Mucus-Trap-Assisted Feeding Is a Common Strategy of the Small Mixoplanktonic Prorocentrum pervagatum and P. cordatum (Prorocentrales, Dinophyceae)

Abstract

Prorocentrum comprises a diverse group of bloom-forming dinophytes with a worldwide distribution. Although photosynthetic, mixoplanktonic phagotrophy has also been described. Recently, the small P. cf. balticum was shown to use a remarkable feeding strategy by crafting globular mucus traps to capture and immobilize potential prey. Here we present evidence showing that two additional related species, the recently described P. pervagatum and the cosmopolitan bloom-forming P. cordatum, also produce large (80–120 µm) mucus traps supporting their mixoplanktonic activity. Prey are captured within the traps either through passive entanglement upon contact with the outside surface, or through active water movement created by rotating Prorocentrum cells eddying particles to the inside surface where trapped live prey cells became immobilized. Entrapment in mucus assisted deployment into the prey of a peduncle extruded from the apical area of the Prorocentrum cell. Phagotrophy by P. pervagatum supported faster growth compared to unfed controls and time series quantification of food vacuoles revealed ingestion rates of ca. 10–12 Teleaulax prey cells day−1. Model calculations show clear advantages of deploying a mucus trap for increasing prey encounter rates. This study demonstrates that the large size and immobilization properties of mucus traps successfully increase the availability of prey for small Prorocentrum species, whose peduncle feeding mode impedes consumption of actively moving prey, and that this strategy is common among certain clades of small planktonic Prorocentrum species.

The succession of epiphytic microalgae conditions fungal community composition: how chytrids respond to blooms of dinoflagellates

“…Mucilage secretion, a prominent feature of Ostreopsis and another microalgal species, provides structure to the epiphytic assemblage [ 72 , 73 ], and serves as a trap for prey acquisition [ 74 ]. In a recent study, it has been proposed that the mucilage acts as a protective barrier against chytrid infection in diatoms [ 75 ].…”

Prokaryotic communities across oceanic depths produce stable dissolved organic nitrogen

“…Indeed, the dominant phytoplankton species at the time of sampling was Prorocentrum sp. (Péquin et al 2022), a dinoflagellate known to exude transparent exopolymers, a class of compound rich in polysaccharides (Larsson et al 2022;Tillmann et al 2023).…”

Prorocentrum canariense sp. nov., a case of pseudo‐cryptic speciation in the cosmopolitan dinoflagellate P. compressum (Prorocentrales, Dinophyceae)

“…The use of mucus to trap prey is a strategy known in mixotrophic dinoflagellates (Blossom et al, 2012), and recent studies remarked on the role of the mucilage in the heterotrophic nutrition of species of the group of Prorocentrum cordatum (Larsson et al, 2022;Tillmann, Mitra, et al, 2023). In the case of P. canariense sp.…”