Rhythmic change of adipokinetic hormones diurnally regulates locust vitellogenesis and egg development

2020 ◽  
Vol 29 (3) ◽  
pp. 283-292 ◽  
Author(s):  
H. Zheng ◽  
C. Chen ◽  
C. Liu ◽  
Q. Song ◽  
S. Zhou
Keyword(s):  
Egg Development ◽  
Rhythmic Change

Mutualistic microalgae co-diversify with reef corals that acquire symbionts during egg development

2021 ◽  
Author(s):  
Kira E. Turnham ◽  
Drew C. Wham ◽  
Eugenia Sampayo ◽  
Todd C. LaJeunesse
Keyword(s):  
Egg Development ◽  
Reef Corals

Laboratory observations on early development of the oncaeid copepod Triconia canadensis from the mesopelagic zone of the western subarctic Pacific

2007 ◽  
Vol 87 (2) ◽  
pp. 479-482 ◽  
Author(s):  
Yuichiro Nishibe ◽  
Tsutomu Ikeda
Keyword(s):  
Lipid Droplets ◽  
Development Time ◽  
Hatching Success ◽  
Egg Development ◽  
Egg Hatching ◽  
Subarctic Pacific ◽  
Western Subarctic Pacific ◽  
Mesopelagic Zone ◽  
Life Cycle Strategy

Egg development time and hatching success were determined for the oncaeid copepod, Triconia canadensis, from the mesopelagic zone of the western subarctic Pacific. The egg development time was estimated to be 74.7–84.5 days at in situ temperature (3°C), which is much longer than those reported previously on the other oncaeid copepods even if the differences in experimental temperatures are taken into account. The egg hatching success varied between 50 and 100%, with a grand mean of 88%. The newly hatched nauplii of T. canadensis were elongate ellipsoid in shape, and had many large-sized lipid droplets in their body. Possible adaptive significance of apparent longer egg developmment time of T. canadensis is discussed in the light of their life cycle strategy.

scholarly journals Bottom temperature and in situ development of chokka squid eggs (Loligo vulgaris reynaudii) on mid-shelf spawning grounds, South Africa

2009 ◽  
Vol 66 (9) ◽  
pp. 1967-1971 ◽  
Author(s):  
Anè Oosthuizen ◽  
Mike J. Roberts
Keyword(s):  
South Africa ◽  
Bottom Temperature ◽  
Egg Development ◽  
Spawning Grounds ◽  
Loligo Vulgaris ◽  
Laboratory Results ◽  
Temperature Environment ◽  
Development Data ◽  
Shelf Temperature

Abstract Oosthuizen, A., and Roberts, M. J. 2009. Bottom temperature and in situ development of chokka squid eggs (Loligo vulgaris reynaudii) on mid-shelf spawning grounds, South Africa. – ICES Journal of Marine Science, 66: 1967–1971. The aim of the study was to test the development success of squid eggs on the mid-shelf (60–150 m deep) spawning grounds in relation to previous laboratory results, and to describe the mid-shelf temperature environment and how it could affect egg development. A series of in situ egg incubation experiments was conducted on the mid-shelf (∼119 m deep) spawning grounds using cages, temperature sensors, and acoustic releases for retrieval. Newly spawned eggs were collected by scuba, and continuous temperature data were collected at two points between the known inshore spawning grounds and the mid-shelf areas. Temperature variations followed a seasonal warming and cooling cycle, with superimposed peaks and troughs. Egg development data indicated that warm temperature peaks (10–13°C) are sufficient for normal development of eggs on the mid-shelf. Egg development time on the mid-shelf was 2–3 times longer (50–60 vs. 20–30 d) than inshore. The scarcity of abnormalities (0.45%) disputes previous laboratory results that suggested that ∼50% of eggs would suffer abnormalities in the colder mid-shelf temperature environment.

THE DISTRIBUTION OF DERMACENTOR TICKS IN CANADA IN RELATION TO BIOCLIMATIC ZONES

1967 ◽  
Vol 45 (4) ◽  
pp. 517-537 ◽  
Author(s):  
P. R. Wilkinson
Keyword(s):  
British Columbia ◽  
Deciduous Forest ◽  
Strong Association ◽  
Eastern Deciduous Forest ◽  
Egg Development ◽  
The North ◽  
Winter Activity ◽  
Bioclimatic Zone ◽  
Soil Temperatures ◽  
Time Of Year

Dermacentor andersoni has been collected north of Jasper, Alberta, close to 54° N. and near 53° N. in British Columbia. Spread to the north and northwest is probably limited by low summer soil temperatures, which would act principally by slowing egg development, thus disrupting the seasonal cycle of the tick. To the southwest, mild winters may fail to release diapause at the correct time of year. Aspect and slope are important factors. Altitude spread of records is from 1000–7000 ft. The most generally applicable description of its distribution is the ecotone between western grassland and moister regions, including clearings and rocky outcrops m the montane and Columbia forests, and shrubby areas of the prairies. In British Columbia, a series of randomly selected transects indicated a strong association between the tick's presence and several species of shrubs growing without tree shade.Each bioclimatic zone tends to have a characteristic group of rodents as main hosts of the immature stages. The prairie and montane regions differ in the indigenous hosts available to the adult tick.East of 105° D. andersoni is replaced by D. variabilis, which is adapted to the more humid summers of the eastern deciduous forest zones, and differs considerably from D. andersoni in its phenology. There are no reliable records of indigenous D. variabilis north of 52° latitude.D. albipictus occurs from the east to the west coast. Because of the winter activity of its larvae, allowing the whole summer for egg development, it is able to penetrate much farther north than the other two species. There are two records close to 60° latitude.

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