Spatial distribution of planktonic ciliates in the western Pacific Ocean: along the transect from Shenzhen (China) to Pohnpei (Micronesia)

Abstract

Planktonic ciliates have been recognized as major consumers of nano-and picoplankton in pelagic ecosystems, playing pivotal roles in the transfer of matter and energy in the microbial loop. However, due to the difficulties in identification, the species composition of ciliate assemblages, especially for the small, fragile, and naked species that usually dominate the ciliate communities in the oceanic waters, remains largely unknown. In the present study, 22 stations along the transect from Shenzhen (China) to Pohnpei (Micronesia) were sampled for the enumeration of picoplankton and nanoflagellates. In addition, pigment analysis of major phytoplankton groups along with the measurements of environmental variables including temperature, salinity, and nutrients were also carried out. Ciliates were identified at species level using quantitative protargol stain to reveal the species composition and their distribution patterns from off-shore to open ocean. Ciliate abundance was positively correlated with phosphate, silicate, and pico-sized pigmented eukaryotes (PPEs), whereas the biomass was closely related with PPEs, heterotrophic nanoflagellates, and chlorophytes. The combination of silicate and pigmented nanoflagellates was identified as the major factor driving the ciliate community composition. The close relationship between silicate and ciliate abundance and community structure needs further validation based on more data collected from oceanic waters. Our study showed the necessity of using techniques that can reveal the community composition at higher taxonomic resolutions in future studies on ciliates.

Genetic Diversity, Community Assembly, and Shaping Factors of Benthic Microbial Eukaryotes in Dongshan Bay, Southeast China

“…21% of total sequences and 10% of total OTUs counts, respectively. Class Spirotrichea comprises morphologically diverse groups of ciliates including naked oligotrichs and tintinnids that sometimes dominated microzooplankton community in both coastal areas and open ocean ( Lynn, 2008 ; Sun et al, 2017 , 2020 ; Huang et al, 2020 ; Xu et al, 2020 ; Yang et al, 2020 ). Based on the present and previous studies, this group of ciliates may play an important yet unclear ecological function in marine sediments.…”

Genetic Diversity in Marine Planktonic Ciliates (Alveolata, Ciliophora) Suggests Distinct Geographical Patterns – Data From Chinese and European Coastal Waters

“…In contrast to previous studies, our dataset is based on a material collection that complements a high temporal resolution (seasonal and daytime shifts) and large geographic distances between samples. Since the sea and the neritic regions are dynamic (Abboud-Abi Saab and Owaygen, 1998;Marteinsson et al, 2016;Huang et al, 2021) and highly structured horizontally and vertically (McManus and Woodson, 2012), environmental patchiness is a question of scale. Additionally, these regions are very heterogeneous for protists effecting together with community assembly processes a patchy distribution highly likely prone to undersampling.…”

Distribution Patterns of Ciliate Diversity in the South China Sea

“…It hosts strong gradients in physico-chemical environments and is known as an important hotspot of marine biodiversity (Chen et al, 2001;Huang et al, 2004;Li et al, 2017;Sun et al, 2019). Many studies on the diversity and distribution of ciliates have been conducted in the SCS in the last two decades (Su et al, 2007;Liu et al, 2010Liu et al, , 2016aTan et al, 2010;Wang et al, 2013Wang et al, , 2014Yu et al, 2014;Wu et al, 2016aWu et al, ,b,c, 2017Wu et al, , 2019Hu et al, 2019;Huang et al, 2021). However, most of these studies were conducted on a small local scale, such as estuaries, bays, and reef islands; this has resulted in knowledge that is more or less patchy, and the overall ciliate distribution pattern in the SCS is still poorly known.…”