نتایج جستجو برای: gambusia holbrooki
تعداد نتایج: 475 فیلتر نتایج به سال:
Aquatic invasions are one of the major threats for freshwater ecosystems. However, in developing countries, knowledge biological invasions, essential implementation appropriate legislation, is often limited if not entirely lacking. In this regard, identification potentially invasive non-native species by risk screening, followed a full assessment ranked as higher risk, enables decision-makers t...
Recent research has suggested that lateralization of aggressive behaviors could follow an homogeneous pattern among all vertebrates. A left eye/right hemisphere dominance in eliciting aggressive responses has been demonstrated for all groups of tetrapods but teleost fish for which data is lacking. Here we studied differential eye use during aggressive interactions in three species of teleosts: ...
Dramatic declines in mercury levels have been reported in Everglades biota in recent years. Yet, methylmercury (MeHg) hot spots remain. This paper summarizes a risk assessment of MeHg exposure to three piscivorous wildlife species (bald eagle, Haliaeetus leucocephalus; wood stork, Mycteria americana; and great egret, Ardea albus) foraging at a MeHg hot spot in northern Everglades National Park ...
Survival of the threespine stickleback, Gasterosteus aculeatus, differed among marshes in a demonstration 9.9-ha multipurpose constructed treatment wetland designed to improve the quality of secondary-treated municipal wastewater in southern California. At a mean loading rate of 3.3 kg NH4-N ha(-1) d(-1) (6 kg total N ha(-1) d(-1)), the suitability of the wetland to support a population of stic...
About 1% of male mosquitofish (Gambusia holbrooki) express melanic (mottled-black) body coloration, which differs dramatically from the wild-type, silvery-gray coloration. Here, I report on the genetic inheritance pattern of melanic coloration, which indicates Y-linkage, and at least one autosomal modifier. Phenotypic expression of melanism is also affected by temperature. Expression is constit...
برخی از فلزات سنگین در غلظت های پایین ضروری اند؛ امّا در اغلب موارد دارای آثار سمی هستند و با تجمع در اندام های مختلف موجودات آبزی باعث آسیب دیدن بافت ها و اختلال در رشد و تکثیر آنها می شوند. هدف از این پژوهش بررسی میزان سمی بودن فلزات سنگین روی، مس و جیوه در محیط آبی باسختی 350 میلی گرم در لیتر کربنات کلسیم در ماهی گامبوزیا (gambusia holbrooki) است. آزمایش هایی در قالب طرحی کاملاً تصادفی به وسیل...
چکیده این مطالعه طی سالهای 1380-1379 جهت تعیین ترکیب و فراوانی در جوامع ماکروبنتوزی ، شناسایی و تنوع گونه ای ماهیان در فصول مختلف درآبراهه ای در تالاب گمیشان واقع در جنوب شرقی دریای خزر صورت گرفت. تجزیه و تحلیل نمونه های بنتوز، وجود سه گروه عمده جانوری شامل نرمتنان، کرم های حلقوی و بندپایان را نشان دادند که فراوانی آنها در ماههای مختلف سال تغییر کرد. فراوانترین گروه ...
were measured on nutrient agar plates. In all three species, 0.1, 0.5, and 1.0% lithium chloride progressively increased the colony sizes. On the other hand, 2.0, 3.5, and 5.0% LiCl progressively reduced the colony diameters, resulting in the isolation of predominantly small-colony variants (Table 1). It is probable that the higher concentrations of LiCl selected small-colony variants from the ...
—Lampropeltis getula is a species of conservation concern in several parts of its wide geographic range. I describe habitat use and movement patterns of L. getula holbrooki in an agricultural landscape, a portion of which has been brought out of agriculture and reforested. Both sexes strongly preferred vegetated shrubby levee habitats, and avoided active agricultural fields. There was no eviden...
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