Answer:
Hector is right
Step-by-step explanation:
The river ecosystem is one of the most dynamic ecosystems on the planet. this is mostly due to the unique nature of the rivers in their life as they change and transform along their courses from the sources to their mouths. River ecosystems change their characteristics in terms of composition and characteristics as they flow over different terrains, climates and regions. they vary according to their chemical composition, their exposure to light, their temperatures, their discharge, and the load that they carry. All these factors or a combination of these influence the type of species that will be found in a river ecosystem. However, the most common types include:
Bacteria, found in larger numbers in flowing than stagnated water. Bacteria exist in many forms such as free-living forms decomposing organic material, bio-film found on the surfaces of rocks and vegetation, suspended within the water column in the guts of parasites and other organisms and many more forms.
Primary producers mostly vegetation, phytoplankton and periphyton.
Other more complex organisms such as insects and other invertebrates can be found within the river ecosystem such as snails clams and crayfish. Fish and other vertebrates including amphibians, mammals and birds. In many rivers that connect the inland waters to the oceans, you might find fish and other species adopted to living in both salty and fresh water conditions during different stages of their development such as the salmon.