Nematodes, nauplii larvae, copepods, acari and gastrotrichs were recorded at all stations.
Even some groups such as kinorhynchs, cumaceans and polychaetes were not recorded in the lower layers, while copepods and gastrotrichs had a wider vertical distribution.
planktophilus apparently exploits nutrients from interstitial pore water, a world occupied by protozoans, diatoms, foraminifera, fiatworms, gastrotrichs
, nematodes, copepods, molluscs, tardi grades, and bacteria that thrives at the boundary of the reduced oxygen layer (Levinton, 1995).
Gastrotrichs figure prominently in metazoan phylogeny because they share a suite of complex morphological characteristics with several other members of the Bilateria, including the Gnathostomulida and the Nematoda.
This cladistic analysis also provides evidence that many characters used to define gastrotrichs in morphology-based phylogenies of extant Metazoa often are apomorphic for the phylum and, therefore, inappropriate.
Oblique striation has been described for muscles of platyhelminths, nematodes, gastrotrichs
, nematomorphs, priapulids, pogonophora, chaetognathes, annelids, molluscs, brachiopods, and an echinoderm (3-7, 9), and dense bodies are an obvious feature in all taxa.