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排序方式: 共有233条查询结果,搜索用时 15 毫秒
1.
Fernanda S. ORREGO Mathias HÜNE Hugo A. BENÍTEZ Mauricio F. LANDAETA 《Integrative zoology》2023,18(2):372-384
Phenotypic variation in organisms depends on the genotype and the environmental constraints of the habitat that they exploit. Therefore, for marine species inhabiting contrasting aquatic conditions, it is expected to find covariation between the shape and its spatial distribution. We studied the morphology of the head and cephalic sensory canals of the eelpout Austrolycus depressiceps (4.5–22.5 cm TL) across its latitudinal distribution in South Pacific (45°S–55°S). Geometric morphometric analyses show that the shape varied from individuals with larger snout and an extended suborbital canal to individuals with shorter snouts and frontally compressed suborbital canal. There was size variation across the sampled populations, but that size does not have a clear latitudinal gradient. Only 8% of the shape variation relates to this size variation (allometry), represented by a decrease in the relative size of the eye, and a depression of the posterior margin of the head. There were spatial differences in the shape of the head, but these differences were probably caused by allometric effects. Additionally, 2 of the canals of the cephalic lateralis pores and the head shape showed modularity in its development. This study shows that the morphology of marine fish with a shallow distribution varies across distances of hundreds of kilometers (i.e., phenotypic modulation). 相似文献
2.
Väli Ülo Mirski Paweł Sein Gunnar Abel Urmas Tõnisalu Grete Sellis Urmas 《Landscape Ecology》2020,35(7):1667-1681
Landscape Ecology - Biodiversity is closely related to landscape heterogeneity, but both are difficult to evaluate directly. Apex predators, such as raptors, are potential surrogate indicators of... 相似文献
3.
A baseline hydrogeochemical investigation was carried out as a contribution to the inventory of wetlands in Büyük Menderes
River (BMR) coastal wetland which is the most important wetland in Turkey that is protected as “Natural Park” by government.
In addition to the wetland values, agricultural activities are also important at this delta. From inland to coastal zone,
the groundwater type is changed from Ca–HCO3 to Na–Cl. Perfect correlation of Cl with Na and SO4 indicated the mixing process between saline and fresh water. The seawater intrusion and “winter-leaching” is the main causes
of salinization. Minor ions as B, Br, and Li versus Cl relationship also showed the marine influence at the BMR coastal wetland.
The δ18O and δD composition of the waters are range between −8.11‰ and −1.65‰ and −49.2‰ and 8.1‰, respectively. Isotope values show
the seawater mixing line and also dissolution of salts in the BMR coastal wetland. Weathering of aluminosilicates in the Paleozoic
schist and clays resulted in the release of silica to the water. Due to the organic activity, iron concentrations reached
to the tolerance limits. On the other hand, the use of phosphate fertilizers increases the phosphorus content in the water.
The high value of As (from 0.6 to 134 μg/l) can be resulted as an evaporation process in the study area. 相似文献
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Effects of cerium oxide supplementation to laying hen diets on performance,egg quality,some antioxidant enzymes in serum and lipid oxidation in egg yolk 下载免费PDF全文
S. C. Bölükbaşı A. A. Al‐sagan H. Ürüşan M. K. Erhan O. Durmuş N. Kurt 《Journal of animal physiology and animal nutrition》2016,100(4):686-693
This study was conducted to determine the effects of dietary cerium oxide levels (0, 100, 200, 300 or 400 mg/kg) on the laying performance, egg quality, some blood serum parameters and egg lipid peroxidation of laying hen. In total, one hundred and twenty 22‐week‐old brown Lohman LSL laying hens were randomly assigned to five groups equally (n = 24). Each treatment was replicated six times. Dietary supplementation of cerium oxide had no significant effect on feed intake and egg weight. The addition of cerium oxide to the laying hens' feed improved feed conversion ratio and increased (p < 0.05) egg production. Quality criteria of egg for except shell breaking strength were not affected by supplementing cerium oxide. In particular, supplementation of 200 and 300 mg/kg cerium oxide to the laying hens feed led to a significant (p < 0. 01) increase in egg shell breaking strength. Calcium and phosphorus concentration of serum increased significantly (p < 0.05) with supplementation of 100 mg/kg cerium oxide to laying hen diets. It was also observed that serum superoxide dismutase (SOD) activity and malondialdehyde (MDA) concentration decreased significantly with supplementation of cerium oxide in diets. Inclusion of cerium oxide resulted in a significant reduction in thiobarbituric acid reactive substance (TBARS) values in egg yolk in this study. It can be concluded that the addition of cerium oxide had positive effects on egg production, feed conversion ratio and egg shelf life. Based on the results of this study, it could be advised to supplement laying hens feed with cerium oxide as feed additives. 相似文献
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Rosa L. OBREGÓN Jose A. SCOLARO Nora R. IBARGÜENGOYTÍA Marlin MEDINA 《Integrative zoology》2021,16(1):53-66
Behavioral and physiological traits of ectotherms are especially sensitive to fluctuations of environmental temperature. In particular, niche-specialist lizards are dependent on their physiological plasticity to adjust to changing environmental conditions. Lizards of the genus Phymaturus are viviparous, mainly herbivorous, and inhabit only rock promontories in the steppe environments of Patagonia and the Andes. Herein, we examine the vulnerability of the southernmost Phymaturus species to global warming: the endemic Phymaturus calcogaster, which lives in a mesic environment in eastern Patagonia. We studied body temperatures in the field (Tb), preferred body temperatures in a thermogradient (Tpref), the operative (Te) and environmental temperatures, and the dependence of running performance on body temperature. P. calcogaster had a mean Tb (27.04°C) and a mean Te (31.15°C) both lower than their preferred temperature (Tpref = 36.61°C) and the optimal temperature for running performance (To = 37.13°C). Lizard activity seems to be restraint during the early afternoon due high environmental temperatures. However, both, the high safety margin and warming tolerance suggest that the expected increase in environmental temperatures due to global warming (IPCC report in 2018) would not threaten, but indeed enhance locomotor performance in this population. 相似文献
9.
【目的】研究膜下滴灌水稻不同水分处理对耗水特征和水分生产效率的影响。【方法】2017年设置5个灌溉定额,对比分析不同水分处理下水稻产量、各生育期耗水量。【结果】W5处理(灌溉定额910.00 mm)的水稻产量比其他处理分别增加21.95%~458.43%。膜下滴灌水稻全生育期5个水分处理的耗水强度分别为3.75~7.14 mm/d。随着灌水量减少叶面积衰减指数逐渐增大,叶片表现出早衰特征,株高受到灌水量抑制。W5处理与其他处理水分生产率相比分别提高7.61%~193.06%。生育阶段耗水强度变化规律为拔节孕穗期>抽穗扬花期>灌浆期>分蘖期>成熟期>苗期。【结论】水稻全生育期适宜灌溉定额910.00 mm,在拔节孕穗期、分蘖期2个关键需水期,满足水稻水分需求。 相似文献
10.
SchÜpfer Y. Lukinger Fabricius M. Hollrung-Halle 《European Journal of Forest Research》1927,49(11):399-408