Effects of deposit-feeder gut passage and fecal pellet encapsulation on germination of dinoflagellate resting cysts

Abstract

Many species of dinoflagellates spend much of their lives buried in sediments as resting cysts. While on the bottom, cysts may pass through the guts of deposit feeders before conditions become favorable for germination. Little is known, however, about how dinoflagellate cysts are affected by deposit-feeder digestion, fecal pellet formation, and translocation within the sediment column. To answer the question of whether gut passage or pelletization reduces cyst germination, we fed cysts of the dinoflagellate Scrippsiella lachrymosa to 3 polychaete deposit feeders, Capitella sp., Streblospio benedicti, and Polydora cornuta. Fecal pellets of these species have different morphologies and represent a wide range of pellet robustness. To examine the effects of longer gut-passage times, cysts were incubated in the digestive fluids of the polychaete Arenicola marina for up to 24 h, and monitored to determine germination success. Cysts were remarkably resistant to digestion by deposit-feeding polychaetes, and were capable of germinating even within the robust fecal pellets of Capitella. In fact, cysts were more likely to germinate within fecal pellets of Capitella than outside those pellets. Thus, pellets may be favorable environments for germination of resting cysts. Our data suggest that deposit-feeder gut passage and pelletization do not substantially reduce germination of dinoflagellate cysts in the field, and may even enhance it.

Factors affecting spore germination in algae — review

“…Gussewa (1931) opined that bacteria in natural water cooperate in GRM of oospores of Oedogonium by digesting their cell wall. Cook (1962) observed that oospores in Bulbochaete hiloensis germinate when placed in tightly closed containers for several weeks and subjected to relatively warm temperature (bacterial and fungal decomposition was also observed under these conditions); Kremp et al (2003) found that deposit-feeder gut passage may enhance GRM of dinoflagellate cysts.…”

Buried alive – germination of up to a century-old marine protist resting stages

“…These two major marine algal groups make up an important part of the base of food webs, responsible for a large part of the primary productivity of aquatic ecosystems. Once present, the fate of testing stages is determined by physical, biological and sedimentological processes, such as degradation, prédation, bioturbation and burial (Keafer et al 1992;Kremp et al 2003;Persson & Rosenberg 2003).…”

Factors regulating the recruitment of cyanobacterial and eukaryotic phytoplankton from littoral and profundal sediments

“…Among cyanobacteria and diatoms, temperature, nutrients, and light have been shown to regulate germination (Hollibaugh et al 1981, Barbiero & Welch 1992, Hansson 1993, van Dok & Hart 1997. Recently, Ståhl-Delbanco & Hansson (2002) showed that bioturbation can enhance recruitment of akinete-forming cyanobacteria, and Kremp et al (2003) found that depositfeeder gut passage may enhance germination of dinoflagellate cysts. Moreover, there are both abiotic and biotic factors that can prevent germination.…”