Growth of Grey Kangaroos and the Reliability of Age Determination from Body Measurements II.* The Western Grey Kangaroos, Macropus fuliginosus fuliginosus, M. f. melanops and M. f. ocydromus

1982 ◽  
Vol 9 (2) ◽  
pp. 203 ◽  
Author(s):  
WE Poole ◽  
SM Carpenter ◽  
JT Wood
Keyword(s):  
Growth Curve ◽  
Young Animal ◽  
Age Determination ◽  
Growth Curves ◽  
Birth Date ◽  
First Year ◽  
Body Measurements ◽  
Grey Kangaroo ◽  
Pass Through

Seven body measurements were taken at regular intervals throughout life from both male and female western grey kangaroos of known birth date. For each sex of three subspecies and for each body measurement a growth curve was fitted, and confidence intervals calculated for determining the age of new animals. As with eastern grey kangaroos, a phase change in the growth curve was apparent at the time when the young vacate the pouch. Join points in the curve for each subspecies of western grey kangaroos were estimated empirically, as three-quarters through the interval between first emergence and final vacation of the pouch by a young animal. The growth curves were represented by a four-parameter non-linear model consisting of two hyperbolas constrained to pass through the common point. Tables presented contrast the ages at which percentile growth values are attained for each subspecies, and also provide examples of the determination of age from body measurements for both males and females, at monthly intervals during their first year. As found for the eastern grey kangaroo, head length proved to be the most reliable criterion, and all measurements of animals older than 2 years were unreliable for age determination.

Growth of Grey Kangaroos and the Reliability of Age Determination from Body Meausrements I. The Eastern Grey Kangaroo, Macropus giganteus

1982 ◽  
Vol 9 (1) ◽  
pp. 9 ◽  
Author(s):  
WE Poole ◽  
SM Carpenter ◽  
JT Wood
Keyword(s):  
Confidence Intervals ◽  
Growth Curve ◽  
Age Determination ◽  
Tail Length ◽  
Birth Date ◽  
First Year ◽  
Grey Kangaroo ◽  
Pass Through ◽  
Join Point

Measurements of bodily parts were taken throughout life from captive male and female eastern grey kangaroos of known birth date. For each body measurement a growth curve was fitted, and confidence intervals calculated for determining the age of any new animal. A change of phase in the growth curve was apparent at the time when the young vacate the pouch. A join point in the curve was empirically estimated to occur at approximately 310 days, and the growth curve was represented by a 4-parameter non-linear model consisting of two hyperbolas constrained to pass through this common point. Tables presented permit determination of age from body measurements with corresponding confidence intervals for both males and females at 30-day intervals in the first year and less frequent intervals for the age of 15-36 months. Head and leg lengths proved to be the most reliable criteria for age determination; arm and foot length were reasonably accurate; ear length, tail length and weight were unreliable criteria.

Age Determination in the Dingo and Crossbreeds.

1991 ◽  
Vol 18 (1) ◽  
pp. 75 ◽  
Author(s):  
PC Catling ◽  
LK Corbett ◽  
M Westcott
Keyword(s):  
Age Estimation ◽  
Canis Familiaris ◽  
Age Determination ◽  
Growth Curves ◽  
Growth Patterns ◽  
Birth Date ◽  
Eye Lens ◽  
Body Measurements ◽  
Confidence Limits ◽  
Regular Body

Growth curves were derived for captive known-age dingoes, Canis familiaris dingo, and their crosses with similarly sized domestic dogs, C. f. familiaris. Regular body measurements including weight and dried eye-lens weights were used. Age calibration curves and confidence limits were then produced to enable age estimation of animals of unknown birth date. Head length was the better predictor of age up to about 120 days, and eye-lens weight to about 500 days. The only difference in growth patterns in dingoes and crossbreeds from central and southern Australia was between sexes.

scholarly journals Radiographic pelvimetry in 0 to 24 month-old pacas (Agouti paca, Linnaeus, 1766)

2019 ◽  
Vol 71 (4) ◽  
pp. 1293-1298
Author(s):  
N.F. Smargiassi ◽  
I.C.C. Lippi ◽  
R.G.S. Oliveira ◽  
M.R.F. Machado ◽  
T.H.C. Sasahara ◽  
...  
Keyword(s):  
Age Determination ◽  
Strong Tendency ◽  
Birth Date ◽  
Scientific Interest ◽  
Closure Time ◽  
Ossification Centers ◽  
Constant Growth

ABSTRACT The pelvimetry consists of the metric determination of the pelvis dimensions and its use is directly related to the reproduction. The cartilage closure time of the ossification centers varies according to the bone, some closing already in the uterine life and others remaining present for many years. The objective was to evaluate, radiographically, the pelvic diameters by pelvimetry during the first 24 months of life in pacas, the second lagest Brazilian rodent and an animal that has shown big recent scientific interest, aiming the estimated age determination. Twelve pacas were used, which were monthly radiographed up from birth until 24 months old, with the animals anesthetized. The pacas are dolicopelvic animals and with pelvis presenting strong tendency to constant growth along the 12 first months of age, fact that can be useful in the approximated animals’ age determination that do not have precise birth date, for example.

Growth of Grey Kangaroos and the Reliablility of Age Determination from Body Measurements III. Interspecific Comparisions between Eastern and Western Grey Kangaroos, Macropus giganteus and M. fuliginosus

1984 ◽  
Vol 11 (1) ◽  
pp. 11 ◽  
Author(s):  
WE Poole ◽  
SM Carpenter ◽  
JT Wood
Keyword(s):  
Growth Models ◽  
Age Determination ◽  
Growth Patterns ◽  
Adult Size ◽  
Body Measurements ◽  
Foot Length ◽  
The Common ◽  
Rates Of Growth ◽  
Body Parameters

Seven body measurements were taken at regular intervals throughout life from both male and female eastern and western grey kangaroos. Evaluation of the reliability of criteria for determination of age and some aspects of the growth models for the two species were presented in earlier papers in this series. In this paper the common patterns and relationships between species in the growth characteristics of their body parameters are described and analysed. Comparison is made between species and sexes of rates of growth and size attained both within the pouch and following vacation of the pouch. Head, arm, leg and foot length were important discriminators, particularly when contrasted in various ways to summarize different body proportions. The insular form M.f. fuliginosus readily separated from the mainland forms, and M.f. ocydromus showed some differences which were related to its longer pouch life. Hybrid animals showed growth patterns intermediate to those of their parents. Sexual dimorphism in patterns ofgrowth was not detected during pouch life but was exhibited by all species after the young vacated the pouch and grew towards their full adult size.

scholarly journals Age determination and growth of Atlantic redfish (Sebastes marinus and S. mentella): bias and precision of age readers and otolith preparation methods

2005 ◽  
Vol 62 (4) ◽  
pp. 655-670 ◽  
Author(s):  
Christoph Stransky ◽  
Sif Gudmundsdóttir ◽  
Thorsteinn Sigurdsson ◽  
Svend Lemvig ◽  
Kjell Nedreaas ◽  
...  
Keyword(s):  
Stock Assessment ◽  
Age Determination ◽  
Growth Curves ◽  
Age And Growth ◽  
Preparation Methods ◽  
Irminger Sea ◽  
Coefficients Of Variation ◽  
Commercial Species ◽  
Almost All

Abstract Age determination of Atlantic redfish (Sebastes spp.) has proven difficult and has led to inconsistent age and growth estimates in the past. Using otoliths of the two major commercial species, golden redfish (Sebastes marinus) and deep-sea redfish (S. mentella), a series of exchange schemes was carried out to assess bias and precision of age readings between four readers and between two preparation methods. Considerable bias between readers and moderate precision were observed for the S. marinus readings, especially for ages >20 years, with coefficients of variation (CV) of 7.7–12.0% and average percent error (APE) of 5.4–8.5%. Agreement between readers increased from 17–28% to 45–61% when allowing deviations of ±1 year, and to 80–92% with ±3 years tolerance. The age of S. marinus determined from broken and burnt otoliths was estimated to be slightly lower than when the age of the same individuals was determined from thin-sectioned otoliths. The bias and precision estimates obtained from the S. mentella material were generally poorer than for S. marinus (CV 8.2–19.1%, APE 5.8–13.5%), but similar to reported values for other long-lived fish species. Better than 50% agreement was only achieved with ±3 years tolerance. Growth rates differed significantly between species, confirming slower growth for S. mentella. For S. marinus, only one reader comparison revealed significantly different growth functions, whereas almost all S. mentella reader pairs showed significant differences in growth curves. Section and break-and-burn readings of S. marinus did not differ significantly. Average ages of around 9–10 years were determined for juvenile S. mentella 24–30 cm long, which were likely to have migrated from East Greenland into the Irminger Sea, based on earlier observations. As some of the error in the age determinations presented could be attributed to interpretation differences between readers, further intercalibration of redfish ageing is urgently needed in order to provide consistent input data for stock assessment.

scholarly journals Natural Growth and Mortality of the Golden Grey Mullet Liza Aurata (Risso, 1810) In the Lagoon of Klisova-Messolonghi (W. Greece)

2019 ◽  
pp. 23-31 ◽  
Author(s):  
George N. Hotos
Keyword(s):  
Growth Parameters ◽  
Age Determination ◽  
Growth Curves ◽  
Growth Function ◽  
First Year ◽  
Annual Growth Rate ◽  
Von Bertalanffy ◽  
Liza Aurata ◽  
Total Length ◽  
Von Bertalanffy Growth Function

Growth and mortality of L. aurata (Risso,1810) were estimated in the lagoon of Klisova-Messolonghi (W. Greece), based on age estimation from scale readings of a total of 1048 individuals, ranging between 10 and 59 cm in total length (TL). Age determination revealed nine age classes (0+ to 8+). Maximum age was found to be 8 years for females and 6 years for males respectively. The growth pattern of L. aurata exhibited allometry (b=3.26). The species seems to achieve 34% of its growth during the first year; thereafter the annual growth rate drops. Both sexes presented similar von Bertalanffy growth curves. The von Bertalanffy growth function for the estimated total length-at-age was found Lt = 70.78 [1 - e -0.129(t+1.345)] for the combined sexes. Otolith weight, length and width were tested and they were found to be very good predictors for age. Between the present L. aurata growth parameters and those of other Mediterranean, Caspian and Atlantic Sea for the same species, there were found significant differences in its growth parameters. The total (Z) and natural (M) mortality rate was found to be 0.54 years-1 and 0.33 years-1 respectively. The estimated exploitation rate was found to be E=0.395 which suggests that the existing fishing pressure on L. aurata is rather moderate in the investigated region.

Effects of altering growth curve and age at photostimulation in female broiler breeders. 1. Reproductive development

2001 ◽  
Vol 81 (4) ◽  
pp. 467-476 ◽  
Author(s):  
R. A. Renema ◽  
F. E. Robinson ◽  
P. R. Goerzen
Keyword(s):  
Growth Curve ◽  
Sexual Maturity ◽  
Growth Curves ◽  
Broiler Breeder ◽  
Carcass Parameters ◽  
Ovarian Morphology ◽  
Plasma Estradiol ◽  
Broiler Breeder Hens ◽  
Estradiol 17Β

An experiment was conducted to evaluate the effect of differences in growth curve and age at photostimulation on carcass traits and ovarian morphology in broiler breeder hens at photostimulation and at sexual maturity. Pullets were grown on one of three growth curves STD (standard), LOW (150 g lighter than STD) and HIGH (150 g heavier than STD), and were photostimulated at either 19 wk of age (19WK) or 21 wk of age (21WK). Weekly blood samples were taken between photostimulation and sexual maturity for determination of estradiol-17β concentration. Twelve birds per interaction were processed at photostimulation for determination of carcass and reproductive morphology, followed by an additional 10 birds per interaction at sexual maturity. Unless otherwise stated, all significance was assessed at the P < 0.05 level. At photostimulation, the HIGH birds were larger and had more carcass lipid (7.44%) than the LOW birds (6.22%). By sexual maturity, carcass lipid as a percentage of BW was similar among the growth curve groups, as were the weights of most carcass parameters measured relative to BW. The large yellow follicle content of ovaries from LOW, STD, and HIGH birds were not different. Ovaries from HIGH birds had 48.2% of large yellow follicles arranged in multiple sets (large yellow follicles weighing within 1 g) compared to 29.5% in STD birds. Birds photostimulated earlier took longer to lay their first egg after photostimulation (19WK = 41.3 d, 21WK = 35.1 d), although this still occurred at a younger age (19WK = 174.3 d of age, 21W K = 182.1 d of age). The profile of plasma estradiol-17β concentration of the 19WK birds appeared to increase more slowly than for the 21WK pullets. As plasma estradiol-17β concentration will increase at a regular rate once it begins to increase, the flatter summary profile of 19WK pullets may be indicative of a less-uniform response to photostimulation. Based on the BW growth curves used in this trial and data collected at photostimulation and sexual maturity, there was no advantage of early photostimulation, and ovarian morphology may be negatively affected by moderate increases in rearing growth curve. Key words: Broiler breeder, sexual maturity, ovarian morphology, growth curve, body weight

Age Determination of Male Bufo bufo (Amphibia, Anura) from the Netherlands, based on Year Rings in Phalanges

1980 ◽  
Vol 1 (3) ◽  
pp. 223-233 ◽  
Author(s):  
Agnes S. M. Hemelaar
Keyword(s):  
The Netherlands ◽  
Cross Sections ◽  
Age Determination ◽  
Bufo Bufo ◽  
First Year ◽  
The Common ◽  
One Year ◽  
Toad Bufo ◽  
Toad Bufo Bufo

AbstractBased on both the pattern of year rings in a particular phalanx of adult male specimens of the common toad Bufo bufo and the thickness of this bone in first-year toads, the rate of resorption of year rings in each toad could be assessed. It appeared that this rate of resorption is small. Therefore the age of male specimens of Bufo bufo from the Netherlands can be determined for about 92% by counting the number of year rings in hematoxylin-stained cross-sections of this particular phalanx. This percentage can be raised to 93-98% by considering the year rings resorbed. The age of the remaining toads may be underestimated by not more than one year.

Effects of altering growth curve and age at photostimulation in female broiler breeders. 2. Egg production parameters

2001 ◽  
Vol 81 (4) ◽  
pp. 477-486 ◽  
Author(s):  
R. A. Renema ◽  
F. E. Robinson ◽  
P. R. Goerzen ◽  
M. J. Zuidhof
Keyword(s):  
Growth Curve ◽  
Egg Production ◽  
Growth Curves ◽  
Sequence Length ◽  
Broiler Breeder ◽  
Production Parameters ◽  
Breeder Hens ◽  
Broiler Breeder Hens ◽  
Egg Production Rate

An experiment was conducted to evaluate the effect of differences in growth curve and age at photostimulation on egg production parameters and carcass traits at 61 wk of age in broiler breeder hens. Pullets were grown on one of three growth curves: STD (standard), LOW (150g lighter than STD) and HIGH (150 g heavier than STD ), and photostimulated at either 19 wk of age (19WK) or 21 wk of age (21WK). The egg production and BW of 36 birds per interaction were individually monitored from photostimulation to 61 wk of age. Individual, daily egg production records were analyzed for total, settable, and defective egg production, rate of production, sequence length, and egg weight. Eggs were incubated for determination of fertility, hatchability, and embryonic mortality parameters. All birds remaining at 61 wk of age were processed for determination of carcass and reproductive morphology. Unless otherwise stated, all significance was assessed at the P < 0.05 level.

scholarly journals Age, growth, maturity, longevity and natural mortality of the shortfin mako shark (Isurus oxyrinchus) in New Zealand waters

2006 ◽  
Vol 57 (2) ◽  
pp. 143 ◽  
Author(s):  
S. D. H. Bishop ◽  
M. P. Francis ◽  
C. Duffy ◽  
J. C. Montgomery
Keyword(s):  
Fork Length ◽  
Growth Curves ◽  
Growth Patterns ◽  
Birth Date ◽  
First Year ◽  
Natural Mortality ◽  
Relative Growth ◽  
Mako Shark ◽  
Shortfin Mako ◽  
Males And Females

Shortfin mako sharks were aged by counting growth bands in sectioned vertebrae (n = 256), and assuming annual band-pair deposition. No systematic ageing bias was present and count precision was high. 0+ juveniles were identified from length–frequency plots and assigned ages based on a theoretical birth date of 1 October and their date of capture. A Schnute generalised growth model fitted to the combined vertebral and 0+ data described the growth patterns best. Shortfin makos grow very rapidly initially, increasing by ~39 cm fork length in their first year. Thereafter, males and females grow at similar but slower rates until about age 7 years, after which the relative growth of males declines. Longevity estimates were 29 and 28 years for males and females respectively. Natural mortality (M) is probably in the range of 0.10–0.15. Median ages at maturity were 7–9 years for males and 19–21 years for females. Comparisons of growth curves reported here and elsewhere suggest no regional differences in growth rates. The shortfin mako is a late-maturing species with moderate longevity and low natural mortality. With these life history characteristics and an unknown stock size and structure worldwide, management should be of a precautionary nature.

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