大窑湾养殖区赤潮甲藻孢囊种类组成及分布的研究

摘要

Dinoflagellate cyst in the Dayao Bay, southern Liaoning, where the scallops and oysters were largely cultivated, was investigated from 2006 to July 2007.10 species of dinoflagellate cysts in total were identified, which represented 4 general kinds of dinoflagellate cysts, including 2 species of Protoperidinioid, 5 species of Gonyaulacoid and 1 species of Calciodinellid.One species of Gymnodinioid, Ensiculifera Balech and one species of Fragilidium mexicanum of dinoflagellate cysts were freshly recorded in the sea area of China.Gonyaulacoid was the most common and abundant cyst type of all species of dinoflagellate cysts, which took up 50％, Protoperidinioid was 30％, Calciodinellid and Gymnodinioid were each 10％ respectively.One species of Protoperidinioid dinoflagellate cysts could not be identified to genus.Three species of dinoflagellate cysts belonged to heterotrophic dinoflagellate cysts, and seven belonged to autotrophic dinoflagellate cysts.Two species of cyst produced by toxic dinoflagellate (Alexandrium tamarense, A.catenella and Gymnodinium catenatum) were also recorded, which produced Paralytic Shellfish Poisoning.The seasonal change curve of dinoflagellate cysts density had two obviously fastigium, which occurred on January and August 2007.The first highest density of dinoflagellate cysts appeared in January 2007, 1090 cysts/g W, and the second highest appeared in August 2007, 855 cysts/g W.The lowest density of dinoflagellate cysts appeared in October 2007, only 280 cysts/g W.The average density of dinoflagellate cysts was 695.5 cysts/g W all the year.The value of Shannon-Weaver diversity index (H) varied between 0.17 to 0.55, which were similar on each month except on September and October 2007.The average of species diversity index was 0.46.%2006-2007年对大窑湾养殖区的甲藻孢囊进行了研究,结果检出10种甲藻孢囊,分属于4大类9种甲藻孢囊,其中原多甲藻类孢囊2种,膝沟藻类孢囊5种,钙质类孢囊1种,裸甲藻类孢囊1种,一种艉杆藻(Ensiculifera Balech)和一种易碎藻(Fragilidium mexicanum)是中国沿海新记录的两个种类,此外还有一种无法鉴定到种的一种原多甲藻孢囊.膝沟藻类孢囊的种类数占绝对优势,占50%,其次是原多甲藻类孢囊占30%,钙质类孢囊和裸甲藻类孢囊各占10%.10种孢囊中有3种异养型孢囊和7种自养型孢囊.并发现两种产麻痹性贝毒(PSP)的孢囊一塔玛亚历山大藻/链状亚历山大藻复合体(Alexandrium tamarense/A.catenella)和链状裸甲藻(Gymnodinium catenatum).孢囊密度的季节分布呈现明显的双峰型,在2007年1月份和2007年的8月份出现了两个高峰.2007年的1月份达到了调查全年的孢囊密度最高值,达到了1.09×103cysts/g湿重,2007年的8月份出现的第二次高峰期孢囊密度达到了0.86×103 eysts/g湿重.孢囊密度最低值出现在2007年的10月,只有280 eysts/g湿重.全年孢囊平均密度为695.5 cysts/g湿重.甲藻孢囊的多样性指数除了2007年的9月和10月以外,相差不大,变化范围为0.17-0.55,全年的平均值为0.46.