Study on the Origin of Deep-sea Hydrothermal Vent Communities at the Lau Back-Arc Basin, Southwest Pacific

2004年9月23日至11月10日，利用日本“新海6500”潜水器及其母船“横须贺”号对西南太平洋Lau和Havre弧后盆地深海热液喷口进行了形态学、生态学、地理学和分子生物学研究。“本研究项目的主要目标是阐明西南太平洋深海热液喷口和冷泉群落的起源和演化。根据我们对深海热液喷口和冷泉群落中双壳类等主成分的研究，与世界上其他此类喷口和冷泉群落相比，西南太平洋Lau和Havre弧后盆地拥有生物多样性较高的群落，腹足类、甲壳类（包括蟹、虾和藤壶）、蠕虫、管虫等，其中藤壶类在世界已知的深海喷口和渗漏区中表现出最高的多样性。 关于我们 我们可以找到所有四个亚目，Scalpellomorpha，Brachylepadomorpha，Verrucomorpha和Balanomorpha从刘盆地。Lau盆地的边缘地区，如北斐济和马努斯盆地，生物多样性处于第二高水平，除短鳞藤壶外，还有3个亚目。对Lau盆地和Havre盆地的藤壶进行了形态学研究，结果表明，刀鳞藤壶Ashikailepas具有最原始的形态特征，在西太平洋分布最广。对Lau盆地和Havre盆地的一些主要喷口动物进行了分子生物学研究与东太平洋、西太平洋（西北至西南）和印度洋组相比，Lau和Havre盆地显示出原始的系统发育地位。与两个日本和一个Havre种群相比，Ashinkailepas种群显示了分子进化中最原始的Scalpellomorph。因此，已知的喷口和渗漏群落的起源似乎是西南太平洋。少

This is report on the morphological, ecological, biogeographic and molecular biological studies for vent communities collected at our expedition to the deep-sea hydrothermal vents at the Lau and Havre Back-arc Basins, Southwest Pacific from September 23 to November 10,2004 using Japanese submersible "Shinkai 6500" and her mother ship "Yokosuka." The main target of this research project is to clarify origin and evolution of the deep-sea hydrothermal vent and cold seep communities of the Southwest Pacific.The Lau and Havre Back-arc Basins, Southwest Pacific hold communities of high biological diversity in comparison with other such vent and seep communities in the world based on our research of principal component in the deep-sea hydrothermal vent and seep communities such as bivalves, gastropods, crustaceans (including crabs, shrimps and barnacles), worms, tube-worms, etc. Particularly, barnacles in crustacean shown the highest diversity in the known deep-sea vent and seep of the world. … More We could found all four suborders, Scalpellomorpha, Brachylepadomorpha, Verrucomorpha, and Balanomorpha from the Lau Basin. And the peripheral areas of the Lau Basin such as North Fiji and Manus Basins show the second high biological diversity hold three suborders except Brachylepadomorpha.The morphological examination of barnacles collected from the Lau and Havre basins shows that scalpellomrphan barnacle Ashikailepas has the most primitive morphological characteristics and also the widest distribution at the West Pacific.The molecular biology of some principal vent animals collected from the Lau and Havre basins shown primitive phylogenetic position in comparison with the group of the East Pacific, West Pacific (Northwest to Southwest) and Indian Oceans. Ashinkailepas in comparison with two Japanese and one Havre populations population shows the most primitive Scalpellomorph in the molecular phylogeny. Therefore, the origin of the known vent and seep communities seems to be Southwest Pacific. Less