Growth and reproduction of some Diaptomus spp. in Saskatchewan ponds

1968 ◽  
Vol 46 (3) ◽  
pp. 511-520 ◽  
Author(s):  
William W. Sawchyn ◽  
U. Theodore Hammer
Keyword(s):  
Water Temperature ◽  
Clutch Size ◽  
Field Studies ◽  
Early Summer ◽  
Life Cycles ◽  
Three Generations ◽  
Chemical Conditions ◽  
Growth And Reproduction

Field studies on the life cycles of seven species of Diaptomus were undertaken in some ponds in southern and central Saskatchewan. D. sanguineus, D. arcticus, D. stagnalis, and D. kiseri have one generation per year, beginning early in the spring and disappearing by early summer. D. leptopus, D. forbesi, and D. nudus appear somewhat later, have two or three generations per year, and persist throughout the rest of the ice-free period. Correlations were found between water temperature and egg clutch size of Diaptomus females. Variations in size of individuals of different generations were related to temperature. Attempts to associate changes in chemical conditions of the ponds with growth and reproduction of Diaptomus spp. were unsuccessful.

scholarly journals Extreme Meteorological Events in a Coastal Lagoon Ecosystem: The Ria de Aveiro Lagoon (Portugal) Case Study

2021 ◽  
Vol 9 (7) ◽  
pp. 727
Author(s):  
José Fortes Lopes ◽  
Carina Lurdes Lopes ◽  
João Miguel Dias
Keyword(s):  
Water Temperature ◽  
Coastal Lagoon ◽  
Early Summer ◽  
Extreme Weather Events ◽  
Climate Change Scenarios ◽  
State Variables ◽  
Ria De Aveiro ◽  
Physical Conditions ◽  
Weather Events ◽  
The Impact

Extreme weather events (EWEs) represent meteorological hazards for coastal lagoon hydrodynamics, of which intensity and frequency are increasing over the last decades as a consequence of climate changes. The imbalances they generated should affect primarily vulnerable low-lying areas while potentially disturbing the physical balances (salt and water temperature) and, therefore, the ecosystem equilibrium. This study arises from the need to assess the impact of EWEs on the Ria de Aveiro, a lagoon situated in the Portuguese coastal area. Furthermore, it was considered that those events occur under the frame of a future sea-level rise, as predicted by several climate change scenarios. Two EWEs scenarios, a dry and an extremely wet early summer reflecting past situations and likely to occur in the future, were considered to assess the departure from the system baseline functioning. It was used as a biogeochemistry model that simulates the hydrodynamics, as well as the baseline physical and biogeochemistry state variables. The dry summer scenario, corresponding to a significant reduction in the river’s inflow, evidences a shift of the system to a situation under oceanic dominance characterized by colder and saltier water (~18 °C; 34 PSU) than the baseline while lowering the concentration of the nutrients and reducing the phytoplankton population to a low-level limit. Under a wet summer scenario, the lagoon shifted to a brackish and warmer situation (~21 °C, <15 PSU) in a time scale of some tidal periods, driven by the combining effect of the tidal transport and the river’s inflow. Phytoplankton patterns respond to variability on local and short-term scales that reflect physical conditions within the lagoon, inducing nutrient-supported growth. Overall, the results indicate that EWEs generate local and transient changes in physical conditions (namely salinity and water temperature) in response to the characteristic variability of the lagoon’s hydrodynamics associated with a tidal-dominated system. Therefore, in addition to the potential impact of changing physical conditions on the ecosystem, saline intrusion along the lagoon or the transfer of brackish water to the mouth of the system are the main consequences of EWEs, while the main biogeochemistry changes tend to remain moderate.

scholarly journals DNA screening of Drosophila suzukii predators in berry field orchards shows new predatory taxonomical groups

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249673
Author(s):  
Sara Sario ◽  
Conceição Santos ◽  
Fátima Gonçalves ◽  
Laura Torres
Keyword(s):  
Large Scale ◽  
Field Studies ◽  
Life Cycles ◽  
Gut Content ◽  
Drosophila Suzukii ◽  
Potential Predator ◽  
The Family ◽  
First Time ◽  
South Europe ◽  
New Habitats

Drosophila suzukii (spotted wing drosophila, SWD) is a pandemic quarantine pest that attacks mostly red fruits. The high number of life cycles per year, its ability to rapidly invade and spread across new habitats, and highly polyphagous nature, makes this a particularly aggressive invasive species, for which efficient control methods are currently lacking. The use of native natural predators is particularly promising to anchor sustainable and efficient measures to control SWD. While several field studies have suggested the presence of potential predatory species in infested orchards, only a few confirmed the presence of SWD DNA in predators’ gut content. Here, we use a DNA-based approach to identify SWD predators among the arthropod diversity in South Europe, by examining the gut content of potential predator specimens collected in SWD-infested berry fields in North Portugal. These specimens were morphologically identified to the family/order, and their gut content was screened for the presence of SWD DNA using PCR. New SWD predatory taxonomical groups were identified, as Opiliones and Hemerobiidae, in addition to known SWD predators, such as Hemerobiidae, Chrysopidae, Miridae, Carabidae, Formicidae and Araneae. Additionally, the presence of a spider family, Uloboridae, in the orchards was recorded for the first time, posing this family as another SWD-candidate predator. This study sets important bases to further investigate the potential large-scale use of some of these confirmed predator taxa for SWD control in South Europe.

Temperature effects on bank filtration: redox conditions and physical-chemical parameters of pore water at Lake Tegel, Berlin, Germany

2010 ◽  
Vol 1 (1) ◽  
pp. 55-66 ◽  
Author(s):  
A. Gross-Wittke ◽  
G. Gunkel ◽  
A. Hoffmann
Keyword(s):  
Water Temperature ◽  
High Water ◽  
Nitrate Respiration ◽  
Redox Processes ◽  
Redox Potentials ◽  
Bank Filtration ◽  
Physical Chemical ◽  
Drinking Water Production ◽  
Chemical Conditions ◽  
Sediment Layers

In the city of Berlin, artificial groundwater recharge techniques, such as bank filtration and infiltration ponds, are an important source for drinking water production. Climate change with increasing surface water temperatures can influence the water purification processes during bank filtration mainly due the intensification of metabolic processes leading to a decrease of oxygen and an increase of anaerobic conditions. In Lake Tegel a significant increase of water temperature in the epilimnion of 2.4°C within the last 30 years was recorded. For a better understanding of induced bank filtration at Lake Tegel, redox processes and physical-chemical conditions within the surface sediment layers (0–26 cm depth) at the littoral infiltration zone were investigated. The influence of temperature in the range of 0–25°C on microbial catalysis of redox processes, such as reduction of nitrate and sulphate, was examined during the period March 2004–June 2005. High water temperatures (16–25°C) were accompanied by negative redox potentials (EH=−47 mV) and decreasing Ninorg concentrations, while the amount of ammonia, Mn2 +  and Fe2 +  was rising. This indicates redox processes such as denitrification, Mn4 +  reduction, nitrate respiration and ammonification, as well as Fe3 +  reduction. The reduction of sulphate, however, has not yet become significant at Lake Tegel, but with increasing water temperature, sulphate reduction must be expected.

Effect of soil moisture and fertilizer application on clonal growth and reproduction in a tristylous weed, Lythrum salicaria

1997 ◽  
Vol 75 (1) ◽  
pp. 46-60 ◽  
Author(s):  
Tarun K. Mal ◽  
Jon Lovett-Doust ◽  
Lesley Lovett-Doust
Keyword(s):  
Soil Moisture ◽  
Clonal Growth ◽  
Spatial Separation ◽  
Field Studies ◽  
Fertilizer Application ◽  
Lythrum Salicaria ◽  
Relative Mass ◽  
Total Length ◽  
Proportional Allocation ◽  
Growth And Reproduction

Clonal growth and reproduction in tristylous Lythrum salicaria L. were examined experimentally, using cloned genotypes of each of the three flower morphs, in field studies involving four moisture and three nutrient treatments. Clonal growth was measured in terms of diameter of clones, number of ramets per clone, and total length of ramets, and an index of reproduction was recorded as the total length of infructescence per clone. Neither clonal growth nor reproduction differed significantly among flower morphs, but both differed significantly as a consequence of both moisture and nutrient treatments. The pattern of seasonal growth indicates that ramet production was restricted mainly to the beginning of the season following vigorous vegetative growth. Although flowering began in June, it was restricted to plants in drier treatments in the water-gradient experiment. Characters intrinsic to tristyly (such as lengths of styles and stamens, and allocation of biomass to stamens and pistil) differed significantly among morphs. Soil moisture levels but not fertilizer treatments significantly affected the size of floral structures and biomass. Although absolute levels of biomass allocation to whole flowers and to attractive structures did not differ significantly among morphs, relative allocation to stamens increased progressively from long morph to mid-morph to short morph, with a corresponding decrease in relative mass of pistil. Although proportional allocation differed significantly among morphs, it was unaffected by moisture treatment, suggesting tight genetic control of herkogamy (spatial separation between anther and stigma). This should maintain the floral polymorphism in different ecological conditions. Key words: Lythrum salicaria, nutrient and water gradients, heterostyly, floral morphometry, floral allocation, clonal growth, sexual reproduction.

Environmental control of reproduction in Perinereis nuntia var. brevicirrus

1994 ◽  
Vol 74 (4) ◽  
pp. 903-918 ◽  
Author(s):  
J.D. Hardege ◽  
H.D. Bartels-Hardege ◽  
Y. Yang ◽  
B.L. Wu ◽  
M.Y. Zhu ◽  
...  
Keyword(s):  
Water Temperature ◽  
Rocky Shore ◽  
Sex Pheromones ◽  
Laboratory Experiments ◽  
Environmental Control ◽  
Early Morning ◽  
Early Summer ◽  
Coelomic Fluid ◽  
Spawning Behaviour ◽  
Perinereis Nuntia

Perinereis nuntia brevicirrus (Grube 1857), collected from a rocky shore at Qingdao (China) were cultured under different temperature, daylength and moonlight regimes. Ripe individuals were found in the field after an increase of water temperature in early summer, with a semilunar spawning peak from the beginning of June to the end of September. In laboratory experiments, daylength has no influence on maturation and reproduction. Temperature-controlled culture produces gravid, reproducing specimens at any time of the year after an increase in water temperature. For reproduction both sexual partners leave their burrows and swarm at the water surface in the early morning, performing a nuptial dance. The spawning behaviour, the nuptial dance and the release of gametes, are controlled by sex pheromones which are present in the coelomic fluid of mature worms. A sex pheromone from Platynereis dumerilü, 5-methyl-3-heptanone, is found in Perinereis nuntia brevicirrus and causes an increase in swimming activity during reproduction and the release of a small amount of sperm from males. This signal induces the release of eggs by the females followed by the release of masses of sperm by the male due to a second female pheromone.

scholarly journals Assessment of Water Quality and Thermal Stress for an Artificial Fish Shelter in an Urban Small Pond during Early Summer

Water ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 139
Author(s):  
Chang Hyuk Ahn ◽  
Saeromi Lee ◽  
Ho Myeon Song ◽  
Jae Roh Park ◽  
Jin Chul Joo
Keyword(s):  
Water Quality ◽  
Thermal Stress ◽  
Water Temperature ◽  
Open Space ◽  
Phenomenological Study ◽  
Quality Parameters ◽  
Early Summer ◽  
Freshwater Ecosystem ◽  
Artificial Wetlands ◽  
Forced Circulation

: This study evaluated water quality variations in an artificial deep pool (ADP), which is an underground artificial structure built in a shallow pond as a fish shelter. The water temperature, pH, dissolved oxygen (DO), and electrical conductivity (EC) were measured on an hourly basis in the open space and inside the ADP, and a phenomenological study was performed, dividing seasons into normal and rainy seasons and environments into stagnant and circulating conditions. The results showed that the water quality parameters inside the ADP exhibit lower fluctuations and diurnal variations compared with the open space. On average, the water temperature inside the ADP is lower than outside it by 1.7–3.7 °C in stagnant conditions, and by 0.6–0.7 °C in circulating conditions during early summer. Thermal stratification occurs inside the ADP but is temporarily disturbed due to the mixing from the forced circulation and the rainwater input through rainfall events. The ADP provided a constant and optimal water temperature for living and spawning for bitterling (i.e., 15.0–21.0 °C), which dominated in experimental pond during spring to summer. Most importantly, the ADP was able to significantly reduce the thermal stress of the fish in the study site, and as a result, the bitterling, a cool water fish species, could successfully become dominant. Finally, the deployment of the ADP appears to provide a practical alternative for effective fishery resources management to improve species diversity and fish communities in an artificial freshwater ecosystem (garden pond, park pond, other artificial wetlands, etc.).

Comparative study of the life cycles of six species of Dinotoperla (Plecoptera: Gripopterygidae) in Victoria

1985 ◽  
Vol 36 (5) ◽  
pp. 717 ◽  
Author(s):  
C Yule
Keyword(s):  
Comparative Study ◽  
Life Span ◽  
Early Summer ◽  
Life Cycles ◽  
Temporary Pools ◽  
Severe Drought

The life cycles of six species of Dinotoperla were studied. One of these, D. bassae, only occurred in temporary pools; three species, D. thwaitesi, D. fontana and D. brevipennis, were found in intermittently flowing creeks; and these three species as well as D. eucumbene and D. christinae inhabited cool, permanent rivers. All the species were univoltine (except for D. eucumbene, which had a nymphal life span of 11-15 months). D. bassae, D. brevipennis, D. christinae and D. eucumbene had seasonal well-synchronized life cycles, although in times of severe drought the eggs of D. bassae may remain in diapause for 18 months or more. Emergence periods of all species were relatively restricted and were completed by early summer.

Some Aspects of the Ecology and Life Cycle of Three Species of Subtidal Sand-Burrowing Amphipods (Crustacea: Haustoriidae)

1969 ◽  
Vol 26 (5) ◽  
pp. 1321-1345 ◽  
Author(s):  
D. D. Sameoto
Keyword(s):  
Life Cycle ◽  
Water Temperature ◽  
Life Cycles ◽  
Cape Cod

The life cycles and some aspects of the ecology of the subtidal haustoriid amphipods Acanthohaustorius millsi Bousfield, Parahaustorius longimerus Bousfield, and Protohaustorius deichmannae Bousfield, found on Cape Cod, Massachusetts, are described. All species are annual breeders, the first two species having one brood of eggs and the last species more than one brood. The first ovigerous females appear when the water temperature reaches 5.5–10 C. All species migrate into the sands just below the low tide zone in May and remain there until late August when they start to migrate into deeper waters. The growth of populations of the three species found at Nobska Beach and Barnstable Harbor are discussed.

Study on the Impact of Water Environmental Factors on Dominant Species of Phytoplankton around the Power Plant in Xiangshan Bay

2012 ◽  
Vol 610-613 ◽  
pp. 3371-3374 ◽  
Author(s):  
Hong Yang ◽  
Ying Zhao ◽  
Hui Rong Zhang ◽  
Gui Xiang Dai ◽  
Jun Ding ◽  
...  
Keyword(s):  
Power Plant ◽  
Environmental Factors ◽  
Statistical Model ◽  
Water Temperature ◽  
Temperature Increase ◽  
Dominant Species ◽  
Thermal Discharge ◽  
Xiangshan Bay ◽  
The Impact ◽  
Growth And Reproduction

The SPSS19.0 software was used to analyse the data of enclosure experiments last for 7 days in summer of 2011. Water temperature increase as a factor to establish the statistical model, and the response relation of thermal discharge warming and Coscinodiscus Jonesianus biomass was analyzed quantitatively. The results showed that, it would promote Coscinodiscus Jonesianus growth and reproduction with the water warming at 0.2°C to 0.79°C , which would be restrained at the water warming at 0.8°C to 2.0°C. When the water temperature increase 0.1°C, 0.4°C and 0.7°Cwill respectively result in Coscinodiscus Jonesianus biomass grow 216.12%, 72.87% and 15.05%. While the water temperature increase 1.0°C, 1.5°C and 2.0°C will respectively result in Coscinodiscus Jonesianus biomass reduce 6.38%, 17.95% and 26.17%.

Life cycles of four species of Pseudocalanus in Nova Scotia

1989 ◽  
Vol 67 (3) ◽  
pp. 552-558 ◽  
Author(s):  
I. A. McLaren ◽  
Estelle Laberge ◽  
C. J. Corkett ◽  
J.-M. Sévigny
Keyword(s):  
Life Cycle ◽  
Nova Scotia ◽  
First Generation ◽  
Early Summer ◽  
Life Cycles ◽  
The Arctic ◽  
Late Winter ◽  
Early Winter ◽  
Temperature Dependent ◽  
Scotian Shelf

The primarily arctic Pseudocalanus acuspes, relict in Bedford Basin, Nova Scotia, produces a first generation (G1) in late winter; most G1 individuals mature in late spring. The G1 then produces a G2, most of which "rest" in copepodite stages III and IV until early winter. These stages store large amounts of lipid in early summer, which slowly diminish subsequently. A small number of G2 individuals continue to develop at temperature-dependent rates, maturing in early autumn and producing G3 adults in November. Copepodites developing in winter and spring store less lipid. The primarily arctic Pseudocalanus minutus, rare in Bedford Basin and on the Scotia Shelf, is strictly annual, developing to a lipid-filled copepodite stage V after spawning in late winter. The arctic–temperate Pseudocalanus newmani is abundant on the Scotian Shelf, but may not be self-sustaining when advected into Bedford Basin. It stores little lipid and appears to have at least three mature generations at temperature-dependent intervals over Browns Bank between May and November. It may rest in winter, or its life-cycle synchrony by spring could result from food-limited development during winter. The temperate Pseudocalanus moultoni appears to have a life cycle similar to that of P. newmani, but was less common during summer on Browns Bank. These life cycles are appropriately adapted to the geographical ranges of the species, and show some parallels with species of Calanus.

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