Regulation of Embryonic Development by Environmental Factors

Author(s):  
Michael T. Kane
1990 ◽  
Vol 41 (5) ◽  
pp. 575 ◽  
Author(s):  
MJ Kokkinn

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.


1988 ◽  
Vol 66 (1) ◽  
pp. 274-276
Author(s):  
J. L. Shipp

A classification system for embryonic development of Simulium arcticum Malloch (IIS-10.11) is described. Embryonic development was divided into five stages based upon the degree of embryogenesis. This simple classification system would be useful for monitoring development of S. arcticum (IIS-10.11) in studies to determine the effects of environmental factors or chemical insecticides on egg development and hatch.


2019 ◽  
pp. 27-28
Author(s):  
M. Bashchenko ◽  
V. Chayka

Goal. The effect of temperature on fertility and the timing of the embryonic development of the chestnut moth under laboratory conditions was studied. Methods. Laboratory. Selected pupae of the chestnut moth were placed in thermostats (at a temperature of 15, 20, 25, 30). Then, 5 pairs of pupae of different sexes were placed in glass cages in which the paper was pre-inserted, as a substrate for egg laying. Experiments were performed in four versions — 10 replications each. Cages with each variant were placed in polythermostats at temperatures of 15, 20, 25 and 30°С. After the butterflies flew out, the paper was taken out of the cage regularly (every two days) and under a microscope of MBS-9 (eyepiece 0.6 magnification 2), the number of laid eggs and caterpillars that hatch were counted. The results were processed statistically by standard methods for biological data. Results. It was determined that at a temperature of 15°C 50% of caterpillars were released from 40 eggs. At 25°C, out of 187 laid chestnut moth eggs, 65% of caterpillars were released. At 20°C, butterflies laid aside 83 instances. 54% of the caterpillars were released. At 30°C, the female chestnut moth was set aside on 17 instances eggs whose embryonic development has not occurred. It was revealed that at 15 and 30°С females are the least active, thus, optimal temperatures for keeping the chestnut moth in laboratory conditions are in the range of 20—25°С. Under these conditions, butterflies mate and lay eggs, the survival rate of which reaches 54—65%. The technique makes it possible in the laboratory to investigate the influence of environmental factors on the state of the chestnut moth population. Findings. It was determined that in laboratory conditions the optimum temperature for the deposition of chestnut moth eggs is 25°C. Butterflies favor the green substrate. Embryonic development lasts 6.1 ± 0.12 days, the survival rate of the populations is 25%. The method of obtaining chestnut moth eggs allows for in-depth experimental studies of the influence of environmental factors on the state of the chestnut moth population.


2007 ◽  
Vol 24 (3) ◽  
pp. 666-672 ◽  
Author(s):  
Clóvis S. Bujes ◽  
Laura Verrastro

The epidermal plates of the carapace and plastron of 51 adults (38 females and 13 males), 07 immature individuals, and 46 hatchlings of the freshwater turtle Trachemys dorbigni (Durémil & Bibron, 1835), originated from the delta of Rio Jacuí region, Rio Grande do Sul state, Brazil, were examined. The results showed that 7.7% of males, 10.52% of females, 14.28% of immature individuals, and 6.52% of the hatchlings presented a kind of anomaly on the shell, as well as a presence of supernumerary epidermal shields. Although the modification in the number of epidermal shields presents a high frequency in Testudines, these are the first descriptions of the variation in the pattern of carapacial scutation in eleven individuals from a population of T. dorbigni. The association of several environmental factors acting on the embryonic development of the individual may be responsible for the alteration of the pattern of carapacial scutation in this species.


2021 ◽  
Vol 03 (01) ◽  
pp. 75-80
Author(s):  
Jalə Hidayət qızı Ələsgərova ◽  

A positive effect in the development of biotechnology for industrial fish breeding is possible only on the basis of knowledge of their biological characteristics at various stages of ontogenesis, among which embryonic development takes the most important place. It is on the results of the incubation of eggs that the further population size of the species in nature and the number of fish farmed in artificial conditions depend. It is known that the temperature regime is a very important ecological factor regulating the spawning of coregonids. However, if the temperature value during the spawning period does not take optimal values, as is often the case when Aral barbel are kept outside their natural range, then the influence of other environmental factors increases. In our opinion, the most significant of these factors is the photoperiod, under the influence of which the nelma producers are able to mature normally at a temperature higher than in the parent reservoir. The study of the embryonic development of nelma was carried out on living material by lateral microscopy. Key words: Aral barbel, embryonic, postembryonic, reproduction, development


2021 ◽  
pp. 1284-1289
Author(s):  
S. M. Abdulateef ◽  
M. A. Al-Bayar ◽  
A. A. Majid ◽  
S. S. Shawkat ◽  
A. Tatar ◽  
...  

Background and Aim: Many environmental factors exist that influence embryonic development which is missing in the poultry industry, such as light in incubation facilities or hatcheries. Light plays an important role in the growth and development of chick embryos, whereas dark environments can lead to hatching failure or embryo distortion. Therefore, this study aimed to demonstrate the importance of light and its various colors on the growth and development of broiler chick embryos. Materials and Methods: Four treatments were used to study the impact of various light colors on the growth of embryos and their neurophysiological traits: Dark without light (D), red light (RL), blue light (BL), and green light (GL), with three replicates per treatment (25 eggs/replicate) for a total of 300 fertile Ross 308 eggs. Each treatment was assigned to one incubator (75 eggs/incubator), whereas all other conditions were kept the same. Results: The results showed a significant increase (p<0.01) in embryonic development for embryo weight, chick body weight, hatchability, and embryo index for RL, BL, and especially GL. RL, BL, and especially GL significantly increased (p<0.01) neurophysiological traits of the neurons, brain weight, and brain index. Conclusion: The use of light during the embryonic period affects the development of the embryo and its neurophysiological traits.


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