Intraspecific chemical communication in microalgae

Abstract

Contents 516I.516II.518III.518IV.521V.523VI.523VII.526526References526 Summary The relevance of infochemicals in the relationships between organisms is emerging as a fundamental aspect of aquatic ecology. Exchanges of chemical cues are likely to occur not only between organisms of different species, but also between conspecific individuals. Especially intriguing is the investigation of chemical communication in microalgae, because of the relevance of these organisms for global primary production and their key role in trophic webs. Intraspecific communication between algae has been investigated mostly in relation to sexuality and mating. The literature also contains information on other types of intraspecific chemical communication that have not always been explicitly tagged as ways to communicate to conspecifics. However, the proposed role of certain compounds as intraspecific infochemicals appears questionable. In this article, we make use of this plethora of information to describe the various instances of intraspecific chemical communication between conspecific microalgae and to identify the common traits and ecological significance of intraspecific communication. We also discuss the evolutionary implications of intraspecific chemical communication and the mechanisms by which it can be inherited. A special focus is the genetic diversity among conspecific algae, including the possibility that genetic diversity is an absolute requirement for intraspecific chemical communication.

Are Drosophila preferences for yeasts stable or contextual?

“…Chemical communication between organisms is ancient and regulates a variety of important intraspecific (Leonhardt, Menzel, Nehring, & Schmitt, ; Venuleo, Raven, & Giordano, ) and interspecific biological interactions within ecological networks (Archie & Theis, ; Pickett & Khan, ). Behavioral responses to olfactory stimuli can be both learned and intrinsic (Bergström, ), and natural selection may operate on traits that are heritable and correlate with fitness for both signal sender and receiver (West, Griffin, & Gardner, ).…”

Intraspecific interactions between algae with different nutritional histories

“…They may consequently interact competitively (see Venuleo et al. for a recent review on the topic). Different competitive performances of the two populations coming in contact may determine a bias on the prevailing genotype in the resulting population.…”

“…Different phenotypes may derive from access to different resources, resulting in different patterns of nutrient allocation and, ultimately, composition and functions. The coexistence of different phenotypes originated through such mechanisms can occur when conspecific cells from two different populations get in contact after the breakdown of a geographical barrier or in boundary zones, between chemically physically distinct areas, with intermediate properties (Venuleo et al 2017). In both cases, algae with distinct histories come to coexist in a communal environment that is different from those of origin.…”

Different Nutritional Histories Affect the Susceptibility of Algae to Grazing

“…Since the prey‐predator relationship between diatoms and copepods is a crucial driver of the energy transfer in the ocean (Runge , Legendre ), our results may have important implications for trophic webs when heterogeneous conspecific cells get in contact, as, for instance, at boundaries between (micro)habitats not divided by geographical barriers (Venuleo et al. and reference therein). Considering that cell composition and environment are strictly related, the nutritional history of algae emerges as a major determinant of the relationships between algae and grazers.…”

“…In our study, the intraspecific diversity among different populations of prey was solely phenotypic, but the same basic arguments could be applied to the coexistence of genotypically distinct populations (see Venuleo et al. and reference therein for cases in which algal populations composed of heterogeneous conspecific cells can be generated).…”