We tested experimentally the hypothesis that prevailing locomotion/feeding strategies and body morphology may lead to more active dispersal of free-living marine nematodes, besides passive transport. Neutral Red was applied to the sediment inside cores and the red plume formed during the flood tide was divided into near, middle, and distant zones. At 0.5 m and 1 m from the stained cores, sampling nets were suspended 5 and 10 cm above the sediment-water interface. Dispersion behaviors were defined as a function of a) the numbers of stained recaptured nematodes in comparison to their mean densities in the sediment, b) movement in the sediment or swimming in the water column, and c) body morphology. Tidal currents with average velocities of 9 cm/s resuspended the numerically dominant nematode taxa Sabatieria sp., Terschellingia longicaudata de Man, 1907, Metachromadora sp. and Viscosia sp. The recapture of stained nematodes as far as 2 m from the original stained cores showed that, despite their small body size, they can disperse through relatively large distances, either passively or actively, via the water column during a single tidal event. Recapture patterns in the sediment and in the water column indicate that nematode dispersal is directly influenced by their body morphology and swimming ability, and indirectly by their feeding strategies, which ultimately define their position in the sediment column. Besides stressing the role played by passive transport in the water column, our experiment additionally showed that mobility and feeding strategies also need to be considered as determinant of short-scale nematode dispersal.
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机译：我们通过实验验证了以下假设：主要的运动/进食策略和身体形态可能导致除被动运输外，更自由地散布自由活动的线虫。在岩心内部的沉积物上施加了中性红，洪潮期间形成的红羽被分为近，中和远区域。在距染色核心0.5 m和1 m处，将采样网悬挂在沉积物-水界面上方5 cm和10 cm处。分散行为定义为以下函数：a）染色的重新捕获线虫的数量与其在沉积物中平均密度的比较，b）在沉积物中的运动或在水柱中游泳，以及c）身体形态。平均速度为9 cm / s的潮汐流重新悬浮了数字优势线虫类群Sabatieria sp。，Terschellingia longicaudata de Man，1907，Metachromadora sp。和Viscosia sp。从原始染色核中重新捕获染色的线虫（最远距离为2 m）表明，尽管它们的体型很小，但在一次潮汐事件中，它们可以通过水柱被动或主动分散较大的距离。沉积物和水柱中的捕获方式表明，线虫的扩散直接受其身体形态和游动能力的影响，而间接受其摄食策略的影响，最终决定了它们在沉积物柱中的位置。除了强调被动运输在水柱中的作用外，我们的实验还表明，流动性和进食策略也应考虑作为短程线虫扩散的决定因素。
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