+soil. On day 30 of culture, the treatment of manure and manure+soil had highest adult population while the highest neonate percentage was observed at treatments of vegetable+soil, algae and algae+soil, respectively. The density, SGR, adult and neonate in population of D. magna significantly correlated with pH, BOD and COD. The maximum body length (2321.9 ± 149.3 mm) and width (1446.9±66.8 mm) of D. magna measured when fed with manure. In conclusion, the treatments of algae and algae+soil had better performance based on growth and production as well as considerable decreasing in BOD and COD compared to other treatments.

Evaluation of different prebiotics showed contradictory results on intestinal microbiota which was mainly depends on the degree of polymerization. Therefore, the present study was performed to investigate the effects of different levels of two prebiotics, Inulin and oligofructose with different degree of polymerization on intestinal microbiota of Common Carp (Cyprinus carpio) larvae. The study was performed as randomized design with 5 treatments and 3 replications in which carp larvae were fed different levels, 0, 0.5 and 1% of Inulin and oligofructose with different 23 and 5 degree of polymerization, respectively (Purity 92%) for 8 weeks. At the end of the feeding trial culture based analysis of intestinal microbiota include lactic acid bacteria levels count agar media. Administration of different levels of Inulin and oligofructose had no significant effects on total bacteria of intestinal microbiota (P>0.05). The lactic acid bacteria levels were significantly increased compared following prebiotics administration in diet (P<0.05). LAB levels in intestinal microbiota of oligofructose fed fish were significantly higher than those in Inulin group. The highest LAB proportion in intestinal microbiota was observed in carp fed diet contains 1% oligofructose (P<0.05). The results of the present study revealed that prebiotics can be used for modulation of carp intestinal microbiota toward beneficial bacterial communities. Furthermore, administrations of the prebiotic with lower degree of polymerization are more efficient for modulation of intestinal microbiota and elevation of LAB levels.

The impact of rearing Beluga (Huso huso) juvenile under five different stocking biomass was investigated depending on the biochemical parameters as indicators of general health state of fish. One-year old Beluga juvenile (48.59±8.52 g) were reared for 35 days. The present study was conducted in a completely randomized design. Fish were cultured in triplicates of fiberglass tanks under stocking biomass of 1250, 2500, 3750, 5000 and 6250 g/m3 as T1, T2, T3, T4 and T5 increasing the stocking biomass caused respectively. Blood plasma biochemical analyses showed that significant increase for value of alanine aminotransferase (ALT) and maximum of ALT was obtained in T5 (stoking of 6250 g/m3). Different stocking levels of Beluga juveniles had variety effects in value of aspartate aminitransferase (AST) and this enzyme decreased in T2, T3 and T5 but increased in T4. (p>0.05). Value of alkaline phosphatase (ALP) showed non-significant difference among treatment Variety in stocking levels of fish had significant effects on values of complement (C4) and this parameter was significantly increased in treatment of T2, T3, T4 and T5 in comparison with T1 (stoking of 1250 g/m3) (p<0.05). The value of immunoglobulin M (IgM) decreased with increasing biomass levels in treatments. The lowest level of IgM (0.24 g/l) were observed in treatment of T4 In some of treatments changing the stocking biomass had significant effect on (stoking of 5000 g/m3). values of cholesterol, triglyceride and albumin (p<0.05). Maximum of cholesterol (90/50 mg/dl) and triglyceride (467/50 mg/dl) was obtained in T1. Blood plasma biochemical analyses showed that increasing the stocking biomass of Beluga juvenile caused increase in values of plasma protein in treatments of T2, T3 and T4 in comparison with T1 and T5. The minimum of this parameter (1/90 g/dl) was detected in T5 (stoking of 6250 g/m3). This study highlighted that the different biomass of Beluga juvenile in rearing tanks had different effects on blood biochemical parameters in this fish.

This study examined the effects during 56 days of feeding of three dietary probiotics on growth performance and feed utilization, intestinal colonization and related health criteria in Oncorhynchus mykiss (rainbow trout). This study included 3 groups: a control group of fish, and fish fed with a basal commercial diet supplemented with 2.5 ´ 108 CFU g-1 Enterococcus faecium strain IR5 (group 1) (was micro-encapsulated with sodium alginate) and 1 ´ 109 CFU g-1 Enterococcus faecium strain IR5 (group 2) (was micro-encapsulated with sodium alginate) singularly in triplicate.270 rainbow trout with an average weight of 35.6 ± 3.8 g (mean±SD) were obtained. Fish were acclimatized for 20 days. The probiotics groups showed improvement with respect to weight gain (WG), body weight index fish (BWI) (%), total length (TL), specific growth rate (SGR), feed conversion ratio (FCR), protein efficiency ratio (PER), lactic acid bacteria (LAB) (%) in intestinal, intestinal colonization (log CFU g-1) and survival (%). At 28 days, group 2 showed improvement with respect to growth performance and feed utilization, intestinal colonization and related health criteria were higher than other groups. At 56 days, the WG and PER in the group 1 were significantly higher than in 2 and control groups (P<0.05). The LAB (%) in intestinal was higher in group 2 than in 1 and it was higher in group 1 than in the control groups after 8 weeks feeding (P<0.05).