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Incubation

About: Incubation is a research topic. Over the lifetime, 5748 publications have been published within this topic receiving 126541 citations.


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Journal ArticleDOI
01 Jul 1993-The Auk
TL;DR: The effect of clutch size on incubation persistence of male Wilson's Phalaropes was studied over two breeding seasons in south-central Saskatchewan and it is demonstrated that males alter their reproductive effort in response to clutch size, and the minimum potential annual reproduction is identified.
Abstract: ABSTRACr.-The effect of clutch size on incubation persistence of male Wilson's Phalaropes (Phalaropus tricolor) was studied over two breeding seasons in south-central Saskatchewan. The Wilson's Phalarope is a "sex-role-reversed" shorebird in which only males incubate and provide parental care. The breeding season is long enough to allow for renesting but not for the rearing of more than one brood per male. Barring secondary mating strategies, the total annual reproduction of a male is limited by the size of its clutch. Females lay determinate clutches of four eggs. By determining the minimum clutch size necessary for male incubation persistence, we demonstrated that males alter their reproductive effort in response to clutch size, and we identified the minimum potential annual reproduction for males necessary to maintain this unusual mating system. Clutch-size reductions led to an increased frequency of abandonment inversely proportional to the number of eggs remaining in the clutch. The timing of egg loss also was critical. Among males with clutches reduced to one egg or reduced to two eggs early in the incubation cycle, all but one abandoned incubation. Among males with clutches reduced to two eggs late in incubation or three eggs early, an intermediate proportion abandoned incubation. All but one male with three eggs late in incubation or a full, four-egg clutch continued to incubate. Experimentally increasing clutch sizes by two eggs over the normal four-egg clutch led to rapid nest failure. This suggests that the determinate, four-egg clutch of females is not suboptimal for males and that nest parasitism of two eggs by females has little potential benefit as an alternative reproductive tactic. Received 24 February 1992, accepted 22 November 1992.

42 citations

Journal ArticleDOI
TL;DR: The hypothesis that one mechanism of inhibition could involve the formation of a chemical complex between EA and AFB1 is supported, as the results of the sequential incubation studies support the hypothesis.
Abstract: Ellagic acid (EA) is a phenolic compound with antimutagenic and anticarcinogenic properties. It occurs naturally in some foods such as strawberries, raspberries, grapes, black currants and walnuts. In the present study, we used the Salmonella microsuspension assay to examine the antimutagenicity of EA against the potent mutagen aflatoxin B1 (AFB1) using tester strains TA98 and TA100. Further, we used a two-stage incubation procedure that incorporates washing the bacterial cells free of the incubation mixture after the first incubation to investigate EA and AFB1 interaction. Three different concentrations of AFB1 (2.5, 5 and 10 ng/tube) were tested against five different concentrations of EA for TA98 and TA100. EA significantly inhibited mutagenicity of all doses of AFB1 in both tester strains with the addition of S9. EA alone was not mutagenic at the concentrations tested. The greatest inhibitory effect of EA on AFB1 mutagenicity occurred when EA and AFB1 were incubated together. Lower inhibition was apparent when the cells were first incubated with EA followed by a second incubation with AFB1, and also when the cells were first incubated with AFB1 followed by a second incubation with EA alone. The results of the sequential incubation studies support the hypothesis that one mechanism of inhibition could involve the formation of a chemical complex between EA and AFB1.

42 citations

Journal ArticleDOI
TL;DR: There are large individual differences in the period of incubation needed for specific stages to be reached, especially between embryos of the short- necked and long-necked species of these pleurodire tortoises.
Abstract: Incubation periods and nest contents of three species of chelid tortoises in northern Victoria were recorded. Mean incubation period for eggs of Emydura macquari (Cuvier) was 75 days and average number of eggs per nest was 15.7; for Chelodina longicollis (Shaw), 138 days and 10.7 eggs per nest; for Chelodina expansa Gray, normally exceeding 324 days and 15.4 eggs per nest. In abnormal seasons C. expansa hatchlings may emerge from the nest in less than 193 days or more than 522 days after eggs were deposited. Eggs artificially incubated at 30°C consistently develop more quickly than those at lower temperatures under natural conditions. In the field nest temperatures closely approximate the mean daily air temperature. Embryos of C. expansa are tolerant to nest temperatures ranging from 4.9°C minimum to 29.6°C maximum. The other species are subject to variations of about 15 degC with up to 8.5 degC variation being recorded in 1 day. Development of early embryos approximated that recorded for cryptodire tortoises. However, there are large individual differences in the period of incubation needed for specific stages to be reached, especially between embryos of the short-necked and long-necked species of these pleurodire tortoises. It is suggested that differences in the anatomy of their eggs are the main factors in the different incubation periods between short-necked and long-necked species.

42 citations

Journal ArticleDOI
TL;DR: Using principal components analysis, this work determined the morphological traits that explained the most variation among hatchlings, which allowed investigation of the relationship between hatchling morphology and terrestrial locomotion speed.
Abstract: The journey of Leatherback (Dermochelys coriacea (Vandelli, 1761)) hatchlings from nest to the sea is a vulnerable life-history stage. Studies have shown that nest incubation temperatures influence...

42 citations

Journal ArticleDOI
TL;DR: The data indicate that the pH sensitivity of sperm motility and fertility depends on the composition of commonly used incubation as well as activation media.
Abstract: This study examined the pH sensitivity of steelhead, Oncorhynchus mykiss (Walbaum), sperm motility relative to the composition of incubation and activation media. The percentage of sperm that initiated motility following incubation in a sperm immobilizing solution (SI) titrated to different pH values and subsequent activation by dilution in buffered swimming medium (SM) at pH 8.5 or 50% ovarian fluid (OF) showed little or no pH sensitivity; sperm diluted in de-ionized water (DI) showed no motility after incubation at any pH. In contrast, motility of sperm diluted in tap water (TAP) was highly sensitive to the pH of the incubation medium. Sperm incubated with buffered seminal plasma at high, but not low pH demonstrated high percent motility when diluted with DI. Sperm incubated in low-pH SI demonstrated high motility only when diluted into high-pH SM. The effects of the composition of incubation and activation media on sperm motility were generally reflected in comparable effects on fertility. Therefore, these data indicate that the pH sensitivity of sperm motility and fertility depends on the composition of commonly used incubation as well as activation media.

42 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20241
2023688
20221,316
2021104
2020123
2019136