We are drawn riverward as we explore the riparian habitat along the river here in Pennsylvania's scenic mountains. Since we have our water shoes on, we'll wade out - and even dive - into this vast and enrapturing underwater world.
The West Branch Susquehanna River, right here at this location, seems almost devoid of life. At least at first glance. Actually, there is an abundance of a relatively few creatures (low biodiversity). This is a result of a combination of physical and abiotic factors, such as acidity... and of course the tolerances of the aquatic creatures.
Two of those abundant creatures are the aquatic insects are living on the rock shown in the photo below.
Another abundant inhabitant of this section of Susquehanna River are one kind of case-building caddisflies. These caddisfly larvae are also filter-feeders. The river brings them their food... all they do is snag it. These caddisfly larvae collect food particles by holding their legs up into the current - like the larva in the photo below (center right). The larva are equipped with combs on their legs which collect fine particulate organic matter, FPOM.
These caddisfly cases are present on many of the rocks in our river. They are more visible on the cobbles in the swift water.
I'll post more about the windsock caddisflies and those tiny, trumpet-shaped cases on the rocks in the near future. Oh, and notice the many tan "tents", or silk caddisfly nets, set up on the river bottom (photo above)... those are "way too cool" to pass up. I'll post about those as well.
Here is a previous post on aquatic life
What happens when a leaf falls into a stream