A dataset on trophic modes of aquatic protists

Abstract

An important functional trait of organisms is their trophic mode. It determines their position within food webs, as well as their function within an ecosystem. For the better part of the 20th century, aquatic protist communities were thought to consist mainly of producers (phytoplankton) and consumers (protozooplankton). Phytoplankton cover their energy requirements through photosynthesis (phototrophy), while protozooplankton graze on prey and organic particles (phagotrophy). However, over the past decades, it was shown that another trophic group (mixoplankton) comprise a notable part of aquatic protist communities. Mixoplankton employ a third trophic mode by combining phototrophy and phagotrophy (mixotrophy). Due to the historical dichotomy, it is not straightforward to gain adequate and correct information on the trophic mode of aquatic protists. Long hours of literature research or expert knowledge are needed to correctly assign trophic modes. Additionally, aquatic protists also have a long history of undergoing taxonomic changes which make it difficult to compare past and present literature. While WoRMS, the World Register of Marine Species, keeps track of the taxonomic changes and assigns each species a unique AphiaID that can be linked to its various historic and present taxonomic hierarchy, there is currently no machine-readable database to query aquatic protists for their trophic modes. This paper describes a dataset that was submitted to WoRMS and links aquatic protist taxa, with a focus on marine taxa, to their AphiaID and their trophic mode. The bulk of the data used for this dataset stems from (routine) monitoring stations in the North Sea and the Baltic Sea. The data were augmented and checked against state-of-the-art knowledge on mixoplankton taxa by consulting literature and experts. Thus, this dataset provides a first attempt to make the trophic mode of aquatic protists easily accessible in both a human- and machine-readable format.

Kleptoplast distribution, photosynthetic efficiency and sequestration mechanisms in intertidal benthic foraminifera

“…Mixotrophic growth involving the acquisition and functionalization of prey chloroplasts in the host is a widespread trait among protists [ 24 – 26 , 74 ], which can have a significant impact in the microbial food web [ 26 ]. Although the role of foraminiferal mixotrophy has been mostly investigated in planktonic communities (e.g.…”

Cell carbon content and biomass assessments of dinoflagellates and diatoms in the oceanic ecosystem of the Southern Gulf of Mexico

“…In the northern Gulf of Mexico, Gyrodinium has been observed ingesting chain-forming diatoms and is described as a major component of microzooplankton [ 54 ]. Although the taxonomic analysis in this study did not fully allow classifying all the dinoflagellate genera measured and counted in each cruise according to trophic mode, a substantial fraction of carbon biomass (~70%) can be attributed to mixotrophic and heterotrophic genera based on descriptions in the literature [ 47 , 55 , 56 ]. This observation suggests that carbon biomass produced in the euphotic zone by diatoms or other autotrophic cells might be transferred to higher trophic levels through these nano- and micro-sized dinoflagellate genera; hence, they are likely to play a major role as consumers within food webs in SGoM ecosystem.…”

Eco-Evolutionary Perspectives on Mixoplankton

“…Studying mixotrophy in its different forms offers an opportunity to gain a better understanding of major ecological and evolutionary processes that have been crucial in the creation of life as we know it today. Mixotrophy has not only been pivotal in the past with visible effects still identifiable today (such as the establishment of permanent organelles through endosymbiosis), but also it is still a prevalent biological phenomenon with a considerable fraction of marine plankton identified as mixoplankton (Flynn et al, 2019;Schneider et al, 2020; Figure 1). In mixotrophic organisms, we may have a glimpse of how life used to look in the past, and how things could change in the future.…”