Seasonal changes in leaf nutrient concentration of male and female hardy kiwifruit grown in Oregon

2018 ◽  
Vol 83 (4) ◽  
pp. 247-258 ◽  
Author(s):  
A.J. Vance ◽  
◽  
B.C. Strik ◽  
Keyword(s):  
Seasonal Changes ◽  
Nutrient Concentration ◽  
Male And Female ◽  
Leaf Nutrient Concentration

scholarly journals Effect of co-application of phosphorus fertilizer and in vitro-produced mycorrhizal fungal inoculants on yield and leaf nutrient concentration of cassava

PLoS ONE ◽  
2019 ◽  
Vol 14 (6) ◽  
pp. e0218969 ◽  
Author(s):  
Ibrahim A. Aliyu ◽  
Ado A. Yusuf ◽  
Edward O. Uyovbisere ◽  
Cargele Masso ◽  
Ian R. Sanders
Keyword(s):  
Nutrient Concentration ◽  
Phosphorus Fertilizer ◽  
Leaf Nutrient Concentration

The reproductive cycle of the viviparous seaperch, Cymatogaster aggregata Gibbons

1968 ◽  
Vol 46 (6) ◽  
pp. 1221-1234 ◽  
Author(s):  
John P. Wiebe
Keyword(s):  
Oocyte Maturation ◽  
Reproductive Cycle ◽  
Sertoli Cells ◽  
Reproductive Behavior ◽  
Seasonal Changes ◽  
Environmental Temperature ◽  
Interstitial Cells ◽  
Early Spring ◽  
Seminiferous Tubules ◽  
Male And Female

The natural reproductive cycle of male and female Cymatogaster aggregata is described with reference to gametogenesis, development of secondary sex structures, reproductive behavior, and gestation. Spermatocytogenesis starts in early spring and by June or July clusters of spermatozoa fill the seminiferous tubules. Concurrently the Sertoli cells and interstitial cells of Leydig increase in size and secondary sex structures develop on the male anal fin. When the sexes mingle in summer, the males perform very elaborate reproductive behavior. Fertilization occurs about mid-December—5 months after mating—and the ovary is then modified to maintain the young embryos until parturition in mid-summer. Oocyte formation is highest in July and August, just after parturition, while vitellogenesis and oocyte maturation occur mainiy from October to December. These seasonal changes are discussed in relation to changes in environmental temperature and photoperiod.

scholarly journals Seasonal changes in group size and composition of Arabian sand gazelle Gazella subgutturosa marica Thomas, 1897 during a period of drought in central western Saudi Arabia

2011 ◽  
Vol 57 (1) ◽  
pp. 36-42 ◽  
Author(s):  
Peter Low Cunningham ◽  
Torsten Wronski
Keyword(s):  
Saudi Arabia ◽  
Group Size ◽  
Protected Area ◽  
Seasonal Changes ◽  
Continuous Monitoring ◽  
Group Structure ◽  
Male And Female ◽  
Adult Sex Ratio ◽  
Gazella Subgutturosa ◽  
Mixed Groups

Abstract Group size variations of the Arabian sand gazelle Gazella subgutturosa marica were studied during a period of drought at the Mahazat as-Sayd Protected Area in central western Saudi Arabia. Significant differences in median group sizes were observed between all seasons except summer. Single animals were observed mainly during summer while group sizes exceeding 10 individuals were observed mainly during winter. Solitary male and female groups were typically observed during winter and mixed groups mainly during the autumn rutting period. Most mixed groups were two to four times larger during winter than summer. The adult sex ratio (male: female) for all seasons combined was in parity and highest during autumn (1:1.23), probably as a result of prolonged drought conditions. The variability in group structure related to environmental conditions may be one factor permitting G. s. marica to adapt to hyper-arid habitats and climatic regimes in central western Saudi Arabia. The value of continuous monitoring of the gazelle population is emphasised for this drought prone region.

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