JOURNAL OF FISHERIES SCIENCE AND TECHNOLOGY (JFST)
Year:2014 | Volume:3 | Issue:2|Papers Count:8

Toxicity and LC50 96-h of Malathion on the Caspian common carp fingerlings, Cyprinuscarpio, and its effects on some blood indices, including hematocrit, glucose, cholesterol and total protein content, were investigated. The median lethal concentration, the lowest effective concentration and the maximum allowable concentration were found to be 1.3, 0.646 and 0.13 mg.L-1, respectively. Based on the LC50 finding, Malathion can be regarded as “moderately toxic” for this fish. Significant differences between the hematocrit, glucose, and cholesterol among treatments were evident, but no significant difference in the total protein of blood plasma was observed. The hematocrit level in the control group was lower than the other groups. The lowest levels of cholesterol and glucose were observed in 0.5 mg/L, and the maximum levels were found in 2.5 and 2 mg/L, respectively. Therefore, malathion which is supposed to be ineffective for non-target species at allowable concentrations, can lead to their blood indicies responses and biodamages.

The effect of pistachio green hull (PGH) at 0, 1.5, 4.5, 13.5 and 27% of the diet on the growth, blood biochemical and hematological parameters of rainbow trout (Oncorhynchus mykiss) of 27.03±0.58 g was investigated in a completely randomized design and in three replications with 14 fish individuals in each. At the end of 8 weeks feeding trial, blood samples were randomly taken from 4 individuals in each replication. Results showed significant differences (p<0.05) in SGR and FCR between 27% treatment and other treatments. No significant differences in Alb, Glo, Tg, GOT (p>0.05) were observed among treatments. Tp (2.76±0.15 g/dl), LDH (2139±44.26 IU/l), ALP (331.9±21.4 IU/l), GPT (407±17.82 IU/l), Hb (8.73±0.7 g/dl) and Hct (33.33±2.28%) had significant differences in group receiving 27% PGH compared with other group (p<0.05). Results showed that high levels of PGH in the diet of rainbow trout had adverse effects on health and growth factors.

Cone snails of the genus Conus are one of the most toxic species of carnivorous marine invertebrates in tropical and subtropical areas. They are highly regarded, due to their medicinal compounds, which derived from their toxins. In order to examine the venom apparatus structure, 12 specimens of C. textile were collected from the coastal zone of Gheshm Island and then they fixed in Bouin's for 48 hours and transferred to laboratory in ethanol. After breaking of shellfish, the venom apparatus were isolated and their different parts (after molding and cutting) were stained by HE and HEG and photographed by Nikon microscope. The stereomicroscope observation showed that the venom apparatus was included: (1) toxin production part (venom duct), (2) toxin transmission part (venom bulb), and (3) injection part (radula and proposcis). Photographs of sections showed that the venom bulb was completely muscular, consisting of longitudinal and transverse muscle fibers, and in their middle part a channel with epithelial cells was observed. Venom duct walls composed of 3 parts including the outer layer of muscle an inner layer of columnar epithelial cells with basal nucleus and the inner lumens which filled by the granules.HEG stained slides showed a much sharper cytoplasmic and nuclear implementation, particularly granules containing toxins were easily countable and measurable. Although the conventional HE staining method clearly showed different parts of the gland, but HEG method in addition to distinguishing different sections of tissue, seemed to be a suitable technique for studying the role of different parts of the organ in producing conotoxin in the form of secretory granules.

The early morphological development and allometric growth pattern of Caspian kutum (Rutilus frisii kutum) during early development (from 0-35 days post hatch=dph) was studied. Morphological data were obtained using ImageJ software from 2D pictures and allometric growth patterns were computed based on Log10 y= Log10 a+bLog x function. Based on inflexion point of morphological traits and body shape changes, the early developmental of kutum were divided into Eleutheroembryo, Propterygio-larval, Pterygio-larval” and younger juvenile phases, each of which included vital developmental events. Rapid and intense changes occurred during Eleuthero-embryo and Propterygio-larvae stages such as development of gills, depletion of yolk-sac and exogenous feeding, development of feeding apparatus, sense organs and organs related to swimming performance. The results also revealed that developmental changes occurred in agreement with the inflexion points of morphological characters and their developmental priority imply on functional importance of feeding, respiration and swimming related structures.

Three types of fish fingers prepared from common carp (Cyprinus carpio) meat (chopped fillet, minced, and surimi) were organoleptically compared. After the molding, glazing and coating, fish fingers were friedinoilat180oC for 8 minutes. Organoleptic indicators in terms of texture, taste, smell, color and general acceptability were assessed by panelists. The fish finger from surimi in terms of organoleptic indicator was significantly different (p<0.05) from other samples. The results of general acceptability showed that the fish fingers from surimi had higher quality than other samples. Therefore, surimi is recommended in preparation of fish finger from common carp.

Edible films and coatings are a thin layer of material that used on the surface and between different layers of nutrients. Biopolymers such as polysaccharides, proteins, lipids and their mixtures are used for the preparation of the edible films and coatings. Due to consumers demand for access to high quality materials and their concern because of the problems caused by the use of artificial preservatives, as well as environmental concerns arising from the accumulation of synthetic polymers, the idea of using biodegradable biopolymers as a replacement for the plastic packaging was strong. Efficiency and functional properties of edible films and coatings is dependent on intrinsic properties of ingredients of films, namely, biopolymers, plasticizer and other additives. The useful properties of edible films and coatings are capability of eating and biodegradation of them. Some properties of edible film sand coatings, such as preventing moisture transport and volatiles out of food, selective throughput oxygen and carbon dioxide, delaying surface dehydration, tissue changes, barrier against fat sand oils transports, increase nutritional value, preventing dripping, microbial growth and rancidity, Maintaining the quality of Aquatic and their products against physical damage caused by their transportation, increase the shelf life of them. For industrial use, more scientific studies are needed to determine the mechanisms of the film formation from biopolymers for optimizing their properties. Biodegradable compounds used in this study for aquatic coating and their effects on maintaining the quality of fish and their action mechanism has been investigated.

The aim of the present study was to evaluate the effects of enriched Artemia with fish and soybean oils supplemented with vitamin E on growth performance, stress resistance, antioxidant enzymes activity and lipid peroxidation of Persian sturgeon (Acipenser persicus) larvae. Five experimental diets including non-enriched Artemia (control diet), Artemia enriched with soybean oil supplemented with 15 or 30% vitamin E (S15 and S30 diets) and fish oil supplemented with 15 or 30% vitamin E (F15 and F30 diets) were used. The larvae were fed to apparent satiation for 17 days. The results indicated that fish fed enriched Artemia had no significant differences compared with control group in terms of growth and survival, but increase in vitamin E levels from 15 to 30 % improved growth performance and resistance to salinity stress. Vitamin E content in fish fed S15 and S30 diets was significantly higher compared with the other treatments. Antioxidant enzymes activity in fish fed non-enriched Artemia, F15 and F30 diets were higher. The highest TBA value was observed in fish fed non-enriched Artemia. The results demonstrated that the addition of vitamin E to the fish and soybean oils for Artemia enrichment could reduce oxidation of oils and beneficial for the health and quality of larvae. In conclusion, enrichment of Artemia with soybean oil supplemented with 30 % vitamin E (S30 diet) is recommended for feeding Persian sturgeon larvae.

In this study, 100 fish (Astronotus ocellatus) with density of 8 to 12 fish per aquarium distributed to four treatments (Control, 0.25%, 0.5% and %1 Macrogard) the experiment lasted for six weeks. In this experiment it was observed that the number of white blood cells, especially neutrophils and serum the lysozyme level in fish fed with different levels Macrogard were significantly increased compared to the control group (p<0.05). Most changes in the white blood cell count was observed in fourth week of feeding for all Macrogard levels. This material affects the immune system of Astronotus ocellatus, and we can say that the all levels Macrogard were safe. They are most effective when the fish are fed for 4 weeks with diets containing Macrogard.