Analyzing the Relationship between Clutch Size and Female Body Size in Reptiles

The tropidurid lizard Tropidurus torquatus (Wied, 1820) has a set of populations inhabiting coastal sand dune habitats (“restinga”) along the eastern Brazilian coast. Despite its wide geographic range, there is no information about geographic variation in reproductive features among its populations. In the present study we compared some reproductive aspects of females in 10 coastal populations of T. torquatus, aiming to evaluate to what extension they vary geographically. The minimum size at maturity was relatively similar to most populations, but mean female body size had a considerable variation. Clutch size of almost all coastal populations of T. torquatus had little variation and was composed predominantly of two eggs. Interpopulational variation in the mean egg volume was relatively wide and strongly influenced by the variation in mean female body size. The data of the present study indicated that females of almost all coastal populations of T. torquatus produce, predominantly, clutches with two eggs and invest more energy in egg size instead of clutch size, probably as a consequence of morphological and environmental factors. The increased reproductive investment in egg size was confirmed by the values obtained for the relative clutch mass, which remained relatively constant along the coastal geographic distribution of T. torquatus.

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Reproduction of a whiptail lizard (Ameivula ocellifera, Teiidae) from a coastal area in northeastern Brazil

Anais da Academia Brasileira de Ciências ◽

10.1590/0001-3765201420130153 ◽

2014 ◽

Vol 86 (3) ◽

pp. 1263-1272 ◽

Cited By ~ 3

Author(s):

DJAN ZANCHI-SILVA ◽

DIVA M. BORGES-NOJOSA ◽

CONRADO A.B. GALDINO

Keyword(s):

Body Size ◽

Clutch Size ◽

Coastal Area ◽

Rainy Season ◽

Female Body ◽

The State ◽

Northeastern Brazil ◽

Egg Volume ◽

Female Reproduction ◽

Female Body Size

The reproductive ecology of Ameivula ocellifera was studied from September 2009 to August 2010 in a coastal area of the state of Ceará, Brazil. Females reproduced continuously throughout the year, with a peak at the end of the rainy season. Even though there was a predominance of pre-reproductive individuals in the sample, gonadal activity of males peaked synchronously to female reproduction. Mean clutch size was 1.98 ± 0.56 and positively associated with female body size, while mean egg volume was 510.54 ± 84.29 mm3 and unrelated to female body size. We did not find any association between clutch size and average egg volume.

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ISOMETRY OF EGG SIZE IN A TEXAS POPULATION OF THE TURTLE STERNOTHERUS ODORATUS THAT EXHIBITS A NEARLY FIXED CLUTCH SIZE

Journal of North American Herpetology ◽

10.17161/jnah.vi.13615 ◽

2020 ◽

pp. 13-17

Author(s):

Peter V. Lindeman

Keyword(s):

Body Size ◽

Clutch Size ◽

Egg Size ◽

Female Body Size ◽

Competing Demands ◽

Sternotherus Odoratus ◽

Central Texas ◽

Relationship Of ◽

The Relationship ◽

Anatomical Constraints

In evaluating optimal egg-size theory and the effects of anatomical constraints on egg size in turtles, pivotal questions concern the significance of the relationship of egg size to female body size and whether the relationship is isometric or hypoallometric. In a central Texas population of the kinosternid turtle Sternotherus odoratus in which clutch size of a sample of turtles was nearly fixed (seven of eight females had two eggs while the largest female had three eggs), there was an isometric increase in egg width with body size among the females with two-egg clutches and significantly reduced egg width in the largest female’s three-egg clutch. Allometric analyses of populations that exhibit little variation in clutch size, as well as analysis of modal clutch sizes in populations with more variable clutch sizes, both have the potential to further illuminate the competing demands of increasing egg size vs. increasing clutch size as females grow larger, enabling them to optimize their reproductive output as it increases with body size.

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Variations in the reproductive strategies of three populations of Phrynocephalus helioscopus in China

PeerJ ◽

10.7717/peerj.5705 ◽

2018 ◽

Vol 6 ◽

pp. e5705

Author(s):

Tao Liang ◽

Lu Zhou ◽

Wenfeng He ◽

Lirong Xiao ◽

Lei Shi

Keyword(s):

Body Size ◽

Clutch Size ◽

Reproductive Strategies ◽

Female Body ◽

Egg Size ◽

Reproductive Traits ◽

Breeding Period ◽

Female Body Size ◽

Trade Offs ◽

Morphological Constraint

Background Egg size and clutch size are key life history traits. During the breeding period, it is possible for females to increase their reproductive output either by increasing the number of eggs if the optimal egg size (OES) is maintained, or by increasing the allocation of energy to each egg. However, the strategies adopted are often influenced by animals’ morphology and environment. Methods Here, we examined variation in female morphological and reproductive traits, tested for trade-offs between egg size and clutch size, and evaluated the relationship between egg size and female morphology in three populations of Phrynocephalus helioscopus. Results Female body size, egg size, and clutch size were larger in the Yi Ning (YN) and Fu Yun (FY) populations than in the Bei Tun (BT) population (the FY and YN populations laid more, and rounder eggs). Egg size was independent of female body size in two populations (BT and FY), even though both populations had an egg-size/clutch size trade-off. In the YN population, egg size and clutch size were independent, but egg size was correlated with female body size, consistent with the hypothesis of morphological constraint. Conclusions Our study found geographical variation in body size and reproductive strategies of P. helioscopus. Egg size was correlated with morphology in the larger-bodied females of the YN population, but not in the smaller-bodied females of the BT population, illustrating that constraints on female body size and egg size are not consistent between populations.

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Geographic variation in female body size and clutch size of the lizard Sceloporus variabilis (Squamata: Phrynosomatidae) in Mexico

Acta Zoologica ◽

10.1111/azo.12372 ◽

2021 ◽

Author(s):

Aurelio Ramírez‐Bautista ◽

Raciel Cruz‐Elizalde ◽

Barry P. Stephenson ◽

Uriel Hernández‐Salinas

Keyword(s):

Body Size ◽

Geographic Variation ◽

Clutch Size ◽

Female Body ◽

Female Body Size

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Quality versus quantity: The balance between egg and clutch size among Australian amphibians is related to life history and environmental conditions

10.1101/2020.03.15.992495 ◽

2020 ◽

Author(s):

John Gould ◽

Chad Beranek ◽

Jose Valdez ◽

Michael Mahony

Keyword(s):

Life History ◽

Body Size ◽

Parental Care ◽

Clutch Size ◽

Female Body ◽

Inverse Relationship ◽

Life History Traits ◽

Egg Laying ◽

Breeding Habitat ◽

Female Body Size

AbstractAn inverse relationship between egg and clutch size has been found repeatedly across animal groups, including birds, reptiles and amphibians, and is considered to be a result of resource limitations and physical constraints on the reproducing female. However, few studies have contextualised this relationship with respect to various environmental selecting pressures and life history traits that have also likely influenced the selection of an optimal egg/clutch size combination, while even fewer have tested these interrelationships using robust natural history datasets. In this study, we aimed to test current hypothesises regarding these relationships on both egg and clutch sizes among the Australian Anurans, which to date have not received this kind of investigation. Specifically, we looked at the influence of environmental selecting pressures (egg laying location, environment persistence and bioregion) and life history traits (adult female body size, egg development type, parental care level, breeding period and temporal breeding pattern). As expected, a clear inverse relationship was found between egg and clutch size, while female body size was positively related to both. Generally speaking, smaller clutches of larger eggs tended to be produced by species that i) oviposit terrestrially, ii) showcase direct development and iii) possess high levels of parental care. Temporal breeding pattern was strongly related to clutch size only, with large clutches occurring in explosive breeding species, while breeding habitat was strongly related to egg size only, with large eggs sizes occurring in terrestrial species. Altogether, these findings indicate that numerous factors have likely influenced the evolution of an optimal clutch type in this group, highlighting the importance of incorporating such variables into animal studies on egg and clutch sizes.

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Size-mediated temperature effect on embryonic development in Eodiaptomus japonicus (Copepoda, Calanoida) in Lake Biwa, Japan

Journal of Plankton Research ◽

10.1093/plankt/fbaa045 ◽

2020 ◽

Author(s):

Xin Liu ◽

Syuhei Ban

Keyword(s):

Body Size ◽

Embryonic Development ◽

Female Body ◽

Egg Size ◽

Lake Biwa ◽

Synergistic Effects ◽

Cold Season ◽

Female Body Size ◽

Food Conditions ◽

The Relationship

Abstract Egg size has numerous ecological implications for zooplankton, and can influence hatching duration and female fecundity. In this study, temperature functions of embryonic development time (EDT) were determined in the copepod Eodiaptomus japonicus from Lake Biwa, in the cold and warm seasons, to clarify synergistic effects of egg size and temperature on EDT. EDT was longer for cold season eggs than warm ones, but both seasons were well fitted by Bĕlehrádek’s function. Egg size was significantly correlated with female body size within seasons, but the relationship did not differ significantly between seasons. These results suggest that seasonal variation in EDT, which was associated with egg size, may result from temperature-mediated variation of female body size, because larger females produced larger eggs as temperature decreased. Larger eggs may enhance fitness under severe food conditions in winter due to high hatchability and naupliar survival.

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Egg burial depth by sockeye salmon (Oncorhynchus nerka): implications for survival of embryos and natural selection on female body size

Canadian Journal of Zoology ◽

10.1139/z99-020 ◽

1999 ◽

Vol 77 (5) ◽

pp. 836-841 ◽

Cited By ~ 44

Author(s):

Ryan P Steen ◽

Thomas P Quinn

Keyword(s):

Body Size ◽

Female Body ◽

Sockeye Salmon ◽

Oncorhynchus Nerka ◽

Female Size ◽

Burial Depth ◽

Female Body Size ◽

Substrate Level ◽

The Relationship ◽

Stream Bed

We studied the relationship between female sockeye salmon (Oncorhynchus nerka) body size and egg burial depth in a small Alaskan stream to better understand the ways in which stream-bed scour or digging by other females might destroy embryos. Two different measurements of egg burial depth were taken: depth from the original stream-bed surface to the top of the egg pocket and depth from the disturbed substrate directly above the egg pocket to the top of the egg pocket. The former may represent the depth to which stream-bed scouring would have to go to reach the eggs, but the latter represents the depth to which a second female would have to dig to disturb the egg pocket. Larger females buried their eggs deeper, relative to the original substrate level, than smaller females. This suggests that streams with frequent scour events would select for larger females. However, mean depth from the disturbed substrate level was significantly shallower than mean depth from the original stream-bed level, suggesting that even the smallest females could dig deep enough to disturb the egg pockets of the largest females. Finally, the egg burial depth - fish size relationship that we observed was compared with published data on other salmonid species, revealing considerable variation but a clear positive relationship between female size and burial depth. Because embryonic survival is affected by scour and nest disturbance, and because changes in fish body size, density, and flow regime can affect the vulnerability of embryos to such mortality, we recommend further, standardized measurements of the relationship between egg burial depth and female body size.

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Breeding traits of Hermann's tortoise Testudo hermanni hermanni in two western populations

Amphibia-Reptilia ◽

10.1163/156853807779798965 ◽

2007 ◽

Vol 28 (1) ◽

pp. 77-85 ◽

Cited By ~ 10

Author(s):

Marc Cheylan ◽

Jean Pierre Nougarède ◽

Aurelio Marín ◽

Albert Bertolero

Keyword(s):

Body Size ◽

Clutch Size ◽

Female Body ◽

Egg Production ◽

Reproductive Traits ◽

Ebro Delta ◽

Female Size ◽

Female Body Size ◽

Testudo Hermanni ◽

Testudo Hermanni Hermanni

AbstractOver a period of two years we used radiology to investigate breeding traits in females of two western populations of the threatened Hermann's tortoise Testudo hermanni hermanni. The main purpose of the study was to see if reproductive traits – clutch size, clutch frequency, annual egg production and egg width – varied between populations in Corsica (France) and the Ebro Delta (Spain), and if these traits were affected by female body size and amounts of spring rainfall. All the breeding traits analysed were greater in the Corsican population than in the Ebro Delta population. These differences were also significant when we used female body size as a covariable. In both populations the amount of spring rainfall affected breeding traits but not clutch size. Nevertheless, only in the Corsican population did clutch frequency, annual egg production and egg width increase significantly in the year with a wet spring. Contrary to the predictions of Optimal Propagule Size theory, we found that egg size and clutch size increased with female size, and that both variables were independent. On the other hand, clutch frequency was not related to female body size. Thus, in the Hermann's tortoise, as clutch size did not change between years and clutch frequency was independent of female size, all females are able to increase their reproductive output in years with favourable conditions by increasing their clutch frequency. Nevertheless, other factors besides female size and rainfall may influence in a highly complex way variability in breeding traits among populations.

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