Baiohelmins elegans n. g., n. sp. (Digenea: Nanophyetidae) from the Australian water rat,Hydromys chrysogaster

1988 ◽  
Vol 12 (2) ◽  
pp. 117-121
Author(s):  
T. H. Cribb ◽  
J. C. Pearson
Keyword(s):  
Australian Water ◽  
Hydromys Chrysogaster

The life-cycle of Echinoparyphium hydromyos sp.nov. (Digenea: Echinostomatidae) from the Australian water-rat

Parasitology ◽  
1967 ◽  
Vol 57 (1) ◽  
pp. 19-30 ◽  
Author(s):  
L. Madeline Angel
Keyword(s):  
Life History ◽  
Life Cycle ◽  
Experimental Work ◽  
Field Work ◽  
Type Material ◽  
South Australian Museum ◽  
The South ◽  
Australian Water ◽  
Australian Museum ◽  
Hydromys Chrysogaster

Echinoparyphium hydromyos sp.nov. with forty-five collar spines is described from the Australian water rat, Hydromys chrysogaster Geoffr.The cercaria occurs naturally in Plananisus isingi (Cotton & Godfrey), and all stages in the life-history have been demonstrated experimentally.Encystation occurs in the kidneys of tadpoles.The adult is most closely related to Echinoparyphium recurvatum (Linstow). It differs from this in its greater number of eggs and in its life-history. E. recurvatum occurs predominantly in birds, and is rarely found naturally in mammals. E. hydromyos has been found only in a mammal.Cercaria echinoparyphii hydromyos is compared with C. clelandae Johnston and Angel; it differs from the latter in the ‘compound’ nature of the excretory granules. The adult of C. clelandae has not been demonstrated in spite of a number of experiments to determine it.Type material has been deposited in the South Australian Museum.I wish to acknowledge the help given by my colleague, Patricia M. Thomas, in field work and in other ways, and by Mr Ian Smith, of this department, in the experimental work on life-history studies.

Habitat preference of the Australian water rat (Hydromys chrysogaster) in a coastal wetland and stream, Two Peoples Bay, south-western Australia

2013 ◽  
Vol 35 (2) ◽  
pp. 188 ◽  
Author(s):  
Peter C. Speldewinde ◽  
Paul Close ◽  
Melissa Weybury ◽  
Sarah Comer
Keyword(s):  
Home Range ◽  
Western Australia ◽  
Nature Reserve ◽  
Coastal Wetland ◽  
Preliminary Investigation ◽  
Canopy Cover ◽  
Home Range Size ◽  
Australian Water ◽  
Linkage Method ◽  
Hydromys Chrysogaster

This study provides a preliminary investigation of the home range and habitat selection of the Australian water rat (Hydromys chrysogaster) in Two Peoples Bay Nature Reserve near Albany, Western Australia. Six individuals were captured (trap success 1.9%) from 810 trap-nights. This low number suggests that the water rat population in Two Peoples Bay Nature Reserve is much smaller than anecdotal evidence would suggest. Home-range size (neighbour-linkage method) averaged 18.9 ha (±11.6). Individuals preferentially utilised wetland habitats characterised by dense, low-lying vegetation (0–30 cm from ground), low-density canopy cover and shallow, narrow water bodies.

The gastrointestinal tract of the Australian water rat (Hydromys chrysogaster) – its morphological adaptations to a carnivorous diet

2016 ◽  
Vol 38 (1) ◽  
pp. 52 ◽  
Author(s):  
K. N. Speight ◽  
M. J. Kokkinn ◽  
W. G. Breed
Keyword(s):  
Small Intestine ◽  
Gastrointestinal Tract ◽  
Large Intestine ◽  
Australian Water ◽  
Intestinal Length ◽  
Morphological Adaptations ◽  
Muroid Rodents ◽  
Murine Rodents ◽  
Hydromys Chrysogaster ◽  
Protein Rich

The Australian water rat (Hydromys chrysogaster), unlike most murine rodents, has a carnivorous diet. In the present study the morphology of its gastrointestinal tract is described and compared with that of other muroid rodents with more typical diets. It was found that the stomach of the water rat is relatively small and has a greater proportion of glandular epithelium than that of other species so far investigated. Comparisons of relative intestinal lengths showed that in the Australian water rat there is a comparatively long small intestine that constitutes ~90% of the total intestinal length, a short large intestine, and a small caecum. This divergent morphology of the gastrointestinal tract of the Australian water rat probably relates to the animal’s protein-rich diet, with the differences from those of other hydromyine rodents indicating considerable plasticity in the evolution of the gastrointestinal tract in this group of mammals. It suggests that, whilst the morphological adaptations of the water rat’s gastrointestinal tract probably evolved before the colonisation of Australia, its highly derived morphology has enabled this species to exploit the Australian environment as an aquatic carnivore.

scholarly journals Klossiella hydromyos n.sp. from the Kidneys of an Australian Water Rat (Hydromys chrysogaster)

1971 ◽  
Vol 8 (3) ◽  
pp. 222-231 ◽  
Author(s):  
H. Winter ◽  
D. Watt
Keyword(s):  
New Species ◽  
Kidney Tubules ◽  
Australian Water ◽  
Renal Vessels ◽  
Hydromys Chrysogaster ◽  
A New Species

Klossiella hydromyos from the kidney of an Australian water rat ( Hydromys chrysogaster) is reported as a new species. Numerous examples of the various stages of the sporogonic cycle were observed in the epithelium of the kidney tubules. In addition there were also schizonts, mainly in the glomeruli and to a lesser extent in the renal vessels

Body Temperature Variability in the Australian Water Rat, Hydromys chrysogaster, in Air and Water

1980 ◽  
Vol 28 (2) ◽  
pp. 229 ◽  
Author(s):  
FD Fanning ◽  
TJ Dawson
Keyword(s):  
Heat Loss ◽  
Cold Water ◽  
Vascular System ◽  
Australian Water ◽  
The Poor ◽  
Air Temperatures ◽  
Level Of Activity ◽  
Eastern Australia ◽  
Stable Core ◽  
Hydromys Chrysogaster

Body and skin temperatures were recorded from water rats exposed to a range of air temperatures and also immersed in water at various temperatures. They were able to maintain stable core temperatures (mean 36.1�C, SD 0.65, n=61) at air temperatures up to 30�C. At 35�C they were unable to avoid hyperthermia despite their use of saliva spreading to enhance heat loss. Regional heterothermia was observed both in air and in water, but water rats were unable to maintain deep body temperatures at water temperatures lower than 25�C. Variations in the level of activity in cold water affected the rate of heat loss. Examination of the vascular system revealed the presence of various networks adapted for heat loss, but no major heat-conserving vascular retia. It is suggested that the poor thermoregulatory performance of water rats during aquatic excursions is largely due to the lack of heat-conserving retia, and to the poor insulative capacity of the fur when wet. The platypus, which possesses excellent fur insulation and a highly developed heat-conserving system, is a very competent homeotherm in cold water. The behavioural responses displayed by water rats which enable them to exploit the aquatic environment in south-eastern Australia are discussed.

scholarly journals Hydrodynamic reception in the Australian water rat, Hydromys chrysogaster

2020 ◽  
Vol 206 (4) ◽  
pp. 517-526
Author(s):  
Wolf Hanke ◽  
Sabine Meyer ◽  
Horst Bleckmann ◽  
Guido Dehnhardt
Keyword(s):  
Australian Water ◽  
Hydromys Chrysogaster

scholarly journals Energetics of locomotion by the Australian water rat (Hydromys chrysogaster): a comparison of swimming and running in a semi-aquatic mammal

1999 ◽  
Vol 202 (4) ◽  
pp. 353-363 ◽  
Author(s):  
F.E. Fish ◽  
R.V. Baudinette
Keyword(s):  
Metabolic Rate ◽  
Bound Water ◽  
Minimum Cost ◽  
Wave Drag ◽  
Swimming Velocity ◽  
Cost Of Transport ◽  
Australian Water ◽  
Aquatic Mammal ◽  
Hydromys Chrysogaster ◽  
Aquatic Mammals

Semi-aquatic mammals occupy a precarious evolutionary position, having to function in both aquatic and terrestrial environments without specializing in locomotor performance in either environment. To examine possible energetic constraints on semi-aquatic mammals, we compared rates of oxygen consumption for the Australian water rat (Hydromys chrysogaster) using different locomotor behaviors: swimming and running. Aquatic locomotion was investigated as animals swam in a water flume at several speeds, whereas water rats were run on a treadmill to measure metabolic effort during terrestrial locomotion. Water rats swam at the surface using alternate pelvic paddling and locomoted on the treadmill using gaits that included walk, trot and half-bound. Water rats were able to run at twice their maximum swimming velocity. Swimming metabolic rate increased with velocity in a pattern similar to the ‘humps’ and ‘hollows’ for wave drag experienced by bodies moving at the water surface. Metabolic rate increased linearly during running. Over equivalent velocities, the metabolic rate for running was 13–40 % greater than for swimming. The minimum cost of transport for swimming (2.61 J N-1 m-1) was equivalent to values for other semi-aquatic mammals. The lowest cost for running (2.08 J N-1 m-1) was 20 % lower than for swimming. When compared with specialists at the extremes of the terrestrial-aquatic continuum, the energetic costs of locomoting either in water or on land were high for the semi-aquatic Hydromys chrysogaster. However, the relative costs for H. chrysogaster were lower than when an aquatic specialist attempts to move on land or a terrestrial specialist attempts to swim.

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