Habitat-Related Variation in Body Size and Reproductive Output and an Examination of Reproductive Allometry in the Sabine Map Turtle (Graptemys sabinensis) across Three River Drainages

Copeia ◽  
2016 ◽  
Vol 104 (2) ◽  
pp. 458-468 ◽  
Author(s):  
Amy K. Fehrenbach ◽  
Irvin Louque ◽  
Stacy L. McFadden ◽  
Cybil Huntzinger ◽  
Eddie Lyons ◽  
...  
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Related Variation ◽  
River Drainages

An ecological explanation for hyperallometric scaling of reproduction

2021 ◽  
Author(s):  
Tomos Potter ◽  
Anja Felmy
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Resource Competition ◽  
Natural Populations ◽  
Scaling Exponent ◽  
Wild Populations ◽  
Wet Season ◽  
Size Dependent ◽  
In The Wild ◽  
The Relationship

AbstractIn wild populations, large individuals have disproportionately higher reproductive output than smaller individuals. We suggest an ecological explanation for this observation: asymmetry within populations in rates of resource assimilation, where greater assimilation causes both increased reproduction and body size. We assessed how the relationship between size and reproduction differs between wild and lab-reared Trinidadian guppies. We show that (i) reproduction increased disproportionately with body size in the wild but not in the lab, where effects of resource competition were eliminated; (ii) in the wild, the scaling exponent was greatest during the wet season, when resource competition is strongest; and (iii) detection of hyperallometric scaling of reproduction is inevitable if individual differences in assimilation are ignored. We propose that variation among individuals in assimilation – caused by size-dependent resource competition, niche expansion, and chance – can explain patterns of hyperallometric scaling of reproduction in natural populations.

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.

Overcoming environmental and morphological constraints: egg size and pelvic kinesis in the smallest tortoise, Homopus signatus

2005 ◽  
Vol 83 (10) ◽  
pp. 1343-1352 ◽  
Author(s):  
M D Hofmeyr ◽  
B T Henen ◽  
V J.T Loehr
Keyword(s):  
Body Size ◽  
Southern Africa ◽  
Egg Size ◽  
Reproductive Output ◽  
Selective Advantage ◽  
Arid Environment ◽  
Harsh Environment ◽  
Offspring Survival ◽  
Aridity Gradient ◽  
East West

The small tortoises of southern Africa include the only testudinid taxa that produce single-egg clutches. This group includes the world's smallest tortoise, Homopus signatus (Gmelin, 1789), which inhabits a harsh, arid environment. Climate and body size may influence reproductive output, so we hypothesized that the east–west aridity gradient in southern Africa affects egg and clutch size of the small indigenous tortoises, and that the morphology of H. signatus constrains egg size, preventing the formation of optimal eggs. Here we show that aridity and unpredictable rainfall determine which of these tortoise taxa produce single-egg clutches. Taxa in less predictable environments produce larger eggs relative to body size than do taxa in more predictable environments. Homopus signatus produces the largest egg relative to body size, probably to enhance offspring survival in its harsh environment. Body size, pelvic aperture size, and the narrow anal gap of H. signatus appear to constrain egg size. Despite these constraints, females produce rigid-shelled eggs larger than the pelvic canal and use pelvic kinesis to pass eggs at oviposition; both features are unknown in other chelonians and emphasize the selective advantage of large eggs to H. signatus.

Fecundity and Reproductive Output in Nine Species of Cancer crabs (Crustacea, Brachyura, Cancridae)

1991 ◽  
Vol 48 (2) ◽  
pp. 267-275 ◽  
Author(s):  
Anson H. Hines
Keyword(s):  
Body Size ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
The North ◽  
Female Body Size ◽  
Body Weights ◽  
Order Of Magnitude ◽  
Maximum Body ◽  
The North Pacific ◽  
Female Weight

The major variables of reproductive output and fecundity were compared among brooding females of nine species of Cancer from the North Pacific and North Atlantic: C. oregonensis, C. gracilis, C. irroratus, C. antennarius, C. productus, C. borealis, C. anthonyi, C. magister, and C. pagurus. Female body size is the principal determinant of reproductive output, with dry body weights spanning two orders of magnitude from 1.2 to 199.5 g among species and often one order of magnitude within species. Mean dry brood weights ranged from 0.21 to 26.7 g among species, with relative brood size varying from 11 to 19% of female weight. The brood mass is partitioned into eggs ranging among species from 311 to 442 μm, resulting in mean fecundities ranging among species from 18 200 to 2 208 000 eggs per brood. Most species produce one or two broods per year over the winter–spring season over a reproductive span averaging 6.6 yr (range 4–10 yr). Cumulative reproductive output and cumulative fecundity over the maximum estimated life span exhibited approximately isometric functions of maximum body size, and they ranged among species from 1.88 to 316 g brood weight and 158 000 to 22 300 000 eggs per lifetime, respectively. The pattern of covariation of reproductive traits in the Cancridae corresponds well with the overall pattern previously determined for a diverse array of brachyurans from seven families.

A comparison of reproductive output of the Omei Treefrog (Rhacophorus omeimontis) between high and low elevations

2011 ◽  
Vol 61 (3) ◽  
pp. 263-276 ◽  
Author(s):  
Wen Bo Liao ◽  
Xin Lu
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Food Resource ◽  
High Elevation ◽  
Cold Climate ◽  
Western China ◽  
Major Influence ◽  
Rhacophorus Omeimontis

AbstractElevation that results in changes in climate, duration of breeding season and food resource has long been considered a major influence on the evolution of life-history traits in amphibians. The present study examined differences in reproductive output (clutch size and egg size) of the Omei Treefrog (Rhacophorus omeimontis) at two elevations (1000 m and 1700 m above sea level) in Baoxing County, western China. Within each population, female attributes (size and age) were responsible for much of the reproductive output variation in that larger or older females produced larger clutches of smaller eggs. Clutch size and egg size showed a significantly negative correlation, which was indicative of a trade-off between the two parameters. The high-elevation females were significantly larger than the low-elevation counterparts. After accounting for interpopulational difference in body size, clutch size, egg size and clutch volume differed significantly between the populations. For the high-elevation population relatively smaller clutches tended to be associated with larger eggs. Our findings suggest that females produce smaller clutches relative to body size and larger eggs in the high-elevation population to ensure that each egg is adequately provisioned in the face of cold climate and short duration of development.

Growth and body size in Blanding's turtles (Emydoidea blandingi): relationships to reproduction

1991 ◽  
Vol 69 (1) ◽  
pp. 239-245 ◽  
Author(s):  
Justin D. Congdon ◽  
Richard C. van Loben Sels
Keyword(s):  
Body Size ◽  
Clutch Size ◽  
Egg Size ◽  
Reproductive Output ◽  
Body Sizes ◽  
Minimum Age ◽  
Average Size ◽  
Average Body ◽  
Clutch Mass ◽  
Growth And Reproduction

Growth and reproduction in Blanding's turtles (Emydoidea blandingi) were studied in southeastern Michigan from 1975 through 1988. Average body sizes of both sexes of adults were similar; however, shapes of males were different from those of females. The average size of a group of females with a mean minimum age of 47 years was not significantly different from a younger group with a mean age of 21 years. Clutch size ranged from 3 to 19 ([Formula: see text], N = 280) eggs over 11 years. Clutch wet mass ranged from 60.4 to 183.4 g ([Formula: see text], N = 17), and relative clutch mass of nine females averaged 0.12. Clutch size, and to a lesser degree egg size, showed a significant positive relationship with body size, but not with age of females. Hatchlings averaged 31.0 mm in plastron length, 35.3 mm in carapace length, and 9.2 g in body wet mass. Differences in juvenile growth rates and age at sexual maturity appear to be the major cause of variation in body size of adult Blanding's turtles and the related reproductive output per clutch.

scholarly journals The sex lives of ctenophores: the influence of light, body size, and self-fertilization on the reproductive output of the sea walnut,Mnemiopsis leidyi

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1846 ◽  
Author(s):  
Daniel A. Sasson ◽  
Joseph F. Ryan
Keyword(s):  
Invasive Species ◽  
Body Size ◽  
Reproductive Output ◽  
Lower Percentage ◽  
Mnemiopsis Leidyi ◽  
Simultaneous Hermaphrodite ◽  
Egg Viability ◽  
Self Fertilization ◽  
The Cost ◽  
Insight Into

Ctenophores (comb jellies) are emerging as important animals for investigating fundamental questions across numerous branches of biology (e.g., evodevo, neuroscience and biogeography). A few ctenophore species including, most notably,Mnemiopsis leidyi, are considered as invasive species, adding to the significance of studying ctenophore ecology. Despite the growing interest in ctenophore biology, relatively little is known about their reproduction. Like most ctenophores,M. leidyiis a simultaneous hermaphrodite capable of self-fertilization. In this study, we assess the influence of light on spawning, the effect of body size on spawning likelihood and reproductive output, and the cost of self-fertilization on egg viability inM. leidyi. Our results suggest thatM. leidyispawning is more strongly influenced by circadian rhythms than specific light cues and that body size significantly impacts spawning and reproductive output.Mnemiopsis leidyiadults that spawned alone produced a lower percentage of viable embryos versus those that spawned in pairs, suggesting that self-fertilization may be costly in this species. These results provide insight into the reproductive ecology ofM. leidyiand provide a fundamental resource for researchers working with them in the laboratory.

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