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

1999 ◽  
Vol 77 (5) ◽  
pp. 836-841 ◽  
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.

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

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.

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

2007 ◽  
Vol 28 (1) ◽  
pp. 77-85 ◽  
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.

scholarly journals Golden Orbweavers Ignore Biological Rules: Phylogenomic and Comparative Analyses Unravel a Complex Evolution of Sexual Size Dimorphism

2018 ◽  
Author(s):  
Matjaž Kuntner ◽  
Chris A. Hamilton ◽  
Cheng Ren-Chung ◽  
Matjaž Gregorič ◽  
Nik Lupše ◽  
...  
Keyword(s):  
Body Size ◽  
Female Body ◽  
Sexual Size Dimorphism ◽  
Female Size ◽  
Male And Female ◽  
Size Dimorphism ◽  
Female Body Size ◽  
Size Evolution ◽  
Web Size ◽  
Cope’S Rule

AbstractInstances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope’s Rule (phyletic size increase), Rensch’s Rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme female-biased SSD (eSSD, female:male body length ≥ 2) is the norm. Nephilid genera construct webs of exaggerated proportions which can be aerial, arboricolous, or intermediate (hybrid). First, we established the backbone phylogeny of Nephilidae using 367 Anchored Hybrid Enrichment (AHE) markers, then combined these data with classical markers for a reference species-level phylogeny. Second, we used the phylogeny to test Cope and Rensch’s Rules, sex specific size optima, and the coevolution of web size, type, and features with female and male body size and their ratio, SSD. Male, but not female, size increases significantly over time, and refutes Cope’s Rule. Allometric analyses reject the converse, Rensch’s Rule. Male and female body sizes are uncorrelated. Female size evolution is random, but males evolve towards an optimum size (3.2–4.9 mm). Overall, female body size correlates positively with absolute web size. However, intermediate sized females build the largest webs (of the hybrid type), giant female Nephila and Trichonephila build smaller webs (of the aerial type), and the smallest females build the smallest webs (of the arboricolous type). We propose taxonomic changes based on the criteria of clade age, monophyly and exclusivity, classification information content, diagnosability, and arachnological community practice. We resurrect the family Nephilidae Simon 1894 that contains Clitaetra Simon 1889, the Cretaceous Geratonephila Poinar & Buckley 2012, Herennia Thorell 1877, Indoetra Kuntner 2006, new rank, Nephila Leach 1815, Nephilengys L. Koch 1872, Nephilingis Kuntner 2013, and Trichonephila Dahl 1911, new rank. We propose the new clade Orbipurae to contain Araneidae Clerck 1757, Phonognathidae Simon 1894, new rank, and Nephilidae. Nephilid female gigantism is a phylogenetically-ancient phenotype (over 100 ma), as is eSSD, though their magnitudes vary by lineage and, to some extent, biogeographically.

The relationship between female body size and egg size in pipefishes

2011 ◽  
Vol 78 (6) ◽  
pp. 1847-1854 ◽  
Author(s):  
I. Braga Goncalves ◽  
I. Ahnesjö ◽  
C. Kvarnemo
Keyword(s):  
Body Size ◽  
Female Body ◽  
Egg Size ◽  
Female Body Size ◽  
The Relationship

Reproductive aspects of the shrimp Cuapetes americanus (Kingsley, 1878) (Caridea, Palaemonidae) from Bocas del Toro, Panama

Crustaceana ◽  
2017 ◽  
Vol 90 (7-10) ◽  
pp. 1061-1078 ◽  
Author(s):  
Mariana Negri ◽  
Tatiana Magalhães ◽  
Natália Rossi ◽  
Darryl L. Felder ◽  
Fernando L. Mantelatto
Keyword(s):  
Body Size ◽  
Female Body ◽  
Reproductive Output ◽  
Reproductive Traits ◽  
The Body ◽  
Female Size ◽  
Energy Investment ◽  
Western Atlantic ◽  
Bocas Del Toro ◽  
Female Body Size

The shrimpCuapetes americanusis widely distributed in shallow waters of the western Atlantic Ocean, inhabiting sandy and rocky bottoms, macroalgae, seagrass beds, and mangrove roots. As the life cycle and ecology of this species remain poorly known, we investigated some reproductive traits of this species at Bocas del Toro, Panama. We collected and examined 167 individuals (63 males, 58 non-ovigerous females and 46 ovigerous females). Although males numerically dominated the larger size classes, ovigerous females were significantly larger than males and non-ovigerous females. All 46 ovigerous females were used to calculate embryo loss and embryo volume increase. Only females with eggs at an initial developmental stage () were used to estimate fecundity and reproductive output. A mean of 75.84 ± 40.16 embryos () occurred per female, a value near those reported for other species of Pontoniinae. A positive correlation between fecundity and female body size was observed, but it lacked significance. Likewise, a significant correlation between female body size and embryo volume was not detected. Embryo volume increased 35%, and females lost 26% of embryos on average during the incubation period, though significant changes were measurable only during early embryonic development. Mean reproductive output in the analysed reproductive event (0.22 ± 0.11, ) suggested a rate of energy investment in reproduction higher than average, as compared to females of most other decapods. A decrease in relative reproductive output was observed with the increase of female size, indicating that larger females were investing proportionally less energy in reproduction than smaller ones, when measured in relation to the body size, but this correlation also lacked significance. We review how these initial insights on reproduction ofC. americanusat Bocas del Toro compare to those of other populations in various localities.

Effects of competition, female size, and their distance on the claw-waving rate of male fiddler crabs (Brachyura, Ocypodidae)

2020 ◽  
Vol 70 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Fahmida Wazed Tina
Keyword(s):  
Logistic Regression ◽  
Body Size ◽  
Female Body ◽  
Carapace Width ◽  
Binary Logistic Regression ◽  
Information Criterion ◽  
Binary Logistic Regression Analysis ◽  
Female Size ◽  
Fiddler Crabs ◽  
Female Body Size

Abstract The alteration of signals of animals in response to changes in environmental factors is a common phenomenon. In male fiddler crabs, waving major claws towards females is energetically costly; thus, males need to adjust their waving in a way that increases the chance of potential mate attraction while reducing the waving cost. In this study, I examined how Austruca perplexa males adjusted their waving rate based on male-male competition (male numbers in a cluster [Austruca perplexa males make groups and wave synchronously towards females]), female body size, and the distances of the receiver females from the signaller males. Forty clusters were selected randomly; from each cluster, I randomly selected one male, video recorded his waving behaviour and calculated waving rate (waves/min). Body size (carapace width) and distances of receiver females were measured. To analyze the effects of competition, female size, and their distances on male waving rate through binary logistic regression analysis, all variables were divided into two categories (male waving rate: low and high, competition: low and high, female size: small and large, and female distances: short and long) based on a median split method. Afterwards a series of binary logistic regression models were built and the relative supports of various models were assessed based on the corrected Akaike information criterion. Results showed that competition, female body size and their distances affected the male waving rate in an additive manner, but their interactions did not show any effect. Further research can be conducted to investigate how breeding season and predation risk along with competition, female size and female distances affect the claw-waving display of male fiddler crabs.

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