Department of Biology, University of Texas at San Antonio, San Antonio, Texas, United States of America.
PLoS One. 2011 Jan 6;6(1):e14491. doi: 10.1371/journal.pone.0014491.
Nematodes occur regularly in macrobenthic samples but are rarely identified from them and are thus considered exclusively a part of the meiobenthos. Our study compares the generic composition of nematode communities and their individual body weight trends with water depth in macrobenthic (>250/300 µm) samples from the deep Arctic (Canada Basin), Gulf of Mexico (GOM) and the Bermuda slope with meiobenthic samples (<45 µm) from GOM. The dry weight per individual (µg) of all macrobenthic nematodes combined showed an increasing trend with increasing water depth, while the dry weight per individual of the meiobenthic GOM nematodes showed a trend to decrease with increasing depth. Multivariate analyses showed that the macrobenthic nematode community in the GOM was more similar to the macrobenthic nematodes of the Canada Basin than to the GOM meiobenthic nematodes. In particular, the genera Enoploides, Crenopharynx, Micoletzkyia, Phanodermella were dominant in the macrobenthos and accounted for most of the difference. Relative abundance of non-selective deposit feeders (1B) significantly decreased with depth in macrobenthos but remained dominant in the meiobenthic community. The occurrence of a distinct assemblage of bigger nematodes of high dry weight per individual in the macrobenthos suggests the need to include nematodes in macrobenthic studies.
线虫通常存在于大型底栖生物样本中，但很少从这些样本中鉴定出来，因此被认为是小型底栖生物的一部分。我们的研究比较了来自北极深海（加拿大盆地）、墨西哥湾（GOM）和百慕大斜坡的大型底栖 (>250/300 µm) 样本与来自 GOM 的小型底栖 (<45 µm) 样本中线虫群落的属组成及其个体体重趋势。所有大型底栖线虫个体的干重（µg）随水深的增加呈上升趋势，而 GOM 小型底栖线虫个体的干重则呈下降趋势。多元分析表明，GOM 的大型底栖线虫群落与加拿大盆地的大型底栖线虫群落更为相似，而与 GOM 的小型底栖线虫群落则不相似。特别是 Enoploides、Crenopharynx、Micoletzkyia 和 Phanodermella 等属在大型底栖动物中占主导地位，占大部分差异。非选择性沉积物食者（1B）的相对丰度在大型底栖动物中随深度显著下降，但在小型底栖动物群落中仍占主导地位。大型底栖动物中存在大量高个体干重的大型线虫的明显组合，表明需要将线虫纳入大型底栖动物研究中。
