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.
Kochi 0 0 0 Arthungal 366 996 0 Sakthi 0 0 0 Veli 0 0 0 Sakthi: Sakthikulangara; Nem: nematode; Poly: polychaete; Oligo: oligochaete; Turb: turbellarian; Hrpc: harpacticoid copepod; Gastro: gastrotrich
; Kinor: Kinorhyncha; Isop: isopod; Cnid: cnidarian.
The absence of a true midpiece evolved convergently in different metazoan phyla such as gastrotrichs
(Marotta et al., 2005) or chordates (Fukomoto, 1981).
A test of this idea might be to look for the expression of members of this gene family in the pharyngeal pores of macrodasyid gastrotrichs (Ruppert and Barnes, 1994) to see if the gene is responsible for pores or openings in the pharynx in general, rather than having an expression that is specific to deuterostome gill pores.
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).
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.
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.