scholarly journals Embryonic Development of the Squid,Illex illecebrosus, and Effect of Temperature on Development Rates

1982 ◽  
Vol 3 ◽  
pp. 41-45 ◽  
Author(s):  
R K O'Dor ◽  
N Balch ◽  
E A Foy ◽  
R W M Hirtle ◽  
D A Johnston ◽  
...  
1991 ◽  
Vol 39 (2) ◽  
pp. 191 ◽  
Author(s):  
JG Hamilton ◽  
MP Zalucki

C. plebejana were reared from egg to adult at a range of constant temperatures. At 10-degrees-C no immature stages survived. Development rates increased over the temperature range 14-34-degrees-C; these were simulated with a non-linear model. Females emerged before males. Fecundity decreased with increased rearing temperature as a direct result of reduced adult female weight. At 34-degrees-C development rate and survival were reduced and all eggs laid were infertile. Optimum temperature for population increase was 28-degrees-C. Validation of a non-linear model for development rate shows that the species of host-plant affects mean development rates of tipworm. Although 5.3 tipworm generations are possible on cotton annually, only one occurs; reasons for this are suggested.


2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
A NAGANO ◽  
Y Narumiya ◽  
N Okutani ◽  
S Mizuta ◽  
T Takeuchi ◽  
...  

Abstract Study question Does direct unequal cleavage (DC) affect embryonic development after ICSI with testicular sperm (TESE-ICSI) in patients with non-obstructive azoospermia (NOA) and/or obstructive azoospermia (OA)? Summary answer The incidence of DC at the first cleavage (DC1) was extremely high and DC1 negatively affected embryonic development in NOA patients. What is known already It has been reported that the blastocyst development of embryos with direct cleavage (DC) was significantly lower than that without DC, but the clinical pregnancy rate after blastocyst transfer was not different with or without DC. The incidence of DC has been reported to be significantly higher after ICSI with testicular sperm (TESE-ICSI) than ICSI with ejaculated sperm (Ej), but to our knowledge, there are few reports investigating that the embryos with DC after TESE-ICSI affect embryonic development. Study design, size, duration We conducted a retrospective cohort study using time-lapse incubators (Geri, Genea Biomedx, Australia) from September 2018 to November 2020. Of 1033 two-pronuclear (2PN) embryos from TESE-ICSI, 486 and 547 embryos were from OA (35.9±5.5 years) and NOA (33.7±5.2 years), respectively. As an age matched control, we chose 581 embryos from ICSI using Ej (36.5±4.4 years). Participants/materials, setting, methods DC embryos were classified as DC1 (DC at first cleavage), DC2 (DC at second cleavage), and non-DC (without DC). The incidences of DC1 or DC2 and blastocyst development rates were compared among OA, NOA and Ej groups. In TESE-ICSI group, we compared blastocyst development rates with or without DC between good and poor quality embryos on day 3. Good quality embryos were defined as 8 cells with G3 or more by the Veeck’s classification. Main results and the role of chance DC1 incidence was significantly higher in NOA (37.3%) than OA (27.8%) and Ej (22.7%) (P < 0.01), whereas DC2 incidence was not statistically different among three groups; NOA (15.7%), OA (15.0%) and Ej (13.4%). Blastocyst development rates in DC1 were 17.8%, 19.5% and 25.8% for NOA, OA and Ej, respectively, which were significantly lower compared to non-DC in corresponding three groups (65.1%, 67.7%, and 68.5%, respectively, P < 0.01). In TESE-ICSI group, good-quality embryo rate on day 3 was significantly lower in DC1 (34.5%, P < 0.01) than DC2 (60.9%) or non-DC (54.2%). Additionally, blastocyst development rates in DC1 and DC2 were significantly lower than non-DC regardless of embryonic grades on day 3 (35.1%, 51.0%, and 81.6% for good-quality embryos on day 3, 10.1%, 27.0%, and 49.1% for poor-quality embryos on day 3, respectively, P < 0.05). When immotile sperm was used for TESE-ICSI, DC1 incidence was 40.0% (6/15), which did not show statistically differences. When performing single frozen-thawed blastocyst transfers, no pregnancies resulted from either DC1 (n = 13) or DC2 (n = 3) embryos in TESE-ICSI group. Limitations, reasons for caution We had a few data about the pregnancy rates after blastocyst transfers with DC, because embryos with DC were seldom transferred due to those lower priority. Although DC might be influenced by the sperm, we did not analyze the incidence of DC by taking the semen factors into account. Wider implications of the findings: The incidence of DC1 was extremely high and DC1 negatively affected embryonic development in NOA patients. Therefore, it is important to observe embryos using time-lapse incubator in order to recognize embryos with/without pregnancy potential, especially for embryos with DC1 in NOA patients. Trial registration number Not applicable


2017 ◽  
Vol 53 (No. 4) ◽  
pp. 226-231 ◽  
Author(s):  
Liu Junhe ◽  
Yan Yan ◽  
Yu Mingfu ◽  
Parajulee Megha N ◽  
Shi Peijian ◽  
...  

Temperature has a significant influence on development rates of insects and mites. Many parametric models were built to describe the temperature-dependent development rates. However, these models provided different shapes of the curves of development rate versus temperature. For different datasets, investigators have to spend much time on considering which the parametric model is the best for describing the temperature-dependent development rates. In the present study, we encourage investigators to use an important non-parametric model, the loess method, which belongs to local regression methods. The loesS method is used to fit some published data on the development rate of aphids to check the goodness-of-fit. We find that the loess method is very flexible for fitting the given datasets. Thus, we consider that the loess method can be used to describe the effect of temperature on the development rate of insects or mites.


2007 ◽  
Vol 28 (2) ◽  
pp. 295-300 ◽  
Author(s):  
Leonardo Vignoli ◽  
Marco Bologna ◽  
Manuela D'Amen

AbstractAmphibian populations are especially sensitive to aquatic parameters, in particular during embryonic and larval life. Our aim was to test for an effect of temperature (T = 13°C, 20°C and 25°C at constant pH = 7) and pH (pH = 5.5, 7 and 8.5 at constant T= 20°C) on embryos of two species of Triturus, T. carnifex carnifex and T. italicus (Amphibia, Salamandridae) using GLM procedure. Trend of embryogenesis processes, time to hatching and rate of development have a similar effect in both species in the used range of temperature and pH. Time to hatching decreased significantly with the increasing temperature. The pH experimental conditions had no effect on T. carnifex embryos survival, while the acidic pH condition raised the mortality rate in T. italicus, whose embryos should be more vulnerable than those of T. carnifex to acidification in nature.


Zygote ◽  
2015 ◽  
Vol 24 (2) ◽  
pp. 301-309 ◽  
Author(s):  
Marcella Costa Radael ◽  
Leonardo Demier Cardoso ◽  
Dalcio Ricardo de Andrade ◽  
André Veloso Ferreira ◽  
Douglas da Cruz Mattos ◽  
...  

SummaryThe present study aimed to provide data on the time required for Melanotaenia boesemani to complete embryonic development, and to investigate the influence that incubation at different temperatures caused in this species. The effects of temperature on the time and hatching rate are presented, as well as information related to embryonic development stages. After fertilization, the eggs were kept in incubators at 23, 26, 29 or 32°C and observed at predetermined times until the moment of hatching. Stages of development were identified and classified according to morphological and physiological characteristics. Oil droplets were visualized inside the eggs as well as filament adhesion present at the chorion. Embryonic development was similar to that observed in other species of the genus Melanotaenia with hatching and faster development in higher temperatures.


2012 ◽  
Vol 416-417 ◽  
pp. 168-175 ◽  
Author(s):  
I. Uriarte ◽  
V. Espinoza ◽  
M. Herrera ◽  
O. Zúñiga ◽  
A. Olivares ◽  
...  

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