Reproductive performance of fairy shrimp Branchinecta orientalis (G. O. Sars 1901) (Crustacea: Anostraca), fed with effluent of rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds

Aquaculture production is predicted to increase sharply. In this regard, live feed plays a crucial role in the larval phase of many aquaculture organisms. Hence, a persistent concern in aquaculture is to find low‐cost and eco‐friendly feed sources to culture live feed organisms. Branchinecta orientalis (G. O. Sars 1901), a fresh/brackish water fairy shrimp, was reared using effluent from rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds, either fresh but supplemented with two species of microalgae, Scenedesmus sp. and Haematococcus sp., or non‐supplemented but after “ageing” of the culture medium. The feeding experiment was designed at a density of 100 individuals L^?1 in 2‐L vessels. The results indicated that differences between final length, survival and most reproductive parameters of the treatment with aged medium and the treatment using fresh medium supplemented with Scenedesmus sp. were non‐significant (p > .05). Better results were obtained for a number of reproductive parameters in the treatment supplemented with Haematococcus sp. Thus, for intensive resting egg production of B. orientalis, microalgae can be replaced by aged non‐supplemented effluent from trout ponds as a nutrient‐rich feed source. This consequently can reduce drainage of nutrients into the environment and thus decrease aquatic pollution.     

Protective Role of Oleuropein against Acute Deltamethrin-Induced Neurotoxicity in Rat Brain

Background:

Deltamethrin (DM) is a synthetic pyrethroid insecticide that can elicit neurotoxicity, leading to apoptosis. There is accumulating evidence that oleuropein (OE) has anti-apoptotic effect. The purpose of this study was to determine the anti-apoptotic effect of OE pretreatment in the neuronal cells of cerebral cortex.

Methods:

Rats were randomly divided into four groups each containing five rats: DM-treated group (12.5 mg/kg, a single dose), OE-treated group (20 mg/kg per day), DM + OE-treated group, and vehicle group. Sections of the brain were obtained 24 hours after DM injection and studied for histopathological and immunohistochemistry assessment.

Results:

The histopathological assessments showed lesser characteristics of neural degeneration in DM + OE group compared with DM group. Greater Bcl-2 and attenuated Bax expression could be detected in the DM + OE treated-mice compared with DM group.

Conclusion:

The results suggested that DM-induced neurotoxicity can be subsided by OE.Key Words: Deltamethrin, Oleuropein, Apoptosis     

The role of dietary L‐ascorbyl‐2‐polyphosphate on the growth and physiological functions of beluga,Huso huso (Linnaeus, 1758)

Effects of dietary ascorbic acid (AA) supplementation were carried out on growth performance and physiological indices in juvenile beluga Huso huso fed different levels of dietary L‐ascorbyl‐2‐polyphosphate as AA source consisting of 0 (control), 100, 200, 400, 800 and 1600 mg AA kg^?1 diet for 16 weeks. No significant differences were found in growth performances between treated groups except for condition factor. Using AA caused significant differences in haemoglobin, number of red blood cells, white blood cells, aspartate aminotranspherase and lactate dehydrogenase, while no significant difference was found in haematocrit, mean corpuscular haemoglobin concentration, differential white blood cells count and alkaline phosphatase activity at the end of the experiment. Lysozyme activity after 8 weeks was significantly affected by dietary treatments with the lowest value in fish fed control diet, but not at completion of 16‐week feeding trial. Liver AA concentration showed a significant increase in correlation with dietary AA increase. Air exposure stress test showed significant differences among the treatments in case of cortisol and glucose concentrations. Also between pre‐ and post stress, significant changes were observed in some of treatments. The lowest and highest levels of cortisol were 9.2 ± 3 (in 200 mg kg^?1) and 16.8 ± 5.1 ng mL^?1 (in control), 6 h post stress (P < 0.05) respectively. Also, the lowest and highest levels of glucose were measured in fish fed 200 and 800 mg AA kg^?1 respectively. The obtained results showed that most growth parameters were not affected by dietary AA, but some physiological and immunological parameters of this species were influenced by this vitamin. We suggest that under rearing conditions, AA should be added to the diet especially during early life stages for improving health status and resistance to stressors.     

Evaluation of genetic diversity among some Iranian wild asparagus populations using morphological characteristics and RAPD markers

An evaluation of genetic diversity in 39 wild asparagus populations was carried out using morphological and RAPD markers. A combination of morphological traits and random RAPD primers was used to examine the level of genetic variation and polymorphisms among the populations. A factor analysis using Ward's method on mean values of morphological characteristics indicated seven main factors resulting in four groups. Analysis of polymorphic bands using Jaccard's similarity coefficient indicated that genetic similarity ranged between 0.71 and 0.29. At a similarity level of 0.64, the populations were divided in three sub-clusters, containing 34, four and one populations, respectively. Significant regression associations were found between 21 morphological characteristics and 18 RAPD markers, revealing some informative markers associated with some traits. The highest R² was related to 18 RAPD markers associated with gender (53.5%) that among them BA-04₂₀₀₀ had a maximum R². The results showed that Iranian wild asparagus with its high levels of genetic variation could be considered as a valuable gene pool for future asparagus breeding programs. Furthermore, it could be inferred that morphological characteristics and RAPD markers are suitable tools to discriminate asparagus populations for the evaluation of genetic diversity.     

Mass culture of fairy shrimp Branchinecta orientalis (G. O. Sars 1901) (Crustacea: Anostraca) using effluent of rainbow trout Oncorhynchus mykiss (Walbaum 1792) ponds

The variable quality and high price of Artemia (Leach 1819) cyst products, used worldwide as live food, motivate aquaculturists to find an appropriate alternative, especially for fresh/brackish water organisms. In this study, Branchinecta orientalis (G. O. Sars 1901), a common fairy shrimp in north‐western Iran, was reared for 15 days using effluent from trout ponds enriched with effluent filtrate as sole feed, or co‐fed with microalgae (Scenedesmus sp.). The effluent filtrate was replaced by algae at different ratios (25% and 50%), and feeding experiments were designed at densities of 100, 200 and 400 individuals/L in 3‐L containers and at 100 individuals/L in 20‐L containers. The results indicated that, at a certain density, the final length and survival were not significantly affected by different feeding regimes (p > .05). In 3‐L containers, the highest length and survival were observed at the lowest density. B. orientalis contained the highest amounts of proteins, carbohydrates and lipids, though, when co‐fed algae, although the differences with the treatment fed solely effluent filtrate were often limited. Inclusion of algae in the diet also resulted in higher levels of a number of PUFAs. Our study proves that B. orientalis can be mass‐cultured successfully using trout effluent as culture medium without additional microalgae. Fish pond effluent is massively available as a cheap food source. Recycling aquaculture effluent for this type of live food production contributes to lowering the use of natural resources and to less discharge of nutrient loads into natural water bodies.     

Expression of reproductive-related genes and changes in oocyte maturation of goldfish broodstock (Carassius auratus) following injection of different exogenous kisspeptins

Kisspeptin, upstream of the hypothalamic-pituitary-gonadal axis, play an essential role in the reproductive process. In the present study, the effect of different types of kisspeptin, including goldfish (Carassius auratus) kiss1 kisspeptin (Kiss1), human kisspeptin (Hkiss) and their combination (Kiss1+H) on the reproductive-related genes (kiss1, Kissr and Cyp19) of adult female goldfish was investigated in comparison with Ovaprim (a synthetic GnRH hormone). Kiss1 and Hkiss were synthesized using a solid-phase synthesis approach. Peptides were injected at a dose of 100 μg/kg body weight. The brain and ovarian tissues of samples were separated for histological studies 24 hr post-injection. The expression of the kiss1, Kissr and Cyp19 genes was measured by RT-PCR. The results showed a significant increase in expression of the reproductive-related genes. Histological analysis revealed higher number of mature oocytes in kisspeptin treated groups compare to other ones. In conclusion, Hkiss and Kiss1+H are the most effective peptides in oocyte maturation and expression of reproductive-related genes. In addition, it seems that kisspeptins in other domestic animals can be used to stimulate the hypothalamus-pituitary-gonadal axis.     

SOURCES OF PRODUCTIVITY GROWTH IN RAINBOW TROUT AQUACULTURE IN IRAN: TECHNICAL EFFICIENCY CHANGE OR TECHNOLOGICAL PROGRESS?

This study investigates the sources of total factor productivity (TFP) growth in rainbow trout production in Iran using data envelopment analysis (DEA). The Malmquist index is then employed to decompose the TFP growth into technical efficiency change and technological progress. We utilized panel data of 207 trout farms in the country over a 5-year period from 2003 to 2007. The results of this study revealed that TFP growth of rainbow trout farming has an increasing trend over the period at an average annual rate of 3.7%. The trend of cumulative technological change is negative and tends to be contrary to cumulative technical efficiency change. Although there is no technological change or innovation on trout farming, the technical efficiency change was found to be the sole source for TFP change, whereas the mean of technical efficiency was estimated to be about 66%. Therefore, there is still a great relative potential for increasing trout production through improvement in managerial efficiency as well as technological progress. The study suggests that Iran also has considerable room to enhance trout aquaculture's TFP growth by shifting the production frontier with adoption of new technologies and improving innovation.     

Antibacterial and hemolytic effects of aqueous and organic extracts from different tissues of sea urchin <Emphasis Type="Italic">Echinometra mathaei</Emphasis> on pathogenic streptococci

In this study, the antibacterial and hemolytic effects of the gonadal tissue, test, spines and Aristotle’s lantern of the sea urchin (Echinometra mathaei) were investigated. The aerobic Gram-positive pathogenic bacteria Streptococcus mutans and Streptococcus sobrinus were selected because of their importance in oral diseases. The samples of sea urchin were collected from an intertidal zone in the Persian Gulf and then dissected. Finally, the crude extracts of the gonadal tissue, test, spines and Aristotle’s lantern of the samples were separately prepared by the solvents, including phosphate-buffered saline (PBS), 96 % ethanol (Et) and 80 % acetonitrile (ACN). The antibacterial activities of the extracts were evaluated using the well diffusion method in two concentrations of 1500 and 600 µg well^?1. The antibacterial effects against streptococcal species were observed in the organic extracts (Et and ACN) of the gonads and test while the extracts of spines and Aristotle’s lantern showed no antibacterial activity. The hemolytic activity of the PBS, 96 % Et, and 80 % ACN extracts from the sea urchin were evaluated using horse red blood cells. Hemolytic activity was observed only in the 80 % Et and ACN extracts of the gonad and test. In conclusion, the organic extracts of gonadal tissue showed the most inhibitory activity on the growth of S. mutans and S. sobrinus.