Les marques de croissance des os et des écailles comme indicateur de l'âge chez Testudo hermanni et Testudo graeca (Reptilia, Chelonia, Testudinidae)

1979 ◽  
Vol 57 (8) ◽  
pp. 1649-1665 ◽  
Author(s):  
Jacques Castanet ◽  
Marc Cheylan
Keyword(s):  
Sexual Maturity ◽  
Bone Growth ◽  
Age Determination ◽  
Close Correlation ◽  
Long Bones ◽  
Histological Observation ◽  
Growth Rings ◽  
Testudo Graeca ◽  
Testudo Hermanni ◽  
Males And Females

This work shows the value of osseous growth marks for age determination in two terrestrial chelonia, Testudo hermanni and Testudo graeca. Careful histological observation of long bones proves that concentric rings show a yearly growth pattern; we have already described similar findings in amphibians, snakes, and lizards.We confirm these data first by the observation of some wild turtles of known age and of a close correlation between the number of bone rings and the number of rings on the cornified scutes. We also confirm in both species that scutes have a yearly growth rhythm and we conclude that bone growth marks provide a good criterion for age determination. Resorption destroys some juvenile rings; we propose a calculation to evaluate the number of resorbed lines to obtain the true individual age.In our turtles, scute growth rings allowed age determination until sexual maturity. With osseous growth marks, we were able to extend accurate ageing until the 20th year. We also established that sexual maturity occurs when animals are 12 or 13 years old in both species, with little difference between males and females.

An assessment of the reliability of growth rings counts for age determination in the Hermann's Tortoise Testudo hermanni

2005 ◽  
Vol 26 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Albert Bertolero ◽  
Miguel Carretero ◽  
Gustavo Llorente
Keyword(s):  
Regression Analysis ◽  
Age Estimation ◽  
Sexual Maturity ◽  
Growth Ring ◽  
Linear Regression Analysis ◽  
Age Determination ◽  
Growth Rings ◽  
Direct Observations ◽  
Testudo Hermanni ◽  
Ne Spain

AbstractGrowth ring counts on the shell have been widely used for age estimation in Chelonians. However, as stated by Wilson et al. (2003), most studies have applied this method without assessing its reliability by proving that 1 : 1 ratio between number of rings and real age exists. In the present study, the reliability of this method is analysed for a population of Hermann's Tortoise, Testudo hermanni introduced in the Ebro Delta (NE Spain). Age estimations were obtained from direct observations of tortoises in the field in 2000 (n = 82) together with those from photographs of the same and other individuals of the population taken between 1991 and 2001 (n= 356). A second photograph was taken at one or more years after the first one for 101 individuals. Results of Model II linear regression analysis indicated that the method was reliable only for tortoises between 0 and 7 years old, whereas tended to underestimate age for those between 8 and 11 years. Since, sexual maturity in this population is attained around 8 years (mean for both sexes), ring counts are only reliable for juveniles and subadults. Finally, it is noteworthy that the results coming for photographs were equivalent to those coming from direct observations in the field.

Évaluation de la méthode de détermination de l'âge en fonction de la masse du cristallin chez le bouquetin (Capra pyrenaica Schinz, 1838)

1988 ◽  
Vol 66 (12) ◽  
pp. 2836-2839 ◽  
Author(s):  
Carlos R. Vigal ◽  
Annie Machordom
Keyword(s):  
Age Determination ◽  
Capra Pyrenaica ◽  
Growth Rings ◽  
Age Class ◽  
Class 1 ◽  
Males And Females ◽  
The Relationship

The relationship between lens mass and age determined in 80 wild goats (Capra pyrenaica Schinz, 1838) from Sierra de Gredos (Avila), follows the equation Y = 79.36 + 259.94 log X, where Y is lens mass (mg) and X wild goat age (months). Lens masses of males and females do not differ significantly. Age-class (1-year classes) cannot be determined with 95% confidence from lens mass in animals 2 years and older. This method of age determination can be useful in cases where the age of young animals cannot be evaluated with accuracy otherwise; age determination by observation of teeth eruption or counting of growth rings of the horns is generally very valuable.

Variation within and between Rivers in Adult Size and Sea Age at Maturity of Anadromous Brown Trout, Salmo trutta

1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund
Keyword(s):  
Brown Trout ◽  
Sexual Maturity ◽  
Salmo Trutta ◽  
Adult Size ◽  
Age At Maturity ◽  
Migration Distance ◽  
Spawning Area ◽  
Brown Trout Salmo Trutta ◽  
Males And Females ◽  
The Mean

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.

scholarly journals Intrapopulation variability in the timing of ontogenetic habitat shifts in sea turtles revealed using δ 15 N values from bone growth rings

2017 ◽  
Vol 86 (3) ◽  
pp. 694-704 ◽  
Author(s):  
Calandra N. Turner Tomaszewicz ◽  
Jeffrey A. Seminoff ◽  
S. Hoyt Peckham ◽  
Larisa Avens ◽  
Carolyn M. Kurle
Keyword(s):  
Bone Growth ◽  
Sea Turtles ◽  
Growth Rings ◽  
Intrapopulation Variability ◽  
Ontogenetic Habitat Shifts

Distribution and abundance of Hemolivia mauritanica (Apicomplexa: Haemogregarinidae) and its vector Hyalomma aegyptium in tortoises of Iran

Biologia ◽  
2015 ◽  
Vol 70 (2) ◽  
Author(s):  
Hossein Javanbakht ◽  
Pavel Široký ◽  
Peter Mikulíček ◽  
Mozafar Sharifi
Keyword(s):  
Distribution Pattern ◽  
Age Groups ◽  
Climatic Conditions ◽  
Blood Parasite ◽  
Iranian Plateau ◽  
Male And Female ◽  
Testudo Graeca ◽  
Vector Tick ◽  
Significant Difference ◽  
Males And Females

AbstractDistribution pattern, prevalence and intensity of parasitaemia of heteroxenous apicomplexan blood parasite Hemolivia mauritanica and its vector tick Hyalomma aegyptium have been studied in 264 tortoises (212 Testudo graeca and 52 T. horsfieldii) throughout the Iranian territory. In T. graeca the highest prevalence and intensity of parasitaemia for H. mauritanica were recorded in the temperate mid and northern parts of the Iranian plateau, while the lowest values were found in the arid central part of Iran. No Hemolivia-positive samples were found in T. horsfieldii. Hyalomma aegyptium ticks were diagnosed in both tortoise species. The highest prevalence and intensity of infestation with H. aegyptium were recorded in western part of Iran, where climatic conditions are not so arid compared to central and eastern parts. No significant differences were found in intensity of parasitaemia of H. mauritanica between males and females. Similarly, no differences in intensity of parasitaemia were detected between different age groups (adults; more than 10 years, young; 5-10 years and juveniles; less that 5 years). Prevalence of H. mauritanica and H. aegyptium in adults was higher than in young and in juveniles. While intensity of infestation with H. aegyptium was significantly higher in adult tortoises compare to juveniles, no significant difference were found between intensity of H. aegyptium infestation in male and female tortoises.

Longitudinal bone growth in vitro: effects of insulin-like growth factor I and growth hormone

1991 ◽  
Vol 124 (5) ◽  
pp. 602-607 ◽  
Author(s):  
Ben A. A. Scheven ◽  
Nicola J. Hamilton
Keyword(s):  
Growth Hormone ◽  
Growth Factor ◽  
Bone Growth ◽  
Long Bone ◽  
Long Bones ◽  
Insulin Like Growth Factor ◽  
Serum Free ◽  
Factor I ◽  
Igf I

Abstract. Longitudinal growth was studied using an in vitro model system of intact rat long bones. Metatarsal bones from 18- and 19-day-old rat fetuses, entirely (18 days) or mainly (19 days) composed of chondrocytes, showed a steady rate of growth and radiolabelled thymidine incorporation for at least 7 days in serum-free media. Addition of recombinant human insulin-like growth factor-I to the culture media resulted in a direct stimulation of the longitudinal growth. Recombinant human growth hormone was also able to stimulate bone growth, although this was generally accomplished after a time lag of more than 2 days. A monoclonal antibody to IGF-I abolished both the IGF-I and GH-stimulated growth. However, the antibody had no effect on the growth of the bone explants in control, serum-free medium. Unlike the fetal long bones, bones from 2-day-old neonatal rats were arrested in their growth after 1-2 days in vitro. The neonatal bones responded to IGF-I and GH in a similar fashion as the fetal bones. Thus in this study in vitro evidence of a direct effect of GH on long bone growth via stimulating local production of IGF by the growth plate chondrocytes is presented. Furthermore, endogenous growth factors, others than IGFs, appear to play a crucial role in the regulation of fetal long bone growth.

scholarly journals Exposure to the RXR agonist SR11237 in early life causes disturbed skeletal morphogenesis in a rat model

2019 ◽  
Author(s):  
Holly Dupuis ◽  
Michael Andrew Pest ◽  
Ermina Hadzic ◽  
Thin Xuan Vo ◽  
Daniel B. Hardy ◽  
...  
Keyword(s):  
Growth Plate ◽  
Bone Growth ◽  
Long Bone ◽  
Tunel Staining ◽  
Long Bones ◽  
Micro Computed Tomography ◽  
Computed Tomography Scanning ◽  
Calcified Tissue ◽  
Trap Staining ◽  
Tomography Scanning

AbstractLongitudinal bone growth occurs through endochondral ossification (EO), controlled by various signaling molecules. Retinoid X Receptor (RXR) is a nuclear receptor with important roles in cell death, development, and metabolism. However, little is known about its role in EO. In this study, the agonist SR11237 was used to evaluate RXR activation on EO.Rats given SR11237 from post-natal day 5 to 15 were harvested for micro-computed tomography scanning and histology. In parallel, newborn CD1 mouse tibiae were cultured with increasing concentrations of SR11237 for histological and whole mount evaluation.RXR agonist-treated rats were smaller than controls, and developed dysmorphia of the growth plate. Cells invading the calcified and dysmorphic growth plate appeared pre-hypertrophic in size and shape corresponding with P57 immunostaining. Additionally, SOX9 positive cells were found surrounding the calcified tissue. The epiphysis of SR11237 treated bones showed increased TRAP staining, and additional TUNEL staining at the osteo-chondral junction. MicroCT revealed morphological disorganization in the long bones of treated animals. Isolated mouse long bones treated with SR11237 grew significantly less than their DMSO controls.This study demonstrates that stimulation of the RXR receptor causes irregular ossification, premature closure of the growth plate, and disrupted long bone growth in rodent models.

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