Allometry and sexual dimorphism in the lung morphology of prairie rattlesnakes, Crotalus viridis viridis

1999 ◽  
Vol 20 (4) ◽  
pp. 377-389 ◽  
Author(s):  
J. Scott Keogh ◽  
V. Wallach
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Intraspecific Variation ◽  
Relative Length ◽  
Single Population ◽  
Crotalus Viridis ◽  
Lung Morphology ◽  
Body Sizes ◽  
Vascular Component

AbstractWe quantified sexual dimorphism and allometric changes in the lung morphology of 160 juvenile and adult specimens of prairie rattlesnake, Crotalus viridis viridis, from a single population. In virtually all lung components, those of males are located more posteriorly than are those of females of the same body size. Males display a longer vascular component than females but there is no sexual dimorphism in size of the avascular component. Thus, males generally have longer lungs than do females at all body sizes. With increasing body size, the lung components are found more anteriorly, relative length of the vascular lung decreases, and relative length of the avascular lung increases in both sexes. However, total lung length increases isometrically with body size. These sexual and allometric differences suggest that intraspecific variation should be taken into account when lung size characters are used in snake systematic studies.

Avian Egg Morphometrics - Allometric Models of Egg Volume, Clutch Volume and Shape

1994 ◽  
Vol 42 (3) ◽  
pp. 307 ◽  
Author(s):  
PD Olsen ◽  
RB Cunningham ◽  
CF Donnelly
Keyword(s):  
Body Weight ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Clutch Size ◽  
Egg Volume ◽  
Simple Power ◽  
Wide Range ◽  
Body Weights ◽  
Body Sizes ◽  
Simple Power Function

This paper describes three comprehensive new models of the allometric relationships between egg volume, clutch volume and shape, and body weight. Mean egg dimensions, clutch sizes and adult body weights were obtained for 326 species, mainly of four bird types: raptors (including owls), shorebirds, frogmouths (including nightjars), and storks (including the New World vultures). These are groups in which there is a wide range of body sizes and of sexual dimorphism in body size (in direction and degree). Female body weight alone accounted for 92% of the variation in egg volume. Sexual dimorphism in body size, phylogenetic relationship, and clutch size were significant contributors to the model of egg volume; their addition increased the explained variance to over 98%. The model was curvilinear (quadratic) in form, rather than linear as assumed in previous models. Larger species laid smaller eggs than expected under a simple power function. For the fitted model, within bird types, generic groupings had parallel curvilinear slopes but differing intercepts. Between bird types, the slopes differed. Clutch volume was scaled to body weight; all the bird types had a common slope, which was curvilinear. Body weight and dimorphism accounted for 89.5% of the variation in clutch volume. For all bird types, eggs became proportionally longer in shape as body weight increased, according to a simple power law. The relevance of these relationships to hypotheses on the evolution and adaptive significance of sexual dimorphism and to the trade-off between egg size and clutch size is discussed briefly.

Interpopulational variation in sexual dimorphism, reproductive output, and parasitism of Liophis miliaris (Colubridae) in the Atlantic forest of Brazil

2006 ◽  
Vol 27 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Lígia Pizzatto ◽  
Otavio Marques
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Atlantic Forest ◽  
Reproductive Output ◽  
Sexual Size Dimorphism ◽  
The Other ◽  
Female Body Size ◽  
Body Sizes ◽  
Northern Atlantic ◽  
Males And Females

AbstractSexual maturity, sexual dimorphism, reproductive output, and parasitism of the colubrid snake Liophis miliaris were compared among populations inhabiting four regions of Brazil: (1) northern coastal Atlantic forest, (2) southern coastal Atlantic forest, (3) northern inland Atlantic forest (4) southern inland Atlantic forest. Females delayed maturity and attained larger body sizes than males in all regions. Males and females from northern Atlantic forest were smaller and attained maturity with a smaller body size than males of other regions. The sexual size dimorphism index ranged from 0.19 to 0.23 and was lowest in the northern Atlantic forest. There was no sexual dimorphism in head length in any of the populations studied. Clutch size was similar in all populations and increased with maternal body size. The reproductive frequency was lower in the northern coastal Atlantic forest and in contrast to the other regions, tended to increase with female body size. The nematoda Ophidiascaris sp. and cystacanths of Oligacanthorynchus spira (Acanthocephala) occurred equally in both sexes. Fewer snakes from the northern coastal Atlantic forest were infested by parasites compared to the other regions and parasitism apparently did not influence reproduction.

Female polymorphism in Chilothrips strobilus (Thysanoptera: Thripidae), with the first description of the male

Zootaxa ◽  
2017 ◽  
Vol 4358 (1) ◽  
pp. 193 ◽  
Author(s):  
YANZE CUI ◽  
JINGHUI XI ◽  
JUN WANG
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Intraspecific Variation ◽  
Abdominal Segment ◽  
Wing Length ◽  
Northeastern China ◽  
Liaoning Province ◽  
Female Polymorphism ◽  
Small Genus ◽  
Different Parts

Polymorphism and sexual dimorphism are common in insects. Thrips have been reported to exhibit intraspecific variation in body size, color and wing length (Mound 2005), also sexual dimorphism in abdominal pore plates, antennal sensoria and fore leg armature (Tyagi et al. 2008). Chilothrips Hood is a small genus that currently comprises seven species (ThripsWiki 2017), three from USA, one from Japan, and three from China. No male has been reported in the three species from China, C. strobilus, C. jiuxiensis and C. hangzhouensis (Hu & Feng 2015), and C. strobilus was described on three female specimens from cones of Pinus in Liaoning Province, northeastern China (Tong & Zhang, 1994). Recently, we have surveyed different parts of northeastern China and collected many male individuals of C. strobilus. We have observed that this species shows sexual dimorphism in mouth cone length, and remarkable variation in form of abdominal segment X among females. 

Brontostoma lilloi Carpintero, 1980, a junior synonym of B. rubrovenosum (Stål, 1860) (Hemiptera: Heteroptera: Reduviidae)

Zootaxa ◽  
2019 ◽  
Vol 4614 (1) ◽  
pp. 180
Author(s):  
HÉLCIO R. GIL-SANTANA ◽  
DIEGO L. CARPINTERO
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Geographic Variation ◽  
Intraspecific Variation ◽  
New World ◽  
Junior Synonym

There are 22 genera and more than 100 described species of Ectrichodiinae in the New World (Gil-Santana et al. 2015). Intraspecific variation in coloration and body size have been recorded in several species of the subfamily. These characteristics can occur in the same population or can suggest geographic variation of the same species (Wygodzinsky 1951, Dougherty 1995, Gil-Santana & Baena 2009, Gil-Santana et al. 2013). Sexual dimorphism is also common: females are almost always more or less larger than males, frequently have thicker fore femora and smaller eyes and ocelli (Dougherty 1995). 

Growth, maturity, and sexual dimorphism in the wood turtle, Clemmys insculpta

1990 ◽  
Vol 68 (4) ◽  
pp. 672-677 ◽  
Author(s):  
Jeffrey E. Lovich ◽  
Carl H. Ernst ◽  
John F. McBreen
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Carapace Length ◽  
Sexual Size Dimorphism ◽  
Von Bertalanffy ◽  
Size Dimorphism ◽  
Adult Females ◽  
Body Sizes ◽  
Von Bertalanffy Growth Model ◽  
Wood Turtle

Growth in the wood turtle (Clemmys insculpta) is described using the von Bertalanffy growth model and nonlinear regression. Growth in both sexes is similar until about 160 mm plastron length. Males grew at a faster rate after this size. Males appear to mature at a larger size and later age than females, although age-specific body size is highly variable. Sexual size dimorphism, in carapace length, is pronounced, with males attaining mean body sizes significantly larger (1.07–1.10 times) than those of adult females. Plastron length is an inappropriate measure of sexual size dimorphism because of the development of plastral concavity in males. Females tend to predominate in samples, possibly owing to differential maturity of the sexes. The direction of sexual size dimorphism may be maintained by intrasexual competition among males for access to females. Data for several adults captured at intervals of from 9 to 20 years support the concept of indeterminate growth.

scholarly journals Intraspecific variation in Artiodactyla social organisation: A Bayesian phylogenetic multilevel analysis of detailed population-level data

2019 ◽  
Author(s):  
M.I. Miles ◽  
A.V. Jaeggi ◽  
M. Festa-Bianchet ◽  
C. Schradin ◽  
L.D. Hayes
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Intraspecific Variation ◽  
Comparative Studies ◽  
Social Evolution ◽  
Multilevel Models ◽  
Social Systems ◽  
Population Level ◽  
Social Organisation ◽  
Specific Variation

AbstractUnderstanding inter-specific variation in social systems is a major goal of behavioural ecology. Previous comparative studies of mammalian social organisation produced inconsistent results, possibly because they ignored intra-specific variation in social organisation (IVSO). The Artiodactyla have been the focus of many comparative studies as they occupy a wide diversity of habitats and exhibit large variation in life history patterns as well as other potential correlates of social organisation. Here we present the first systematic data on IVSO among Artiodactyla, infer their ancestral social organisation, and test whether habitat, sexual dimorphism, seasonal breeding, and body size predict inter- and intraspecific variation in social organisation. We found data on social organisation for 110 of 226 artiodactyl species, of which 74.5% showed IVSO. Using Bayesian phylogenetic multilevel models, the ancestral artiodactyl population was predicted to have a variable social organisation with significantly higher probability (0.77, 95% CI 0.29-1.00) than any non-variable form (i.e. solitary, pair-living, group-living). Greater sexual dimorphism and smaller body size both predicted more IVSO; smaller body size also predicted a higher likelihood of pair-living. Our results challenge the long-held assumption that ancestral Artiodactyla were pair-living and strongly imply that taking IVSO into account is crucial for understanding mammalian social evolution.

Ecology of the dominant copepod species at a Low Arctic site

1985 ◽  
Vol 63 (5) ◽  
pp. 1138-1147 ◽  
Author(s):  
Paul D. N. Hebert
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Resource Use ◽  
Brood Size ◽  
Calanoid Copepod ◽  
Size Dependent ◽  
Body Sizes ◽  
Low Arctic ◽  
Herbivorous Species ◽  
Tundra Ponds

Four species of calanoid copepod regularly co-occur in tundra ponds near Churchill, Manitoba. Despite the physical uniformity of the habitats they occupy, twofold variation in body size and fivefold variation in brood size existed among conspecific populations of each species. Size shifts were concordant in the sexes, but the extent of sexual dimorphism was size dependent in each species. Size differences among populations persisted through two summers. The three herbivorous species showed parallel variation in body sizes and fecundities, while the predatory species did not. The size covariation in the herbivorous taxa may reflect significant overlap in resource use despite their size divergence.

Reproduction and feeding of the colubrid snake Tomodon dorsatus from south-eastern Brazil

2005 ◽  
Vol 26 (1) ◽  
pp. 33-38 ◽  
Author(s):  
Ivan Sazima ◽  
Otavio Marques ◽  
Alessandra Bizerra
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Rainy Season ◽  
Feeding Behaviour ◽  
South Eastern ◽  
Eastern Brazil ◽  
Body Sizes ◽  
Upper Jaw ◽  
Reproductive Cycles ◽  
Clutch Mass

AbstractBody size, sexual dimorphism, reproductive cycles, fecundity, diet and feeding behaviour of the colubrid snake Tomodon dorsatus from south-eastern Brazil were studied. Females of this viviparous species attained larger body sizes than males, the latter maturing with smaller body size than the former. Vitellogenesis occurred at the onset of rainy season, ovulation by mid rainy season, and parturition from late dry to early rainy season. Reproductive cycle was extended, maybe as a consequence of the low metabolism and food intake. Litter size ranged 4-26 offspring and was correlated with maternal body size. Relative clutch mass ranged 0.48-0.82, and neonates ranged 12-17 cm in snout-vent length. Tomodon dorsatus was shown to feed exclusively on veronicellid slugs quickly swallowed by long excursions of the specialized upper jaw units.

scholarly journals Pelage color of red bats Lasiurus borealis varies with body size: An image analysis of museum specimens

2010 ◽  
Vol 56 (4) ◽  
pp. 401-405 ◽  
Author(s):  
Andrew K. Davis ◽  
Steven B. Castleberry
Keyword(s):  
Image Analysis ◽  
Body Size ◽  
Sexual Dimorphism ◽  
Empirical Research ◽  
Intraspecific Variation ◽  
Statistical Analyses ◽  
Museum Specimens ◽  
Analysis Program ◽  
Lasiurus Borealis ◽  
Pelage Color

Abstract Mammalian pelage color can vary among individuals of many species, although this intraspecific variation is often overlooked by researchers, perhaps because of its sometimes subtle nature and difficulty in assessing it quantitatively. Thus, such variation is rarely studied in mammals, and this is especially true within the order Chiroptera, where there has been very little empirical research. We examined museum specimens of red bats (Lasiurus borealis, family Vespertilionidae) from Georgia, USA, to determine the extent of sexual dimorphism in pelage color and to explore possible associations between body size and pelage color. We photographed 54 specimens under uniform lighting, and used an image analysis program to measure pelage hue on the uropatagium region, which is fully furred in members of the genus Lasiurus. Statistical analyses of pelage hue scores showed males had significantly redder pelage than females when considered alone, but when examined together with effects of body size and collection year, sex was not significant, and collection year and body size were. More recent specimens tended to be less red than older specimens, which might indicate a wearing of the buffy tips of hairs from older specimens, and smaller bats of both sexes tended to be more red. These interesting findings are encouraging and we suggest that future explorations into intraspecific variation in pelage color of bats using this or similar approaches are warranted to clarify the significance of the patterns. This study also demonstrated that care must be taken in analyses of mammalian pelage color from older museum skins, or at least that researchers must take into account the age of the specimens.

Sign in / Sign up

Export Citation Format

Share Document