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

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.

2015 ◽  
Vol 73 (3) ◽  
pp. 650-658 ◽  
Author(s):  
Stamatina Isari ◽  
Soultana Zervoudaki ◽  
Janna Peters ◽  
Georgia Papantoniou ◽  
Carles Pelejero ◽  
...  

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.


Aquaculture ◽  
2017 ◽  
Vol 468 ◽  
pp. 569-578 ◽  
Author(s):  
Sofia C. Franco ◽  
Christina B. Augustin ◽  
Audrey J. Geffen ◽  
Maria Teresa Dinis

2015 ◽  
Vol 12 (22) ◽  
pp. 18541-18570 ◽  
Author(s):  
A. Vehmaa ◽  
A.-K. Almén ◽  
A. Brutemark ◽  
A. Paul ◽  
U. Riebesell ◽  
...  

Abstract. Ocean acidification is challenging phenotypic plasticity of individuals and populations. Calanoid copepods (zooplankton) are shown to be fairly plastic against altered pH conditions, and laboratory studies indicate that transgenerational effects are one mechanism behind this plasticity. We studied phenotypic plasticity of the copepod Acartia bifilosa in the course of a pelagic, large-volume mesocosm study that was conducted to investigate ecosystem and biogeochemical responses to ocean acidification. We measured copepod egg production rate, egg hatching success, adult female size and adult female antioxidant capacity (ORAC) as a function of acidification (fCO2 ~ 365–1231 μatm), and as a function of quantity and quality of their diet. We used an egg transplant experiment to reveal if transgenerational effects can alleviate the possible negative effects of ocean acidification on offspring development. We found significant negative effects of ocean acidification on adult female copepod size and egg hatching success. In addition, we found a threshold of fCO2 concentration (~ 1000 μatm), above which adaptive maternal effects cannot alleviate the negative effects of acidification on egg hatching and nauplii development. We did not find support for the hypothesis that insufficient food quantity (total particulate carbon ~ 55 μm) or quality (C : N) weakens the transgenerational effects. However, females with high ORAC produced eggs with high hatching success. Overall, these results indicate that A. bifilosa could be affected by projected near future CO2 levels.


Sign in / Sign up

Export Citation Format

Share Document