جستجوی مقالات مرتبط با کلیدواژه « morphometry » در نشریات گروه « زیست شناسی »

Stock Assessment of marine aquatic is essential for modern management and sustainable conservation of fishery species, which has been rapidly developed by improving the ability of computer simulation with stock assessment methods, and for sustainable management and exploitation of fish stocks, knowledge of parameters such as age, growth and reproductive biology fishes are essential, and the output information can be used to plan and develop fisheries programs in the future. Fishing management has a wide range of goals, which include identification of aquatic population, assessment of stocks, use and development of fishing tools in order to efficiently exploit the stock and ensure the benefits of fishing users by providing a sustainable harvest deal. Stock assessment models are one of the strategies used to preserve fishery species.

In this study, some biological characteristics of greenback mullet fish were investigated during six months of 2023 in the coastal waters of Bandar Abbas. For this purpose, after sampling, 120 of the fishes caught were transferred to the laboratory for biometry of length and weight parameters and were subjected to biometrics. After morphometric analysis of greenback mullet samples, fish growth parameters such as Growth performance index, condition index, von Bertalaneffy growth function (VBGF), mortality coefficients and exploitation ratio were calculated using FiSAT software processing.

The results of the study showed that the average total length and weight of greenback mullet fish were 11.06 cm and 21.90 gr, respectively. In this fish, the relationship between total length and total weight was obtained as W=0.1886TL1.9226. The parameter of condition index in the entire sampling period had strong fluctuations in the first half of the sampling period and did not change significantly in the second half and was almost the same. Among the parameters calculated, we can mention the growth function of von Bertalaneffy growth function and factors such as forked length, growth coefficient and t0 were calculated as 20 cm, 1.1 and -0.1 per year, respectively. Total and natural mortality rates were estimated as 2.56 and 2.07 per year for the samples, respectively.

Stock assessment is the process of collecting, analyzing and reporting fish population information to determine changes in the abundance of fishery stocks in response to fishing and to predict the future trends of stock abundance as much as possible. In this study, the results showed that greenback mullet fish in the coastal waters of Bandar Abbas are young fish. For both males and females, the growth index is the highest, and overfishing, especially during the spawning seasons, has messed up the regeneration of the young population, Therefore, not having proper management in fishing can damage this valuable stock in the coastal waters of Bandar Abbas. Therefore, it is suggested that this study be re-evaluated in a longer period of time and with a larger number of samples so that the results can be proven with more certainty.

Canola with the scientific name Brassica napus L., due to its high oil content in the seed, produces one third of all edible oils worldwide, which plays an important role in improving the nutritional needs of societies. Accelerated aging test is one of the most important tests used to evaluate the viability and physiological potential of seeds. Unsuitable environmental conditions as well as seed storage conditions can cause oxidative stress in seeds and other plant tissues. In this study, the improvement effect of pretreatment of vitamin C and Hydroquinone on canola seed under accelerated aging and the developmental and phytochemical characteristics of seedlings obtained from aged canola seed including morphological traits, germination indices and phytochemical changes were investigated. Pre-treatment of seeds with antioxidant compounds reduced the damage caused by decay, improved the quality of canola seeds and seedlings, and also changed the phytochemical composition of the seedlings. The reduction of seed germination and weak morphometric characteristics of seedlings obtained from old seeds indicate the relationship between the phytochemical changes of seeds and the aging process. Seedlings obtained from old seeds showed phytochemical changes in the metabolic pathways of carbohydrates and proteins. If the aging process of the seed does not lead to death of seed, the resulting seedlings will have a different destiny with high power to deal with oxidative stress. It seems that the seedlings receive the signal from the free radicals of seed aging and cause the growth of intelligent seedlings to deal with the stress.

Considering the important role of Nitric Oxide (NO) in many biologic processes of cells and tissues including during pregnancy and its different stages, this study investigated the effects of L-Arginine as a NO precursor and L-NAME as a NO inhibitor on structural and stereological changes of the thymus in pregnant rats. In this experimental study, thirty-two female Wistar rats, aged 8 weeks and weighing 200-250g, were randomly divided into 4 groups: Control, L-Arginine (200 mg / kg), L-NAME (20 mg / kg) and L-Arginine + L-NAME; 8 rats in each group. On the 18th day of pregnancy, the rats anesthetized with ether, then, their thymus was extracted and fixed in 10% formalin. After tissue passage, the sections were stained with H&E and the histological and morphometric studies were performed. L-Arginine with its stimulative effect on NO synthesis in thymus causes to increase T-lymphocyte population, therefore thickness of cortex is increased and thickness of medulla decreased. Analysis of variance showed that the thickness of cortex and medulla of thymus in the L-Arginine group was significantly different in comparison with the control group, with p=0.000 and p=0.002, respectively. The thickness of cortex and medulla in the L-NAME group showed a significant decrease, with p=0.000, compared to the control group.

 Female polymorphism is visible in some populations of Odonata species for unknown reasons. In general, one of the female forms which is more or less similar to males is called andromorph. Andromorph females show similar color patterns and sometimes, even some structural and behavioral aspects to the conspecific males, whereas gynochrome females are different from males. One mentioned reason for the existence and survival of this phenomenon in the odonates is the avoidance of male harassment toward females during the breeding season. Males and females of Calopteryx intermedia have sexual dimorphism in the wing shape. It represents differences in flight dynamic models of the two sexes. Therefore, the decrease of harassment of females by males needs mimicry of male’s flight dynamic, but this could be possible with the same wing shape as males but not gynomorph females. The results of the present study revealed that the shape of fore and hindwing of andromorph females were significantly different from males but not gynomorph females. As a result, it seems that andromorph females are not able to mimic the males’ flight and it seems that the andromorph females with a wing spot, approximately the same as that of conspecific males, cannot mislead the males. Thus, we have to seek other places for their existential reason(s) and survival.

Tomato pulp is one of the by-products of the food industry that is produced in large quantities in Iran and due to the high percentage of fiber, its level of consumption in broiler diets may be limited.Therefore, the aim of this study was to improve the nutritional value of tomato pulp using a multivalent enzyme in the nutrition of broiler chickens.

In this experimentthebroiler chicks fed diets without tomato pulp and enzyme (control), containing 5% tomato pomace without enzyme, containing 5% tomato pomace and 0.2% multi-enzyme, containing 10% tomato pomace without enzyme and 10% tomato pomace and 0.2% multi-enzyme for 42 days.

During the Finisher and the whole the experiment period, chicks fed different levels of tomato pomace with enzyme had a higher weight gain than enzyme free comparable diets (P<0.05). There was an increase in the the empty gizzard weight in chickens fed 5% tomato pomace with enzyme compared to the control group and also the 10% tomato pomace and enzyme group (P <0.05).Serum lipids including cholesterol, triglyceride and LDL were not affected by the experimental diets, but diets containing tomato pomace had higher HDL concentration than the control group (P <0.05). The villi height of jejunum and ileum of chicks fed 5% tomato pomace with enzyme was significantly higher than other treatments, but highest amount of villi of jejunum and ileum was observed in the group fed 5% tomato pomace without enzym. (P <0.05).The 10% level of tomato pomace reduced feed cost per unit of live weight gain by 5%.

The results of this study showed a positive effect of multi-enzyme use on increasing the nutritional value of tomato pomace up to 10% of broiler diet.
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