Is the rate of Embryonic development a predictor of overall development rate in Tanytarsus barbitarsis Freeman (Diptera: Chironomidae)?

1990 ◽  
Vol 41 (5) ◽  
pp. 575 ◽  
Author(s):  
MJ Kokkinn
Keyword(s):  
Environmental Factors ◽  
Embryonic Development ◽  
Significant Relationship ◽  
Generation Time ◽  
South Australia ◽  
Additional Term ◽  
Development Rate ◽  
Time Data ◽  
Egg Hatching ◽  
Mathematical Relationships

Mathematical relationships describing the effect of water temperature on embryonic development and generation time for Tanytarsus barbitarsis, a nuisance chironomid from salt lakes near Port Augusta, South Australia, were compared. The aim of the comparison was to determine whether the relation- ship describing egg hatching could be extrapolated to determine the overall development rate of the species. Results indicated that the power function that closely described embryonic development, D(t) = 8712.32t-2.70, could not be fitted to the generation-time data. However, when an additional term, water salinity, was included, a highly significant relationship was derived: D(s,t)*=S4.0308t-4.471. This suggested that laboratory egg-hatching experiments could not account for the attenuating effect of environmental factors on overall development rates in the field.

scholarly journals Timing of increased temperature sensitivity coincides with nervous system development in winter moth embryos

2021 ◽  
Author(s):  
Natalie E. van Dis ◽  
Maurijn van der Zee ◽  
Roelof A. Hut ◽  
Bregje Wertheim ◽  
Marcel E. Visser
Keyword(s):  
Climate Change ◽  
Temperature Sensitivity ◽  
Development Rate ◽  
Egg Development ◽  
Egg Hatching ◽  
Seasonal Timing ◽  
Winter Moth ◽  
Developmental Progression ◽  
Phylotypic Stage ◽  
Insect Embryos

Climate change is rapidly altering the environment and many species will need to genetically adapt their seasonal timing to keep up with these changes. Insect development rate is largely influenced by temperature, but we know little about the mechanisms underlying temperature sensitivity of development. Here we investigate seasonal timing of egg hatching in the winter moth, one of the few species which has been found to genetically adapt to climate change, likely through selection on temperature sensitivity of egg development rate. To study when during development winter moth embryos are most sensitive to changes in ambient temperature, we gave eggs an increase or decrease in temperature at different moments during their development. We measured their developmental progression and timing of egg hatching, and used fluorescence microscopy to construct a timeline of embryonic development for the winter moth. We found that egg development rate responded more strongly to temperature once embryos were in the fully extended germband stage. This is the phylotypic stage at which all insect embryos have developed a rudimentary nervous system. Furthermore, at this stage timing of ecdysone signaling determines developmental progression, which could act as an environment dependent gateway. Intriguingly, this may suggest that, from the phylotypic stage onward, insect embryos can start to integrate internal and environmental stimuli to actively regulate important developmental processes. As we found evidence that there is genetic variation for temperature sensitivity of egg development rate in our study population, such regulation could be a target of selection imposed by climate change.

scholarly journals Comparison of the transcriptomes of two tardigrades with different hatching coordination

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Yuki Yoshida ◽  
Kenta Sugiura ◽  
Masaru Tomita ◽  
Midori Matsumoto ◽  
Kazuharu Arakawa
Keyword(s):  
Gene Expression ◽  
Embryonic Development ◽  
Juvenile Hormone ◽  
Extreme Environments ◽  
Regulation Mechanism ◽  
Egg Hatching ◽  
Terrestrial Species ◽  
Juvenile Hormone Analog ◽  
Hormone Analog ◽  
Multiple Species

Abstract Background Tardigrades are microscopic organisms, famous for their tolerance against extreme environments. The establishment of rearing systems of multiple species has allowed for comparison of tardigrade physiology, in particular in embryogenesis. Interestingly, in-lab cultures of limnic species showed smaller variation in hatching timing than terrestrial species, suggesting a hatching regulation mechanism acquired by adaptation to their habitat. Results To this end, we screened for coordinated gene expression during the development of two species of tardigrades, Hypsibius exemplaris and Ramazzottius varieornatus, and observed induction of the arthropod molting pathway. Exposure of ecdysteroids and juvenile hormone analog affected egg hatching but not embryonic development in only the limnic H. exemplaris. Conclusion These observations suggest a hatching regulation mechanism by the molting pathway in H. exemplaris.

Embryonic Development, Early Growth, and Meristic Variation in Rainbow Trout (Salmo gairdneri) Exposed to Combinations of Light Intensity and Temperature

1975 ◽  
Vol 32 (3) ◽  
pp. 397-402 ◽  
Author(s):  
Wen-hwa Kwain
Keyword(s):  
Rainbow Trout ◽  
Embryonic Development ◽  
Mortality Rates ◽  
Early Growth ◽  
Development Rate ◽  
Salmo Gairdneri ◽  
Initial Weight ◽  
Light Intensities ◽  
Incubation Periods ◽  
Meristic Variation

Lowest mortality rates of rainbow trout (Salmo gairdneri) embryos were obtained at temperatures of 7 and 10 C and light intensities of 0.2 and 20 lx. Temperatures of 3 and 15 C and an intensity of 400 lx were near the thresholds for development. Eggs exposed to 0.2 lx required 111 days to reach 50% hatch at 3 C, but 26 days at 15 C; those exposed to 20 lx, 97 days at 3 C and 25 days at 15 C.Growth rates of rainbow trout 145 days after hatch were significantly different (P < 0.05) at 10 and 3 C, and 20, 2, and 0.2 lx. The fastest growth occurred at 10 C and 2 lx, and the lowest growth at 3 C and 0.2 lx. For increment of body weight it was about 23.8%/day of initial weight and 6.6% at 3 C. At light intensities of 20, 2, and 0.2 lx, the rate per day was 24.7, 17.2, and 11.2%, respectively. However, increases in length occurred at a much reduced rate.Variations in numbers of vertebrae, gill rakers, and fin rays were positively correlated with the embryonic development rate. Longer incubation periods were usually associated with more meristic elements, regardless of the environmental factors involved.

Low Variability of Growth Parameters among Six O157:H7 and Non-O157:H7 Escherichia coli Strains

2014 ◽  
Vol 77 (11) ◽  
pp. 1988-1991
Author(s):  
I. FERNÁNDEZ-ESCUDERO ◽  
I. CARO ◽  
J. MATEO ◽  
J. TEJERO ◽  
E. J. QUINTO
Keyword(s):  
Escherichia Coli ◽  
Generation Time ◽  
Growth Parameters ◽  
Brain Heart Infusion ◽  
Lag Time ◽  
Coli Strain ◽  
Time Data ◽  
E Coli ◽  
Confidence Levels ◽  
Coefficients Of Variation

Five Escherichia coli O157:H7 strains and one nonpathogenic E. coli strain were used. All strains were cultured in brain heart infusion broth and were inoculated in 16-well disposable module cassettes of a Bactometer impedance system. Two initial concentrations were obtained in the wells: 1.37 × 103 and 1.36 × 105 CFU/ml. The impedance measurements were monitored for 72 h at 5, 10, or 15°C, 48 h at 20°C, and 24 h at 25, 30, 35, 40, 45, 50 or 55°C. The lag time and the generation time of each culture were calculated from the detection time data. The coefficients of variation between the strains' growth parameters were low (0.009 to 0.105 for generation time and 0.074 to 0.475 for lag time). An F test showed no significant differences between strains at 5 or 1% confidence levels.

TEMPERATURE-DEPENDENT DEVELOPMENT OF EGGS AND LARVAE OF WINTHEMIA FUMIFERANAE TOTH. (DIPTERA: TACHINIDAE), A LARVAL–PUPAL PARASITOID OF THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

1990 ◽  
Vol 122 (2) ◽  
pp. 329-341 ◽  
Author(s):  
Christian Hébert ◽  
Conrad Cloutier
Keyword(s):  
Spruce Budworm ◽  
Development Rate ◽  
Temperature Dependent ◽  
Egg Development ◽  
Egg Hatching ◽  
Egg Deposition ◽  
Different Temperatures ◽  
Time Required ◽  
The Relationship ◽  
Eggs And Larvae

AbstractRelationships between temperature and development rates of eggs and larvae of Winthemia fumiferanae Toth. were experimentally determined, using the spruce budworm as host. Hatching of parasitoid eggs was triggered by host pupation. The median time required to complete egg development at different temperatures was estimated from distributions of percentage development success of the parasitoid over time between egg deposition and host pupation. For parasitoid eggs that had sufficient time to hatch, detachment from the host before pupation was the most important cause of mortality at 15 °C or higher, but was negligible below this temperature. A curvilinear model describing egg development rate as a function of temperature was used to simulate the development of W. fumiferanae eggs in the field. The relationship between larval development rate and temperature also was modelled, and the variability described. Simulations initiated by host pupation-driven egg hatching, and terminated with prepupal drop to the ground, are presented and discussed with respect to the appropriateness of using host pupation as an indicator of parasitoid egg hatching in the field.

Embryonic stages: morphology, timing, and variance in the toad Bombina orientalis

1978 ◽  
Vol 56 (7) ◽  
pp. 1540-1545 ◽  
Author(s):  
Paul Sussman ◽  
T. W. Betz
Keyword(s):  
Embryonic Development ◽  
Rana Pipiens ◽  
Time Lapse ◽  
Time Data ◽  
Bombina Orientalis ◽  
Stage Of Development ◽  
Curve Fit ◽  
Stage Change ◽  
Over Time ◽  
Time Lapse Photography

A Staged series (n = 25–476} with time data for Bombina orientalis embryonic development is presented. Stages for Bombina and Rana pipiens seem identical except that approximately 50% of opercular closures are symmetrical in Bombina. Counting numbers of embryos at a stage at regular intervals allowed mathematical interpolation of the average time of stage change. A single systematic curve fit the average time per stage of embryonic development, while the increase with time in variance per stage of development was primarily linear. It is possible that the increasing complexity of morphological interstage changes causes increases in the interstage interval and variance per stage over time. The reported method of arriving al a staged series for a previously undocumented species seems more efficient than time-lapse photography. The unusually easy maintenance and dependability or Bombina, contrasting with some amphibians, suggest its use where others have been less practical.

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