Effect of larval body size on overwinter survival and emerging adult size in the burying beetle, Nicrophorus investigator

2002 ◽  
Vol 80 (9) ◽  
pp. 1588-1593 ◽  
Author(s):  
Rosemary J Smith
Keyword(s):  
Body Size ◽  
Parental Care ◽  
Emerging Adults ◽  
Survival Data ◽  
Life Stage ◽  
Large Body ◽  
Winter Period ◽  
Adult Size ◽  
Larval Size ◽  
Overwinter Survival

Body size may influence both adult fecundity and the probability of survival through each life stage. Previous studies of burying beetles (Nicrophorus, Coleoptera: Silphidae) have revealed reproductive advantages for larger adults and the role of parental care in determining larval size and number. In this study I measure the effect of size on survival over the winter period and the correlation between larval size and the size of emerging adults. I collected data from 24 groups of 20–25 larvae sorted by size and overwintered outside under natural conditions in Colorado, U.S.A. There was a significant positive correlation between larval size and adult size at emergence and a significant effect of size on overwinter survival. Data from 2 years yielded the following mean survival rates: small, 47.3 ± 1.0%; medium, 73.2 ± 0.7%; large, 85.7 ± 0.4%. These values were then used to accurately predict adult emergence from broods of larvae whose range of size was measured prior to the overwinter period. The results indicate that selection for large body size may result from an overwinter survival advantage and not just from reproductive success. This has implications for fitness models of parental care and models of population dynamics.

New smallest specimen of the pterosaurPteranodonand ontogenetic niches in pterosaurs

2017 ◽  
Vol 92 (2) ◽  
pp. 254-271 ◽  
Author(s):  
S. Christopher Bennett
Keyword(s):  
Body Size ◽  
Parental Care ◽  
Large Body ◽  
Taxonomic Diversity ◽  
Ecological Niches ◽  
Adult Size ◽  
Niobrara Formation ◽  
Large Body Size ◽  
Juvenile Specimen

AbstractA new juvenile specimen ofPteranodonfrom the Smoky Hill Chalk Member of the Niobrara Formation of western Kansas had an estimated wingspan in life of 1.76 m, ~45% smaller than the smallest previously known specimens, but does not differ in morphology from larger specimens. Its presence indicates that juveniles were capable of flying long distances, so it falsifies the interpretation ofPteranodonas growing rapidly to adult size under parental care before flying. Instead juveniles were precocial, growing more slowly to adult size while flying and feeding independently for several years before going to sea. Because juveniles are otherwise unknown in the Smoky Hill Chalk Member, they must have occupied different environments and ecological niches than adults; thusPteranodonexhibited ontogenetic niches. Evidence is presented that most other pterosaurs (e.g.,Rhamphorhynchus,Pterodactylus,Anhanguera) also exhibited various ontogenetic niches, which, along with their large body size, suggests that pterosaur taxonomic diversity was rather low, like that of crocodilians.

scholarly journals The ecological genetics of growth in Drosophila 6. The genetic correlation between the duration of the larval period and body size in relation to larval diet.

1963 ◽  
Vol 4 (1) ◽  
pp. 74-92 ◽  
Author(s):  
Forbes W. Robertson
Keyword(s):  
Body Size ◽  
Development Time ◽  
Larval Growth ◽  
Large Body ◽  
Ecological Genetics ◽  
Larval Period ◽  
Limiting Factor ◽  
Adult Size ◽  
Critical Stage ◽  
Larval Size

1. The low but regular positive correlation between body-size and the duration of the larval period in populations of D. melanogaster has been studied by selecting for large size or shorter development time on aseptic defined diets deficient in RNA and comparing the results with parallel selection on unrestricted yeast diets or on media in which RNA is not a limiting factor.2. There is a striking contrast according to the nature of the diet during selection. On unrestricted diets and where RNA is adequate there is little or no evidence of correlation between the two characters, but on low RNA media there is a striking correlation whether selection is for large body size or shorter development time.3. This contrast is accounted for in terms of particular changes in larval growth which can be divided into a first stage of growth to a critical size in the early 3rd instar and a second stage thereafter. The duration of the first stage can be greatly prolonged by inadequate diet but the duration of the later stage appears to be virtually unaffected by such variation although the amount of growth and hence final body-size, may be drastically reduced. The different diets which lead to presence or absence of correlation have enabled selection either to extend the growing period, so that the critical stage is reached later at a larger larval size, or to accelerate the growth rate in the later stage.4. Variation in the final stage of growth predominates on unrestricted diets and is responsible for the greater part of the variation in body size in unselected populations. Stabilization of body-size about an intermediate optimum refers especially to growth in this later stage.5. Lines selected for fast development on low RNA media are especially sensitive to minor nutritional variation. Probably only under rather special conditions is it possible to shorten the duration of the larval period and this is compatible with the importance of development time in fitness generally.6. There is evidence that the restriction of early growth, in the 2nd instar, reduces the size of the 3rd instar mouth-parts. Such reduction is correlated with changes in adult size probably because smaller mouth-parts restrict food intake.7. The pattern of larval growth suggests a flexible system which can be adjusted to different ecological conditions since the same body-size can be attained by adjusting the amount of growth effected before or after the critical stage. Differ ences in this respect will involve characteristic differences in reaction to environ mental variation and particular nutritional conditions are likely to influence the way in which adaptive changes are realized.

Effects of initial (larval) size and host body temperature on growth in trematodes

2003 ◽  
Vol 81 (4) ◽  
pp. 574-581 ◽  
Author(s):  
Robert Poulin ◽  
A David M. Latham
Keyword(s):  
Body Size ◽  
Body Temperature ◽  
Adult Stage ◽  
Species Variation ◽  
Adult Size ◽  
Model Group ◽  
Larval Size ◽  
Relative Growth ◽  
Host Body ◽  
Adult Body

For ectotherms, temperature is an important correlate of variation in body size within species. Variation in body size among related species could also be attributable in part to temperature if the different species grow under different thermal regimes. The roles of both initial (larval) size and host body temperature on final (adult) size of parasitic trematodes were investigated in a comparative analysis. Trematodes are a good model group for such a study, with almost half of known species growing at high and constant temperatures in endothermic vertebrates and the rest at lower and fluctuating temperatures in ectothermic vertebrates. The relative growth of trematodes, i.e., their growth relative to the size of their larvae, varied greatly among species. Increases in body size from the cercarial larval stage to the adult stage averaged almost 40-fold (maximum 1300-fold), whereas increases in size from the metacercarial stage to the adult stage averaged 6-fold (maximum 110-fold). There were no differences between trematodes in ectothermic hosts and trematodes in endothermic hosts with respect to these measures of relative growth, however, which suggests that host type and the thermal regime provided by the host have no effect on the growth of trematodes from larval to adult stages. In contrast, the final (adult) body size of trematodes appears to be determined to some extent by their initial (larval) size, independently of the type of host in which they developed.

Causes of variation in body size and consequences for the life history of Sitodiplosis mosellana

2004 ◽  
Vol 136 (6) ◽  
pp. 839-850 ◽  
Author(s):  
M.A.H. Smith ◽  
R.J. Lamb
Keyword(s):  
Life History ◽  
Body Size ◽  
Larval Instar ◽  
Larval Density ◽  
Egg Parasitoid ◽  
The Body ◽  
Adult Size ◽  
Larval Size ◽  
Sitodiplosis Mosellana ◽  
Developing Seed

AbstractThe body sizes of mature larvae and adults from field and laboratory populations of the wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), were measured to determine possible causes of variation in size and consequences of such variation through the life history. Mature larvae varied eightfold in mass. Female larvae were 80% heavier than males, on average. Variation in mass was associated with both the position of larvae on a wheat spike and the number feeding together on a developing seed. Larvae were 9% smaller when they developed on smaller, later developing seeds and 15%–18% smaller when they competed with five other larvae on an average-sized seed. Fewer small larvae survived winter. Larval density per infested seed increased with number of larvae per spike, suggesting that larval size may have density-dependent population effects. Small larvae produced few adults of Macroglenes penetrans (Kirby) (Hymenoptera: Pteromalidae), an egg parasitoid that overwinters as a larva in the third larval instar of S. mosellana. These effects were probably due to size, but sex may also have been a factor. The size of adults, measured by wing and abdomen length, was also variable, although less so than the size of larvae. Adult size was not associated with time of emergence and both large and small females dispersed, but female fecundity (4–105 mature eggs per individual) increased with body size.

A new species of the subgenus Scheloribates (Topobates) (Acari: Oribatida: Scheloribatidae) from Panama

2020 ◽  
Vol 29 (2) ◽  
pp. 278-283
Author(s):  
S.G. Ermilov
Keyword(s):  
New Species ◽  
Body Size ◽  
Leaf Litter ◽  
Related Species ◽  
Large Body ◽  
Oribatid Mite ◽  
Neotropical Region ◽  
Large Body Size ◽  
First Time ◽  
A New Species

The oribatid mite subgenus Scheloribates (Topobates) Grandjean, 1958, is recorded from the Neotropical region for the first time. A new species of this subgenus is described from the leaf litter collected in Cayo Agua Island, Panama. Scheloribates (Topobates) panamaensis sp. nov. differs from its related species by the very large body size and presence of a strong ventrodistal process on the leg femora II–IV.

scholarly journals Independent evolution towards larger body size in the distinctive Faroe Island mice

2021 ◽  
Author(s):  
Ricardo Wilches ◽  
William H Beluch ◽  
Ellen McConnell ◽  
Diethard Tautz ◽  
Yingguang Frank Chan
Keyword(s):  
Body Size ◽  
Meta Analysis ◽  
Small Body ◽  
Laboratory Mouse ◽  
Large Body ◽  
Natural Populations ◽  
Size Variation ◽  
Phenotypic Traits ◽  
Island Population ◽  
Multiple Loci

Abstract Most phenotypic traits in nature involve the collective action of many genes. Traits that evolve repeatedly are particularly useful for understanding how selection may act on changing trait values. In mice, large body size has evolved repeatedly on islands and under artificial selection in the laboratory. Identifying the loci and genes involved in this process may shed light on the evolution of complex, polygenic traits. Here, we have mapped the genetic basis of body size variation by making a genetic cross between mice from the Faroe Islands, which are among the largest and most distinctive natural populations of mice in the world, and a laboratory mouse strain selected for small body size, SM/J. Using this F2 intercross of 841 animals, we have identified 111 loci controlling various aspects of body size, weight and growth hormone levels. By comparing against other studies, including the use of a joint meta-analysis, we found that the loci involved in the evolution of large size in the Faroese mice were largely independent from those of a different island population or other laboratory strains. We hypothesize that colonization bottleneck, historical hybridization, or the redundancy between multiple loci have resulted in the Faroese mice achieving an outwardly similar phenotype through a distinct evolutionary path.

Capture of conspecific planktonic larvae by the suspension-feeding gastropod Crepipatella peruviana: association between adult and larval size

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
G A Rivera-Figueroa ◽  
J A Büchner-Miranda ◽  
L P Salas-Yanquin ◽  
J A Montory ◽  
V M Cubillos ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Larval Mortality ◽  
Feeding Preference ◽  
The Other ◽  
Suspension Feeding ◽  
Adult Size ◽  
Free Living ◽  
Larval Size ◽  
Suspension Feeders ◽  
Planktonic Larvae

ABSTRACT Free-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.

scholarly journals Age of maturation and behavioral tactics in male yellow ground squirrel Spermophilus fulvus during mating season

2014 ◽  
Vol 60 (6) ◽  
pp. 700-711 ◽  
Author(s):  
Nina A. Vasilieva ◽  
Ekaterina V. Pavlova ◽  
Sergey V. Naidenko ◽  
Andrey V. Tchabovsky
Keyword(s):  
Body Size ◽  
Ground Squirrel ◽  
Life History Theory ◽  
Social Activity ◽  
Indirect Evidence ◽  
Adult Size ◽  
Adult Males ◽  
Mating Season ◽  
Active Season ◽  
Good Physical Condition

Abstract Life-history theory predicts that in hibernators age of maturation is related positively to body size and negatively to the duration of active season aboveground. Yellow souslik is a large-sized ground squirrel with long hibernation, which suggests late maturation. We used four-year field observations of marked individuals to determine the age of maturation in males through analysis of age-dependent variation in body size, mass, androgen status, timing of spring emergence, ranging patterns and social behavior during the mating season. Yearling males were smaller, lighter, had lower level of fecal testosterone, emerged later and had smaller home ranges than older males. Social activity and the number of females encountered did not differ between age classes. After the second hibernation none of the studied parameters varied with age. Cluster analysis revealed two behavioral tactics: “active” males (adults only) emerged earlier, ranged more widely, initiated more contacts, encountered more females and were heavier than “passive” males (both yearling and adult). Thus, males of S. fulvus reached adult size and matured after two hibernations, which is relatively fast for such a big species with short active period. Indirect evidence for copulations and high variation among yearlings in all parameters suggest that some of them might successfully compete with adults. Active tactic of wandering and searching for females is energetically costly, and probably only adult males in good physical condition can afford it, whereas passive tactic of residing is energy saving and good for adults in poor condition and for yearlings that are continuing to grow.

scholarly journals Atmospheric Hypoxia Limits Selection for Large Body Size in Insects

PLoS ONE ◽  
2009 ◽  
Vol 4 (1) ◽  
pp. e3876 ◽  
Author(s):  
C. Jaco Klok ◽  
Jon F. Harrison
Keyword(s):  
Body Size ◽  
Large Body ◽  
Large Body Size ◽  
Selection For
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