mesoplankton
/ˌmɛsə(ʊ)ˈplaŋ(k)tən/Biology
noun
Plankton inhabiting the region between about 200 metres (approx. 670 feet) from the sea floor and 200 metres from the surface. More generally: relatively large microplankton.
Origin
Late 19th century. From meso- + plankton.