فصلنامه شیلات
سال هفتاد و دوم شماره 2 (تابستان 1398)

The present study was carried out with a purpose to compare the species composition and diversity of the Gargoor's trapped aquatics in different depths and soak times in the winter season. This study was done in the port of Bushehr from February to March 2017. The using Gargoors had mesh size of 3.5-4 cm, cross section 150 cm, height 87-92 cm, outer span size 70-79 cm and internal span size 35-36 cm. Comparisons of species composition and diversity were based on weight furthermore number and the Shannon index, respectively. The species composition of the Gargoor's trapped aquatics included 12 species of bony fishes belonging to 7 families, one species of crustaceans, and one species of mollusks (Pharaoh Cuttlefish); While there was a significant difference in different depths as well as soak times (p <0.05). Gargoor's Shannon index for depths of 25-40 meters and 10-25 meters was 1.421 (±0.362 S.D.) and 1.229 (±0.345 S.D.), respectively. This index for soak times of 8-14 days and 2-8 days was 1.441 (±0.302 S.D.) and 1.228 (±0.393 S.D.), respectively. The Shannon index represented the more biodiversity of Gargoors between depths of 25-40 meters compared to 10-25 meters, as well as the soak times of 8-14 days compared to 2-8 days (p ˃0.05). In winter, with the arrival of Pharaoh Cuttlefish in the Gargoor's fishing grounds in Bushehr port is evident, this has high effect on the species composition of Gargoors and it was responsible for the most dissimilarity in the species composition of different depths and soak times as well. Also, if the interaction between depth and soak time taking into account, the highest values of the Shannon index observed in the depths between 10-25 meters, with 8-14 days of soak time.

This study was carried out to evaluate the combined effect of culture system (biofloc and no-biofloc) and dietary additives (control, Yucca schidigera, Conocarpus erectus and Paulownia fortunei) the feed and growth performance, enzyme activities and culture water quality of Litopenaeus vannamei. White leg shrimp with an average weight of 1.47 ± 0.07 g and 7.00± 0.37 cm were stocked into 24 tanks with 50 L capacity for 30 days. The experiment was based on a completely randomized design with 8 treatments by triplicate including; Biofloc +1% herbal extracts Yucca (BY), Conocarpus (BCO), Palonia (BP), Control (BC) and Without Biofloc+ 1% herbal extracts Yucca (Y), Conocarpus (CO), Palonia (P), Control (C). There were no significant differences in shrimp production parameters between treatments. The highest weight (4.66 ± 0.14 g) and the lowest feed conversion ratio (0.92 ± 0.04) were obtained for shrimp reared in BCO. The highest levels of amylase, lipase and protease are obtained in the Y and BY treatments. Yucca extract in the diet leads to a reduction in ammonia. The results showed that Conocarpus erectus extract could be used to enhance growth and Yucca schidigera extract to improve water quality in Bio-floc system.

Toll-like receptors (TLRs) generally are involved in host immune responses against microbial invasions. Mono meric felagellin, the structure component of bacterial felagella is the agonist of TLR5m. After binding to felagellin, TLR5m initiates specific signal transduction pathways and triggers immune responses. Single nucleotide polymorphisms (SNPs) in this gene regulate inflammatory pathways and are associated with susceptibility/resistance to infection. In this study using polymerase chain reaction, sequencing and aligning the sequences, we investigated TLR5m gene of Rainbow Trout (Oncorhynchus mykiss) and identified 6 polymorphisms consist in 3 SNPs: (2412, T/A), (2415,T/A) and (2385, G/A) and 3 insert/deletion: (inser/dele. C, C/T, 2091), (inser/dele. T, 2566) and (inser/dele. C, 2102). A bacterial challenge was performed to explore their association with humoral immune responses such as lysozym content and complement activity levels in serum. The results show that polymorphisms (inser/dele. C, C/T, 2091) and (inserldele. T, 2566) were significantly correlated with higher complement activity levels (p<0.05).These results suggested that these 2 polymorphisms could be potential markers applied in future selection of Rainbow Trout with enhanced resistance to Aeromonas hydrophila.

The replacement of wheat flour with bream (Abramis brama) fish powder in pasta making at 5, 7.5, 10, 15 and 20 g/100 g levels was carried out to evaluate the effects on cooking quality and chemical properties of the supplemented pasta samples. The results demonstrated that pasta with fish protein had increased protein (25.91±0.70), lipid (6.94±0.50), (P < 0.05), decreased cooking time (13.30min) and increased cooking loss (8.2%) compared with wheat flour control pasta. However, except 20%, all pasta protein samples were in the acceptable range (8 g/100 g) for cooking loss. Thus, pasta fortified with fish powder has the potential to be a technological alternative for the food industry to provide protein enriched pasta.

The purpose of this study was to investigate the effects of dietary flaxseed meal on growth performance and hematological indices of Siberian sturgeon Acipenser baerii, 32 farmed fish with an average individual weight of 955.06 ± 53.38 g were randomly distributed in 8 fish tanks (500 L). The experimental diets were different levels of flaxseed meal in diet including 0 (control), 5 (F5), 10 (F10) and 15 (F15) percent in two replicates. At the end of the experiment period (six months), the results showed no significant difference in growth parameters. In hematological parameters, the number of red blood cells counts and hematocrit had a significant increase in F15 compared to the control but hemoglobin, mean corpuscular volume, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration had no any significant differences. Result of white blood cells showed a significant decrease in the number of white blood cells counts in control and also there was a significant increase in neutrophil and lymphocyte in F15 and control respectively, but there were not any significant differences in monocyte and eosinophil rates. The results revealed that adding the flaxseed meal in Siberian diet had not any effect on growth, while the hematological indices changed.

In this study, quality characteristics of incorporated burgers containing 25, 50, 75 and 100 silver carp (Hypophthalmichthys molitrix) surimi was evaluated. Proximate composition (moisture, fat, protein and ash content), texture profile analysis (TPA), water holding capacity (WHC) and sensory attributes (taste, smell, texture, color and general acceptability), of burgers were determined. According to the data, burgers containing surimi showed lower amount of protein, fat and ash compare to the meat burger with no surimi (control) (P<0.05), but the moisture content of former burgers was significantly higher that the control (P<0.05). Based on TPA test's data, incorporation of surimi into burger caused significant reduction in hardness, chewiness and gumminess compared to control and the burgars containing 50, 75 and 100 surimi were significantly (P<0.05) different compare to control. Sensory evaluation indicated that burgers with 75 and 100 meat obtained the highest texture scores (P<0.05), whereas, did not show any significant difference in terms of color, taste and flavor compared to the control (P>0.05(.

To study the osteological charactrestics of Nazak fish (Chondrostoma regium), the 12 specimens were caught from the Karun, Karkhe and Jarrahi rivers in the Tigris basin by electroschoking device and seine net. After anesthesizing with 1% clove oil solution, then they were fixed in 10% buffered formalin, clarified and stained by alizarin red and alsian blue for osteological examination. Afterthat, the osteological features of this species were described. The skeletal structure of the maxilla and premaxilla, quadrate, symplectic, parasphenoid, basioccipital and urohyal indicated some differences compared to other species in Cyprinidae. In the premaxilla, only an appendage was seen. The Posterior process in the maxilla bone was downward. Anterior part of the parasphenoid bone was narrow and long. Posterior pharyngeal process of basioccipital bone was long, elongate and roughly rectangular in the shape and Ventral masticatory plate of basioccipital bone was big and wide. Anterior part of urohyal bone was narrow, elongate and forked. Quadrate was long and developed and symplectic was roughly long and forked. These traits could be usefull as diagnostics for this species.

Owing to the antibacterial activities of sea cucumber and the abundance of Holoturia locuspila in the Persian Gulf, the antibacterial activity of ß amberine extreacted from the gonad of this sea cucumber species was studied. In this investigation, acetone extract was prepared from the dried powder of sea cucumber. Isolation of ß amberine was carried out by column chromatography on silica gel and identification was carried out by TLC and GC/MS. In vitro antibacterial screening was determined by broth dilution against bacteria; Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, Salmonella typhi, Proteus vulgaris, Staphylococcus aureus, Bacillus cereus, Bacillus subtilis and Nocardia brasiliensis. The ß amberine formula C30H48O was detected by GC/MS from no. 11 fraction with 98% purity. This component showed considerable activity against Bacillus cereus, Bacillus subtilis (MBC = 1000 µg/mL) and Salmonella typhi, Staphylococcus aureus (MBC = 2000 µg/mL). According to our results, ß amberine extracted from sea cucumber can be considered as a source of novel antibacterial drug.