Faunal survey of benthic invertebrates of shallow water in southern part of Izu Peninsula

对伊豆半岛南部浅水区大型底栖动物进行了区系调查，重点研究了大型底栖动物的物种多样性和生态环境。通过疏浚，在50个覆盖不同深度（3 m-150 m）和栖息地（泥底到岩石海岸）的地点采集样本。收集了大约3000个无脊椎动物标本。优势动物为腹足类和双壳类软体动物、多毛类环节动物和蛇类。以下门（亚门）也被确认：poriferans，珊瑚虫和水螅虫刺胞动物，扁形动物，纽形动物，线虫，胃足类，双壳类，舟足类，polyplacophoran和头足类软体动物，星虫，echiurans，endoproctans，苔藓虫，关节和无关节腕足动物，lophophophorates，海百合，星，蛇，echinoid和海参棘皮动物，半索动物，尾索动物和头索动物。在日本大部分地区已经消失的枝口鱼和小舌鱼在这个地区被发现繁殖。发现了大量的濒危双壳类物种，如日本蝇、细脆蝇、厚壳蝇。此外，还发现了许多新的腹足类物种，如epitoniid和naticid腹足类，lepidopleurinanpolyplacophora和enteropleurinanhemicordate，其中一些类群似乎是该地区特有的。无脊椎动物区系以日本中南部太平洋沿岸分布的种类为主，保存了部分濒危和可能特有的无脊椎动物的基因组DNA。目前正在对这些样本进行分子遗传分析。

In the present study, a faunal survey of macro-benthos in shallow water of southern part of Izu peninsula, focusing on the species diversity and ecological habitat was carried out. Sampling was collected at 50 sites that cover various depth(3m-150m)and habitats(muddy bottom to rocky shore)by dredging. Approximately 3000 specimens of invertebrates was collected. Dominated animals were gastopod and bivalve molluscs, polychaet annelids and ophiuroids. Following phyla(subphyla)was also cofirmed : poriferans, anthozoan and hydrozoan cnidarians, platyhelminthes, nemerteans, nematode, gastopod, bivalve, scaphopod, polyplacophoran and cephalopodan molluscs, sipunculans, echiurans, endoproctans, bryozoans, articulare and inarticulate brachiopods, lophophorates, crinoid, asteroid, ophiuroid, echinoid and holothurian echinoderms, hemichordates, urochordate and cephalochordates. Branchyostoma and Lingula that have disappeared in most Japanese area are found to be reproducing in this area. A large population of some endangered bivalve species, Musculista japonica, M.perfragilis, Pitar japonicus, was discovered. In addition, many new species of various taxa, such as new species of epitoniid and naticid gastropods, lepidopleurinan polyplacophora and enteropneustan hemichordate were also discovered and some of these taxa seem to be endemic to this area. Major component of the invertebrates fauna are the species distributed in pacific coast of mid-southern area of Japan.Total genomic DNA of some endangered and possible endemic inveretebrates were preserved. Molecular genetic analysis on these samples is now in progress.