نتایج جستجو برای: reptiles
تعداد نتایج: 5168 فیلتر نتایج به سال:
Despite more than a century of debate, the evolutionary position of turtles (Testudines) relative to other amniotes (reptiles, birds, and mammals) remains uncertain. One of the major impediments to resolving this important evolutionary problem is the highly distinctive and enigmatic morphology of turtles that led to their traditional placement apart from diapsid reptiles as sole descendants of ...
Reptile-associated salmonellosis (RAS) in children has been reported primarily due to direct contact with turtles, but recently also due to indirect contact with more exotic reptiles, causing disease in infants. To evaluate risk factors for RAS, we reviewed the RAS cases published in the literature since 1965. A case was defined as a child ≤18 years of age with an epidemiological link by identi...
Most hypotheses that have been put forward in order to explain the persistence of environmental sex determination (ESD) in reptiles assume a relatively fixed association of sex with temperature-induced phenotype and no maternal influence on offspring sex. Here we demonstrate the association of maternally derived yolk hormone levels with the offspring sex ratio and describe two new aspects of te...
Reptiles posses two main mechanisms of sex determination. In some species the sex of the individual is determined at conception by sex factors contained in sex chromosomes (termed genotypic sex determination or GSD). However, in other species sex is determined after conception by the environmental temperature during incubation and cannot be predicted by zygotic genotype (Bull, 1983; Valenzuela ...
of a widespread species than to be faced with the challenge of conserving every population because all are distinctive. Undoubtedly, some reptile species have already gone extinct before we even knew they existed. But a lot remain to be discovered: for example, a single square kilometre of Australian desert can contain 14 co-existing species of the lizard genus Ctenotus (many of them so similar...
The purpose of this perspective is to highlight the merit of the reptile integument as an experimental model. Reptiles represent the first amniotes. From stem reptiles, extant reptiles, birds and mammals have evolved. Mammal hairs and feathers evolved from Therapsid and Sauropsid reptiles, respectively. The early reptilian integument had to adapt to the challenges of terrestrial life, developin...
Amphibians and reptiles are popular pet animals in about 90.000 Austrian households despite their frequently debated capacity to transmit diseases associated with animal keeping. We studied the epidemiological significance of the triangle animal keeper, exotic pet animal, and feed mice by investigating the frequency of three intestinal infestations, caused by cryptosporidia, opportunistic free-...
As nontraditional model organisms with extreme physiological and morphological phenotypes, snakes are believed to possess an inferior taste system. However, the bitter taste sensation is essential to distinguish the nutritious and poisonous food resources and the genomic evidence of bitter taste in snakes is largely scarce. To explore the genetic basis of the bitter taste of snakes and characte...
Environmental pollution and habitat loss are described as underlying causes for population declines in reptiles and especially affect species in agricultural landscapes. Studies dealing with effects of pesticide exposure on reptiles are limited, mainly addressing the orders Testudines and Crocodylia, but largely neglecting the most diverse reptile order Squamata (lizards and snakes). As a conse...
FitzgeRald, l. a. 2012. Finding and capturing reptiles. In R. W. McDiarmid, M. S. Foster, C. Guyer, J. W. Gibbons, and N. Chernoff (eds.), Reptile Biodiversity: Standard Methods for Inventory and Monitoring, pp. 77–80. University of California Press, Los Angeles, California. ———, M. l. tReglia, n. F. angeli, t. J. hibbitts, d. J. leaVitt, a. l. subalusky, i. lundgRen, and z. hillis-staRR. 2015....
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید