Comparative life history features of the western spotted frog, Rana pretiosa, from low- and high-elevation populations

1975 ◽  
Vol 53 (9) ◽  
pp. 1254-1257 ◽  
Author(s):  
Lawrence E. Licht
Keyword(s):  
British Columbia ◽  
Life History ◽  
Body Size ◽  
Sexual Maturity ◽  
High Elevation ◽  
The Body ◽  
Female Fecundity ◽  
Size At Sexual Maturity ◽  
Rana Pretiosa

Comparisons are made of life history features of the western spotted frog, Rana pretiosa pretiosa, living at 70 m in southwestern British Columbia, and 2600 m in Yellowstone Park, Wyoming.Lowland tadpoles remain longer as larvae and transform at twice the body size as highland tadpoles.Growth rates of juveniles and adults are rapid in the lowland population and the same amount of growth achieved by them in 2–3 years takes 8–10 years for highland frogs.Body size at sexual maturity is the same for frogs from both populations, but B.C. frogs breed at half the age of Wyoming frogs. Female fecundity, the number of eggs at spawning, is the same, but lowland females breed annually, while high-elevation females breed only every 2 or 3 years.Various explanations are put forth to account for observed differences.

scholarly journals Life-history strategies associated to reproduction of three Hyphessobrycon species (Characidae) in lentic environments of upper Paraná River basin

2013 ◽  
Vol 25 (4) ◽  
pp. 398-405 ◽  
Author(s):  
Cristina da Silva Gonçalves ◽  
Ursulla Pereira Souza ◽  
Fabio Cop Ferreira ◽  
Alexandre Peressin ◽  
Francisco Manoel de Souza Braga
Keyword(s):  
Life History ◽  
River Basin ◽  
Sexual Maturity ◽  
Life History Strategies ◽  
Oxbow Lakes ◽  
Parana River ◽  
Three Samples ◽  
Size At Sexual Maturity ◽  
Upper Paraná River ◽  
Upper Paraná River Basin

AIM: Life-history strategies in fish include essential parameters related to offspring survivorship, fecundity and time of reproduction, which represent adaptive traits that enable a species to deal with spatial and temporal variability of abiotic conditions. This study aimed to compare reproductive traits associated to life-history theory for three Hyphessobrycon species from two lentic environments (four natural oxbow lakes and a man-made reservoir) of Mogi Guaçu River, upper Paraná River basin. METHODS: Specimens were collected with four minnow traps between August 2005 and July 2006 to cover dry and wet seasons (three samples in each season, and three samples in each environment). RESULTS: Reproductive strategy of H. bifasciatus and H. eques, which predominated in the oxbow lakes, differed from H. anisitsi in the reservoir. Hyphessobrycon bifasciatus and H. eques were single spawners with lower fecundity and size at sexual maturity, but invested more in number of eggs per body gram, while H. anisitsi was a multiple spawner species with higher fecundity, larger size at sexual maturity and body size. CONCLUSIONS: In seasonal environments, single spawners are synchronized with the floods to maximize juvenile survivorship, while reservoirs harbors multiple spawners’ fish due to the reduced fluctuation between high and low floods resulting from dam operation. Therefore, the seasonal condition in the oxbow lakes due to the flood pulse favored single spawners’ tactic, as showed by H. bifasciatus and H. eques. In contrast, the multiple spawning of H. anisitsi seems to be related to the more stable environmental condition throughout the year provided by the dam. Life-histories reported herein to Hyphessobrycon species must be common to other characid fishes inhabiting similar environments.

Maturation génitale des varans du nil mâles (Varanus niloticus) dans trois populations du Sahel

1999 ◽  
Vol 77 (2) ◽  
pp. 222-232 ◽  
Author(s):  
Vivian de Buffrénil ◽  
Jacques Castanet ◽  
Frédérique Rimblot
Keyword(s):  
Body Size ◽  
Sexual Maturity ◽  
Morphometric Study ◽  
Lake Chad ◽  
Breeding Stock ◽  
Size At Sexual Maturity ◽  
Monitor Lizards ◽  
Mature Spermatozoa ◽  
Accurate Indicator

Genital maturation of male monitor lizards, a subject poorly documented up to now in spite of the heavy exploitation of these animals, was studied on a sample of 211 Nile monitors (Varanus niloticus) from Chad (Lake Chad), Mali (central delta of the Niger), and Nigeria (Hadejia-N'Guru wetlands). Snout-vent lengths (LC) in the sample ranged from 15.6 to 85.5 cm. After a morphometric study of the monitors, their testes were sampled, weighed at ±0.01 g and fixed for histology. The age of each specimen was estimated by skeletochronology. The testes of monitors less than 36 cm LC (Malian specimens) or 40 cm LC (Chadian and Nigerian individuals) do not contain mature spermatozoa, whereas the testes of larger specimens do. Most Malian monitors aged 18 months (1.5 years) have mature spermatozoa. Conversely, in Chadian and Nigerian individuals, mature gametes appear only in specimens aged 30 months (2.5 years). These data indicate that genital maturity in the Nile monitor is reached at 36-40 cm LC and 1.5-2.5 years according to the populations. The growth in mass of the testes, compared with LC, is an accurate indicator of body size at sexual maturity, and confirms the precocity of Malian specimens. Conversely, testis growth is poorly related to age. These results are discussed with reference to the possible accommodation of Nile monitor populations to heavy exploitation by means of precocious recruitment of the male breeding stock.

Life history and ecology of the elegant snake-eyed skink (Cryptoblepharus pulcher) in south-eastern Australia

2019 ◽  
Vol 67 (1) ◽  
pp. 51
Author(s):  
David A. Pike ◽  
Elizabeth A. Roznik ◽  
Jonathan K. Webb ◽  
Richard Shine
Keyword(s):  
Life History ◽  
Body Size ◽  
Natural Habitat ◽  
The Body ◽  
Lizard Species ◽  
Tropical Environments ◽  
Eastern Australia ◽  
Taxonomic Changes ◽  
Gravid Females ◽  
Incubation Temperatures

Detailed information on life history and ecology is essential for successful conservation and management. However, we have relatively little detailed data on the life history and ecology of most small lizard species, relative to other vertebrates, especially those that have undergone recent taxonomic changes. We studied the ecology of the elegant snake-eyed skink (Cryptoblepharus pulcher), a lizard that occurs on trees, fences, walls, and rock outcroppings in eastern Australia that spans temperate to tropical environments. In our temperate-zone study population living in natural habitat, individuals are active year-round, and gravid females were found during the months of September through December. Sexual maturity is reached in 12 months, lifespan is at least three years, and clutch size is typically two eggs. In laboratory incubation experiments, larger eggs were more likely to hatch. Low incubation temperatures (averaging 23 ± 7.5°C versus high temperatures averaging 26 ± 7.5°C) increased incubation duration significantly (range 56–72 days versus 40–51 days) and reduced the body size of hatchlings significantly (17.8 mm versus 18.7 mm snout–vent length). Skinks sheltered beneath small rocks that were not shared simultaneously with predatory snakes, and that reached average temperatures that were up to 3°C warmer during the day than unused rocks. Preferred microhabitats include substrates of rock or soil, and the largest rocks were occasionally shared by up to four individuals of all body size/sex combinations (5.8% of observations were shared, 30.2% of individual rocks were shared). Our study expands upon knowledge of the widespread genus Cryptoblepharus by providing detailed life history and ecological information on C. pulcher that can serve as a baseline for future studies.

scholarly journals Comparison of body size, relative growth and size at onset sexual maturity of Uca uruguayensis (Crustacea: Decapoda: Ocypodidae) from different latitudes in the south-western Atlantic

2012 ◽  
Vol 93 (3) ◽  
pp. 781-788 ◽  
Author(s):  
Gustavo Luis Hirose ◽  
Vivian Fransozo ◽  
Carolina Tropea ◽  
Laura S. López-Greco ◽  
Maria Lucia Negreiros-Fransozo
Keyword(s):  
Body Size ◽  
Sexual Maturity ◽  
Fiddler Crab ◽  
Carapace Width ◽  
The Body ◽  
Brazilian Population ◽  
The South ◽  
Western Atlantic ◽  
Males And Females ◽  
Uca Uruguayensis

Some crustaceans show variations of their reproductive biology within their geographical distribution, and knowledge about such variations is important for the comprehension of their reproductive adaptations. This study compared two populations of the fiddler crab Uca uruguayensis from two locations on the south-western Atlantic coast: Ubatuba Bay, São Paulo, Brazil and Samborombón Bay, Buenos Aires, Argentina. The population features analysed were the body size variation (carapace width = CW) and the size at the onset of sexual maturity (SOM) in order to test the hypothesis that the size at SOM, should be the same in relative terms (RSOM), independently of the latitudinal position. In the Brazilian population the CW ranged from 4.18 to 11.60 mm for males and 3.90 to 9.80 mm for females, and in the Argentinean population from 3.60 to 14.10 mm for males and 2.85 to 12.00 mm for females. In the Brazilian population the SOM was 7.1 (RSOM = 0.58) and 5.9 mm CW (RSOM = 0.57) for males and females, respectively, and in the Argentinean population it was 7.0 (RSOM = 0.42) and 6.75 mm CW (RSOM = 0.53) for males and females, respectively. This fact is probably related to a great plasticity in the life history features of Uca uruguayensis under different environmental conditions.

scholarly journals Life history of Tendaguru sauropods as inferred from long bone histology

Fossil Record ◽  
1999 ◽  
Vol 2 (1) ◽  
pp. 103-112 ◽  
Author(s):  
P. M. Sander
Keyword(s):  
Life History ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Sexual Maturity ◽  
Upper Jurassic ◽  
Bone Histology ◽  
Long Bone ◽  
Large Mammals ◽  
Growth Series ◽  
History Of

Abstract. Sauropod dinosaurs present exceptional challenges in understanding their biology because of their exceptional body size. One of these, life history, can be inferred from the histology of their bones. For this purpose, the diverse sauropod assemblage of the Upper Jurassic Tendaguru beds was sampled with a new coring method which provided unprecented access to and insights into sauropod bone histology. Growth series of humeri and femora as well as long growth records from single bones suggest that all four sauropod taxa are characterized by continued growth after sexual maturity but that growth was determinate. Fibrolamellär bone is dominant in the samples, indicating that the bones of the Tendaguru sauropods grew at rates comparable to those of modern large mammals. The growth pattern of these sauropods thus combines typically reptilian traits with typically mammalian traits. In the details of their bone histology, the Tendaguru sauropod taxa show considerable variation which reflects life history. In addition, Barosaurus exhibits probable sexual dimorphism in bone histology. Das Verständnis der Biologie der sauropoden Dinosaurier wird durch ihre enorme Körpergröße außerordentlich erschwert. Allerdings kann ein Aspekt, die Lebensgeschichte, anhand der Histologie ihrer Knochen untersucht werden. Zu diesem Zweck wurde die diverse Sauropoden-Vergesellschaftung der oberjurassischen Tendaguru-Schichten beprobt, und zwar mit einer neuartigen Kernbohrmethode, die einen herausragenden Zugang und Einblick in die Knochenhistologie der Sauropoden ermöglichte. Wachstumsserien von Humeri und Femora sowie umfassende Überlieferungen des Wachstums von Individuen anhand einzelner Knochen machen es wahrscheinlich, daß alle vier Sauropoden-Taxa der Tendaguru-Schichten durch ein auch nach der Geschlechtsreife anhaltendes Wachstum gekennzeichnet waren. Allerdings ging das Wachstum nicht bis zum Tode des Tieres weiter, sondern kam bei einer etwas variablen Maximalgröße zum Stillstand. Fibrolamellärer Knochen ist der vorherrschende Knochentyp in den Proben, was anzeigt, daß die Tendaguru-Sauropoden mit für Säugetieren typische Raten wuchsen. Die Tendaguru-Sauropoden kombinerten also ein für Reptilien typisches Muster des Wachstums, nämlich nach der Geschlechtsreife anhaltendes Wachstum, mit für Säuger typischen Raten des Wachstums. Die verschiedenen Sauropoden-Taxa zeigen erstaunliche Unterschiede in den Details ihrer Knochenhistologie, die Unterschiede in der Lebensgeschichte belegen. Bei Barosaurus scheint außerdem ein Geschlechtsdimorphismus in der Histologie der Langknochen vorzukommen. doi:1002/mmng.1999.4860020107

Genome size is not related to life-history traits in primates

Genome ◽  
2005 ◽  
Vol 48 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Serge Morand ◽  
Robert E Ricklefs
Keyword(s):  
Life History ◽  
Body Size ◽  
Genome Size ◽  
Dna Content ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Age At Maturity ◽  
Brain Mass ◽  
Gestation Time ◽  
C Value

Genome size (C value, the haploid DNA content of the nucleus) varies widely among eukaryotes, increasing through duplication or insertion of transposable elements and decreasing through deletions. Here, we investigate relationships between genome size and life-history attributes potentially related to fitness, including body mass, brain mass, gestation time, age at sexual maturity, and longevity, in 42 species of primates. Using multivariate and phylogenetically informed analyses, we show that genome size is unrelated to any of these traits. Genome size exhibits little variation within primates and its evolution does not appear to be correlated with changes in life-history traits. This further indicates that the phenotypic consequences of variation in genome size are dependent on the particular biology of the group in question.Key words: age at maturity, body size, brain mass, C value, genome size, gestation time, life history, primate.

scholarly journals Age structure and body size of the endangered species Darevskia bendimahiensis (Schmidtler, Eiselt & Darevsky, 1994) from eastern Turkey (Squamata, Sauria, Lacertidae)

Herpetozoa ◽  
2019 ◽  
Vol 32 ◽  
pp. 159-163
Author(s):  
Elif Yıldırım ◽  
Yusuf Kumlutaş ◽  
Kamil Candan ◽  
Çetin Ilgaz
Keyword(s):  
Life History ◽  
Body Size ◽  
Endangered Species ◽  
Age Structure ◽  
Sexual Maturity ◽  
Life History Traits ◽  
Eastern Turkey ◽  
The Future ◽  
The Mean ◽  
Spearman’S Correlation

The life-history traits of the parthenogenetic lizard Darevskiabendimahiensis were studied by skeletochronology in a population inhabiting highlands in Çaldıran, Van, Turkey. Endosteal resorption was observed in 18 specimens (55%). The mean age was 4.91 ± 0.19 SD years. The mean snout-vent length (SVL) was 51.11 ± 1.15 SD mm. The age at sexual maturity was estimated as 3 years. Longevity was 7 years. Snout-vent length and age were positively correlated (Spearman’s correlation; r = 0.797, P = 0.000). The aim of this study is to contribute to the future conservation activities for this endangered species.

Life history and reproductive biology of the invasive amphipod Melita palmata (Amphipoda: Melitidae) in the Mar Chiquita coastal lagoon, Argentina

2006 ◽  
Vol 86 (6) ◽  
pp. 1381-1387 ◽  
Author(s):  
S. Obenat ◽  
E. Spivak ◽  
L. Garrido
Keyword(s):  
Life History ◽  
Body Size ◽  
Population Density ◽  
Sex Ratio ◽  
Reproductive Biology ◽  
Coastal Lagoon ◽  
Brood Size ◽  
Maximum Size ◽  
The Body ◽  
Invasive Amphipod

The life history and reproductive biology of the gammaridean amphipod Melita palmata was studied in the Mar Chiquita coastal lagoon (Argentina). The animals were collected fortnightly or monthly from Ficopomatus enigmaticus reefs from December 2000 to March 2002. The population density reached a maximum of 1556.67±1560 ind/m3 (mean±SD) in March 2001, decreased dramatically after intense rainfalls in winter 2001, and had a minimum value of 141.67±27.54 ind/m3 (mean±SD) in March 2002. Size differed significantly between sexes. The maximum size of males was 11.5 mm and this was 1.4 times longer than the length of females. The average sex ratio (0.44) did not differ significantly from an expected 1:1 value. Ovigerous females were present from December to March, when the temperature was above 18°C. The body size of ovigerous females ranged from 2.9 to 6.81 mm. There was a positive correlation between the brood size and body length of ovigerous females, and the maximum number of eggs per female was ten. Recruitment took place during the whole breeding season; juveniles recruited at the beginning of the season matured at the end of the same season, those recruited late would probably reach maturity in the following season.

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