1) Tiny sea creatures 
in soil science, animals that are one centimetre or more long but smaller than an earthworm. Potworms, myriapods, centipedes, millipedes, slugs, ... [2 related articles]
typically refers to larger animals that can be seen without a microscope. Organisms in the macrofauna are usually larger than 1 mm in size.
Animals large enough to be seen with the naked eye. ... (09 Oct 1997) ... 
macrofauna 1. Widely distributed fauna. 2. Fauna of a macrohabitat (a habitat that contains a variety of environments and ecological niches capable of supporting a wide range of plants and animals). 3. In zoology, animals visible to the naked eye. —Word Info image © Copyright, 2006.
Animals whose shortest dimension is greater than or equal to 0.5 mm