295 research outputs found
Sexual system and Sexual dimorphism in the shrimp Arete indicus, symbiont with the sea urchin Echinometra mathaei in the Persian Gulf, Iran
259-262The sexual system and sexual dimorphism of the shrimp Arete indicus are described. The following were measured for all shrimp under stereomicroscope to the nearest ±0.01 mm: carapace length (CL), merus length (ML) and carpus length (CrL) of the largest of the first pair of chelipeds, pleural width of the second abdominal segment (PW), and propodus length (PL) of the second (larger) pair of chelipeds. Sex determinations were based on presence of the appendix masculina on the base of the endopod of the second pleopods. With a view to determine whether or not a linear relationship exists between the CL, PL, ML, CrL and PW, the allometric model y = axb was used. A correlation was found between CL and ML in both sexes of Arete indicus. The status of allometry differed among various body parts of both sexes, and degree of allometry differed among various body parts between the sexes. According to ANCOVA, PW, PL, and ML of females are not larger than that of males at any given body size .The CL of Arete indicus females was not larger than the males. Due to observation a few of males with tiny appendices masculina, also based on earlier literature worked on Arete indicus, we believe this species is partially protandric
Mating system in the shrimp Arete indicus, a symbiont of Echinometra mathaei
248-252Due to their solitary life style, it appears that Arete indicus have a ‘search and attend’ mating system. There was a correlation between the body size (carapace length) of males and females found in pairs. There was a tight correlation between the numbers of total spine of their host and the number of individuals inhabiting the urchin. There was a weak and non-significant relationship between the number of males and females present and the volume of their host
Modeling of wheat yield and sensitivity analysis based on energy inputs for three years in Abyek town, Ghazvin, Iran
To get a proper energy consumption pattern and an increase in energy productivity, determining a relationship between energy inputs and outputs is necessary. In this study, the equivalent energy of inputs and outputs data used in wheat production in Abyek town of Ghazvin province, Iran was collected from farmers over three years. The energy ratio was obtained as 2.11, 2.08 and 2.03 and energy productivity was obtained as 0.15, 0.14 and 0.14 (kg MJ-1) for 2010, 2009 and 2008, respectively. It was found that the contributions of indirect and non-renewable energies on wheat yield were more than the impacts of direct and renewable energies. To determine the effects of energy inputs on wheat yield, the Cobb–Douglas production function was used. Model 1 was composed of individual energy inputs: labor, machinery, electricity, diesel fuel, water for irrigation, fertilizer, chemicals and seed energies In Model 2 energy inputs divided to direct and indirect energies and in Model 3 they divided to renewable and non-renewable energies. The R2 values in all three models were more than 0.98 and showed that the models can estimate well. The sensitivity analysis results for Model I showed that the major marginal physical productivities (MPPs) were water for irrigation, human labor and water for irrigation in 2010, 2009 and 2008, respectively. In Model II, the major MPP belongs to for renewable energy in the same years. Keywords: energy consumption pattern, Cobb-Dauglas, marginal physical productivity, renewable, return to scal
In Vitro Study of Mebendazole (Anthelmintic drug) Effects on the Aspartate Aminotransferase (AST) Enzyme Activity of Hydatid Cyst Parasite
Hydatid disease is caused by the larva of Echinococcus granulosus parasite. Mebendazole (MBZ) is used as an alternative choice for the treatment of the disease. Aspartate aminotransferase (AST) is an essential enzyme in amino acid metabolism. The aim of the present study is to evaluate the effect of MBZ on AST activity of hydatid cyst parasite in order to detect enzymatic parameter for drug efficiency. In the present study, AST activity was estimated in the extracts of untreated parasite (hydatid cyst protoscolices) and treated samples by MBZ (100 µg final concentration). Samples’ protein quantity and quality were detected by Bradford and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) methods respectively. For the purpose of determining the significant difference between the two independent samples, t-test was conducted. The values of the assayed AST specific activities of treated and untreated parasite samples were measured as 0.18 and 1.53U/ml/mg protein respectively. The difference between AST activities mean values of the two groups proved to be significant (P<0.05). SDS-PAGE demonstrated protein band of 50 kDa for AST enzyme. Considering the effect of the MBZ drug on AST activity in parasite, it can be concluded that this enzyme is useful for improving the drug efficiency
Species Composition and Functiona Traits of Macrofauna in Different Mangrove Habitats in the Persian Gulf
Macrofauna play a key role in the functioning of mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of macrofaunal communities across different habitats in the mangrove forests of the Persian Gulf is limited. In this study, we investigated species diversity and biological trait patterns of macrofauna in different mangrove-associated habitats, i.e., encompassing actual mangrove forests, and adjacent Beaches and Creeks, which exhibit different levels of habitat heterogeneity. Samples were collected from the different habitats in five different locations, over four seasons. A total of 122 macrofauna taxa were identified. The diversity of species was higher in summer than in winter. In the Beach habitats, species diversity showed an increasing trend from land toward the mangrove, whereas in Creek habitats diversity decreased from the Creek toward the mangrove. Multivariate community analysis showed differences in the distribution of abundant species and biological traits across all habitats. Deposit-feeding, crawlers, medium-size, and free-living were the dominant trait modalities in all habitats. The similarities within habitats over the four seasons had the same specific pattern of species and biological trait abundance in the Beach and the Creek, increasing from the non-covered habitat into the mangrove trees. Although many species shared similar traits, the abundance-driven differences in trait expression between habitats showed the importance of habitat filtering. The results of this study will be useful in the conservation of mangrove forests and they give a deeper understanding of the ecological patterns and functions of benthic macrofaunal communities in the Persian Gulf.Peer reviewe
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