Early Growth of Magpie Geese, Anseranas-Semipalmata - Sex-Differences and Influence of Egg Size

1990 ◽  
Vol 38 (3) ◽  
pp. 249 ◽  
Author(s):  
PJ Whitehead ◽  
WJ Freeland ◽  
K Tschirner
Keyword(s):  
Sex Differences ◽  
Growth Rates ◽  
Egg Size ◽  
Growth Patterns ◽  
Juvenile Growth ◽  
Seasonal Wetlands ◽  
Adult Body ◽  
Wing Growth ◽  
Juvenile Males ◽  
Polygynous Mating System

The magpie goose, Anseranas semipalmata, is the most conspicuous and among the most numerous of waterfowl inhabiting the seasonal wetlands of tropical northern Australia. Modelling of juvenile growth rates of captive birds with the logistic equation showed that magpie geese grow at rates similar to the fast-growing anserine geese. High juvenile growth rates permit exploitation of seasonally favourable environments that, although highly productive, may deteriorate rapidly and unpredictably. Sex differences in juvenile growth patterns are consistent with pronounced sexual dimorphism in adult body size (larger males), which is associated with an unusual polygynous mating system. Although smaller, females grow relatively faster than males, so that at a given age they have completed a greater proportion of the pre-fledging growth phase; wing growth is particularly advanced and females fly earlier. Slower development may increase mortality among juvenile males when family groups are forced to abandon drying swamps, and contribute to skewing of the sex ratio towards females. Larger hatchlings from large eggs tend to maintain a size advantage, at least until fledging.

scholarly journals Enamel formation and growth in non-mammalian cynodonts

2018 ◽  
Vol 5 (5) ◽  
pp. 172293 ◽  
Author(s):  
Rachel N. O'Meara ◽  
Wendy Dirks ◽  
Agustín G. Martinelli
Keyword(s):  
Growth Rates ◽  
Polarized Light ◽  
Growth Patterns ◽  
Juvenile Growth ◽  
Tooth Replacement ◽  
Replacement Rate ◽  
Adult Growth ◽  
Evolution Of Mammals ◽  
Additional Explanation ◽  
Incremental Lines

The early evolution of mammals is associated with the linked evolutionary origin of diphyodont tooth replacement, rapid juvenile growth and determinate adult growth. However, specific relationships among these characters during non-mammalian cynodont evolution require further exploration. Here, polarized light microscopy revealed incremental lines, resembling daily laminations of extant mammals, in histological sections of enamel in eight non-mammalian cynodont species. In the more basal non-probainognathian group, enamel extends extremely rapidly from cusp to cervix. By contrast, the enamel of mammaliamorphs is gradually accreted, with slow rates of crown extension, more typical of the majority of non-hypsodont crown mammals. These results are consistent with the reduction in dental replacement rate across the non-mammalian cynodont lineage, with greater rates of crown extension required in most non-probainognathians, and slower crown extension rates permitted in mammaliamorphs, which have reduced patterns of dental replacement in comparison with many non-probainognathians. The evolution of mammal-like growth patterns, with faster juvenile growth and more abruptly terminating adult growth, is linked with this reduction in dental replacement rates and may provide an additional explanation for the observed pattern in enamel growth rates. It is possible that the reduction in enamel extension rates in mammaliamorphs reflects an underlying reduction in skeletal growth rates at the time of postcanine formation, due to a more abruptly terminating pattern of adult growth in these more mammal-like, crownward species.

Microstructural growth patterns in the otoliths of larval and juvenile starry flounder, Platichthys stellatus

1984 ◽  
Vol 62 (8) ◽  
pp. 1507-1512 ◽  
Author(s):  
Steven E. Campana
Keyword(s):  
Growth Rates ◽  
Larval Growth ◽  
Light And Electron Microscopy ◽  
Growth Patterns ◽  
Curvilinear Relationship ◽  
Juvenile Growth ◽  
Increment Width ◽  
Fish Size ◽  
Growth Increments ◽  
Platichthys Stellatus

Microstructural growth patterns were examined and interpreted in the otoliths of both wild and laboratory-reared starry flounders, Platichthys stellatus. Growth increments were not formed with a daily periodicity in laboratory-reared larvae. However, increment counts increased with the degree of sample preparation, suggesting that increments near the resolving limit of light microscopy were not being observed. Increments in wild flounder sagittae were more clearly defined under both light and electron microscopy; in addition, larval and juvenile growth patterns could be easily differentiated. A transition zone between the growth regions corresponded to the size and age at metamorphosis. An increase of increment width with larval age resulted from a curvilinear relationship between otolith diameter and fish size. Larval growth rates of wild fish remained relatively constant at 0.25 mm/day until metamorphosis; juvenile growth rates were substantially higher. Metamorphosis was characterized by a sudden but temporary decline in growth rate.

scholarly journals Egg size-dependent expression of growth hormone receptor accompanies compensatory growth in fish

2011 ◽  
Vol 279 (1728) ◽  
pp. 592-600 ◽  
Author(s):  
F. H. I. D. Segers ◽  
G. Berishvili ◽  
B. Taborsky
Keyword(s):  
Growth Hormone ◽  
Hormone Receptor ◽  
Egg Size ◽  
Growth Hormone Receptor ◽  
Yolk Sac ◽  
Juvenile Growth ◽  
Somatotropic Axis ◽  
Expression Levels ◽  
Potential Link ◽  
Adaptive Adjustment

Large egg size usually boosts offspring survival, but mothers have to trade off egg size against egg number. Therefore, females often produce smaller eggs when environmental conditions for offspring are favourable, which is subsequently compensated for by accelerated juvenile growth. How this rapid growth is modulated on a molecular level is still unclear. As the somatotropic axis is a key regulator of early growth in vertebrates, we investigated the effect of egg size on three key genes belonging to this axis, at different ontogenetic stages in a mouthbrooding cichlid ( Simochromis pleurospilus ). The expression levels of one of them, the growth hormone receptor ( GHR ), were significantly higher in large than in small eggs, but remarkably, this pattern was reversed after hatching: young originating from small eggs had significantly higher GHR expression levels as yolk sac larvae and as juveniles. GHR expression in yolk sac larvae was positively correlated with juvenile growth rate and correspondingly fish originating from small eggs grew faster. This enabled them to catch up fully in size within eight weeks with conspecifics from larger eggs. This is the first evidence for a potential link between egg size, an important maternal effect, and offspring gene expression, which mediates an adaptive adjustment in a relevant hormonal axis.

scholarly journals Erratum: Corrigendum: Dinosaurian growth patterns and rapid avian growth rates

Nature ◽  
2015 ◽  
Vol 531 (7595) ◽  
pp. 538-538
Author(s):  
Gregory M. Erickson ◽  
Kristina Curry Rogers ◽  
Scott A. Yerby
Keyword(s):  
Growth Rates ◽  
Growth Patterns

The effect of level of environment on sex differences in pre-weaning growth rate in beef cattle

1977 ◽  
Vol 25 (1) ◽  
pp. 47-51 ◽  
Author(s):  
I. R. Hopkins
Keyword(s):  
Growth Rate ◽  
Sex Differences ◽  
Beef Cattle ◽  
Growth Rates ◽  
Additive Models ◽  
Regression Equations ◽  
Male And Female ◽  
Breed Differences ◽  
Per Se ◽  
Simple Regression

SUMMARYUsing pre-weaning records of 3822 calves from 11 Victorian herds, mean male and female growth rates and corresponding sex differences were calculated for each dam age and herd-year class. From these means simple regression equations relating sex differences and growth rates were calculated. There was a close similarity between equations based on dam age means and those based on herd-year means while correlations between sex differences and male growth rates were high.These results showed that sex differences and female growth rates could be predicted reliably from the level of environment as measured by male growth rate. Sex differences predicted by these regression relationships differed markedly from those predicted by the simple multiplicative and simple additive models generally used in adjusting for sex differences in selection.The results also suggested that other differences such as breed differences may be predictable in the same way and that such differences are determined primarily by the level of environment per se rather than differences in the nature of the components contributing to that level.

GROWTH DEPRESSING FACTORS IN RAPESEED OILMEAL: II. STUDIES ON COUNTERACTION BY DIETARY SUPPLEMENTS

1957 ◽  
Vol 37 (1) ◽  
pp. 21-30 ◽  
Author(s):  
J. M. Bell ◽  
Elinor Baker
Keyword(s):  
Sex Differences ◽  
Dietary Supplements ◽  
Potassium Iodide ◽  
Growth Rates ◽  
Feed Utilization ◽  
Tissue Composition ◽  
Lactation Performance ◽  
Feed Supplement ◽  
Feeding Trials

Five experiments were reported, involving a total of over 350 mice, in feeding trials concerned mainly with growth rates and feed utilization. One experiment involved gestation-lactation performance of mice fed rapeseed oilmeal as a ration component.Proportions of rapeseed oilmeal ranged from 17 to 50 per cent of the diet. The feeding of iodinated casein or of potassium iodide failed to counteract the growth-depressant factor in rapeseed oilmeal. Aureomycin as a feed supplement was ineffective against the factor.Growth, tissue composition and lactation data confirmed the deleterious nature of high levels of rapeseed oilmeal in the ration and provided evidence that species and sex differences in response to the rapeseed oilmeal factor exist. Males appeared to be more severely affected than females. Mice did not respond to iodine and to iodinated casein as has been reported for chickens and turkeys.

scholarly journals Growth and body weight of free-range reindeer in western Alaska

Rangifer ◽  
2000 ◽  
Vol 20 (2-3) ◽  
pp. 221 ◽  
Author(s):  
Greg L. Finstad ◽  
Alexander K. Prichard
Keyword(s):  
Body Weight ◽  
Growth Rates ◽  
Total Body Weight ◽  
Growth Patterns ◽  
Spatial And Temporal Variation ◽  
Adult Males ◽  
Body Weights ◽  
Total Body ◽  
Reproductive Females ◽  
Average Body

Total body weight of 9749 reindeer calves and 4798 adult reindeer were measured from 1984 to 1999 on the Seward Peninsula, western Alaska, USA. Growth rates of male and female calves, and annual growth patterns of adults were determined. Male calves grew faster than female calves. Reproductive females were lighter than non-reproductive females during summer but there was no effect of reproduction on average body weights the following winter. Adult males age 3-5 were heavier during summer than winter. Castrated males weighed the same as uncastrated males in summer, but were significantly heavier in winter, and did not display the large annual fluctuations in weight typical of reproductive males and females. Growth rates were higher and body weights greater in this herd than many other cir-cumpolar reindeer populations. We suggest these kinds of physiological indices should be used to monitor the possible effects of spatial and temporal variation in population density and to evaluate changes in herding practices.

scholarly journals Seasonal patterns of pasture production in the Bay of Plenty and Waikato

1991 ◽  
pp. 67-72
Author(s):  
J.A. Baars ◽  
G.J. Goold ◽  
M.F. Hawke ◽  
P.J. Kilgarriff ◽  
M.D. Rolm
Keyword(s):  
Growth Rates ◽  
Early Spring ◽  
Early Summer ◽  
Growth Patterns ◽  
Climatic Data ◽  
Large Contribution ◽  
Pasture Production ◽  
Summer Peak ◽  
The Difference

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates

Abstract 13513: Serial CT Surveillance of Abdominal Aortic Aneurysm Diameter Demonstrates Predominantly Linear Growth (N-TA 3 CT)

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Sydney Olson ◽  
Marniker Wijesinha ◽  
Annalise Panthofer ◽  
William Blackwelder ◽  
Gilbert R Upchurch ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Linear Growth ◽  
Growth Patterns ◽  
Aortic Aneurysms ◽  
Transverse Diameter ◽  
Invasive Treatment ◽  
Abdominal Aortic ◽  
Risk Of Rupture ◽  
Serial Ct

Objective: Small abdominal aortic aneurysms (AAAs) have a low risk of rupture. Intervention is indicated when diameters exceed established thresholds. This study assessed the growth rates and patterns of AAAs over 2 years as documented on serial CT scans from the Non-Invasive Treatment of AAA Clinical Trial. Methods: 254 patients, 35 females with baseline AAA maximum transverse diameter (MTD) between 3.5-4.5 cm and 219 males with baseline MTD 3.5-5.0 cm, were included in this study. Linear regressions and segmental growth rates were used to model growth rates and patterns. Results: The yearly growth rates of AAA MTDs had a median of 0.17 cm/yr and mean of 0.19 cm/yr ± 0.14 (Figure 1). 10% of AAA displayed minimal to no growth (< 0.05 cm/yr), 62% low growth (0.05-0.25 cm/yr), 28% high growth (> 0.25 cm/yr). Baseline AAA diameter accounted for only 5.4% of growth rate variance (P<0.001, R 2 0.05). Most AAAs displayed linear growth (70%); large variations in interval growth rates occurred infrequently (3% staccato growth, 4% exponential growth); a minority of subjects’ growth patterns were not clearly classifiable (11% indeterminate-not growing, 12% indeterminate-growing) (Figure 2). No patients with baseline MTD < 4.25 cm exceeded sex-specific repair thresholds (males 0 / 92, [95% CI, 0.00-0.06]; females 0 / 25 [95% CI, 0.00-0.25]) in the course of follow-up for as long as two years. Conclusions: The majority of small AAAs exhibit linear growth; large intra-patient growth rate variations were infrequently observed over 2 years. AAA < 4.25 cm can be followed with a CT scan in 2 years with little chance of exceeding interventional MTD thresholds of 5.5 cm for men.

Sign in / Sign up

Export Citation Format

Share Document