The relationship between female body size and egg size in pipefishes

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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Clutch and egg size of the tropical lizard Tropidurus torquatus (Tropiduridae) along its geographic range in coastal eastern Brazil

Canadian Journal of Zoology ◽

10.1139/z08-106 ◽

2008 ◽

Vol 86 (12) ◽

pp. 1376-1388 ◽

Cited By ~ 17

Author(s):

M. C. Kiefer ◽

M. Van Sluys ◽

C. F.D. Rocha

Keyword(s):

Body Size ◽

Clutch Size ◽

Female Body ◽

Egg Size ◽

Reproductive Investment ◽

Geographic Range ◽

Minimum Size ◽

Brazilian Coast ◽

Female Body Size ◽

Almost All

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

Journal of Herpetology ◽

10.2307/1565253 ◽

2000 ◽

Vol 34 (1) ◽

pp. 148 ◽

Cited By ~ 53

Author(s):

Richard B. King

Keyword(s):

Body Size ◽

Clutch Size ◽

Female Body ◽

Female Body Size ◽

The Relationship

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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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