scholarly journals Effects of low pH and raised temperature on egg production, hatching and metabolic rates of a Mediterranean copepod species (Acartia clausi) under oligotrophic conditions

2013 ◽  
Vol 15 (1) ◽  
pp. 74 ◽  
Author(s):  
S. ZERVOUDAKI ◽  
C. FRANGOULIS ◽  
L. GIANNOUDI ◽  
E. KRASAKOPOULOU
Keyword(s):  
Ocean Acidification ◽  
Egg Production ◽  
Multiple Stressors ◽  
Low Ph ◽  
Combined Effect ◽  
Vital Rates ◽  
Coastal Station ◽  
Acartia Clausi ◽  
Negative Effect ◽  
Egg Production Rate

This study includes the first information on the combined effect of low pH and raised temperature on egg production rate (EP), hatching success (HS), excretion and respiration of the Mediterranean copepod Acartia clausi. Adult individuals of A. clausi and fresh surface seawater were collected at a coastal station in Saronikos Gulf during April 2012. Four different conditions were applied: two different pH levels (present: 8.09 and future: 7.83) at two temperature values (present: 16°C and present+4 °C= 20°C). EP and HS success decreased significantly over the duration of exposure at future pH at both temperature conditions. However, the analysis of the combined effect of pH, T, chlorophyll α and the duration of the experiments on EP and HS revealed that ocean acidification had no discernible effect, whereas warming; food and the duration of exposure were more significant for the reproductive output of A. clausi. Temperature appeared to have a positive effect on respiration and excretion. Acidification had no clear effect on respiration, but a negative effect on the A. clausi excretion was observed. Acidification and warming resulted in the increase of the excretion rate and the increase was higher than that observed by warming only. Our findings showed that a direct effect of ocean acidification on copepod’s vital rates was not obvious, except maybe in the case of excretion. Therefore, the combination of acidification with the ambient oligotrophic conditions and the warming could result in species being less able to allocate resources for coping with multiple stressors.

scholarly journals Antagonistic interplay between pH and food resources affects copepod traits and performance in a year-round upwelling system

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Victor M. Aguilera ◽  
Cristian A. Vargas ◽  
Hans G. Dam
Keyword(s):  
Ocean Acidification ◽  
Egg Production ◽  
Egg Size ◽  
Ingestion Rate ◽  
Food Resources ◽  
Low Ph ◽  
Phenotypic Traits ◽  
Upwelling System ◽  
And Performance ◽  
The Impact

AbstractLinking pH/pCO2 natural variation to phenotypic traits and performance of foundational species provides essential information for assessing and predicting the impact of ocean acidification (OA) on marine ecosystems. Yet, evidence of such linkage for copepods, the most abundant metazoans in the oceans, remains scarce, particularly for naturally corrosive Eastern Boundary Upwelling systems (EBUs). This study assessed the relationship between pH levels and traits (body and egg size) and performance (ingestion rate (IR) and egg reproduction rate (EPR)) of the numerically dominant neritic copepod Acartia tonsa, in a year-round upwelling system of the northern (23° S) Humboldt EBUs. The study revealed decreases in chlorophyll (Chl) ingestion rate, egg production rate and egg size with decreasing pH as well as egg production efficiency, but the opposite for copepod body size. Further, ingestion rate increased hyperbolically with Chl, and saturated at ~1 µg Chl. L−1. Food resources categorized as high (H, >1 µg L−1) and low (L, <1 µg L−1) levels, and pH-values categorized as equivalent to present day (≤400 µatm pCO2, pH > 7.89) and future (>400 µatm pCO2, pH < 7.89) were used to compare our observations to values globally employed to experimentally test copepod sensitivity to OA. A comparison (PERMANOVA) test with Chl/pH (2*2) design showed that partially overlapping OA levels expected for the year 2100 in other ocean regions, low-pH conditions in this system negatively impacted traits and performance associated with copepod fitness. However, interacting antagonistically with pH, food resource (Chl) maintained copepod production in spite of low pH levels. Thus, the deleterious effects of ocean acidification are modulated by resource availability in this system.

scholarly journals Effects of Temperature and pH on the Egg Production and Hatching Success of a Common Korean Copepod

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 372
Author(s):  
Eun Hye Lee ◽  
Seo Yeol Choi ◽  
Min Ho Seo ◽  
Seok Ju Lee ◽  
Ho Young Soh
Keyword(s):  
Global Warming ◽  
Ocean Acidification ◽  
Atmospheric Carbon Dioxide ◽  
Egg Production ◽  
Hatching Success ◽  
Marine Animals ◽  
Ph Conditions ◽  
Effects Of Temperature ◽  
Egg Production Rate ◽  
Fresh Surface

The recent accelerated ocean acidification and global warming caused by increased atmospheric carbon dioxide may have an impact on the physiology and ecology of marine animals. This study was conducted to determine the egg production rate (EPR) and hatching success (EHS) of Acartia ohtsukai in response to the combined effects of an increase in temperature and a lower pH. Acartiaohtsukai with fresh surface seawater were collected in the northwestern Yeoja Bay of Korea in September 2017. The temperature and pH conditions applied included two different pH levels (representing the present: 7.9 and the future: 7.6) and three temperature values (26 °C, 28 °C, and 30 °C). In the pH 7.9, EPR significantly increased with increased temperature, but in pH 7.6, it significantly decreased as the temperature increased. EHS was lower in pH 7.6 than in pH 7.9. These results suggest that changes in the marine environment due to global warming and ocean acidification may affect Acartia populations and cause overall fluctuations in copepods of the genus Acartia.

scholarly journals Does resource availability influence the vital rates of the tropical copepod Apocyclops royi (Lindberg, 1940) under changing salinities?

2020 ◽  
Vol 42 (4) ◽  
pp. 467-478 ◽  
Author(s):  
Hans Van Someren Gréve ◽  
Per Meyer Jepsen ◽  
Benni Winding Hansen
Keyword(s):  
Production Rate ◽  
Food Availability ◽  
Egg Production ◽  
Food Concentration ◽  
Threshold Concentration ◽  
Cyclopoid Copepod ◽  
Vital Rates ◽  
Food Concentrations ◽  
Salinity Levels ◽  
Egg Production Rate

Abstract The physiology of invertebrates inhabiting many coastal ecosystems is challenged by strong temporal fluctuations in salinity. We investigated how food availability influences vital rates in the tropical cyclopoid copepod Apocyclops royi subjected to different salinities (5–32 PSU). We hypothesized that (i) mortality decreases and egg production rate increases with food availability; (ii) under suboptimal salinity, mortality increases and the egg production rate is reduced and (iii) the threshold concentration for egg production (the lowest food concentration where egg production is initiated) shifts to higher food concentrations when challenged by salinity. Surprisingly, A. royi survived, ingested food and produced eggs at all tested salinities. Mortality rate was, however, dependent on salinity level, but not on food availability. Mortality increased (~12% h−1) during short-term (1 h) salinity acclimatization to 5 PSU and during the following 24-h incubations (~5% d−1) compared with higher salinities. Feeding and egg production rates increased with food availability up to an optimum at all salinity levels, with no effect of salinity on the lowest food concentration initiating egg production. This reveals a high-salinity tolerance by A. royi and may partly explain why this particular copepod is so successful compared with its congeners in occupying extreme habitats.

scholarly journals The Influence of Ocean Acidification and Warming on DMSP & DMS in New Zealand Coastal Water

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 181
Author(s):  
Alexia D. Saint-Macary ◽  
Neill Barr ◽  
Evelyn Armstrong ◽  
Karl Safi ◽  
Andrew Marriner ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Coastal Water ◽  
Phytoplankton Community ◽  
Dimethyl Sulfide ◽  
Temperature Treatment ◽  
Low Ph ◽  
Trace Gas ◽  
Mesocosm Experiments ◽  
Future Warming ◽  
Higher Temperature

The cycling of the trace gas dimethyl sulfide (DMS) and its precursor dimethylsulfoniopropionate (DMSP) may be affected by future ocean acidification and warming. DMSP and DMS concentrations were monitored over 20-days in four mesocosm experiments in which the temperature and pH of coastal water were manipulated to projected values for the year 2100 and 2150. This had no effect on DMSP in the two-initial nutrient-depleted experiments; however, in the two nutrient-amended experiments, warmer temperature combined with lower pH had a more significant effect on DMSP & DMS concentrations than lower pH alone. Overall, this indicates that future warming may have greater influence on DMS production than ocean acidification. The observed reduction in DMSP at warmer temperatures was associated with changes in phytoplankton community and in particular with small flagellate biomass. A small decrease in DMS concentration was measured in the treatments relative to other studies, from −2% in the nutrient-amended low pH treatment to −16% in the year 2150 pH and temperature conditions. Temporal variation was also observed with DMS concentration increasing earlier in the higher temperature treatment. Nutrient availability and community composition should be considered in models of future DMS.

The impact of dietary protein:carbohydrate balance on lifespan and reproduction in Protaetia brevitarsis (Coleoptera: Scarabaeidae: Cetoniinae)

2021 ◽  
pp. 1-8
Author(s):  
S.-H. Kim ◽  
H. Park ◽  
W. Kim ◽  
J.-H. Song ◽  
S.J. Roh ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Egg Production ◽  
Detailed Knowledge ◽  
Reproductive Senescence ◽  
Egg Hatchability ◽  
Edible Insect ◽  
Age Related ◽  
Medicinal Value ◽  
Egg Production Rate ◽  
The Impact

The establishment of efficient and sustainable production of industrially important insects necessitates the detailed knowledge of the optimal mixture of macronutrients required for maximising their performance and fitness. The white spotted flower chafer, Protaetia brevitarsis (Coleoptera: Scarabaeidae: Cetoniinae), is one of the most important edible insects in East Asia with high nutritional and medicinal value. Here, we report how the ratio of protein to digestible carbohydrate (P:C) in the diet influenced lifespan and reproductive performance in the adults of P. brevitarsis. Throughout their lifespan, beetles were fed ad libitum one of five diets with differing P:C ratio (0:1, 3:7, 1:1, 7:3, 1:0). Both lifespan and the number of eggs produced over the lifetime were maximised at the P:C ratio of 3:7 and declined as the ratio deviated away from this optimal P:C composition. Beetles fed a diet containing only protein (P:C 1:0) not only had the shortest lifespan but also exhibited substantially reduced lifetime egg production compared to those fed the other diets. However, the effects of dietary P:C ratio on daily egg production rate and egg hatchability were marginal. The number of eggs produced at each age stage peaked at the age of week 2 and then gradually declined with increasing age, showing the sign of reproductive senescence. Age-specific egg production was higher in beetles confined to three intermediate P:C ratios (3:7, 1:1, 7:3) than those confined to two extreme P:C ratios (0:1, 1:0) throughout their lifespan. The speed of age-related decrease in reproductive performance was the slowest at P:C 3:7. Our data have implications for optimising the production of this edible insect with emerging economic importance.

scholarly journals Dynamic response in the larval geoduck clam proteome to elevated pCO2

2019 ◽  
Author(s):  
Emma Timmins-Schiffman ◽  
José M. Guzmán ◽  
Rhonda Elliott ◽  
Brent Vadopalas ◽  
Steven B. Roberts
Keyword(s):  
Ocean Acidification ◽  
Pacific Coast ◽  
Low Ph ◽  
Molecular Physiology ◽  
Proteomics Analysis ◽  
Bivalve Larvae ◽  
Energetic Stress ◽  
The Pacific ◽  
Aquaculture Industry ◽  
Ph Conditions

AbstractPacific geoduck clams (Panopea generosa) are found along the Northeast Pacific coast where they are significant components of coastal and estuarine ecosystems and the basis of a growing and highly profitable aquaculture industry. The Pacific coastline, however, is also the sight of rapidly changing ocean habitat, including significant reductions in pH. The impacts of ocean acidification on invertebrate bivalve larvae have been widely documented and it is well established that many species experience growth and developmental deficiencies when exposed to low pH. As a native of environments that have historically lower pH than the open ocean, it is possible that geoduck larvae are less impacted by these effects than other species. Over two weeks in larval development (days 6-19 post-fertilization) geoduck larvae were reared at pH 7.5 or 7.1 in a commercial shellfish hatchery. Larvae were sampled at six time points throughout the period for a in-depth proteomics analysis of developmental molecular physiology. Larvae reared at low pH were smaller than those reared at ambient pH, especially in the prodissoconch II phase of development. Competency for settlement was also delayed in larvae from the low pH conditions. A comparison of proteomic profiles over the course of development reveal that these differing phenotypic outcomes are likely due to environmental disruptions to the timing of molecular physiological events as suites of proteins showed differing profiles of abundance between the two pH environments. Ocean acidification likely caused an energetic stress on the larvae at pH 7.1, causing a shift in physiological prioritization with resulting loss of fitness.

scholarly journals Performance Evaluation of Kuroiler and Sasso Chicken Breeds Reared under On-farm and On-station Management Conditions in Tanzania

2021 ◽  
Vol 3 (2) ◽  
pp. 53-59
Author(s):  
Fadhili S. Guni ◽  
Said H. Mbaga ◽  
Andalwisye M. Katule
Keyword(s):  
Body Weight ◽  
Egg Production ◽  
Linear Models ◽  
Farm Management ◽  
General Effect ◽  
Production Traits ◽  
Gxe Interaction ◽  
Live Body Weight ◽  
Egg Production Rate ◽  
On Farm

A study was conducted to evaluate the effect of management, breed, and their interaction on growth performance, egg production, and survivability under on-station and on-farm management conditions in Tanzania. A total of 1200 chicks, 600 for each breed, Kuroiler, and Sasso of mixed sexes were used. Birds under on-station management were confined and fed commercial ration throughout the experiment while those under on-farm management were allowed to semi-scavenge and supplemented with available feeds in the household. Brooding was carried out on-station for six weeks. Thereafter, birds were sub-divided for on-station and on-farm evaluation where data on body weight, egg production traits, and survival rate were taken at different ages from week 6 up to 52. The General Linear Models procedure fitting management, breed, and interaction between management and breed was used to analyze the data. Results show that management conditions had a significant influence on the performance of the breeds. Birds reared on-station performed better in all traits measured than those reared on-farm. The general effect of the breed was significant only for hen-day egg production (HDEP %) and hen-housed egg production (HHEP) in favour of Sasso chickens. Similarly, Sasso was more efficient at converting feed to live body weight. Interactions between management and breed were observed for all traits except peak egg production rate and mortality rate. While Sasso performance was better than that of Kuroiler on body weight, age at first egg, HDEP, age at peak egg production, and HHEP under the on-station management system, their performance in these traits were similar under the on-farm management except for body weight and age at first egg where Kuroiler was superior to Sasso. The survivability was also higher for Kuroiler than for Sasso under both management systems. It is concluded that genotype by environment (GxE) interaction had significant effects on the performance of the two breeds thus, a need to consider such effect when promoting them for either on-station or on-farm rearing.

scholarly journals Variation in brachiopod microstructure and isotope geochemistry under low pH–ocean acidification–conditions

2018 ◽  
Author(s):  
Facheng Ye ◽  
Hana Jurikova ◽  
Lucia Angiolini ◽  
Uwe Brand ◽  
Gaia Crippa ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Ocean Acidification ◽  
Isotope Geochemistry ◽  
Shell Growth ◽  
Low Ph ◽  
Secondary Layer ◽  
Ph Conditions ◽  
One Year ◽  
The Impact ◽  
Δ13c And Δ18o

Abstract. Throughout the last few decades and in the near future CO2–induced ocean acidification is potentially a big threat to marine calcite-shelled animals (e.g., brachiopods, bivalves, corals and gastropods). Despite the great number of studies focusing on the effects of acidification on shell growth, metabolism, shell dissolution and shell repair, the consequences on biomineral formation remain poorly understood, and only few studies addressed contemporarily the impact of acidification on shell microstructure and geochemistry. In this study, a detailed microstructure and stable isotope geochemistry investigation was performed on nine adult brachiopod specimens of Magellania venosa (Dixon, 1789), grown in the natural environment as well as in controlled culturing experiments at different pH conditions (ranging 7.35 to 8.15 ± 0.05) over different time intervals (214 to 335 days). Details of shell microstructural features, such as thickness of the primary layer, density and size of endopunctae and morphology of the basic structural unit of the secondary layer were analysed using scanning electron microscopy (SEM). Stable isotope compositions (δ13C and δ18O) were tested from the secondary shell layer along shell ontogenetic increments in both dorsal and ventral valves. Based on our comprehensive dataset, we observed that, under low pH conditions, M. venosa produced a more organic-rich shell with higher density of and larger endopunctae, and smaller secondary layer fibres, when subjected to about one year of culturing. Also, increasingly negative δ13C and δ18O values are recorded by the shell produced during culturing and are related to the CO2–source in the culture setup. Both the microstructural changes and the stable isotope results are similar to observations on brachiopods from the fossil record and strongly support the value of brachiopods as robust archives of proxies for studying ocean acidification events in the geologic past.

scholarly journals A gender bias in the calcification response to ocean acidification

2011 ◽  
Vol 8 (4) ◽  
pp. 8485-8513 ◽  
Author(s):  
M. Holcomb ◽  
A. L. Cohen ◽  
D. C. McCorkle
Keyword(s):  
Ocean Acidification ◽  
Elevated Co2 ◽  
Egg Production ◽  
Elevated Pco2 ◽  
Future Research ◽  
Astrangia Poculata ◽  
Population Structures ◽  
Different Temperatures ◽  
Increased Sensitivity ◽  
Ambient Co2

Abstract. The effects of nutrients and pCO2 on zooxanthellate and azooxanthellate colonies of the temperate scleractinian coral Astrangia poculata (Ellis and Solander, 1786) were investigated at two different temperatures (16 °C and 24 °C). Corals exposed to elevated pCO2 tended to have lower relative calcification rates, as estimated from changes in buoyant weights. No nutrient effect was observed. At 16 °C, gamete release was not observed, and no gender differences in calcification rate were observed. However, corals grown at 24 °C spawned repeatedly and male and female corals exhibited two different growth rate patterns. Female corals grown at 24 °C and exposed to CO2 had calcification rates 39 % lower than females grown at ambient CO2, while males showed only a 5 % decline in calcification under elevated CO2. At 16 °C, female and male corals showed similar reductions in calcification rates in response to elevated CO2 (15 % and 19 % respectively). At 24 °C, corals spawned repeatedly, while no spawning was observed at 16 °C. The increased sensitivity of females to elevated pCO2 may reflect a greater investment of energy in reproduction (egg production) relative to males (sperm production). These results suggest that both gender and spawning are important factors in determining the sensitivity of corals to ocean acidification and their inclusion in future research may be critical to predicting how the population structures of marine calcifiers will change in response to ocean acidification.

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