Extreme life history change of white-spotted char (Salvelinus leucomaenis) after damming

2000 ◽  
Vol 57 (6) ◽  
pp. 1300-1306 ◽  
Author(s):  
Kentaro Morita ◽  
Shoichiro Yamamoto ◽  
Noboru Hoshino
Keyword(s):  
Life History ◽  
High Growth ◽  
Migratory Behavior ◽  
Transplant Experiment ◽  
Dam Construction ◽  
Low Density ◽  
Salvelinus Leucomaenis ◽  
Migration Barriers ◽  
Potential Migrant ◽  
White Spotted Char

Dam construction has serious consequences for anadromous fishes. We examined the effects of migration barriers formed following dam construction on the migratory behavior of white-spotted char (Salvelinus leucomaenis) by comparing migrants in accessible below-dam river sections with migrants in inaccessible above-dam river sections. The frequency of smolts (i.e., potential migrant) was higher for the below-dam sections than for the above-dam sections, and in contrast, the frequency of residents was higher for the above-dam sections. Above-dam sections had lower fry (age 0+) densities and consequently had higher growth rates compared with below-dam sections. A transplant experiment revealed that the majority of the below-dam fish adopted a resident strategy, as well as above-dam fish, when both had experienced the above-dam environment. We conclude that high growth as a result of low density promotes residency in the above-dam sections.

Effect of maternal growth history on egg number and size in wild white-spotted char (Salvelinus leucomaenis)

1999 ◽  
Vol 56 (9) ◽  
pp. 1585-1589 ◽  
Author(s):  
Kentaro Morita ◽  
Shoichiro Yamamoto ◽  
Yoshinobu Takashima ◽  
Takashi Matsuishi ◽  
Yasuji Kanno ◽  
...  
Keyword(s):  
Egg Size ◽  
Size Variation ◽  
High Growth ◽  
First Year ◽  
Salvelinus Leucomaenis ◽  
Growth History ◽  
Egg Number ◽  
Size Growth ◽  
Back Calculation ◽  
White Spotted Char

Differences in egg number and egg size within a wild population of white-spotted char (Salvelinus leucomaenis) were examined from the perspective of maternal growth history by using a back-calculation method. Relatively greater egg size variation occurred among females (61.6%) than within females (38.4%). Larger females produced a larger number of eggs, which were also larger in size. To understand the causes of variation in egg number and egg size, several contributory factors determining maternal size were considered (initial size, growth rate for each age, total age). Egg number was not associated with maternal growth history. Contrary to egg number, egg size was strongly associated with maternal growth history; high growth in the first year was negatively associated with egg size, but high growth in the second year was positively associated with egg size. The results indicated that white-spotted char potentially exhibit phenotypic plasticity in egg size according to their growth history.

Microsatellite variation in white-spotted char Salvelinus leucomaenis from Sakhalin oblast

2013 ◽  
Vol 49 (9) ◽  
pp. 945-949 ◽  
Author(s):  
K. I. Afanas’ev ◽  
G. A. Rubtsova ◽  
E. G. Shaikhaev ◽  
L. A. Zhivotovskii
Keyword(s):  
Microsatellite Variation ◽  
Salvelinus Leucomaenis ◽  
White Spotted Char ◽  
Sakhalin Oblast

A field study of competition and interaction between Lemna minor and Lemna trisulca

1989 ◽  
Vol 67 (10) ◽  
pp. 2904-2911 ◽  
Author(s):  
Alexander L. McIlraith ◽  
Gordon G. C. Robinson ◽  
Jennifer M. Shay
Keyword(s):  
Life History ◽  
Field Study ◽  
Key Words ◽  
Field Experiments ◽  
Lemna Minor ◽  
Survey Methods ◽  
The Other ◽  
Transplant Experiment ◽  
Replacement Series ◽  
Vegetative Biomass

Field experiments and survey methods were used to assess competition and interaction between Lemna minor L. and Lemna trisulca L. at Delta Marsh, Manitoba. Sites were dominated by one or the other species or codominated by both. Replacement series experiments predicted codominance of L. minor and L. trisulca in an unshaded eutrophic site but predicted L. minor dominance when run for a longer time. Similar experiments conducted in a shaded eutrophic site predicted L. minor dominance. Addition series experiments showed that intraspecific and interspecific competition occurred in the unshaded site. In a eutrophic unshaded ditch, high densities of L. minor suppressed L. trisulca. In a eutrophic shaded site, high densities of L. minor and green algae inhibited L. trisulca, and in a sunny, less eutrophic site high density of each species inhibited the other. In a transplant experiment, L. minor biomass in shaded enclosures approached that found naturally in two shaded sites. Lemna trisulca persisted when shaded. Vegetative biomass trends in an unshaded eutrophic marsh ditch indicated spring and fall L. trisulca dominance and summer L. minor dominance. Shaded eutrophic sites were dominated by L. minor, whereas a less eutrophic site was dominated by L. trisulca. A model is developed to explain dominance patterns, and seasonal life-history responses are considered. Key words: Lemna, duckweed, competition, interaction, resources, light, nutrients.

SiC Solution Growth on Si Face with Extremely Low Density of Threading Screw Dislocations for Suppression of Polytype Transformation

2017 ◽  
Vol 897 ◽  
pp. 24-27 ◽  
Author(s):  
Kenta Murayama ◽  
Tsukasa Hori ◽  
S. Harada ◽  
S. Xiao ◽  
M. Tagawa ◽  
...  
Keyword(s):  
Temperature Distribution ◽  
Growth Temperature ◽  
Thick Layer ◽  
High Growth ◽  
Solution Growth ◽  
Threading Dislocation ◽  
Low Density ◽  
Screw Dislocations ◽  
Threading Dislocation Density ◽  
Polytype Transformation

In order to achieve a high-quality SiC crystal in solution growth, one of the most difficult issues is to grow a thick layer on Si face avoiding polytype transformation. In this case, two-dimensional nucleation, which leads to the polytype transformation, is frequently induced because a density of threading screw dislocations acting as a source of spiral step decreases and wide terraces form by step bunching as growth proceeds. Therefore, it is very difficult to stabilize the polytype of crystals grown with extremely low density of threading screw dislocations. In this study, we tried to overcome these problems by using specially designed seed crystal and optimizing growth temperature and temperature distribution. We successfully grew thick low-threading-dislocation density SiC crystal without polytype transformation under the condition of high growth temperature and homogeneous temperature distribution.

Migratory Behavior and Physiological Development as Potential Determinants of Life History Diversity in Fall Chinook Salmon in the Clearwater River

2018 ◽  
Vol 147 (2) ◽  
pp. 400-413
Author(s):  
Kenneth F. Tiffan ◽  
Tobias J. Kock ◽  
William P. Connor ◽  
Marshall C. Richmond ◽  
William A. Perkins
Keyword(s):  
Life History ◽  
Chinook Salmon ◽  
Migratory Behavior ◽  
Clearwater River
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