Effects of Complete Redd Dewatering on Salmonid Egg-Hatching Success and Development of Juveniles

1983 ◽  
Vol 112 (4) ◽  
pp. 532-540 ◽  
Author(s):  
Dudley W. Reiser ◽  
Robert G. White
Keyword(s):  
Hatching Success ◽  
Egg Hatching

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.

Influence of prey species and concentration on egg production efficiency and hatching success in Acartia tonsa Dana (Copepoda, Calanoida)

Crustaceana ◽  
2015 ◽  
Vol 88 (6) ◽  
pp. 675-687 ◽  
Author(s):  
I. Wendt ◽  
P. Thor
Keyword(s):  
Egg Production ◽  
Production Efficiency ◽  
Prey Species ◽  
Hatching Success ◽  
Ingestion Rate ◽  
Acartia Tonsa ◽  
Egg Hatching ◽  
Prey Concentration ◽  
Algal Diets ◽  
Demand Limit

We measured ingestion rate (IR), egg production rate (EPR) and egg hatching success (EHS) at increasing prey concentrations and calculated egg production efficiency (EPE) and maintenance rate (MR) in the estuarine copepod Acartia tonsa fed three different algal diets. EPR and EHS were relatively more affected by prey species than by prey concentration. EPEs were constant among carbon concentrations (C) on a diet of Rhodomonas baltica (0.202 ± 0.055, mean ± SD) and Dunaliella tertiolecta (0.034 ± 0.015), but decreased significantly from 0.371 ± 0.062 (mean of two lowest prey concentrations) to 0.200 ± 0.019 at the highest concentration of Thalassiosira weissflogii. In general it seems that other requirements than C demand limit EPE and EHS in A. tonsa. The MR (IR when EPR = 0) was significantly higher on D. tertiolecta, which also yielded the lowest EPEs, and it seems that variations in maintenance requirements may have been instrumental in evoking EPE variations as well.

scholarly journals Lack of evidence for elevated CO2-induced bottom-up effects on marine copepods: a dinoflagellate–calanoid prey–predator pair

2015 ◽  
Vol 73 (3) ◽  
pp. 650-658 ◽  
Author(s):  
Stamatina Isari ◽  
Soultana Zervoudaki ◽  
Janna Peters ◽  
Georgia Papantoniou ◽  
Carles Pelejero ◽  
...  
Keyword(s):  
Elevated Co2 ◽  
Egg Production ◽  
Hatching Success ◽  
Laboratory Culture ◽  
Automated System ◽  
Egg Hatching ◽  
Seawater Acidification ◽  
Interspecific Differences ◽  
Significant Difference ◽  
Induced Changes

Abstract Rising levels of atmospheric CO2 are responsible for a change in the carbonate chemistry of seawater with associated pH drops (acidification) projected to reach 0.4 units from 1950 to 2100. We investigated possible indirect effects of seawater acidification on the feeding, fecundity, and hatching success of the calanoid copepod Acartia grani, mediated by potential CO2-induced changes in the nutritional characteristics of their prey. We used as prey the autotrophic dinoflagellate Heterocapsa sp., cultured at three distinct pH levels (control: 8.17, medium: 7.96, and low: 7.75) by bubbling pure CO2 via a computer automated system. Acartia grani adults collected from a laboratory culture were acclimatized for 3 d at food suspensions of Heterocapsa from each pH treatment (ca. 500 cells ml−1; 300 μg C l−1). Feeding and egg production rates of the preconditioned females did not differ significantly among the three Heterocapsa diets. Egg hatching success, monitored once per day for the 72 h, did not reveal significant difference among treatments. These results are in agreement with the lack of difference in the cellular stoichiometry (C : N, C : P, and N : P ratios) and fatty acid concentration and composition encountered between the three tested Heterocapsa treatments. Our findings disagree with those of other studies using distinct types of prey, suggesting that this kind of indirect influence of acidification on copepods may be largely associated with interspecific differences among prey items with regard to their sensitivity to elevated CO2 levels.

scholarly journals Risk-taking restraints in a bird with reduced egg–hatching success

2000 ◽  
Vol 267 (1441) ◽  
pp. 333-338 ◽  
Author(s):  
Marcel M. Lambrechts ◽  
Brigitte Prieur ◽  
Alain Caizergues ◽  
Olivier Dehorter ◽  
Marie-José Galan ◽  
...  
Keyword(s):  
Risk Taking ◽  
Hatching Success ◽  
Egg Hatching
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