A study was done in River Ethiope in Nigeria to compare the types and amounts of tiny plant-like organisms in the water during the dry and rainy seasons. They found that different kinds of algae were more common in each season, with some types only appearing in the rainy season. The rainy season had more centric diatoms, while the dry season had more pennate diatoms. Aulacoseira spp. were the most common in the rainy season, while Desmidium aptogonium var. tetragonium and Fragillaria construens were dominant in the dry season. The researchers also noticed differences in the community structure of the phytoplankton in different parts of the river.