Centropages typicus(Crustacea, Copepoda) reacts to volatile compounds produced by planktonic algae

Abstract

Volatile organic compounds (VOCs) may play the role of infochemicals and trigger chemotaxis and ecologically relevant responses in freshwater and marine invertebrates. Aquatic grazers use these signals as chemical cues to trace the presence of their food or to detect their predators. However, detailed data are still needed to fully understand the role of these relationships in marine plankton. We investigated the ability of the copepod Centropages typicus to perceive the odour of three planktonic diatoms (Skeletonema marinoi, Pseudonitzschia delicatissima and Chaetoceros affinis) and a dinoflagellate (Prorocentrum minimum). This information is ecologically relevant for orientation, habitat selection, predator avoidance and communication. In addition, as the pH of the medium influences the perception of chemical cues in aquatic environments, we tested the effect of seawater acidification resulting from increasing levels of CO2, and its influences on the olfactory reactions of copepods. For this reason, our tests were repeated in normal (pH 8.10) and acidified (pH 7.76) seawater in order to simulate future ocean acidification scenarios. Using replicated chemokinetic assays we demonstrated that VOCs produced by Ps. delicatissima and Pr. minimum attract copepods at normal pH, but this effect is lowered in acidified water. By contrast, the odour of S. marinoi mainly induces a reaction of repulsion, but in acidified water and at higher concentrations this toxic diatom becomes attractive for copepods. Our experiments demonstrate, for the first time, that copepods are sensitive to the volatile compounds contained in various microalgae; VOCs prompt chemokinesis according to algal species and odour concentrations. However, seawater acidification induces changes in copepods' perception of odours. These findings highlight the sensitivity of chemically mediated interactions to global changes

Volatile Metabolites Emission by In Vivo Microalgae—An Overlooked Opportunity?

“…These failures included abortions, congenital malformation of offspring, and decreased larval growth, collectively contributing to securing the prey [ 185 ]. In a role reversal, VOCs produced by Pseudonitzschia delicatissima (planktonic diatom) and Prorocentrum minimum (dinoflagellate) attracted their predator, a zooplankton grazer, Centropages typicus , an example of negative allelopathy [ 186 ]. On the other hand, VOCs emitted by Skeletonema marinoi (another planktonic diatom) was favorable to the survival of the emitter by repelling the grazer and protecting the diatom [ 186 ].…”

“…In a role reversal, VOCs produced by Pseudonitzschia delicatissima (planktonic diatom) and Prorocentrum minimum (dinoflagellate) attracted their predator, a zooplankton grazer, Centropages typicus , an example of negative allelopathy [ 186 ]. On the other hand, VOCs emitted by Skeletonema marinoi (another planktonic diatom) was favorable to the survival of the emitter by repelling the grazer and protecting the diatom [ 186 ]. It was concluded that these VOCs prompt chemokinesis according to the particular type of microalgal species and the concentration of the VOCs being produced [ 186 ].…”

“…On the other hand, VOCs emitted by Skeletonema marinoi (another planktonic diatom) was favorable to the survival of the emitter by repelling the grazer and protecting the diatom [ 186 ]. It was concluded that these VOCs prompt chemokinesis according to the particular type of microalgal species and the concentration of the VOCs being produced [ 186 ].…”

Diatom‐produced allelochemicals trigger trophic cascades in the planktonic food web

“…1), thus forcing us to reject H3. The odor of phytoplankton may repulse (J€ uttner 2005) or attract pelagic crustaceans (Maibam et al 2015). The copepod Temora stylifera increased P. minimum ingestion rates in culture when exposed to 0.5 lM to 2 lM of 2E, 4E-decadienal (Ka et al 2014).…”

Современные Тенденции Развития Биологии Водных Экосистем

“…Оказалось, что копепод-диатомовые взаимо-действия сложнее: оксилипины диатомей влияют не только на репродукцию копепод, но и на уровень экспрессии стрессовых белков (белков теплового шока, каталазы, глутатион-S-трансферазы, альдегид-дегидрогеназы), обеспечивая тем самым ответную защитную реакцию консументов на молекулярном уровне. Недавно впервые показано [47], что летучие органические компоненты (VOCs, volatile organic compounds), выделяемые планктонными водорослями, могут восприниматься копеподами как сигналь-ные молекулы присутствия пищи, включая у них механизм хемотаксиса. Освобождающиеся VOC из бентосных диатомей, разрушенных в результате их поедания гастроподами, также воспринимаются как сигнал обнаружения пищи для других консументов [49].…”