Molar progression and tooth wear in tammar (Macropus eugenii) and parma (Macropus parma) wallabies

2003 ◽  
Vol 51 (2) ◽  
pp. 137 ◽  
Author(s):  
R. G. Lentle ◽  
I. D. Hume ◽  
K. J. Stafford ◽  
M. Kennedy ◽  
S. Haslett ◽  
...  
Keyword(s):  
Theoretical Model ◽  
Body Mass ◽  
Functional Significance ◽  
Tooth Wear ◽  
Tammar Wallaby ◽  
Molar Tooth ◽  
Forward Movement ◽  
Tooth Morphology ◽  
Macropus Eugenii ◽  
Tooth Length

We investigated the functional significance of molar progression and the influence of diet on the usefulness of molar progression as an index of age in two macropodid marsupials, the tammar wallaby (Macropus eugenii), a grazing species, and the parma wallaby (Macropus parma), a browser/grazer, by exploring the relationships between the index of molar progression and several skull and tooth parameters. We also tested allometric models that related molar progression and aspects of tooth morphology to body mass. Results support the notion that molar progression in these closely related macropods results from 'mesial shift'(forward movement resulting from growth of the bones of the skull bearing the dentary, the anterior viscerocranium) rather than from 'mesial drift' (forward movement of molars relative to the anterior viscerocranium).There were no significant differences between the two species in the rate of molar progression despite differences in diet. Instead, the greater reliance of tammar wallabies on grasses was reflected in differences in their tooth morphology from that of parma wallabies. The sum of the breadths of erupted molariform teeth of tammars increased significantly faster with body mass and with length of the anterior viscerocranium than in parma wallabies and approximated a theoretical model for compensation with metabolic body mass more closely than models based on other morphological parameters.The total mesiodistal length of dentition, the mesiodistal lengths of the component teeth of the proximal molar row, and the distance between the mesial and distal lophs were all significantly lower in tammar wallabies than in parma wallabies. These differences result in tammar wallabies having greater numbers of transverse cutting edges per unit of molar tooth length, which maximises the efficiency of comminution of long grass fibres.

Comparisons of indices of molar progression and dental function of brush-tailed rock-wallabies (Petrogale penicillata) with tammar (Macropus eugenii) and parma (Macropus parma) wallabies

2003 ◽  
Vol 51 (3) ◽  
pp. 259 ◽  
Author(s):  
R. G. Lentle ◽  
I. D. Hume ◽  
K. J. Stafford ◽  
M. Kennedy ◽  
S. Haslett ◽  
...  
Keyword(s):  
Body Mass ◽  
Tammar Wallaby ◽  
Mean Value ◽  
Dietary Habit ◽  
Macropus Eugenii ◽  
Total Length ◽  
Rate Of Increase ◽  
The Mean

We measured parameters of molar progression and dental function in the brush-tailed rock-wallaby (Petrogale pencilliata) (a browser/grazer) and compared them with data from the tammar wallaby (Macropus eugenii) (a grazer) and the parma wallaby (Macropus parma) (a grazer/browser).Although the mean value of the molar index (MI) was higher in rock-wallabies than in parma and tammar wallabies the mean rate of increase of log(MI) with log(body mass) was similar in the three species. Reported differences between these species in their rates of molar progression with age may therefore result from differences in their rates of bodily growth. The findings indicate that molar progression in the rock-wallaby is governed by the growth of the bones of the viscerocranium (mesial shift), rather than by diet-induced movement of the teeth within the bones of the viscerocranium (mesial drift), and was not influenced by the persistence of P4 premolars. It is therefore unlikely that differences in the rate of molar progression are directly linked to differences in diet.The relationship between functional dental parameters and body mass differed between brush-tailed rock-wallabies and tammar wallabies, species of differing dietary habit, but did not differ between brush-tailed rock-wallabies and parma wallabies, species of more similar dietary habit. Thus the total length of upper transverse lophine ridges and the interlophine distances of the M1 to M3 upper molars of brush-tailed rock-wallabies were not different from those of parma wallabies but were significantly greater than those of tammar wallabies. These differences can be interpreted in terms of greater emphasis on crushing/grinding of browse in the rock-wallabies and parma wallabies.

scholarly journals Digestive plasticity of the small intestine and the fermentative hindgut in a marsupial herbivore, the tammar wallaby (Macropus eugenii)

2006 ◽  
Vol 54 (4) ◽  
pp. 287 ◽  
Author(s):  
Adam J. Munn ◽  
Peter Banks ◽  
Ian D. Hume
Keyword(s):  
Small Intestine ◽  
Body Mass ◽  
Alimentary Tract ◽  
Nutritional Ecology ◽  
Tammar Wallaby ◽  
Proximal Colon ◽  
The Body ◽  
Macropus Eugenii ◽  
Diet Versus ◽  
Pelleted Diet

We investigated the effects of a ground, pelleted diet versus natural forage on the gross morphology of the gastrointestinal tract of a medium-sized (5–7 kg body mass) macropodid marsupial, the tammar wallaby (Macropus eugenii). The empty wet mass (g) of the small intestine of tammar wallabies maintained on a pelleted diet for 6 weeks was 22% greater than that of animals maintained on natural forage, once body mass was taken into account by ANCOVA. Similarly, the body-mass-adjusted length of the tammar wallaby caecum and proximal colon combined was 25% longer in animals maintained on the pelleted diet compared with those maintained on forage. Our data suggest that food particle size may be directly involved in controlling the size of the post-gastric alimentary tract in tammar wallabies, and thus in their diet choice and nutritional ecology. Notably, this is the first study that links phenotypic plasticity of the gut directly to diet in a marsupial and we conclude that the tammar wallaby is an excellent model for exploring the causes and consequences of digestive plasticity in macropodid marsupials.

scholarly journals Growth of the corpus luteum and its progesterone content during pregnancy in the tammar wallaby, Macropus eugenii

Reproduction ◽  
1979 ◽  
Vol 57 (1) ◽  
pp. 131-136 ◽  
Author(s):  
M. B. Renfree ◽  
S. W. Green ◽  
I. R. Young
Keyword(s):  
Corpus Luteum ◽  
Tammar Wallaby ◽  
Macropus Eugenii

Mullerian inhibiting substance production and testicular migration and descent in the pouch young of a marsupial

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 549-556 ◽  
Author(s):  
J.M. Hutson ◽  
G. Shaw ◽  
W.S. O ◽  
R.V. Short ◽  
M.B. Renfree
Keyword(s):  
Tammar Wallaby ◽  
Testicular Descent ◽  
Future Studies ◽  
Macropus Eugenii ◽  
Müllerian Inhibiting Substance ◽  
Sequence Of Events ◽  
Testicular Differentiation ◽  
Testicular Migration ◽  
Australian Marsupial ◽  
Mullerian Inhibiting Substance

The ontogeny of Mullerian inhibiting substance (MIS) production by the developing testis of an Australian marsupial, the tammar wallaby (Macropus eugenii), was determined during pouch life using an organ-culture bioassay of mouse fetal urogenital ridge. This information was related to the morphological events during testicular migration and descent. MIS biological activity was found in testes (but not ovaries or liver) of pouch young from 2 to 85 days of age. MIS production had commenced by day 2, which is within a day of the first gross morphological signs of testicular differentiation. Mullerian duct regression occurred between 10 and 30 days, which partly coincided with testicular migration to the inguinal region and enlargement of the gubernacular bulb (15 to 30 days). These observations are consistent with the hypothesis that MIS may be involved in testicular transabdominal migration. The epididymis commenced development and growth only after the testis had descended through the inguinal ring. This provides no support for the suggestion that the epididymis is involved in testicular descent into the scrotum. The basic sequence of events in post-testicular sexual differentiation in the wallaby is sufficiently similar to that seen in eutherian mammals to make it an excellent experimental model for future studies of testicular differentiation, migration and descent.

Biochemical studies of intrauterine components of the tammar wallaby Macropus eugenii during pregnancy

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 325-338
Author(s):  
Elizabeth J. Thornber ◽  
Marilyn B. Renfree ◽  
Gregory I. Wallace
Keyword(s):  
Protein Concentration ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Fold Increase ◽  
Tammar Wallaby ◽  
Macropus Eugenii ◽  
Tenfold Increase ◽  
Specific Proteins ◽  
Wet Weight

The in vitro uptake and incorporation of [3H]ui idine by blastocysts of the tammar wallaby showed a 16- and 30-fold increase from day 0 to day 10 after removal of pouch young, respectively. Two of the six non-expanded blastocysts recovered on day 5 showed a tenfold increase in incorporation. During the first ten days after removal of pouch young the diameter of the blastocyst increased threefold. Endometrial exudate from gravid uteri had a higher protein concentration than exudate from nongravid uteri (39·5 ± 0·9 and 32·0 ± 2·0 mg/ml (mean ± s.e.m.), respectively). Endometrial exudates from uteri where the blastocyst was actively growing were found to contain six uterine-specific proteins. These were separated by gradient polyacrylamide gel electrophoresis. Two of the proteins were pre-albumins and the others were larger molecules (M.W. 153000–670000). Two proteins were only present at particular stages of pregnancy: the other four were present at all stages from diapause to birth, in exudate from gravid and nongravid uteri. The specific binding of progesterone and androstenedione to proteins in endometrial exudates or uterine flushings from pregnant wallabies was less than one per cent of the value obtained from day-5 pregnant rabbits. The ability of mouse blastocysts to take up and incorporate [3H]uridine into acidinsoluble material increased threefold in the presence of day-10 endometrial exudates from wallabies. However, this was less than ten percent of the values obtained in the presence of bovine serum albumin. The concentration of calcium in endometrial exudates increased from 23·6 to 45·2 μg/ml during pregnancy; in endometrium it remained at 88·7 μg/g (wet weight) throughout pregnancy, and in plasma it was 53·3 μg/ml. The concentration of zinc in endometrial exudates was 4·5 μg/ml; in endometrium it decreased from 21·8 to 13·3 μg/g (wet weight) during pregnancy and in plasma it was 0·6 μg/ml.

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