scholarly journals Branchial Na+:K+:2Cl− cotransporter 1 and Na+/K+-ATPase α-subunit in a brackish water-type ionocyte of the euryhaline freshwater white-rimmed stingray, Himantura signifer

2013 ◽  
Vol 4 ◽  
Author(s):  
Yuen K. Ip ◽  
Kum C. Hiong ◽  
Samuel Z. H. Wong ◽  
Biyun Ching ◽  
Xiu L. Chen ◽  
...  
Keyword(s):  
Brackish Water ◽  
Water Type ◽  
Α Subunit ◽  
Himantura Signifer

Assortative mating and divergent male courtship behaviours between two cryptic species of nine-spined sticklebacks (genus Pungitius)

Behaviour ◽  
2016 ◽  
Vol 153 (15) ◽  
pp. 1879-1911 ◽  
Author(s):  
Yu-ichiro Meguro ◽  
Hiroshi Takahashi ◽  
Yoshiyasu Machida ◽  
Hokuto Shirakawa ◽  
Michelle R. Gaither ◽  
...  
Keyword(s):  
Reproductive Isolation ◽  
Cryptic Species ◽  
Assortative Mating ◽  
Brackish Water ◽  
Courtship Behaviour ◽  
Water Type ◽  
Male Courtship ◽  
Future Studies ◽  
Kinematic Analyses

Assortative mating based on ecologically divergent traits is a major driver of speciation among three-spined sticklebacks, however, little is known about reproductive isolation and variations in courtship behaviour among nine-spined sticklebacks. Here we demonstrate assortative mating and divergent courtship behaviours between two cryptic species of nine-spined sticklebacks using no-choice mate trials and kinematic analyses. Strong assortative mating was demonstrated in our tank experiments, highlighting the importance of prezygotic reproductive isolation in these species. Kinematic analyses showed that the freshwater type exhibited aggressive courtship behaviour with frequent ‘Attacking’ and spent more time exhibiting displacement activities. In contrast, the brackish-water type demonstrated a higher frequency of the ‘Zigzag-dance’ and ‘Nest-showing’. Our study highlights the value of nine-spined sticklebacks as a comparative system for the study of speciation and paves the way for future studies on the role of courtship behaviours and assortative mating in the evolution of sticklebacks.

scholarly journals A Preliminary Study of Groundwater Conditions in a Transitional Environment of Niger Delta using Direct – Current Soundings

2020 ◽  
Vol 12 (3) ◽  
pp. 279-288
Author(s):  
K. E. Aweto
Keyword(s):  
Direct Current ◽  
Brackish Water ◽  
Niger Delta ◽  
Dynamic Balance ◽  
Water Type ◽  
River Bank ◽  
The North ◽  
Adequate Information ◽  
Transitional Environment ◽  
Preliminary Study

The study area Burutu lies within the transitional environment of the Niger delta. The area is sectioned by a compact network of rivers and creeks, which maintain a fragile but dynamic balance between saline, estuarine and freshwater surface bodies. Twenty direct current resistivity soundings were carried out to provide adequate information on the spatial lithological variation and groundwater conditions in Burutu. Resistivity contrasts and water analysis were used as a means of characterizing probable lithology and water type present within the pore spaces of aquiferous units. The results revealed spatial development of the aquifer architectural facies that follows a trend of mostly sand with little clay in the south to sand with abundant of clayey facies in the north near the Forcados River. The groundwater conditions indicated that salty/brackish water constituting about 4 % of water present was confined to the bank of the Forcados River and extend laterally landwards to about 120 m. Further away from the river bank, the water was mostly poor to good quality freshwater. The depth to the freshwater constituting about 96 % groundwater present varied from about 49.0 – 63.3 m near the Forcados River and became as shallow as 1.6 m in inland areas.

scholarly journals Ascorbic Acid Biosynthesis and Brackish Water Acclimation in the Euryhaline Freshwater White-Rimmed Stingray, Himantura signifer

PLoS ONE ◽  
2013 ◽  
Vol 8 (6) ◽  
pp. e66691 ◽  
Author(s):  
Samuel Z. H. Wong ◽  
Biyun Ching ◽  
You R. Chng ◽  
Wai P. Wong ◽  
Shit F. Chew ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Brackish Water ◽  
Acid Biosynthesis ◽  
Ascorbic Acid Biosynthesis ◽  
Himantura Signifer

Population structure of two ecologically distinct forms of ninespine stickleback, Pungitius pungitius: gene flow regimes and genetic diversity based on mtDNA sequence variations

2003 ◽  
Vol 60 (4) ◽  
pp. 421-432 ◽  
Author(s):  
Hiroshi Takahashi ◽  
Tetsuya Tsuruta ◽  
Akira Goto
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Brackish Water ◽  
Gene Pools ◽  
Water Type ◽  
Pungitius Pungitius ◽  
Ninespine Stickleback ◽  
Sequence Variations ◽  
Mtdna Sequence ◽  
Mtdna Lineages

The population structure and its effect on genetic diversity were investigated in two ecologically distinct forms (fresh- and brackish-water types) of ninespine stickleback (Pungitius pungitius L.), which coexist on the coast of eastern Hokkaido, Japan. Obvious population subdivision (φST = 0.102 to 0.668) between freshwater systems in the freshwater type compared with that in the brackish-water type (φST = <0 to 0.078) was revealed on the basis of mitochondrial DNA (mtDNA) control region sequence variations. Results of the nested clade analysis suggested that the geographic distribution patterns of mtDNA lineages were mainly due to the contemporary population structure, rather than population histories. Although local populations were sampled from a similar geographic range for the two types, gene and nucleotide diversities of the freshwater type were significantly greater (0.94 and 0.016) than those of the brackish-water type (0.55 and 0.003). The increment of genetic diversity should be attributable to the obvious population structure and existence of divergent mtDNA lineages in the former, which clearly increased the effective population size of a subdivided population. Although these two forms maintain distinct gene pools, small sequence differences among mtDNA haplotypes obtained from each type suggested that mtDNA introgression has occurred between them.

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