scholarly journals Polyp expansion of passive suspension feeders: a red coral case study

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7076 ◽  
Author(s):  
Sergio Rossi ◽  
Lucia Rizzo ◽  
Jean-Claude Duchêne
Keyword(s):  
Water Temperature ◽  
Laboratory Experiments ◽  
Prey Capture ◽  
Driving Forces ◽  
Water Movement ◽  
Maximum Activity ◽  
Current Speed ◽  
Passive Suspension ◽  
Suspension Feeders ◽  
Biological Variables

Polyp activity in passive suspension feeders has been considered to be affected by several environmental factors such as hydrodynamics, water temperature and food concentration. To better elucidate the driving forces controlling polyp expansion in these organisms and the potential role of particle concentration, the octocoral Corallium rubrum was investigated in accordance with two approaches: (1) high-frequency in-situ observations examining various environmental and biological variables affecting the water column, and (2) video-recorded flume-controlled laboratory experiments performed under a range of environmental and biological conditions, in terms of water temperature, flow speed, chemical signals and zooplankton. In the field, C. rubrum polyp expansion correlated positively with particle (seston and zooplankton) concentration and current speed. This observation was confirmed by the flume video records of the laboratory experiments, which showed differences in polyp activity due to changes in temperature and current speed, but especially in response to increasing nutritional stimuli. The maximum activity was observed at the highest level of nutritional stimulus consisting of zooplankton. Zooplankton and water movement appeared to be the main factors controlling polyp expansion. These results suggest that the energy budget of passive suspension feeders (and probably the benthic community as a whole) may rely on their ability to maximise prey capture during food pulses. The latter, which may be described as discontinuous organic matter (dead or alive) input, may be the key to a better understanding of benthic-pelagic coupling processes and trophic impacts on animal forests composed of sessile suspension feeders.

scholarly journals Polyp expansion of passive suspension feeders: a red coral case study

2019 ◽  
Author(s):  
Sergio Rossi ◽  
Lucia Rizzo ◽  
Jean-Claude Duchêne
Keyword(s):  
Water Temperature ◽  
Laboratory Experiments ◽  
Prey Capture ◽  
Driving Forces ◽  
Water Movement ◽  
Flow Speed ◽  
Current Speed ◽  
Passive Suspension ◽  
Suspension Feeders ◽  
Biological Variables

Polyp activity in passive suspension feeders has been linked to several environmental factors such as hydrodynamics, water temperature and food concentration. To better elucidate the driving forces controlling polyp expansion in these organisms and the potential role of particle concentration, the octocoral Corallium rubrum was investigated in accordance with two approaches: 1) High-frequency in-situ observations testing various environmental and biological variables affecting the water column, and 2) Video-recorded flume-controlled laboratory experiments performed under a range of environmental and biological conditions in terms of water temperature, flow speed, chemical signals and zooplankton. In the field, C. rubrum polyp activity correlated positively with particle (seston and zooplankton) concentration, which was related to current speed. This observation was confirmed by the flume video records of the laboratory experiments, which showed differences in polyp activity due to changes in temperature and current speed, but especially in response to nutritional stimuli and the presence of zooplankton. Zooplankton and water movement appeared to be the main factors controlling polyp expansion. These results suggest that the energy budget of passive suspension feeders (and probably the benthic community as a whole) may rely on their ability to maximise prey capture during food pulses. The latter, which may be described as discontinuous organic matter (dead or alive) input, may be the key to a better understanding of benthic-pelagic coupling processes and trophic impacts on animal forests composed of sessile suspension feeders.

scholarly journals Polyp expansion of passive suspension feeders: a red coral case study

2019 ◽  
Author(s):  
Sergio Rossi ◽  
Lucia Rizzo ◽  
Jean-Claude Duchêne
Keyword(s):  
Water Temperature ◽  
Laboratory Experiments ◽  
Prey Capture ◽  
Driving Forces ◽  
Water Movement ◽  
Flow Speed ◽  
Current Speed ◽  
Passive Suspension ◽  
Suspension Feeders ◽  
Biological Variables

Polyp activity in passive suspension feeders has been linked to several environmental factors such as hydrodynamics, water temperature and food concentration. To better elucidate the driving forces controlling polyp expansion in these organisms and the potential role of particle concentration, the octocoral Corallium rubrum was investigated in accordance with two approaches: 1) High-frequency in-situ observations testing various environmental and biological variables affecting the water column, and 2) Video-recorded flume-controlled laboratory experiments performed under a range of environmental and biological conditions in terms of water temperature, flow speed, chemical signals and zooplankton. In the field, C. rubrum polyp activity correlated positively with particle (seston and zooplankton) concentration, which was related to current speed. This observation was confirmed by the flume video records of the laboratory experiments, which showed differences in polyp activity due to changes in temperature and current speed, but especially in response to nutritional stimuli and the presence of zooplankton. Zooplankton and water movement appeared to be the main factors controlling polyp expansion. These results suggest that the energy budget of passive suspension feeders (and probably the benthic community as a whole) may rely on their ability to maximise prey capture during food pulses. The latter, which may be described as discontinuous organic matter (dead or alive) input, may be the key to a better understanding of benthic-pelagic coupling processes and trophic impacts on animal forests composed of sessile suspension feeders.

Capture of conspecific planktonic larvae by the suspension-feeding gastropod Crepipatella peruviana: association between adult and larval size

2021 ◽  
Vol 87 (1) ◽  
Author(s):  
G A Rivera-Figueroa ◽  
J A Büchner-Miranda ◽  
L P Salas-Yanquin ◽  
J A Montory ◽  
V M Cubillos ◽  
...  
Keyword(s):  
Laboratory Experiments ◽  
Larval Mortality ◽  
Feeding Preference ◽  
The Other ◽  
Suspension Feeding ◽  
Adult Size ◽  
Free Living ◽  
Larval Size ◽  
Suspension Feeders ◽  
Planktonic Larvae

ABSTRACT Free-living, planktonic larvae can be vulnerable to capture and ingestion by adult suspension-feeders. This is particularly the case for larvae that settle gregariously in benthic environments where suspension-feeders occur at high densities. Larvae of gregarious suspension-feeding species are at particularly high risk, as adults of their own species often serve as cues for metamorphosis. We conducted laboratory experiments to assess the extent to which adults of the suspension-feeding caenogastropod Crepipatella peruviana would capture and ingest their own larvae. Experiments were conducted with adults of different sizes, with larvae of different ages and sizes, and in the presence or absence of phytoplankton. Adults captured larvae in all experiments. The presence of microalgae in the water did not influence the extent of larval capture. On average, 39% of larvae were captured during the 3-h feeding periods, regardless of adult size. However, up to 34% of the larvae that were captured on the gill were later discarded as pseudofaeces; the other 64% were ingested. The extent of capture by adults was not related to adult size, or to larval size and, thus, to larval age. Our results suggest that the filtration of congeneric larvae by adult C. peruviana is a result of accidental capture rather than a deliberate feeding preference. Such ingestion could, however, still be an important source of larval mortality, especially when the advanced larvae of this species are searching for a suitable substrate for metamorphosis.

The Influence of Current Speed, Body Size and Water Temperature On the Filtration Rate of Five Species of Bivalves

1972 ◽  
Vol 52 (2) ◽  
pp. 345-374 ◽  
Author(s):  
P. R. Walne
Keyword(s):  
Body Size ◽  
Water Temperature ◽  
Filtration Rate ◽  
Current Speed ◽  
Suitable Method ◽  
Water Filtration ◽  
Water Current ◽  
Water Requirements ◽  
Important Species ◽  
Shellfish Culture

The rate of water filtration by bivalves has long excited interest, but it has in practice proved difficult to measure in conditions where the animal is relatively free from constraint. Its estimation is important from a number of aspects: feeding studies; as an indicator of the animal's reaction to its environment; and for predicting the flow of water required for the culture of economically important species. The work reported in this paper started as part of the general programme on shellfish culture in progress at this laboratory. During the development of a suitable method for studying the water requirements it became clear that one factor, water current, had a more important influence than has been generally recognized.

The effects of age, temperature, light quantity and wavelength on the swimming behaviour of the cercariae of Cryptocotyle lingua (Digenea: Heterophyidae)

Parasitology ◽  
1992 ◽  
Vol 105 (1) ◽  
pp. 131-137 ◽  
Author(s):  
J. G. Rea ◽  
S. W. B. Irwin
Keyword(s):  
Life Span ◽  
Water Temperature ◽  
Light Source ◽  
Laboratory Experiments ◽  
Temperature Dependent ◽  
Release Point ◽  
Successful Transmission ◽  
Active Life ◽  
Light Quantity ◽  
Precipitous Decline

Laboratory experiments indicated that the active life-span of the cercariae of Cryptocotyle lingua was temperature-dependent. An increase in water temperature and population age both correlated with a tendency for the organisms to become decaudate. The larvae were strongly photoresponsive to lateral light but with time, horizontal swimming rates (HSRs) from release point to light source progressively declined. When measured over a range of light quantities, HSRs peaked at 30 μM/m2/s. HSRs were also influenced by water temperature. A rapid increase occurred up to 15 °C after which there was a precipitous decline. HSRs to coloured light were negatively correlated with increasing wavelength. When offered a choice between colours, cercariae favoured the shorter wavelengths. The implications of these responses for successful transmission are discussed.

scholarly journals Fleshy Red Algae Mats Influence Their Environment in the Mediterranean Sea

2021 ◽  
Vol 8 ◽  
Author(s):  
Neele Schmidt ◽  
Yusuf C. El-Khaled ◽  
Felix I. Roßbach ◽  
Christian Wild
Keyword(s):  
Environmental Factors ◽  
Light Intensity ◽  
Water Temperature ◽  
Mediterranean Sea ◽  
Water Column ◽  
Red Algae ◽  
Water Movement ◽  
Ecosystem Engineer ◽  
Overlying Water ◽  
The Mediterranean

In the Mediterranean Sea, the fleshy red alga Phyllophora crispa forms dense mats of up to 15 cm thickness, mainly located on rocky substrates in water depths below 20 m. Because of the observed density of these mats and some first observations, we hypothesize that P. crispa is a yet undescribed ecosystem engineer that provides a multitude of ecological niches for associated organisms along small-scale environmental gradients. Therefore, we conducted an in-situ pilot study in the Western Mediterranean Sea to assess potential influence of the algae mats on the key environmental factors water movement, temperature and light intensity. We comparatively and simultaneously measured in P. crispa mats, in neighboring Posidonia oceanica seagrass meadows, on neighboring bare rocky substrates without algae mats, and in the directly overlying water column. We used several underwater logging sensors and gypsum clod cards. Findings revealed that P. crispa significantly reduced water movement by 41% compared to the overlying water column, whereas water movement was not affected by P. oceanica meadows and bare rocky substrates. Surprisingly, P. crispa increased the water temperature by 0.3°C relative to the water column, while the water temperature in P. oceanica and on bare rocky substrates was reduced by 0.5°C. Light intensity inside the red algae mats was reduced significantly by 69% compared to the water column. This was similar to measured light reduction of 77% by P. oceanica. These findings highlight the strong influence of the dense red algae mats on some key environmental factors. Their influence is obviously similar or even higher than for the well-known seagrass ecosystem engineer. This may be a factor that facilitates associated biodiversity similarly as described for P. oceanica.

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.

Causes of Soil Salinization, Sodification, and Alkalinization

2017 ◽  
Author(s):  
Elisabeth N. Bui
Keyword(s):  
Ion Exchange ◽  
Driving Forces ◽  
Water Movement ◽  
Soil Salinization ◽  
Natural Soil ◽  
Sodic Soils ◽  
Mineral Equilibria ◽  
Evaporative Concentration ◽  
Soluble Ions ◽  
Alkaline Conditions

Driving forces for natural soil salinity and alkalinity are climate, rock weathering, ion exchange, and mineral equilibria reactions that ultimately control the chemical composition of soil and water. The major weathering reactions that produce soluble ions are tabled. Where evapotranspiration is greater than precipitation, downward water movement is insufficient to leach solutes out of the soil profile and salts can precipitate. Microbes involved in organic matter mineralization and thus the carbon, nitrogen, and sulfur biogeochemical cycles are also implicated. Seasonal contrast and evaporative concentration during dry periods accelerate short-term oxidation-reduction reactions and local and regional accumulation of carbonate and sulfur minerals. The presence of salts and alkaline conditions, together with the occurrence of drought and seasonal waterlogging, creates some of the most extreme soil environments where only specially adapted organisms are able to survive. Sodic soils are alkaline, rich in sodium carbonates, with an exchange complex dominated by sodium ions. Such sodic soils, when low in other salts, exhibit dispersive behavior, and they are difficult to manage for cropping. Maintaining the productivity of sodic soils requires control of the flocculation-dispersion behavior of the soil. Poor land management can also lead to anthropogenically induced secondary salinity. New developments in physical chemistry are providing insights into ion exchange and how it controls flocculation-dispersion in soil. New water and solute transport models are enabling better options of remediation of saline and/or sodic soils.

scholarly journals Autecology of Shallow-Water Octocorallia from Mediterranean Rocky Substrata, I. The Banyuls Area

1979 ◽  
Vol 49 (1) ◽  
pp. 1-15 ◽  
Author(s):  
Steven Weinberg
Keyword(s):  
Water Temperature ◽  
Experimental Work ◽  
Ecological Niche ◽  
Water Movement ◽  
Abiotic Factors ◽  
Scuba Diving ◽  
Survival Strategy ◽  
Field Observations ◽  
Southern France ◽  
Juvenile Stages

The autecology of eleven mediterranean octocoral species (3 Stolonifera, 4 Alcyonacea, 4 Gorgonacea) was studied near Banyuls-sur-Mer (southern France). Field observations were carried out by means of SCUBA-diving in forty underwater stations. The ecological amplitude of each species was determined for a number of abiotic factors, viz. water temperature, submarine irradiance, water movement, slope of substratum and sediment. In this way the ecological niche for the different species was defined. The niches of several species partly overlap: the survival “strategy” of these species was defined as “competitivity”. Other species display “specialization”, a strategy by which they avoid competitive situations. A third survival mechanism is “opportunism”, encountered in species which are extremely tolerant with respect to their environment. Although experimental work is needed to determine how niche selection occurs, larval and juvenile stages are considered to be critical in this respect.

Sign in / Sign up

Export Citation Format

Share Document