Preliminary report on the nematofauna of the Chuuk Islands, southwest Pacific Ocean

Abstract

The main goal of this survey is to study and evaluate the nematofauna around the Chuuk Islands, southwest Pacific Ocean. The nematodes were obtained from the washings of shallow subtidal coarse sediments and shell gravels, which were collected from two to 35 m deep by SCUBA diving around Chuuk Islands. Samples were filtered through a 67 ㎛ mesh sieve in the field after freshwater rinsing for less than a minute to reduce osmotic shock, and then fixed in 4% buffered formalin in sea water. Specimens were transferred to anhydrous glycerin and mounted in anhydrous glycerin between two coverslips on H-S slides. Nematodes were observed and photographed with an Olympus BX51 microscope equipped with Nomarski differential interference contrast and a Nikon Coolpix 990 digital camera. The digital images were manipulated with Adobe Photoshop V7.0. In the present study, a taxonomic survey was carried out in order to see nematode fauna of the Chuuk Islands. As a result of the present study, a total of 30 taxa of free-living marine nematodes are now known to occur in this area. In this report, a total of 30 species are listed with differential interference contrast (DIC) photomicrographs and ecological remarks. This is the first scientific survey of the free-living marine nematodes recorded from the Chuuk Islands, southwest Pacific Ocean.