Age structure and growth pattern in two populations of the golden-striped salamander Chioglossa lusitanica (Caudata, Salamandridae)

2001 ◽  
Vol 22 (1) ◽  
pp. 55-68 ◽  
Author(s):  
◽  
◽  

AbstractWe studied age structure and growth in two populations of the golden-striped salamander, Chioglossa lusitanica, in northern Portugal by cohort analysis and skeletochronology. Lines of Arrested Growth (LAG) deposited during the larval phase could be distinguished from LAG deposited after metamorphosis. One or two LAG were found in larvae, with counts corresponding to age in years as predicted from larval size distributions. Post-metamorphic modal age was 5 to 6 years and longevity was 8 years. Von Bertalanffy growth curves for males and females from both populations were different from one another. Sexual maturity was reached 4 to 5 years after metamorphosis and corresponded with a snout-vent length of 43-44 mm in both sexes. A tendency was observed for females to be older than males. Mature females were on average larger than mature males. Larval growth was higher in spring than in winter and differed between populations and years. The population in which larvae grew relatively slowly was characterized by large young adults and vice versa, perhaps reflecting contrasting aquatic and terrestrial feeding conditions. The knowledge here presented is important for the better understanding of the population dynamics and ecological and conservation requirements of the golden-striped salamander.

2020 ◽  
Vol 27 (4) ◽  
pp. 195-200
Author(s):  
Ufuk Bülbül ◽  
Halime Koç ◽  
Yasemin Odabaş ◽  
Ali İhsan Eroğlu ◽  
Muammer Kurnaz ◽  
...  

Age structure of the eastern spadefoot toad, Pelobates syriacus from the Kızılırmak Delta (Turkey) were assessed using phalangeal skeletochronology. Snout-vent length (SVL) ranged from 42.05 to 86.63 mm in males and 34.03 to 53.27 mm in females. Age of adults ranged from 2 to 8 years in males and 3 to 5 years in females. For both sexes, SVL was significantly correlated with age. Males and females of the toads reached maturity at 2 years of age.


2011 ◽  
Vol 89 (9) ◽  
pp. 831-839 ◽  
Author(s):  
H. Dawn Marshall ◽  
Edward S. Yaskowiak ◽  
Casidhe Dyke ◽  
Elizabeth A. Perry

We investigated population structure of black bears ( Ursus americanus hamiltoni Cameron, 1957) from insular Newfoundland using the microsatellite profiles of 12 loci from three broadly distributed areas (Northern, Baie Verte, and Bonavista peninsulas). Our goals were to revisit earlier findings of low heterozygosity in Newfoundland and increase knowledge of intraspecific variability in black bears, and make inferences about postglacial colonization and contemporary movements of island black bears. Ninety-three individuals (42 males) were identified among 543 hair samples: 21 from Bonavista, 25 from Northern Peninsula, and 47 from Baie Verte. Genetic diversity is relatively low (HE = 0.42) and decreases from northwest to southeast. Small but significant subpopulation differentiation revealed by F statistics is greatest between Northern and Baie Verte peninsulas; it is lower and comparable in the remaining pairwise comparisons. We hypothesize that postglacial colonization proceeded from the Northern Peninsula southeastward. Bears migrated from the Northern Peninsula to Baie Verte at some more distant time in the past, then diverged by genetic drift. More recently, migration occurred from these two populations to Bonavista, characterized by positive FIS indicative of admixture. Tests of biased dispersal and posterior probability of correct assignment to locality reveal contemporary movements of both males and females with historical dispersal attributable to males.


Author(s):  
Silvina Botta ◽  
Eduardo R. Secchi ◽  
Mônica M.C. Muelbert ◽  
Daniel Danilewicz ◽  
Maria Fernanda Negri ◽  
...  

Age and length data of 291 franciscana dolphins (Pontoporia blainvillei) incidentally captured on the coast of Rio Grande do Sul State (RS), southern Brazil, were used to fit growth curves using Gompertz and Von Bertalanffy growth models. A small sample of franciscanas (N = 35) from Buenos Aires Province (BA), Argentina, were used to see if there are apparent growth differences between the populations. Male and female franciscana samples from both areas were primarily (78–85%) <4 years of age. The Von Bertalanffy growth model with a data set that excluded animals <1 year of age provided the best fit to data. Based on this model, dolphins from the RS population reached asymptotic length at 136.0 cm and 158.4 cm, for males and females, respectively. No remarkable differences were observed in the growth trajectories of males and females between the RS and BA populations.


2004 ◽  
Vol 21 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Paula Beatriz Araujo ◽  
Georgina Bond-Buckup

The terrestrial isopod Atlantoscia floridana (van Name, 1940) occurs from the U.S.A. (Florida) to Brazil and Argentina. In the southernmost Brazilian State, Rio Grande do Sul, the species is recorded in many localities, in urban and in non-urban areas. The growth curve of Atlantoscia floridana based on field data is presented. The specimens were sampled from April, 2000 to October, 2001 at the Reserva Biológica do Lami (RBL), Rio Grande do Sul. Captured individuals were sexed and had their cephalothorax width measured, with the data analyzed with von Bertalanffy's model. The growth curves for males and females are described, respectively, by the equations: Wt = 1.303 [1 - e-0.00941 (t + 50.37)] and Wt = 1.682 [1 - e-0.00575 (t + 59.13)]. The curves showed differential growth between sexes, where females reach a higher Wµ with a slower growth rate. Based on the growth curves it was also possible to estimate life expectancy for males and females.


1991 ◽  
Vol 48 (10) ◽  
pp. 1820-1828 ◽  
Author(s):  
Pierre Pepin ◽  
Ransom A. Myers

Recruitment variability is commonly associated with fluctuations in abundance of marine fish populations. Previous studies have focussed on stock-specific correlative or mechanistic models or on comparisons of recruitment variations of several stocks or species. The purpose of this study is to determine whether recruitment variability of commercial marine fish populations is associated with either size or the duration of early life history stages. The analysis was performed with data from 86 stocks representing 21 species of commercial marine fish. Univariate analysis shows that neither egg size nor the length at hatch is significantly correlated with recruitment variability. The change in length during the larval phase, which is representative of the duration of the stage, is significantly positively correlated with recruitment variability. Multivariate analysis shows that recruitment variability increases with increasing length at metamorphosis but that recruitment variability is poorly associated with length at hatch. The degree of serial correlation is related to the relative duration of egg and larval stages. The results clearly indicate that recruitment variability is linked to characteristics of early life history stages.


ZooKeys ◽  
2021 ◽  
Vol 1048 ◽  
pp. 145-175
Author(s):  
Vladimir I. Lantsov ◽  
Valentin E. Pilipenko

The caucasica species group in the subgenus Lunatipula is redefined and now consists of five species native to the Caucasus. Tipula (L.) eleniyasp. nov. is described as new to science, and variations in the male terminalia in two populations are noted. Two subspecies (quadridentataquadridentata and quadridentatapaupera) are elevated to species rank. Detailed photo’s complement the descriptions of all five species (caucasica, eleniya, paupera, quadridentata, talyshensis), and data on ecology and distribution patterns are included as well as identification keys to males and females. Tipula caucasica is recorded from the West Caucasus and Tipula quadridentata is recorded from Dagestan (Russia) for the first time. Parallel evolution is traced in the male terminalia of the new species and in several non caucasica species group of Palaearctic Lunatipula.


Author(s):  
Chunhui Li ◽  
Songbo Hu ◽  
Chuanhua Yu

The aim was to study the variation trends of all-cause and cancer mortality during 1984–2013 in Macheng City, China. The mortality data were collected from Macheng City disease surveillance points system and Hubei Center for Disease Control and Prevention. The model life table system was used to adjust mortality rates due to an under-reporting problem. An age-period-cohort model and intrinsic estimator algorithm were used to estimate the age effect, period effect, and cohort effect of all-cause mortality and cancer mortality for males and females. Age effect of all-cause mortality for both sexes increased with age, while the age effect of cancer mortality for both sexes reached a peak at the age group of 55–59 years old and then decreased. The relative risks (RRs) of all-cause mortality for males and females declined with the period and decreased by 51.13% and 63.27% during the whole study period, respectively. Furthermore, the period effect of cancer mortality in both sexes decreased at first and then increased. The cohort effect of all-cause and cancer mortality for both sexes born after 1904 presented the pattern of “rise first and then fall,” and decreased by 82.18% and 90.77% from cohort 1904–1908 to 1989–1993, respectively; especially, the risk of all-cause and cancer mortality for both sexes born before 1949 was much higher than that for those born after 1949.


Author(s):  
Preeti Gupta ◽  
Udai Pratap Singh

Dermatoglyphic characters vary widely and are unaffected by age, gender and least by environment. Unlike configurations and their distinctiveness with every individual, it also shows bilateral, bisexual and population variations. Palm prints once created are unchangeable throughout life and are unaffected by environmental factors. This paper is based upon the palmar dermatoglyphic. The study reports on bisexual and bilateral palm prints among Lodhis and Thakurs of Rudahi village of Bakshi Ka Talab, Lucknow District. The palmar dermatoglyphic traits have been analyzed among the two populations which are Main line Formula, Endings of main lines D and A, Position of Axial triradius, Angle atd, Main line Index, Hypothenar, Thenar/ Ist Interdigital area, IInd Interdigital area, IIIrd Interdigital area, IVth Interdigital area, and Palmar Ridge Counts. The prints have been obtained by using the duplicating ink method on white paper. On the perusal of Principal Main line Formula among Lodhis and Thakurs, it has been noticed that the frequency is more in Lodhi males than females in formula 11.9.7. On the other hand, the frequency of Thakur males is more than Thakur females in formula 9.7.5. The Ending of Main Line D in position 11 as clearly indicated in Lodhis is higher in both the genders in comparison to Thakurs, while the position 9 indicates highest frequency in Thakur females. The Ending of main line A at position 5’ has higher frequency in Lodhi males. The Main line index value 16 is observed higher in Lodhis in comparison to Thakurs. Higher frequency has been observed in Lodhis than Thakurs in Axial triradius in modal type‘t’. The range of Angle atd is observed to have higher frequency in 36º- 40º among the Lodhis as compared to Thakurs. The palmar ridge counts mean, is found higher in Lodhi females and Thakur males. Thus this paper shows the similarity and dissimilarity among the males and females of Thakurs and Lodhis in Palmar dermatoglyphics.


1984 ◽  
Vol 41 (7) ◽  
pp. 1055-1065 ◽  
Author(s):  
M. Sinclair ◽  
M. J. Tremblay

Each population of Atlantic herring (Clupea harengus harengus) has its own seasonally fixed spawning period of a few weeks duration, but the mean spawning times of different populations differ substantially. The extant theory explains the population-specific timing of spawning relative to the plankton production blooms in the inferred larval distributional area. Support of this theory is evaluated, and found lacking, in the light of a recent "stock" hypothesis involving larval retention. The new hypothesis involves two constraints. First, the larvae of a discrete herring population develop within, and are thus adapted to, the specific oceanographic conditions of their larval retention area. Second, metamorphosis from the larval to juvenile form occurs primarily within a restricted period of the year (April to October). Given these two constraints, it is hypothesized that the timing of spawning of a herring population is a function of the time necessary to complete the larval phase and yet metamorphose within the acceptable seasonal envelope. Populations that have "good" larval retention areas can spawn in the spring and still metamorphose within the seasonal envelope. Populations with larval retention areas that are less "good" for larval growth have to spawn earlier to satisfy the two constraints. The implications of the hypothesis on the "match–mismatch" theory are briefly discussed.


2000 ◽  
Vol 51 (3) ◽  
pp. 229 ◽  
Author(s):  
Kimberley A. Smith

Distributions of small and large larvae of Centroberyx affinis (Berycidae) and Gonorynchus greyi (Gonorynchidae) were examined along a shore-normal transect across the Sydney continental shelf, south-eastern Australia during January and April 1994. Both species were abundant, and 3016 individuals of C. affinis and 3184 individuals of G. greyi were taken. Distributions of small and large C. affinis reflected hydrographic variability and suggested passive dispersal. Previous observations of high year-class variability for this species may therefore reflect oceanographic variability during the larval stage. In contrast, the distributions of G. greyi only partially reflected hydrography and appeared to be influenced by larval behaviour at both sizes. Size distributions during each month indicated protracted spawning periods for both species. Spawning by C. affinis may have occurred over the inner shelf although the location was unclear because of the complexity of nearshore currents. Spawning by G. greyi probably occurred over the outer shelf. An increasing influence of larval behaviour with larval size on the distribution of G. greyi restricted larger individuals to the shelf break; this may have been a response to higher productivity in this region.


Sign in / Sign up

Export Citation Format

Share Document