differentiation of sex chromosomes and karyotypic evolution in the eye-lid geckos (squamata: gekkota: eublepharidae), a group with different modes of sex determination. | the eyelid geckos (family eublepharidae) include both species with temperature-dependent sex determination and species where genotypic sex determination (gsd) was suggested based on the observation of equal sex ratios at several incubation temperatures. in this study, we present data on karyotypes and chromosomal characteristics in 12 species (aeluroscalabotes felinus, coleonyx brevis, coleonyx elegans, coleonyx variegatus, eublepharis angramainyu, eublepharis macularius, goniurosaurus araneus, ... | 2010 | 20811940 |
frequency sensitivity of single auditory neurons in the gecko coleonyx variegatus. | although acoustic communication is not pronounced in reptiles, analysis of single auditory neurons in the medulla oblongata shows that the cochlea is a frequency analyser. auditory neurons of the lizard coleonyx variegatus respond to acoustic stimuli over a range of less than 0.1 to 17 kilohertz and are maximally responsive between 0.8 and 2.0 kilohertz. the frequencies to which they are most sensitive differ from neuron to neuron, ranging from 0.11 to 4 kilohertz. some neurons have an inhibitor ... | 1967 | 6026673 |
the role of the thyroid in testicular function in the gecko, coleonyx variegatus. | | 1973 | 4699367 |
geckos: adaptive significance and energetics of tail autotomy. | coleonyx variegatus is adapted to readily sacrifice its tail to predators. this adaptation is associated with characteristic tail behavior and rapid tail regeneration. there is no facultative metabolic increase associated with tail regeneration, and energy normally allocated to body growth and maintenance is diverted to tail regeneration. this supports the contention that tail behavior, autotomy, and rapid regeneration evolved as mechanisms promoting survival in terms of predator escape. | 1974 | 4833262 |
efficiency of uphill locomotion in nocturnal and diurnal lizards | nocturnal geckos can walk on level ground more economically than diurnal lizards. one hypothesis for why nocturnal geckos have a low cost of locomotion is that they can perform mechanical work during locomotion more efficiently than other lizards. to test this hypothesis, we compared the efficiency of the nocturnal gecko coleonyx variegatus (average body mass 4.2 g) and the diurnal skink eumeces skiltonianus (average body mass 4.8 g) when they performed vertical work during uphill locomotion. we ... | 1996 | 9318297 |
mechanics of locomotion in lizards. | lizards bend their trunks laterally with each step of locomotion and, as a result, their locomotion appears to be fundamentally different from mammalian locomotion. the goal of the present study was to determine whether lizards use the same two basic gaits as other legged animals or whether they use a mechanically unique gait due to lateral trunk bending. force platform and kinematic measurements revealed that two species of lizards, coleonyx variegatus and eumeces skiltonianus, used two basic g ... | 1997 | 9286099 |
maximum speed and mechanical power output in lizards. | the goal of the present study was to test the hypothesis that maximum running speed is limited by how much mechanical power the muscular system can produce. to test this hypothesis, two species of lizards, coleonyx variegatus and eumeces skiltonianus, sprinted on hills of different slopes. according to the hypothesis, maximum speed should decrease on steeper uphill slopes but mechanical power output at maximum speed should be independent of slope. for level sprinting, the external mechanical pow ... | 1997 | 9286100 |
low cost of locomotion in the banded gecko: a test of the nocturnality hypothesis. | this study tested the hypothesis that there has been an evolutionary increase in locomotor performance capacity at low temperature in nocturnal lizards. nocturnal lizards are often active at low and suboptimal body temperatures. an evolutionary decrease in the minimum cost of locomotion could increase endurance capacity at low temperature, partially offsetting the thermal handicap of nocturnality. in support of the nocturnality hypothesis, we discovered that minimum cost of locomotion of a noctu ... | 2010 | 9361140 |
comparison of otoacoustic emissions within gecko subfamilies: morphological implications for auditory function in lizards. | otoacoustic emissions (oaes) are sounds emitted by the ear and provide a non-invasive probe into mechanisms underlying peripheral auditory transduction. this study focuses upon a comparison of emission properties in two phylogenetically similar pairs of gecko: gekko gecko and hemidactylus turcicus and eublepharis macularius and coleonyx variegatus. each pair consists of two closely related species within the same subfamily, with quantitatively known morphological properties at the level of the a ... | 2011 | 21136278 |
auditory hair cell innervational patterns in lizards. | the pattern of afferent and efferent innervation of two to four unidirectional (uhc) and two to nine bidirectional (bhc) hair cells of five different types of lizard auditory papillae was determined by reconstruction of serial tem sections. the species studies were crotaphytus wislizeni (iguanid), podarcis (lacerta) sicula and p. muralis (lacertids), ameiva ameiva (teiid), coleonyx variegatus (gekkonid), and mabuya multifasciata (scincid). the main object was to determine in which species and in ... | 1988 | 3385019 |
heterotopic synaptic bodies in the auditory hair cells of adult lizards. | the auditory hair cells of adults of eight species of lizards (three gekkonids: coleonyx variegatus, gekko gecko, and cosymbotus platyurus; two teiids: ameiva ameiva and cnemidophorus tigris; one anguid: celestus costatus; one lacertid: podarcis (lacerta) sicula; and one iguanid: crotaphytus wislizeni) were studied by transmission electron microscopy. heterotopic synaptic bodies were found in some of the auditory hair cells of all of the above species, occurring frequently in the gekkonids but i ... | 2010 | 2820267 |
studies on the retina of the gecko coleonyx variegatus. 3. photoreceptor cross-sectional area relationships. | | 1966 | 5954547 |
studies on the retina of the gecko coleonyx variegatus. ii. the rectilinear visual cell mosaic. | | 1966 | 5954546 |
studies on the retina of the gecko coleonyx variegatus. i. the visual cell classification. | | 1966 | 5954545 |