scholarly journals Ventilatory Accommodation of Oxygen Demand and Respiratory Water Loss in Kangaroos from Mesic and Arid Environments, the Eastern Grey Kangaroo (Macropus giganteus) and the Red Kangaroo (Macropus rufus)

2000 ◽  
Vol 73 (3) ◽  
pp. 382-388 ◽  
Author(s):  
Terence J. Dawson ◽  
Adam J. Munn ◽  
Cyntina E. Blaney ◽  
Andrew Krockenberger ◽  
Shane K. Maloney
Keyword(s):  
Water Loss ◽  
Oxygen Demand ◽  
Arid Environments ◽  
Red Kangaroo ◽  
Grey Kangaroo ◽  
Macropus Rufus

A comparative study of macroscopic and microscopic dimensions of the intensine in five macropods (Marsupialia: Macropodidae). I. Allometric relationships.

1992 ◽  
Vol 40 (1) ◽  
pp. 91 ◽  
Author(s):  
R Osawa ◽  
PF Woodall
Keyword(s):  
Body Size ◽  
Confidence Limits ◽  
Surface Areas ◽  
Red Kangaroo ◽  
A Value ◽  
Grey Kangaroo ◽  
Macropus Rufus ◽  
Villous Height ◽  
Kleiber’S Law ◽  
Swamp Wallaby

Macroscopic and microscopic dimensions of the intestines in five macropod species (the red kangaroo, Macropus rufus; the eastern grey kangaroo, M. giganteus; the agile wallaby, M. agilis; the swamp wallaby, Wallabia bicolor; and the red-necked pademelon, Thylogale thetis) were investigated allometrically in relation to body mass. In general, the length of the small intestine changed in an area : volume (A:V) compensating manner, but the circumference showed negative allometry such that the overall change in surface areas, both ground and mucosal (including the contribution of villi), were isometric but also included the coefficient derived from 'Kleiber's Law' (0.75) in their 95 and 99% confidence limits, respectively. Villous height and width generally showed no significant correlations with body size, but villous density was lower in large individuals. The allometry coefficient for the length of the large intestine was generally near the A:V compensating value (0.5) in most intraspecific analyses but much higher in the interspecific analysis, suggesting that some factor other than body size might be important (possibly dietary fibre). Caecal length was significantly correlated with body size only in two largest species (M. rufus and M. giganteus) and the interspecific analysis gave a value near A:V compensation).

SRY and karyotypic status of one abnormal and two intersexual marsupials

1997 ◽  
Vol 9 (2) ◽  
pp. 233 ◽  
Author(s):  
C. M. Watson ◽  
P. G. Johnston ◽  
K. A. Rodger ◽  
L. M. McKenzie ◽  
R. J. Waugh O'Neill ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Y Chromosome ◽  
Sex Chromosome ◽  
Sex Differentiation ◽  
Sry Gene ◽  
Genetic Studies ◽  
Cultured Fibroblasts ◽  
Red Kangaroo ◽  
Grey Kangaroo ◽  
Macropus Rufus

An intersexual agile wallaby (Macropus agilis) with a penis, a pouch and four teats had a sex-chromosome constitution of XXY in lymphocytes and cultured fibroblasts; the sex-determining region Y (SRY) gene was present, consistent with the presence of a testis. An intersexual eastern grey kangaroo (Macropus giganteus) with a small empty scrotum and no penis, and an abnormal red kangaroo (Macropus rufus) with no penis, pouch or teats, both had XX sex-chromosome complements; the SRY gene was not present, consistent with testis absence. The agile wallaby and grey kangaroo described here provide further evidence that scrotal development in marsupials is independent of the Y chromosome. The cause of the abnormalities in the XX individuals cannot be determined until candidate genes are identified. These animals provide a basis for further genetic studies into marsupial intersexuality and sex differentiation.

Diagnosis and treatment of mesenteric volvulus in a red kangaroo (Macropus rufus)

2014 ◽  
Vol 244 (7) ◽  
pp. 844-850 ◽  
Author(s):  
S. Emmanuelle Knafo ◽  
Alana J. Rosenblatt ◽  
James K. Morrisey ◽  
James A. Flanders ◽  
Margret S. Thompson ◽  
...  
Keyword(s):  
Diagnosis And Treatment ◽  
Red Kangaroo ◽  
Macropus Rufus

Evolution of water balance in the genusDrosophila

2001 ◽  
Vol 204 (13) ◽  
pp. 2331-2338 ◽  
Author(s):  
Allen G. Gibbs ◽  
Luciano M. Matzkin
Keyword(s):  
Water Balance ◽  
Water Loss ◽  
The Body ◽  
The Other ◽  
Arid Environments ◽  
Physiological Mechanisms ◽  
Dehydration Tolerance ◽  
Cactophilic Drosophila ◽  
Adaptive Mechanisms ◽  
The World

SUMMARYFruit flies of the genus Drosophila have independently invaded deserts around the world on numerous occasions. To understand the physiological mechanisms allowing these small organisms to survive and thrive in arid environments, we performed a phylogenetic analysis of water balance in Drosophila species from different habitats. Desert (cactophilic) species were more resistant to desiccation than mesic ones. This resistance could be accomplished in three ways: by increasing the amount of water in the body, by reducing rates of water loss or by tolerating the loss of a greater percentage of body water (dehydration tolerance). Cactophilic Drosophila lost water less rapidly and appeared to be more tolerant of low water content, although males actually contained less water than their mesic congeners. However, when the phylogenetic relationships between the species were taken into account, greater dehydration tolerance was not correlated with increased desiccation resistance. Therefore, only one of the three expected adaptive mechanisms, lower rates of water loss, has actually evolved in desert Drosophila, and the other apparently adaptive difference between arid and mesic species (increased dehydration tolerance) instead reflects phylogenetic history.

Diets and foraging behaviour of red and eastern grey kangaroos in arid shrub land: is feeding behaviour involved in the range expansion of the eastern grey kangaroo into the arid zone?

2004 ◽  
Vol 26 (2) ◽  
pp. 169 ◽  
Author(s):  
TJ Dawson ◽  
KJ McTavish ◽  
BA Ellis
Keyword(s):  
Feeding Behaviour ◽  
Foraging Behaviour ◽  
Arid Zone ◽  
Foraging Strategies ◽  
Foraging Patterns ◽  
Grey Kangaroo ◽  
Macropus Rufus ◽  
Dietary Niche ◽  
Domestic Stock ◽  
Total Feeding

Eastern grey kangaroos (Macropus giganteus) have expanded into arid areas usually the habitat of red kangaroos (Macropus rufus). Extra watering sites for domestic stock is the suggested reason. However, changes in vegetation also have occurred due to grazing from domestic stock. We investigated the foraging strategies of M. giganteus and M. rufus in arid rangeland to see if these are involved in the range changes. Foraging patterns were similar, with both species mostly foraging at night; total feeding times were the same. M. giganteus and M. rufus had differing diets, though there was considerable overlap of 81 - 87%. Both species were highly selective, having similar narrow dietary niche breaths. Differences in plant preferences occurred and though both species had a preference for grass that of M. giganteus was higher. A larger foregut in M. giganteus reinforces its focus on grass. M. rufus also selected dicot forbs and malvaceous sub-shrubs. Both kangaroos showed avoidance of abundant chenopod shrubs (saltbushes and bluebushes) and trees. It is likely that the changes to arid-zone vegetation, with a shift to grass and annual dicot forbs, has been important for the expansion of M. giganteus, possibly combined with the greater availability of water.

Bilateral radial and ulnar fractures in a red kangaroo (Macropus rufus)

2019 ◽  
Vol 255 (8) ◽  
pp. 942-948 ◽  
Author(s):  
Katherine L. Ballor ◽  
Krista M. Gazzola ◽  
Karen L. Perry
Keyword(s):  
Red Kangaroo ◽  
Macropus Rufus

The ontogeny of the pancreas in macropodid marsupials

1978 ◽  
Vol 26 (3) ◽  
pp. 487
Author(s):  
AW White ◽  
CJF Harrop
Keyword(s):  
Connective Tissue ◽  
Relative Size ◽  
Pancreatic Tissue ◽  
Pancreatic Development ◽  
Endocrine Tissue ◽  
Red Kangaroo ◽  
Slow Development ◽  
Grey Kangaroo ◽  
Insulin Secreting Cells ◽  
Acinar Tissue

The development of the endocrine pancreas in kangaroos was examined histologically with tissue from three kangaroo species, the red kangaroo Megaleia rufa, the euro Macropus robustus erubescens, and the grey kangaroo Macropus giganteus. The relative size of the pancreas of the pouch young was found not to differ significantly from that of adults. Stages of pancreatic development were described from the frequency of the occurrence of the pancreatic epithelial ducts and the B or insulin-secreting cells, while the development and distribution of the A2 or glucagon-producing cells was also observed. In pouch young of less than 22 days of age the pancreas is dominated by ductular epithelial and undifferentiated pancreatic cells. From days 42 to 97 of pouch life B endocrine cells tend to be concentrated together and ductular tissue encroaches into areas previously dominated by connective tissue. After 120-135 days the first A2 cells are apparent and are usually located at the periphery of the islets, which now take on a distinctive appearance as the acinar tissue expands and separates them. After 135 days of pouch life A2 cells outnumber B cells; the endocrine tissue assumes an adult appearance after 150-160 days. The major difference between the development of pancreatic tissue in foetal sheep and pouch-young kangaroo is the prolonged dominance of connective tissue and the slow development of endocrine tissue in the former.

PETERS ANOMALY IN A RED KANGAROO (MACROPUS RUFUS)

2014 ◽  
Vol 45 (3) ◽  
pp. 715-718 ◽  
Author(s):  
Wm. Kirk Suedmeyer ◽  
Jacqueline Pearce ◽  
Meredith Persky ◽  
Marlys L. Houck
Keyword(s):  
Red Kangaroo ◽  
Peters Anomaly ◽  
Macropus Rufus
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