The effects of food and density on growth and metamorphosis in larval wood frogs (Rana sylvatica) from central Labrador

1990 ◽  
Vol 68 (6) ◽  
pp. 1221-1226 ◽  
Author(s):  
Dennis L. Murray
Keyword(s):  
Growth Rate ◽  
Larval Stage ◽  
Larval Density ◽  
Life History Strategy ◽  
Rana Sylvatica ◽  
Food Density ◽  
Immature Stages ◽  
Growth Inhibitors ◽  
Wood Frogs ◽  
Positive Effects

Two experiments were performed on Rana sylvatica tadpoles from central Labrador to test for effects of food and density on growth and metamorphosis. In an experiment examining for the presence of diffusible growth inhibitors, one group of tadpoles was given water treated by adding a high density of sibling tadpoles, and another group was given filtered lake water. No diffusible growth inhibitors existed in this population, as body weight measured weekly, weight at metamorphosis, and duration of larval stage did not differ between control and treated groups. In a food-density experiment, effects of food and larval density were examined by subjecting tadpoles at four different densities to four food levels, creating a 4 × 4 food–density matrix. Food and density both affected growth rate, weight at metamorphosis, and duration of larval stage. Socially governed negative density-dependent interactions are either nonexistent in northern populations, or were completely masked by slight positive effects of grouping. Results suggest that northern larvae differ in life-history strategy from southern populations, and the possibility of overwintering in immature stages of high-latitude populations is discussed.

scholarly journals Density and body size of the larval stages of the invasive golden mussel (Limnoperna fortunei) in two neotropical rivers

2012 ◽  
Vol 23 (3) ◽  
pp. 282-292 ◽  
Author(s):  
Vivianne Eilers ◽  
Márcia Divina de Oliveira ◽  
Kennedy Francis Roche
Keyword(s):  
Body Size ◽  
Larval Stage ◽  
Larval Density ◽  
Limnoperna Fortunei ◽  
Larval Size ◽  
Larval Stages ◽  
Positive Effects ◽  
Paraguay River ◽  
Body Sizes ◽  
Golden Mussel

AIM: The present study involved an analysis of the monthly variations in the population densities and body sizes of the different stages of planktonic larvae of the invasive golden mussel (Limnoperna fortunei), in the rivers Paraguay and Miranda; METHODS: The study was carried out between February 2004 and January 2005. Monthly collection of the plankton samples was accompanied by physical, chemical and biological analyses of the water; RESULTS: The Miranda River presented higher values of calcium, pH, alkalinity, conductivity and total phosphorous. Larval density varied from 0-24 individuals.L-1 in the Paraguay River, with a peak in March of 2004, while in the Miranda River, densities varied between 0-9 individuals.L-1 with a peak in February of 2004. No larvae were encountered during the coldest months, May and June. No significant correlations were found between environmental variables and larval density in either river. Only the valved larval stages were recorded. The "D" and veliger forms were most abundant; umbonate larvae were rare in the Miranda River samples. Mean body sizes of "D", veliger and umbonate larval stages were, respectively, 111, 135 and 152 µm, in the Paraguay River, and 112, 134 and 154 µm in the Miranda River. Principal Components Analysis indicated positive relationships between "D" larval stage size and the ratio between inorganic and organic suspended solids, while negative relationships were found between larval size and calcium and chlorophyll-<img border=0 width=7 height=8 src="/img/revistas/alb/2012nahead/ALB_AOP_230307car01.jpg">; CONCLUSIONS: The larvae were recorded in the plankton during most of the year, with the exception of the two colder months. Neither densities nor larval stage body sizes were significantly different between the two rivers. Possible positive effects of food and calcium concentrations on body size were not recorded. This species may be adapted to grow in environments with elevated sediment concentrations.

scholarly journals Species loss in developed landscapes: an experimental evaluation

2014 ◽  
Author(s):  
Alex Shepack ◽  
Kealoha Freidenburg ◽  
David Skelly
Keyword(s):  
Growth Rate ◽  
Experimental Evaluation ◽  
Rana Sylvatica ◽  
Development Rate ◽  
Wood Frog ◽  
Species Loss ◽  
Landscape Development ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Human Use

Conversion of landscapes for human uses is widely associated with loss of biodiversity. Here we focus on limits to distribution defined by intensity of landscape development. Using a translocation experiment, we ask does degradation of wetland habitat contribute to species loss? Wood frog larvae (Rana sylvatica = Lithobates sylvaticus), were reared within enclosures in 7 ponds harboring populations of wood frogs and in 5 ponds where they are absent. Survival, growth rate, and development rate were equivalent between ‘present’ and ‘absent’ ponds. While it is clear that landscapes surrounding ‘absent’ ponds had been heavily influenced by human use, we find no evidence that such wetlands provide inferior habitat for wood frog recruitment. Their absence in human altered landscapes may stem from influences outside of pond basins. The results provide a caution to the typically unexamined presumption that relictual habitats in developed landscapes are degraded in their utility for wildlife.

scholarly journals Species loss in developed landscapes: an experimental evaluation

2014 ◽  
Author(s):  
Alex Shepack ◽  
Kealoha Freidenburg ◽  
David Skelly
Keyword(s):  
Growth Rate ◽  
Experimental Evaluation ◽  
Rana Sylvatica ◽  
Development Rate ◽  
Wood Frog ◽  
Species Loss ◽  
Landscape Development ◽  
Wood Frogs ◽  
Lithobates Sylvaticus ◽  
Human Use

Conversion of landscapes for human uses is widely associated with loss of biodiversity. Here we focus on limits to distribution defined by intensity of landscape development. Using a translocation experiment, we ask does degradation of wetland habitat contribute to species loss? Wood frog larvae (Rana sylvatica = Lithobates sylvaticus), were reared within enclosures in 7 ponds harboring populations of wood frogs and in 5 ponds where they are absent. Survival, growth rate, and development rate were equivalent between ‘present’ and ‘absent’ ponds. While it is clear that landscapes surrounding ‘absent’ ponds had been heavily influenced by human use, we find no evidence that such wetlands provide inferior habitat for wood frog recruitment. Their absence in human altered landscapes may stem from influences outside of pond basins. The results provide a caution to the typically unexamined presumption that relictual habitats in developed landscapes are degraded in their utility for wildlife.

Environmental drivers of carry-over effects in a pond-breeding amphibian, the Wood Frog (Rana sylvatica)

2017 ◽  
Vol 95 (4) ◽  
pp. 255-262 ◽  
Author(s):  
L.K. Freidenburg
Keyword(s):  
High Performance ◽  
Rana Sylvatica ◽  
Oviposition Site ◽  
Environmental Drivers ◽  
Larval Performance ◽  
Wood Frogs ◽  
Positive Effects ◽  
Alternative Site ◽  
Carry Over ◽  
Oviposition Sites

Breeding animals confront a complex environment when deciding where to oviposit, and this decision may depend on fine-scale variation in environmental conditions that have the potential to affect not only embryos but also subsequent larvae. I evaluated the influences of two variables, light and temperature, at oviposition sites of Wood Frogs (Rana sylvatica LeConte, 1825). First, in four ponds varying in canopy cover, I moved a subset of egg masses from the original oviposition site to an alternative site in the same pond and monitored embryos until hatching commenced. I found that embryos in the alternative site experienced delays in hatching a mean of 2.5 days. Second, in each of the four ponds, I placed hatchlings from the two sites in enclosures throughout the pond. After 2 weeks, larval performance was assessed with respect to development and growth. Larvae from the alternative oviposition site gained less mass (on average, 15% less) and developed more slowly (up to two Gosner stages) than larvae from the original oviposition site. Collectively, these results show that in selecting oviposition sites, Wood Frogs can use local cues to support high performance of their offspring and that those positive effects can carry over well into the larval period.

scholarly journals Impact of Comingled Heterospecific Assemblages on Developmentally Based Estimates of the Post-Mortem Interval—A Study with Lucilia sericata (Meigen), Phormia regina (Meigen) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae)

Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 280
Author(s):  
Krystal R. Hans ◽  
Sherah L. Vanlaerhoven
Keyword(s):  
Growth Rate ◽  
Development Time ◽  
Lucilia Sericata ◽  
Phormia Regina ◽  
Calliphora Vicina ◽  
Immature Stages ◽  
Post Mortem ◽  
Blow Fly ◽  
Blow Flies ◽  
Post Mortem Interval

Estimates of the minimum post-mortem interval (mPMI) using the development rate of blow flies (Diptera: Calliphoridae) are common in modern forensic entomology casework. These estimates are based on single species developing in the absence of heterospecific interactions. Yet, in real-world situations, it is not uncommon to have 2 or more blow fly species developing on a body. Species interactions have the potential to change the acceptance of resources as suitable for oviposition, the timing of oviposition, growth rate, size and development time of immature stages, as well as impacting the survival of immature stages to reach adult. This study measured larval development and growth rate of the blow flies Lucilia sericata (Meigen, 1826), Phormia regina (Meigen, 1826) and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae) over five constant temperatures (15, 20, 25, 30, 35 °C), in the presence of conspecifics or two-species heterospecific assemblages. Temperature and species treatment interacted such that L. sericata larvae gained mass more rapidly when in the presence of P. regina at 20 and 30 °C, however only developed faster at first instar. At later stages, the presence of P. regina slowed development of L. sericata immatures. Development time of C. vicina immatures was not affected by the presence of P. regina, however larvae gained mass more slowly. Development time of P. regina immatures was faster in the presence of either L. sericata or C. vicina until third instar, at which point, the presence of L. sericata was neutral whereas C. vicina negatively impacted development time. Phormia regina larvae gained mass more rapidly in the presence of L. sericata at 20 °C but were negatively impacted at 25 °C by the presence of either L. sericata or C. vicina. The results of this study indicate that metrics such as development time or larval mass used for estimating mPMI with blow flies are impacted by the presence of comingled heterospecific blow fly assemblages. As the effects of heterospecific assemblages are not uniformly positive or negative between stages, temperatures or species combinations, more research into these effects is vital. Until then, caution should be used when estimating mPMI in cases with multiple blow fly species interacting on a body.

Additive and non-additive genetic effects of growth-curve parameters of Holstein, Ayrshire and crossbred females

1994 ◽  
Vol 74 (3) ◽  
pp. 401-409 ◽  
Author(s):  
D. Perotto ◽  
R. I. Cue ◽  
A. J. Lee ◽  
A. J. McAllister ◽  
J. R. Batra ◽  
...  
Keyword(s):  
Growth Rate ◽  
Dairy Cattle ◽  
Growth Curve ◽  
Growth Traits ◽  
Individual Performance ◽  
Breeding Value ◽  
Average Lifetime ◽  
Additive Effects ◽  
Positive Effects ◽  
Maternal Performance

Crossbreeding parameters (line additive, dominance and additive × additive epistatic effects for individual and for maternal performance) on growth traits of females from a crossbreeding experiment between Holstein-based (HS) and Ayrshire-based (AS) lines were estimated by individual animal models, incorporating all known additive genetic relationships among animals, through restricted maximum likelihood and mixed-model methodologies. The growth traits [asymptotic weight (A), rate parameter (k), inflection parameter (m), average lifetime absolute growth rate (AGR), average lifetime absolute maturing rate (AMR) and average lifetime relative growth rate (RGR)] were estimated by fitting the Richards function to the observed growth curve of 3076 individuals. The statistical model included the random effect of the animal breeding value and the fixed effects of genetic group and station–year–season of birth. Results indicated that the HS exceeded (P < 0.001) the AS in additive effects for individual performance for both A and AGR. The HS exceeded (P < 0.05) the AS in additive effects for maternal performance for A. Individual heterosis was positive for A (P < 0.001) and for AGR (P < 0.01). Maternal heterosis was negative for A (P < 0.05) and positive for AMR (P < 0.05). Total heterosis (TH) had positive effects on both AGR and AMR (P < 0.05). Heterosis retained in advanced crossbred generations was not significant (P > 0.05) for any of the studied traits. The results suggest that crossbreeding designed to exploit TH can alter the shape of the growth curve of dairy cattle. Key words: Crossbreeding, dairy cattle, growth curve

Variation in amount of surrounding forest habitat influences the initial orientation of juvenile amphibians emigrating from breeding ponds

2008 ◽  
Vol 86 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Leroy J. Walston ◽  
Stephen J. Mullin
Keyword(s):  
Positive Relationship ◽  
Rana Sylvatica ◽  
Environmental Cues ◽  
Bufo Americanus ◽  
Forest Habitat ◽  
Amphibian Species ◽  
Wood Frogs ◽  
Juvenile Dispersal ◽  
Woodland Ponds ◽  
Emigration Behavior

Juvenile dispersal is important for the persistence of ​amphibian populations. Previous studies have observed nonrandom orientation in juvenile amphibians emigrating from breeding ponds; however, the environmental cues associated with these movements are not well understood. We examined the emigration behavior of recently metamorphosed juveniles of three pond-breeding amphibian species from three woodland ponds. We found that juvenile small-mouthed salamanders ( Ambystoma texanum (Matthes, 1855)), American toads ( Bufo americanus Holbrook, 1836), and wood frogs ( Rana sylvatica LeConte, 1825) exhibited nonrandom orientation upon exiting the breeding ponds. Furthermore, we found a positive relationship between captures of juvenile small-mouthed salamanders and wood frogs and width of the surrounding forest habitat, indicating that these species are selecting areas with broader forested habitat upon exiting the breeding ponds. Our results indicate that migrating juvenile amphibians may rely on direct environmental cues because the orientation of small-mouthed salamanders and wood frogs was influenced by width of the surrounding forested habitat. These observations support previous studies suggesting that maintaining forest habitat, along at least a portion of breeding ponds, is important for the persistence of amphibian populations.

Kin recognition by larval wood frogs (Rana sylvatica): effects of diet and prior exposure to conspecifics

Oecologia ◽  
1991 ◽  
Vol 86 (3) ◽  
pp. 319-324 ◽  
Author(s):  
George J. Gamboa ◽  
Keith A. Berven ◽  
Randy A. Schemidt ◽  
Thomas G. Fishwild ◽  
Kelli M. Jankens
Keyword(s):  
Kin Recognition ◽  
Rana Sylvatica ◽  
Prior Exposure ◽  
Wood Frogs

Sexual differences in color and color change in wood frogs

1991 ◽  
Vol 69 (7) ◽  
pp. 1963-1968 ◽  
Author(s):  
Richard B. King ◽  
Bethia King
Keyword(s):  
Color Change ◽  
Red Light ◽  
Green Light ◽  
Rana Sylvatica ◽  
Sexual Differences ◽  
Wood Frog ◽  
Color Classification ◽  
Wood Frogs ◽  
Evolutionary Response ◽  
Males And Females

An observer-free method of color classification was used to determine whether wood frogs, Rana sylvatica, exhibit sexual differences in color and color change. Males and females captured from breeding aggregations differed significantly in color: females reflected a greater amount of long-wavelength (yellow–red) light and less short-wavelength (blue–green) light than males. The color difference was not just a result of differences in the state of physiological color change at the time of capture but persisted for a month after capture. Males and females also differed in their color-change responses to black and white backgrounds: both sexes changed in brightness, but only males changed in the relative amount of light reflected at different wavelengths. Wood frog color may function in predator avoidance through crypsis. There was a good match between frogs and some of the leaves from the leaf litter surrounding the breeding ponds. Hypotheses for the development of sexual differences in wood frog color include sexual differences in availability of pigment and pigment precursors, morphological color change, and evolutionary response to different selection pressures.

Lack of an association between heterozygosity and growth rate in the wood frog, Rana sylvatica

1995 ◽  
Vol 73 (3) ◽  
pp. 569-575 ◽  
Author(s):  
Michael F. Wright ◽  
Sheldon I. Guttman
Keyword(s):  
Growth Rate ◽  
Multiple Regression ◽  
Rana Sylvatica ◽  
Developmental Period ◽  
Wood Frog ◽  
Single Locus ◽  
Regression Analyses ◽  
Enzyme Loci ◽  
Effect On Growth

The effect of both multilocus and single-locus heterozygosity on growth rate was examined in a cohort of larvae of the wood frog, Rana sylvatica, collected from a pond during the later stages of premetamorphic development. Seven electrophoretically detected enzyme loci were used to determine individual heterozygosity, whereas the growth rate was measured as wet mass. In all cases, no significant correlation was found between multilocus heterozygosity and mass among larvae collected at intervals during the developmental period. In addition, multiple regression analyses indicated that no single locus had a demonstrable effect on growth rate. The results of this study, therefore, provide no evidence for a link between enzyme heterozygosity and growth rate during the later stages of premetamorphic development in wood frog larvae.

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