三亚珊瑚礁水域纤毛虫种类组成和数量分布及与环境因子的关系

The relationships between ciliate composition,abundance,and environmental factors in Sanya Bay coral reef waters

2004年8月通过对三亚珊瑚礁水域纤毛虫进行表、底层采集分析,共鉴定6纲14目33属58种浮游纤毛虫,其中旋毛纲41种,叶口纲6种,寡膜纲5种,叶咽纲4种,前口纲和伪纤毛纲各1种。在14个目中,以旋毛纲环毛亚纲砂壳目纤毛虫种类最多,达到31种。主要优势种为布氏拟铃虫Tintinnopsis bütschlii、小拟铃虫Tintinnopsis minuta、丁丁急游虫Strombidium tintinnodes和具沟急游虫Strombidium sulcatum等,底层纤毛虫数量和种类都较表层高,底、表层平均丰度分别为375个/L和346个/L,表、底层纤毛虫种类差异明显,表层主要由浮游纤毛虫组成,以旋毛纲环毛亚纲砂壳目纤毛虫为主,急游目纤毛虫次之;而底层主要由缘毛目组成,如长圆靴纤虫Cothurnia oblonga、透明鞘居虫Vaginicola crystalline、钟虫Vorticella sp.以及吸管目的壳吸管虫Acineta sp.等。结果显示,在活珊瑚覆盖率高的站位(S4,S7和S9)纤毛虫数量明显低于珊瑚覆盖率低或没有珊瑚覆盖的站位,这暗示了珊瑚对纤毛虫的摄食作用。典型对应分析结果表明,影响三亚湾海域纤毛虫分布的主要因素有Chla、颗粒悬浮物SS和活性磷,以及水体溶解有机碳含量。通过对纤毛虫数量与环境因子关系的分析表明,三亚湾珊瑚礁水域纤毛虫的数量与叶绿素呈明显的正相关性。

Sanya Bay is located in the southernmost of Hainan Island,located 109 ° 20′—109 ° 30′E,18°11′—18°18′N,with sea area of about 120 km^2,and water depth from 5 to 20m,it is an open tropical bay,and also an important part of national coral reef reserve.Ciliates and environmental factors in coral reef waters in Sanya Bay were sampled and analyzed during August 22 to 26,2004.Fifty-eight species of ciliates representing 33 genera,14 orders and 6 classes（41,6,5,4,1and 1 one species,respectively from Spirotrichea,Phyllopharyngea,Litostomatea,Oligohymenophorea,Pseudociliatea and Prostomatea） were recorded.,Tintinnids predominated in terms of species richness and numerical abundance,with 31 species Tintinnopsis minuta,T.bütschlii,T.tubolosa and T.tocantinencis were dominant followed by Strombidium tintinnodes,S.sulcatum and Laboea strobila.Generally,ciliates were more abundant and diverse in the bottom waters of Sanya Bay relative to surface waters,with average abundances of 375 cell/L and species 38 ciliates,346 cell/L and 39 species in the bottom water and surface water,respectively.Surface waters were dominated by planktonic ciliates,primarily Tintinnina and Stombidiida.In contrast,ciliate species belonging to the orders Suctorida（such as Acineta sp.） and Peritrichida predominated in bottom waters,this is because the study area are shallow coral reef waters,coral substrate by the impact of accounting for a certain number of attached ciliates.The distribution of ciliate abundance at surface and bottom water show a similar trend,there are two orders of high-value areas,a high value area appears in the northwest central part between the Dongmao Island and the Ximao Island,another high value area appears in the Sanya River mouth.While the spatial distribution of chlorophyll a content had the similar trend of ciliate abundance.DOC concentrations in study waters are in high level,and accounting for 90% of TOC.Our results show that at stations with higher live coral cover,such as station S9,S4,and S7,the abundance of ciliates was significantly lower than other stations with little or low coral coverage.Suggesting the role of coral feeding on the ciliates are.There was a significant positive correlation between concentration of chlorophyll a（Chl a） and ciliate abundance.Our canonical correspondence analysis study also showed that there was a positive correlation between ciliates abundance and the DOC concentration.The DOC concentration was also correlated with bacterial biomass.Ciliates such as Eutintinnus fraknoii and Mesodinium pulex like to live in more suspended particles waters,while many species prefer to live in low suspended particles and the clear waters,as seen in Amphorellopsis acuta,Codonellopsis ostenfeldi and Helicostomella subulta etc.The Tontonia gracillima and Dadayiella acutiformis live environment with high PO4-P,while S.acutum and T.bütschlii like high chla water.Most of the other species live in low chlorophyll a waters,and with lower abundance,but also it can be seen,these ciliates are planktonic oceanic species.We conclude that Chl a,suspended solids,phosphate,and dissolved organic carbon are the main factors affecting the distribution of ciliates in the waters over the coral reef in Sanya Bay.