Effects of body size, sibship, and tail injury on the susceptibility of tadpoles to dragonfly predation

1990 ◽  
Vol 68 (5) ◽  
pp. 1027-1030 ◽  
Author(s):  
Raymond D. Semlitsch
Keyword(s):  
Body Size ◽  
Antipredator Behavior ◽  
Genetic Differences ◽  
Factorial Experiment ◽  
Hyla Chrysoscelis ◽  
Effective Mechanism ◽  
Dramatic Effect ◽  
Tail Loss ◽  
Alarm Substances

The effect of tadpole body size, sibship, and tail injury on the survival of treefrog tadpoles (Hyla chrysoscelis) in the presence of dragonfly larvae (Tramea lacerata) was examined in a three-way factorial experiment. Tadpole body size had a dramatic effect on survival; large tadpoles had higher survival than medium-sized or small tadpoles. The presence of tail injury simulating an unsuccessful predation attempt significantly reduced survival. Survival of control tadpoles without tail injury in the presence of a predator was almost twice as high as that of tadpoles with 75% tail loss. Tadpole sibship had no effect on survival and indicated that genetic differences in antipredator behavior or production of alarm substances and allelochemicals, independent of body size, were not apparent. There were no significant interactions between tail injury and body size or tail injury and sibship. These results indicate that increasing body size is an effective mechanism for reducing predation and that injury from an unsuccessful predation attempt reduces subsequent survival by increasing the risk of future predation.

scholarly journals Gender, Age, Race and Lactose Intolerance: Is There Evidence to Support a Differential Symptom Response? A Scoping Review

Nutrients ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1956 ◽  
Author(s):  
Rebecca Lapides ◽  
Dennis Savaiano
Keyword(s):  
Body Size ◽  
Scoping Review ◽  
Lactose Intolerance ◽  
The Elderly ◽  
Genetic Differences ◽  
Exhaustive Search ◽  
Google Scholar ◽  
Racial Groups ◽  
Symptom Response ◽  
The Relationship

Research evaluating the relationship between lactose intolerance (LI) symptoms and age, gender and race is reviewed. An exhaustive search was conducted on the Google Scholar and PubMed databases. The evidence suggests that women, the elderly or specific racial groups are not more susceptible to LI, but rather dose, body size and genetic differences in lactase non-persistence (LNP) are the primary drivers of intolerance symptoms.

Body Size Is Related to Temperature Preference in Hyla chrysoscelis Tadpoles

2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Danielle R. Kirsch ◽  
Shawna Fix ◽  
Jon M. Davenport ◽  
Kristen K. Cecala ◽  
Joshua R. Ennen
Keyword(s):  
Body Size ◽  
Hyla Chrysoscelis ◽  
Temperature Preference

Mating behavior and determinants of male mating success in the gray treefrog, Hyla chrysoscelis

1991 ◽  
Vol 69 (1) ◽  
pp. 246-250 ◽  
Author(s):  
Mark E. Ritke ◽  
Raymond D. Semlitsch
Keyword(s):  
Body Size ◽  
Mating Behavior ◽  
Mating Success ◽  
Male Mating ◽  
Hyla Chrysoscelis ◽  
Male Mating Success ◽  
Male Aggression ◽  
Previous Night ◽  
Significant Difference ◽  
Gray Treefrog

We studied mating behavior and male mating success in a population of gray treefrogs (Hyla chrysoscelis) during 1987 and 1988 in western Tennessee. During 1988, individual males called from 1 to 7 nights ([Formula: see text]) and mated 0–4 times ([Formula: see text]). The number of nights that males called or achieved amplexus was not related to body size, but males that called on more nights had a relatively greater chance of mating. There was no significant difference in body size between mated and unmated males on any of the nights tested. Males that mated or called on a previous night were not more likely to achieve amplexus than males that had not mated previously or those that were new to the population. We have no strong evidence to suggest that assortative mating was characteristic of our population or that male–male aggression directly influences female choice.

Third Report on a Test of Mcdougall'S Lamarckian Experiment on the Training of Rats

1948 ◽  
Vol 25 (2) ◽  
pp. 103-122
Author(s):  
W. E. AGAR ◽  
F. H. DRUMMOND ◽  
O. W. TIEGS
Keyword(s):  
Body Size ◽  
Genetic Differences ◽  
Colour Pattern ◽  
Control Line ◽  
Present Position ◽  
Progressive Decline ◽  
Lamarckian Inheritance ◽  
Successive Generations ◽  
And Control

This experiment, to test McDougall's conclusion that the effects of training are inherited, has now been carried on for thirty-six generations, involving the training of 2827 rats. The present position of the problem raised by McDougall may be summarized as follows: Neither our own experiment, nor that of Crew, shows any evidence of increasing facility in learning attributable to trained ancestry. McDougall's claim that the progressive decline in the number of errors which he found in successive generations of trained rats is an example of Lamarckian inheritance cannot be maintained in face of the facts (a) that he did not keep a control line, (b) that we have found a progressive decline in our trained line similar to McDougall's, but this was paralleled by the control line; moreover, after about twenty-eight generations, the number of errors progressively increased again in both lines. McDougall's further argument from the change from a zero-day preference for the bright gangway in earlier generations to a preference for the dim gangway in later generations is invalid; it is shown, from his own figures, to be capable of a different explanation. The discovery of genetic differences in colour pattern and body size between our trained and control lines, presumably due to mutations, emphasizes the difficulty of interpreting genetic differences in facility of learning, even if they should occur, as due to the Lamarckian factor. The experiment is being continued.

Unveiling a spatial tail breakage outbreak in a lizard population

2017 ◽  
Vol 38 (2) ◽  
pp. 238-242
Author(s):  
Conrado Galdino ◽  
Stefânia Ventura ◽  
Gladston Moreira
Keyword(s):  
Body Size ◽  
Cluster Formation ◽  
Spatial Relation ◽  
Spatial Cluster ◽  
Intraspecific Aggression ◽  
Agonistic Interactions ◽  
Ecological Attributes ◽  
Tail Loss ◽  
Tail Autotomy

Many ecological attributes of organisms vary spatially. This strict dependency upon space generally arises by individuals occupying places with the necessary resources and conditions for survival. For lizards, losing the tail is an evolved mechanism that allows them to escape predators or to avoid aggressive intraspecific agonistic interactions. We evaluated the spatial relation of tail loss in a population of the lizard Tropidurus montanus. Our results support the occurrence of a spatial cluster of autotomized lizards. However, we cannot relate the cluster formation to the crowding of neighbouring lizards nor to individuals’ body size. Tail loss in lizards is known to be related to predatory attacks or intraspecific aggression, and we now show that tail autotomy occurs in a non-random way regarding space, and thus is also related to the space occupied by individuals in populations.

Ontogenetic variation in antipredator behavior of Iberian rock lizards (Lacerta monticola): effects of body-size-dependent thermal-exchange rates and costs of refuge use

2003 ◽  
Vol 81 (7) ◽  
pp. 1131-1137 ◽  
Author(s):  
José Martín ◽  
Pilar López
Keyword(s):  
Body Size ◽  
Exchange Rates ◽  
Antipredator Behavior ◽  
Physical Property ◽  
Theory Approach ◽  
Ontogenetic Changes ◽  
Refuge Use ◽  
Thermal Exchange ◽  
Escape Theory ◽  
Heating And Cooling

In lizards, ontogenetic changes in body size affect thermal-exchange rates. This simple physical property may have consequences for thermoregulation, and also for antipredator behavior. We examined how ontogenetic changes in body mass affect rates of heating and cooling of the lizard Lacerta monticola, confirming the general result obtained for other lizards. We further analyzed the differences between juveniles and adults in approach distances to a simulated predator and in time to emerge from refuges. Juvenile lizards have a lower absolute running speed, making them more vulnerable to predation. However, in contrast to results expected from optimal-escape theory, approach distances were shorter for juveniles than for adults. Juveniles may be confident in their small size and only flee when the probability of being detected is high. On the other hand, differences in thermal properties might affect costs of refuge use. Thus, juveniles might delay fleeing because their costs of hiding are higher, as they cool faster than adults. Differences in thermal costs may also explain the juveniles' shorter times of emergence from refuges. Because of the behavioral adjustments involved in antipredator behavior, the physiological costs of reaching a low body temperature in refuges probably do not differ between age classes.

The causes of differences in production between dairy herds

1961 ◽  
Vol 3 (03) ◽  
pp. 277-294 ◽  
Author(s):  
P. J. Brumby
Keyword(s):  
Body Size ◽  
New Zealand ◽  
Protein Content ◽  
Milk Production ◽  
Experimental Approach ◽  
Milk Composition ◽  
Genetic Differences ◽  
Dairy Herds ◽  
Production Potential ◽  
High Group

The extent of the genetic differences existing among a sample of the dairy herds of New Zealand was assessed by a direct experimental approach. In part one of the experiment, 240 young calves were taken from 40 herds of markedly different production levels and reared and milked as a uniformly treated herd of cattle at Ruakura. In part two of the experiment 120 sets of identical twin calves were divided amongst these 40 high- and low-producing herds.Results indicated that in general there were no obvious genetic differences between the cattle in the high and low herds in body size, fertility, milk production or days in lactation. There were, however, genetic differences between the high and low herds in milk composition; approximately 50% of the differences between herds in butterfat and protein content and 25% of the SNF content were due to genetic differences between herds.Genetic differences between herds in yield were found within the high group of herds but not in the low.Evidence was obtained indicating that interactions between herd environment and the genotype of individual animals provided an appreciable source of variation.The production level of a herd in which an animal was reared was without effect upon its subsequent production potential for milk yield.

Effects of nonlethal injury and habitat complexity on predation in tadpole populations

1991 ◽  
Vol 69 (4) ◽  
pp. 830-834 ◽  
Author(s):  
Chester R. Figiel Jr. ◽  
Raymond D. Semlitsch
Keyword(s):  
Habitat Complexity ◽  
Swimming Performance ◽  
Tail Length ◽  
Swimming Velocity ◽  
Hyla Chrysoscelis ◽  
Predator Prey ◽  
Sprint Speed ◽  
Tail Loss ◽  
Four Levels ◽  
Procambarus Acutus

Our purpose was to determine how nonlethal prey injury and habitat complexity mediate the dynamics of a predator–prey system. We assessed rates of predation by the crayfish Procambarus acutus acutus on Hyla chrysoscelis tadpoles with four levels of tail loss (0, 25, 50, and 75% total tail length removed), and in habitats of three levels of complexity (zero, low, and high density of screen) in a 4 × 3 factorial design. We also examined the effects of tail loss on tadpole sprint velocity and distance traveled. Tadpoles with 75% tail loss were preyed upon significantly more often than tadpoles in the other tail-loss treatments. Habitat complexity did not affect tadpole survival. In addition, there was no interaction between tail loss and habitat complexity. Tail loss significantly affected both tadpole swimming velocity and sprint distance traveled. Tadpoles with 75% tail loss had slower sprint speed and swam a shorter distance than tadpoles with 0 and 25% tail loss, and tadpoles with 50% tail loss had slower sprint speed and swam a shorter distance than tadpoles in the 0% tail loss treatment. Although tadpoles generally rely on short bursts of speed, generated by the tail, to escape predators, tail injury and apparently reduced swimming performance did not increase vulnerability to predation in a simple linear fashion.

scholarly journals Heritability and selection on body size in a natural population of Drosophila buzzatii.

Genetics ◽  
1995 ◽  
Vol 141 (1) ◽  
pp. 181-189
Author(s):  
A Leibowitz ◽  
M Santos ◽  
A Fontdevila
Keyword(s):  
Genetic Variation ◽  
Body Size ◽  
Random Sample ◽  
Phenotypic Variation ◽  
Development Time ◽  
Wing Length ◽  
Genetic Differences ◽  
Phenotypic Differences ◽  
Drosophila Buzzatii ◽  
Average Development

Abstract An attempt was made to assess whether the phenotypic differences in body size (as measured by wing length) between wild-caught mating and single Drosophila buzzatii males could be attributed to genetic differences between the samples. Mating males were found to be larger and less variable than a random sample of the population. The progeny of the mating males (produced by crossing to a random female from a stock derived from the same population) were on average larger than those of the single males, but not significantly so (P = 0.063), and less phenotypically variable. This difference in variance between the samples suggests that there are indeed genetic differences between the paternal samples but tests for significant differences in the additive genetic component of variance proved inconclusive. For both samples it was found that while the ratio of additive genetic variation in the laboratory to phenotypic variation in the field yielded estimates of ĥs2(N) congruent to 10% the regression of offspring reared in the laboratory on parents from the wild was not significantly different from zero. In addition, it was found that the average development time of the progeny of the mating males is shorter than that of the random sample.

Genetic differences in milk production in relation to mature body weight

1973 ◽  
Vol 2 ◽  
pp. 15-25 ◽  
Author(s):  
C. S. Taylor
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Experimental Evidence ◽  
Milk Production ◽  
Genetic Differences ◽  
General Effect ◽  
Input Output ◽  
Time Variables ◽  
Treat All ◽  
Inputs And Outputs

A survey of the accumulated experimental evidence suggests that the general effect of genetic differences in body size on input-output relationships in livestock might be largely accounted for by the following two genetic sizescaling rules:1. treat all age and time variables for the ith genotype as directly proportional to Mi0·27, where Mi is the mature body weight of the ith genotype;2. at every age standardized as in (1), treat all cumulated inputs and outputs for the zth genotype as directly proportional to Mi.

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