Study On Ciliate Abundance And Biomass In Yellow Sea

Planktonic ciliates are a kind of protozoa with the size of 5-200μm including Oligotrichina and Tintinnina. As an important component of microzooplankton, they are ubiquitous in marine environment and play an important role in the transfer of energy and material through the pelagic food web.In this paper the abundance, biomass, spacial and seasonal distribution of ciliate, species richness of tintinnid in Yellow Sea (including Jiaozhou Bay) were investigated during April 2006 to December 2007.The study methods were as follows. Water samples were taken using Rosette Niskin water samplers. One liter water samples were fixed with 1% acid Lugol iodine solution in plastic bottles. The samples were counted using Olympus CKX41 inverted microscope at 100×magnification after pre-concentration by serial settling method. To estimate the carbon biomass of ciliate, cell volume was calculated by measuring cell dimensions. The conversion factor to convert cell volume to carbon biomass was 0.19 pgC/μm3 for aloricate ciliates. For tintinnids, the body volume was equal to 1/3 of loricate volume.Results are:Jiaozhou Bay:Abundance and biomass of ciliate and species richness of tintinnid varied during 2007. The maximum abundance of total ciliates was 6065 ind./L in June and the minimum was 843 ind./L in December. The maximum biomass of total ciliates were 18.5μg C/L in August and the minimum were 0.6μg C/L in June. There were 25 species of tintinnid in August and 6 species in January. Abundance in the Bay was higher than that out of Bay all year except in June and August. Aloricate ciliates were absolutely dominant. The percentage of tintinnid to total ciliate was 8-57% (on average 25%).Central Yellow Sea:Abundance in surface in April (1490 ind./L) was higher than that in October (972 ind./L). Laboea strobila was patchy during both cruises with 0-10000 ind./L in April Cruise and 11-350 ind./L in October Cruise. Ptychocylis obtusa was only found in April Cruise with maximum abundance 2859 ind./L. Furthermore, in April Cruise abundance of Tintinnopsis beroidea was 0-1920 ind./L and Tintinnopsis karajacensis was 10-93 ind./L.In October Cruise, the biomass of total ciliates ranged from 0.14 to 5.33μg C/L. The most abundant species was Tintinnidium primitivum (35-700 ind./L). Amphorella acuta, Codonellopsis mobilis, Tintinnopsis tubulosoides, Favella spp. and Eutintinnus sp. were also found in October Cruise. Craterella torulata mainly distributed in station 15694 with abundance 0-120 ind./L. Ciliate occurred almost above thermocline, which appeard around 30 m depth.Thermocline appeared in May, June, August and September. During these months ciliate almost occurred above thermocline. Ciliate abundance were highest in August (3103 ind./L) and lowest in December (406 ind./L). The biomass of total ciliates ranged from 0.02 to 5.5μg C/L in spring and summer and from 0.04 to 1.99μg C/L in winter. Small aloricate ciliates were absolutely dominant. Tintinnopsis orientalis, Tintinnopsis tubulosoides, Codonellopsis mobilis were ubiquitous tintinnids. Craterella torulata and Tintinnidium primitivum appeared almost in all cruises.