OVERLAPPING MICROSCALE DISPERSION PATTERNS OF MEIOFAUNA AND MICROPHYTOBENTHOS

In an oyster pond on the French Atlantic coast microalgae genera and meiobenthos taxa (except turbellarians in May 1987 and single groups of harpacticoid copepods in April 1988) exhibited patchy distributions. Meiofauna patches ranged from <4-154 cm2, large diatom (>4 μm) patches from <4-113 cm2 and smaller cell (<40 μm) patches from <4-79 cm2. High variability in patch size was observed between taxa or genera, between years, and a 2nd aggregation level (small patches within large clumps) was shown by harpacticoid copepods. There were spatial associations among meiofauna and microphytobenthos assemblages but not with nanophytobenthos (cells <40 μm), but no very close overlap was detected and microphytobenthos was thought to only partially influence meiofauna dispersion. Selectivity of trophic interactions seems to exist and meiofauna spatial patterns may be generated by feeding preferences. -from Author