Mesopsammic

Therefore, the researches carried out by Prof. Vezio Cottarelli (Viterbo) in the mesopsammic marine environment of Mindoro Island and by Dr Mauro Daccordi (Verona) in the phreatic fresh water of Palawan Island, are quite interesting in this regard.

As is the case with mesopsammic representatives of other major taxa, interstitial nemertines constitute a unique biological grouping recognizable by specializations that are characteristic of mesopsammon (see Swedmark, 1964, for review of the nature of interstitial organisms).

Although about 45% of all adenophoran nematodes are interstitial, there are few morphological features that occur regularly in mesopsammic species and can be considered typical for a mesopsammic life, although their function is not always clear (Lorenzen 1986): A strongly bent tail with adhesive glands (nematodes normally lie on their side when moving), additional adhesive organs (e.g. in Epsilonematidae), a flexible, tapering "neck" region, extremely long setae (Thrichotheristus), aberrant position of amphids (Epsilonematidae), flattened body (rare, e.g. Neochromadora angelica).