Studies On Taxonomy And Distributions Of Tintinnids In Several Different Seas

Microzooplankton is a key trophic group in pelagic ecosystems, as theseorganisms consume most of the primary production. Tintinnids are one of the bestknown groups of planktonic ciliates because of their loricae, which make themconspicuous in plankton samples and permit species identification. Although usuallynot the dominant component of the microzooplankton, tintinnids are regarded as modelsfor marine plankton research, as more is known about tintinnids than most any othergroup of microzooplankters (Dolan et al.,2013). In this study, a check list ofcontemporary living tintinnids around the world was compiled according toreferences available since Kofoid&Campbell (1929). Based on this work, we studiedthe distribution of tintinnid communities in South China Sea, Jiaozhou Bay,Kongsfjorden (Svalbard, Arctic), Tokara Strait, near Celebes Sea and coast off CostaRica. Besides, a long-term monitoring was conducted on tintinnid communities inJiaozhou Bay from May2003to December2012.Check list of contemporary tintinnid speciesA check list of contemporary living tintinnid (Ciliophora, Spirotrichea, Tintinnida)ciliates around the world was compiled according to available references since Kofoid&Campbell (1929). A total of931species belonging to67genera and15families werelisted in marine and fresh waters all over the world. Among them,900species live inmarine habitats and31species live in fresh water biotopes. Tintinnopsis is the mostabundant genus (141species). In China,163species including20species in freshwaters, belonging to36genera and13families, have been recorded. There were9species, namely Codonella crater, Stenosemella lacustris, Tintinnidium ephemeridum,Tintinnidium ranunculi, Tintinnidium semiciliatum, Tintinnopsis fusiformis,Tintinnopsis illinoisensis, Tintinnopsis ovalis, and Tintinnopsis cylindrata, living infresh waters in the list were not recorded in China. In the list, Chinese species name were given, of which159were adopted from the present literatures.We found a new tintinnid ciliate species, Tintinnopsis estuariensis in the YangtzeRiver estuary, China in2005. Its arenaceous lorica is cylindro-conical in shape,(120–180)×(50–75) μm in size, agglutinated with mineral particles, and open at both ends.Therefore, we assigned it to the genus Tintinnopsis (Phylum Ciliophora, ClassSpirotrichea, Subclass Choreotrichia, Order Tintinnida, Family Codonellidae). Twocharacters distinguish it from its congeners: the unique lateral flattened posteriorportion with a vertical aboral opening and wider oral diameter. It occurred in water witha surface temperature of14–27°C and surface salinity of3.9–29.8.Ecological studies of tintinnid communities in different seasKongsfjordenWe studied the tintinnid communities in Kongsfjorden, Svalbard (Arctic) duringJuly2012, which is the first to provide quantitative, species-specific data about thetintinnids there. Eight morphotypes were found: Acanthostomella norvegica,Leprotintinnus pellucidus, Parafavella edentata, P. gigantea, Ptychocylis obtusa,Stenosemella spp., Tintinnopsis parvula, and Tintinnopsis spp. Total tintinnidabundance and biomass ranged from undetectable (<1ind L–1) to2435ind L–1and0to6.33μg C L–1, respectively. Tintinnid community composition, in terms of speciespresent, appeared uniform throughout the fjord. However, four species showed distinctvertical distributions: Tintinnopsis parvula occurred throughout the water column butshowed a peak at the surface; Tintinnopsis spp. occurred only in the upper30m; A.norvegica occurred in low abundance throughout the water column; and Stenosemellaspp. was not detected in surface waters. The vertical distribution of tintinnid speciesmay be influenced by the presence of glacier melt water. At the coastal station, thetintinnid community showed considerable temporal variation in total abundance andthe identity of the most abundant species. These changes were not related to tide-andwind-induced salinity shifts. The observed temporal and spatial variations suggest thatthe marine plankton community of the Kongsfjorden is highly dynamic and thattintinnids can be used to assess the variation of marine planktonic communities.Three sites around Pacific Ocean Primary investigation of tintinnid communities around the Pacific Ocean in TokaraStrait, near Celebes Sea and off the coast of Costa Rica. Twelve families,27genera,40species were found off coast of Costa Rica,10families,25genera,39species werefound in Celebes Sea, and10families24genera36species were found in Tokara Strait.Most of the tintinnids had hyaline loricae.South China SeaThe abundance, biomass and species richness of large tintinnids (>76m) in thenorthern South China Sea (in82stations in13sections) were investigated in October,2007. Totally22species in7genera were found, in which genus Tintinnopsis wasdominant in abundance. Seven species were new recorded for the South China Sea. Theabundance of tintinnids ranged from0to41768ind m-3, on average (28517244) indm-3, and their biomass ranged from0to609.92g C m-3, on average (42.75110.80)g C m-3. Compared with those in pelagic area, the abundance and biomass of tintinnidswere higher in coastal shallow waters in the east of Leizhou Peninsula, where the waterwas warmer, less salty and with more Chl a. Most species were distributed in patches.The species richness of all stations was from0to12. The abundance, biomass andspecies richness of tintinnids were closely related to Chl a concentration. Tintinnopsisschotti and T. radix were dominant species.A total of12species of tintinnids in7genera were found in the western SouthChina Sea in summer2007and2species (Eutintinnus elegans and Xystonellopsisbrandti) were recorded for the first time in South China Sea. The range of tintinnidsabundance was from0to11622ind m-2with an average of2218±2254ind m-2, andthe species richness was from0to6. Five dominant species were Cyttarocylisacutiformis, Cyttarocylis eucecryphalus, Xystonellopsis favata, Codonellopsismeridionalis and Rhabdonella conica, while the dominance index of R. conica washighest. R. conica was observed for the highest aggregation intensity, which meant thatit was more closely related to environmental changes. Cyttarocylis acutiformis and C.eucecryphalus had the lowest aggregation intensity and more evenly distributed. Boththe species diversity and species evenness in the western South China Sea were lowdue to the effect of a variety of monsoon, ocean currents and water masses, which indicated that tintinnids community were under an unstable state. Correlation analysisby SPSS software revealed no significant correlation among tintinnids abundance,species abundance and environment factors. The community structure wascharacterized by more pelagic species and more unstable in the western South ChinaSea than in the northern part of South China Sea. R. conica was considered as biologicalindicator species of water masses for its high average abundance and maximumabundance, high aggregation intensity and fine correlation with environmental factors.Long-term monitoring of tintinnid communities in Jiaozhou BaySeveral studies on tintinnids in Jiaozhou Bay have been conducted since1952, yetstudies focusing on temporal variation of tintinnid community are still lack. Long-termvariations in tintinnid abundance and species composition were investigated monthlyfor more than9years at4sites in Jiaozhou Bay (Yellow Sea) from May2003toDecember2012. A total of27species belonging to10genera were recorded. Amongthem genus Tintinnopsis has more species (15) than other genus, and the remaininggenera were represented by one or two species. Species richness at every sampling dateranged from0to21. At the monthly scale, tintinnid abundance reached maximum inJune from the minimum of January. Abundance stayed high in July and August, andthen went down to December. Species richness reached its maximum in August.Distinct clusters of tintinnid communities were revealed associated with differentmonths and seasonal patterns: Spring-summer cluster (February-June), Summer-autumn cluster (July-October), and winter cluster (November-January). Winter clusterswas tightest among the three clusters, which showed that the winter communities wererelatively stable. The structure of tintinnid communities changed dramatically duringJune-July and October-November.Temporally, tintinnid abundances increased from2004to2007, and thendecreased to2012. Spatially, tintinnid abundances were higher in inner bay than in outerbay. Tintinnid abundance was found positively correlated to temperature (p<0.01),while species richness was positively correlated to temperature (p<0.01) and negativelyto salinity (p<0.01). No correlation was found between Chl a and tintinnid abundanceor species richness. It was supposed there was a combined effect on the tintinnid communities from temperature and salinity. Tintinnopsis beroidea and Stenosemellanivalis are identified as the key species of tintinnid communities in Jiaozhou Bay andthe key factor for temporal variations of tintinnid abundance during2003–2012.