scholarly journals Patterns and processes of free‐living and particle‐associated bacterioplankton and archaeaplankton communities in a subtropical river‐bay system in South China

2020 ◽  
Vol 65 (S1) ◽  
Author(s):  
Yongming Wang ◽  
Jie Pan ◽  
Jun Yang ◽  
Zhichao Zhou ◽  
Yueping Pan ◽  
...  
Keyword(s):  
South China ◽  
Free Living ◽  
Patterns And Processes

Distinct successional patterns and processes of free‐living and particle‐attached bacterial communities throughout a phytoplankton bloom

2020 ◽  
Vol 65 (8) ◽  
pp. 1363-1375 ◽  
Author(s):  
Huimin Xu ◽  
Dayong Zhao ◽  
Jin Zeng ◽  
Congcong Jiao ◽  
Zhongbo Yu ◽  
...  
Keyword(s):  
Bacterial Communities ◽  
Phytoplankton Bloom ◽  
Free Living ◽  
Patterns And Processes

Wieseria bicepes sp. nov. (Nematoda: Oxystominidae) from the South China Sea

Zootaxa ◽  
2020 ◽  
Vol 4722 (4) ◽  
pp. 389-394
Author(s):  
SUSU JIA ◽  
YONG HUANG
Keyword(s):  
South China Sea ◽  
South China ◽  
The South China Sea ◽  
Present Species ◽  
Marine Nematodes ◽  
Congeneric Species ◽  
The South ◽  
Free Living ◽  
China Sea ◽  
Tail Tip

One unrecorded species of free-living marine nematodes from the South China Sea is described as Wieseria bicepes sp. nov. The present species is characterized by three circles of anterior sensilla nearly equal in length; four cephalic setae just behind the outer labial setae; oblong amphideal fovea with double contours and a handle-like protrusion at the base; tail tip bifurcate; spicules slightly curved with proximally cephalated and distally tapered; gubernaculum absent. The species is easily distinguished from the congeneric species by tail with a bifurcate tip and cephalic setae closely adjacent to labial setae. 

PATTERNS AND PROCESSES OF LATEST ORDOVICIAN GRAPTOLITE EXTINCTION AND RECOVERY BASED ON DATA FROM SOUTH CHINA

2005 ◽  
Vol 79 (5) ◽  
pp. 842-861 ◽  
Author(s):  
CHEN XU ◽  
MICHAEL J. MELCHIN ◽  
H. DAVID SHEETS ◽  
CHARLES E. MITCHELL ◽  
FAN JUN-XUAN
Keyword(s):  
South China ◽  
Patterns And Processes

Three new free-living marine nematode species of Dorylaimopsis (Nematoda: Araeolaimida: Comesomatidae) from the South China Sea and the Chukchi Sea

Zootaxa ◽  
2019 ◽  
Vol 4608 (3) ◽  
pp. 433 ◽  
Author(s):  
SUJING FU ◽  
DANIEL LEDUC ◽  
YIYONG RAO ◽  
LIZHE CAI
Keyword(s):  
South China Sea ◽  
South China ◽  
Chukchi Sea ◽  
The South China Sea ◽  
Valid Species ◽  
Marine Nematode ◽  
The South ◽  
Free Living ◽  
Pharyngeal Bulb ◽  
China Sea

Three new species of the free-living marine nematode genus Dorylaimopsis are described from the South China Sea and the Chukchi Sea. Dorylaimopsis longispicula sp. n. is characterized by cuticle with lateral differentiation consisting of four longitudinal rows of larger dots in pharyngeal and tail regions, two rows of larger dots elsewhere, long curved spicules, and 12–16 tubular precloacal supplements. Dorylaimopsis boucheri sp. n. is characterized by lateral differentiation consisting of 3–4 longitudinal rows of larger dots in males and 4–6 rows in females, beginning about 30 μm posterior to amphids and terminating at the conical portion of the tail, 13–16 tubular precloacal supplements, and distal part of tail cylindrical without terminal setae. Dorylaimopsis jinyuei sp. n. is characterized by cuticle with lateral differentiation in the form of longitudinal rows of larger dots in two separate regions, not along entire body. One region is from posterior edge of amphid to anterior of intestine or anterior border of pharyngeal bulb in some females (4–7 longitudinal rows), the other is the tail region (5–7 longitudinal rows). In this paper, Dorylaimopsis metatypica Chitwood, 1936 is transferred to Hopperia because it is characterized by lateral differentiation consisting of larger, irregularly-distributed coarse dots (as in Hopperia), and Hopperia communis Gagarin & Nguyen, 2006 is transferred to Dorylaimopsis based on the presence of longitudinal rows of coarse dots and a cylindrical buccal cavity in most specimens of this species. A dichotomous key to valid species of Dorylaimopsis Ditlevsen, 1918 is provided. 

Trematode behaviours and the perceptual worlds of parasites

2004 ◽  
Vol 82 (2) ◽  
pp. 292-315 ◽  
Author(s):  
M V.K Sukhdeo ◽  
S C Sukhdeo
Keyword(s):  
Life Histories ◽  
Empirical Studies ◽  
Host Finding ◽  
Free Living ◽  
Theoretical Predictions ◽  
Neuromuscular Systems ◽  
Innate Behaviour ◽  
Complex Patterns ◽  
Patterns And Processes ◽  
Trematode Parasites

There is a great deal of empirical data and theoretical predictions on the patterns and processes of trematode behaviour, particularly in relation to host-finding activities by the free-living stages and site-finding migrations by the parasitic stages within their hosts. Ecological and evolutionary models of trematode life histories often make explicit assumptions about how these organisms must perceive and respond to signals in their worlds as they move from host to host and as they parasitize each host. Nevertheless, it is unclear how natural selection shapes the parasites' behavioural strategies. In addition, at each stage in their life cycle, trematodes are adorned with elaborate sensory organs and possess sophisticated neuromuscular systems, but it is not clear how they use these complex machinery to perceive their worlds. The purpose of this review is to address this question through insights gathered from a century of research on trematode behaviour. Core theoretical assumptions from modern animal behaviour are used to provide the context for this analysis; a key concept is that all animals have unique perceptual worlds that may be inferred from their behaviours. A critical idea is that all animals possess complex patterns of innate behaviour which can be released by extremely specific signals from the environment. The evidence suggests that trematode parasites live in ecologically predictable aquatic and internal host environments where they perceive only small subsets of the total information available from the environment. A general conclusion is that host finding in miracidia and cercaria, and site-finding by trematodes migrating within their definitive hosts, is accomplished through the release of innate patterns of behaviours which are adaptive within the context of conditions in the worm's environment. Examples from empirical studies are used to support the contention that, despite the apparent complexity of their free-living and parasitic environments, the perceptual worlds of trematodes are impoverished, and complex patterns of behaviour may be released by only a few signals in their environment.

scholarly journals Characterization of particle-associated and free-living bacterial and archaeal communities along the water columns of the South China Sea

2020 ◽  
Author(s):  
Jiangtao Li ◽  
Lingyuan Gu ◽  
Shijie Bai ◽  
Jie Wang ◽  
Lei Su ◽  
...  
Keyword(s):  
South China Sea ◽  
Microbial Communities ◽  
South China ◽  
Deep Ocean ◽  
Archaeal Community ◽  
The South China Sea ◽  
The South ◽  
Free Living ◽  
China Sea ◽  
Archaeal Communities

Abstract. There is a growing recognition of the role of particle-attached (PA) and free-living (FL) microorganisms in marine carbon cycle. However, current understanding of PA and FL microbial communities is largely on those in the upper photic zone, and relatively fewer studies have focused on microbial communities of the deep ocean. Moreover, archaeal populations receive even less attention. In this study, we determined bacterial and archaeal community structures of both the PA and FL assemblages at different depths, from the surface to the bathypelagic zone along two water column profiles in the South China Sea. Our results suggest that environmental parameters including depth, seawater age, salinity, POC, DOC, DO and silicate play a role in structuring these microbial communities. Generally, the PA microbial communities have relatively low abundance and diversity compared with the FL microbial communities at most depths. Further microbial community analysis revealed that PA and FL fractions generally accommodate significantly divergent microbial compositions at each depth. The PA bacterial communities mainly comprise members of Actinobacteria and γ-Proteobacteria, together with some from Bacteroidetes, Planctomycetes and δ-Proteobacteria, while the FL bacterial lineages are mostly distributed within α-, γ-Proteobacteria, Actinobacteria and Bacteroidetes, along with certain members from β-, δ-Proteobacteria, Planctomycetes and Firmicutes. Moreover, there is an obvious shifting in the dominant PA and FL bacterial compositions along the depth profiles from the surface to the bathypelagic deep. By contrast, both PA and FL archaeal communities dominantly consist of Marine Group II (MGII) and Marine Group I (MGI), together with variable minor Marine Group III (MGIII), Methanosarcinales, Marine Benthic Group A (MBG-A) and Woesearchaeota. However, the pronounced distinction of archaeal community compositions between PA and FL fractions are observed at finer taxonomic level. A high proportion overlap of microbial compositions between PA and FL fractions implies that most microorganisms are potentially generalists with PA and FL dual lifestyle for versatile metabolic flexibility. In addition, microbial distribution along the depth profile indicates a potential vertical connectivity between the surface-specific microbial lineages and those in the deep ocean, likely through microbial attachment to sinking particles.

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