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Search Results: 1 - 6 of 6 matches for " skeletochronology "
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Skeletochronological Age Determination and Comparative Demographic Analysis of Two Populations of the Gold-spotted Pond Frog (Rana chosenica)
Cheong, Seokwan,Daesik Park,Ha-Cheol Sung,Jung Hyun Lee
Journal of Ecology and Field Biology , 2007,
Abstract: To obtain demographic information on threatened gold-spotted pond frog (Rana chosenica Okada,1931) populations, we determined the ages of 45 male and 13 female frogs (20 males and 9 females fromCheongwon and 25 males and 4 females from Tae-an) and compared the age structures and growth patternsof the two populations in 2006. The snout-vent length (SVL) and body weight of female frogs were greater thanthose of male frogs in both populations. Male frogs’ ages ranged 2 to 7 years old and females’ ages ranged3 to 6 years old. In both populations, 4 years old male frogs were the most abundant age-sex class. The agestructures of the two populations were significantly different and the growth coefficients of male frogs from theCheongwon population were greater than those from the Tae-an population. The mean age of males from theTae-an population was higher than that from the Cheongwon population. However, the SVL and body weightsof male frogs were not different between two populations and there was no difference between the twopopulations in the mean male SVL at any age. The results could increase our understanding of the life-historyof this threatened frog and may be useful in conservation planning.
Annular bone growth in phalanges of five Neotropical Harlequin Frogs (Anura: Bufonidae: Atelopus)
Erik Lindquist,Michael Redmer,Emily Brantner
Phyllomedusa : Journal of Herpetology , 2012,
Abstract: Skeletochronological studies were conducted on museum specimensrepresenting five species of the highly threatened Neotropical genus Atelopus (Bufonidae). We detected annular bone growth (expressed as lines of arrested growth [LAGs]) patterns in each species, and this might provide insight to understand demographic constituency infuture studies. In four of the five species under consideration, LAG counts in fore and hind limb bone occurred in a 1:1 ratio, indicating that bone growth was consistent within each individual. The use of skeletochronology in understanding historic and existing populations of Atelopus might assist in situ and ex situ population managers in making informed strategic conservation plans.
Effects of Physical Parameters and Age on the Order of Entrance of Hynobius leechii to a Breeding Pond
Lee, Jung-Hyun,Daesik Park
Journal of Ecology and Field Biology , 2008,
Abstract: To determine the age structure of a Hynobius leechii breeding population and analyze relationshipsbetween the order of entrance to breeding ponds and physical parameters and age, we studied a wild populationof the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Koreafrom March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of femalesranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm,respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-ventlength (SVL), head length, and body mass of males were all positively correlated with their age, but female agedid not show a significant relationship with any physical parameter. The tail depth, body mass, and conditionfactors (SVL/body mass × 100) of both males and females were negatively related with the order of entranceto the breeding pond. The head width and SVL of males were also negatively correlated with the order ofentrance, but the SVL of females was positively related with the order of entrance. These results suggest thatphysical parameters are more important determinants of breeding migration patterns than age. We discuss whichof two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explainthe order of entrance to breeding ponds for male and female H. leechii.
Population Dynamics of the Long-Tailed Clawed Salamander Larva, Onychodactylus fischeri, and Its Age Structure in Korea
Lee, Jung-Hyun,Nam-Yong Ra,Junho Eom,Daesik Park
Journal of Ecology and Field Biology , 2008,
Abstract: Larvae of the long-tailed clawed salamander, Onychodactylus fischeri, have a relatively long larval period,spending a year or more within the stream where they hatch; therefore, a well-established larval population could becritical for the conservation of adult populations. To study the population dynamics of long-tailed clawed salamanderlarvae, we surveyed a field population once or twice a month from September, 2005 to June, 2006, and determined theage of larval clawed salamanders collected from three different populations in October, 2004 using skeletochronology. Theage of long-tailed clawed salamander larvae ranged from 0 to 3 years. New recruitment of larvae in the populationprimarily occurred in November, 2005, and mid-March, 2006. Larvae with a snout-vent length of more than 30 mmdisappeared from the streams in September, 2005, suggesting that two to three year-old clawed salamander larvaemetamorphosed during this period.
Assessment of age and intersexual size differences in Bufo bufo
Cvetkovi? Dragana D.,Toma?evi? Nata?a,Aleksi? Ivan D.,Crnobrnja-Isailovi? Jelka M.
Archives of Biological Sciences , 2005, DOI: 10.2298/abs0502157c
Abstract: Numerous studies have underlined the complex nature of relationship between age, size, and reproductive traits in anurans. One of the most intriguing problems for evolutionary biologists is intersexual difference in body size (SSD). For testing various hypotheses about SSD, we need reliable estimates of its extent (the important issue being the choice of trait for analysis) as well as the accurate determination of individual age. The measures of SSD may be subject to error if estimated from populations with unknown age distribution; amphibians continue to grow throughout their life and SSD is linked to sex differences in traits such as age at maturity and lifespan. In the present paper, we analyze problems involved in accurate determination of age structure and factors that may lead to under- or overestimation of individual age, as well as the problem of appropriate choice of traits, in the light of our experience and results of investigating populations of common toad (Bufo bufo) in the vicinity of Belgrade.
SKELETOCHRONOLOGICAL AGE ESTIMATES FOR THE Enhydris chinensis
骨龄学方法测定中国水蛇的年龄

YI Zu,sheng,HE Hai,yan,CHEN Yue,ying,
易祖盛
,何海晏

动物学研究 , 2000,
Abstract: Enhydris chinensis (29 females,14 males,1 focus) got in the market were used in the examination of the middle cross sections of vertebrae ground in an ordinary abrasive disc way (taking five vertebraes near the heart).Under a microscope their annual rings were observed.We can see that the older the snakes are,the clearer their rings are.Correctness of the resorbed growth layers in the process of the skeleton growth by the regression equation of vertebrae radius vs growth layer width and von Bertalanffy growth equation indicates that the ages of the Enhydric chinensis specimens range from 0-11 2 years,their ages and their body length form a ringe relationship,the regression equation of the females is L (total length)=272 4+647 2lg A (year), r =0 9598, P <0 01;that of the males being L =317 5+46 3 A (year), r =0 9527, P <0 01,and the earliest sexual maturity of the females appears at the age of 1 8 years,that of the males at 1 0 year.
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