Environmental status of the Lake Michigan region /

Vols. 7, 9 and 15, issued in 1974, prepared for the U. S. Atomic Energy Commission; vols. issued 1975- prepared for the U. S. Energy Research and Development Administration.

Elémens de zoologie; ou, Leçons sur l'anatomie, la physiologie, la classification et les moeurs des animaux.

ptie. 1. Introduction. Anatomie et physiologie. -- [ptie. 2] Mammiféres. -- [ptie. 3] Oiseaux. Reptiles. Poissons. -- [ptie. 4] Animaux sans vertèbres.

The Pictorial museum of animated nature.

Coloured frontis. in each vol.

Nature lovers library.

Earlier editions have titles: The people's natural history (1903) The library of natural history (1906) The standard library of natural history (1908)

The Cambridge natural history,

--VI. Insects, pt. II. Hymenoptera continued (Tubilifera and Aculeata), Coleoptera, Strepsiptera, Lepidotera, Diptera, Aphaniptera, Thysanoptera, Hemiptera, Anoplura. By David Sharp. 1901.--VII. Hemichordata, by S.F. Harmer. Ascidians and Amphioxus, by W.A. Herdman. Fishes (exclusive of th systematic account of Teleostei) by T.W. Bridge. Fishes (systematic account of Teleostei) by G.A. Bonlenger. 1904.--VIII. Amphibia and reptiles, by Hans Gadow. 1901.--IX. Birds, by A.H. Evans. 1900--X. Mammalia, by F.E. Beddard. 1902.

Comparative osteology of the snake families Typhlopidae and Leptotyphlopidae.

Bibliography: p. 104-106.

Prostaglandins are important in thermoregulation of a reptile (Pogona vitticeps)

The effectiveness of behavioural thermoregulation in reptiles is amplified by cardiovascular responses, particularly by differential rates of heart beat in response to heating and cooling (heart-rate hysteresis). Heart-rate hysteresis is ecologically important in most lineages of ectothermic reptile' and we demonstrate that heart-rate hysteresis in the lizard Pogona vitticeps is mediated by prostaglandins. In a control treatment (administration of saline), heart rates during heating were significantly faster than during cooling at any given body temperature. When cyclooxygenase 1 and 2 enzymes were inhibited, heart rates during heating were not significantly different from those during cooling. Administration of agonists showed that thromboxane B-2 did not have a significant effect on heart rate, but prostacyclin and prostaglandin F-2alpha caused a significant increase (3.5 and 13.6 beats min(-1), respectively) in heart rate compared with control treatments. We speculate that heart-rate hysteresis evolved as a thermoregulatory mechanism that may ultimately be controlled by neurally induced stimulation of nitric oxide production, or maybe via photolytically induced production of vitamin D.

The fuzzy frontier

THE STORY OF HOW FEATHERS EVOLVED IS FAR FROM OVER. IN 1868, THOMAS HUXLEY declared that dinosaurs gave rise to birds. He based his claim on Compsognathus, a 150-million-year-old dinosaur fossil from Solnhofen, Germany, whose delicate hind legs were remarkably similar to those of table fowl. The discovery seven years earlier of Archaeopteryx, a fossil bird with a long bony tail, toothed jaws and clawed fingers, had convinced many people that birds were somehow related to reptiles. But Compsognathus was the fossil that placed dinosaurs firmly in the middle of this complex evolutionary equation. Wings, claimed Huxley, must have grown out of rudimentary forelimbs. And feathers? Whether Compsognathus had them, Huxley could only guess. Nevertheless, his theory clearly required that scales had somehow transformed into feathers. The question was not just how, but why?

Coloured oil droplets enhance colour discrimination

The eyes of most diurnal reptiles and birds contain coloured retinal filters-oil droplets. Although these filters are widespread, their adaptive advantage remains uncertain. To understand why coloured oil droplets appeared and were retained during evolution, I consider both the benefits and the costs of light filtering in the retina. Oil droplets decrease cone quantum catch and reduce the overlap in sensitivity between spectrally adjacent cones. The reduction of spectral overlap increases the volume occupied by object colours in a cone space, whereas the decrease in quantum catch increases noise, and thus reduces the discriminability of similar colours. The trade-off between these two effects determines the total benefit of oil droplets. Calculations show that coloured oil droplets increase the number of object colours that can be discriminated, and thus are beneficial for colour vision.

Morphological and physiological specialization for digging in amphisbaenians, an ancient lineage of fossorial vertebrates

Amphisbaenians are legless reptiles that differ significantly from other vertebrate lineages. Most species dig underground galleries of similar diameter to that of the animal. We studied the muscle physiology and morphological attributes of digging effort in the Brazilian amphisbaenid Leposternon microcephalum (Squamata; Amphisbaenia), which burrows by compressing soil against the upper wall of the tunnel by means of upward strokes of the head. The individuals tested (

Single copy nuclear DNA markers characterized for comparative phylogeography in Australian wet tropics rainforest skinks

In order to investigate population history and demography in skinks endemic to the wet tropics of Australia, multiple nuclear DNA markers were sought. The utility of 72 primers (including 63 published intron-spanning 'CATS' primers) was tested.. Seven loci were characterized and shown to be single copy by single-strand conformation polymorphism analysis. Primers to five nuclear loci were developed, four with utility in skinks and three with utility in frogs. These observations extend the available information on intron-spanning primers for amphibians and reptiles.

Integration of autonomic and local mechanisms in regulating cardiovascular responses to heating and cooling in a reptile (Crocodylus porosus)

Reptiles change heart rate and blood flow patterns in response to heating and cooling, thereby decreasing the behavioural cost of thermoregulation. We tested the hypothesis that locally produced vasoactive substances, nitric oxide and prostaglandins, mediate the cardiovascular response of reptiles to heat. Heart rate and blood pressure were measured in eight crocodiles (Crocodylus porosus) during heating and cooling and while sequentially inhibiting nitric-oxide synthase and cyclooxygenase enzymes. Heart rate and blood pressure were significantly higher during heating than during cooling in all treatments. Power spectral density of heart rate and blood pressure increased significantly during heating and cooling compared to the preceding period of thermal equilibrium. Spectral density of heart rate in the high frequency band (0.19-0.70 Hz) was significantly greater during cooling in the saline treatment compared to when nitric-oxide synthase and cyclooxygenase enzymes were inhibited. Cross spectral analysis showed that changes in blood pressure preceded heart rate changes at low frequencies (

Physiological thermoregulation in a crustacean? Heart rate hysteresis in the freshwater crayfish Cherax destructor

Differential heart rates during heating and cooling (heart rate hysteresis) are an important thermoregulatory mechanism in ectothermic reptiles. We speculate that heart rate hysteresis has evolved alongside vascularisation, and to determine whether this phenomenon occurs in a lineage with vascularised circulatory systems that is phylogenetically distant from reptiles, we measured the response of heart rate to convective heat transfer in the Australian freshwater crayfish, Cherax destructor. Heart rate during convective heating (from 20 to 30 degreesC) was significantly faster than during cooling for any given body temperature. Heart rate declined rapidly immediately following the removal of the heat source, despite only negligible losses in body temperature. This heart rate 'hysteresis' is similar to the pattern reported in many reptiles and, by varying peripheral blood flow, it is presumed to confer thermoregulatory benefits particularly given the thermal sensitivity of many physiological rate functions in crustaceans. (C) 2004 Published by Elsevier Inc.

Temperature-dependent sex ratio in a bird

To our knowledge, there is, so far, no evidence that incubation temperature can affect sex ratios in birds, although this is common in reptiles. Here, we show that incubation temperature does affect sex ratios in megapodes, which are exceptional among birds because they use environmental heat sources for incubation. In the Australian brush-turkey Alectura lathami, a mound-building megapode, more males hatch at low incubation temperatures and more females hatch at high temperatures, whereas the proportion is 1 : 1 at the average temperature found in natural mounds. Chicks from lower temperatures weigh less, which probably affects offspring survival, but are not smaller. Megapodes possess heteromorphic sex chromosomes like other birds, which eliminates temperature-dependent sex determination, as described for reptiles, as the mechanism behind the skewed sex ratios at high and low temperatures. Instead, our data suggest a sex-biased temperature-sensitive embryo mortality because mortality was greater at the lower and higher temperatures, and minimal at the middle temperature where the sex ratio was 1 : 1.

Sox8 is expressed at similar levels in gonads of both sexes during the sex determining period in turtles

A critical gene involved in mammalian sex determination and differentiation is the Sty-related gene Sox9. In reptiles, Sox9 resembles that of mammals in both structure and expression pattern in the developing gonad, but a causal role in male sex determination has not been established. A closely related gene, Sox8, is conserved in human, mouse, and trout and is expressed in developing testes and not developing ovaries in mouse. In this study, we tested the possibility of Sox8 being important for sex determination or sex differentiation in the red-eared slider turtle Trachemys scripta, in which sex is determined by egg incubation temperature between stages 15 and 20. We cloned partial turtle Sox8 and anti-Mullerian hormone (Amh) cDNAs, and analyzed the expression patterns of these genes in developing gonads by reverse transcriptase-polymerase chain reaction and whole-mount in situ hybridization. While Amh is expressed more strongly in males than in females at stage 17, Sox8 is expressed at similar levels in males and females throughout the sex-determining period. These observations suggest that differential transcription of Sill is not responsible for regulation of Amh, nor responsible for sex determination in turtle. (C) 2004 Wiley-Liss, Inc.