Freshwater Invertebrate Underwater Pictures, Page 6

A large school of water boatman swims over a strange purple substance at a crystal clear spring.

In this picture: True Bug Family Corixidae (Water Boatmen).

There are a couple Epeorus mayfly nymphs clinging to this rock. One interesting thing I've noticed is that even though the stream has a lot of clingers, they rarely show up in my photos, and I've started paying more attention to the river bottom while I'm fishing I've noticed that clinger nymphs generally see or feel me coming and scurry to the undersides of their rocks before I can get in picture range. I think I have the same problem with stoneflies.

In this picture: Mayfly Genus Epeorus (Little Maryatts).

This is a close-up underwater view of a stillborn (

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This stillborn Ephemerella subvaria dun is trapped in its shuck.

Stillborn: In fly fishing, a stillborn insect is one which got stuck in its nymphal or pupal shuck during emergence and floats helplessly on the surface instead of flying away. It is a specific class of cripple, although it is sometimes used interchangeably with that term.) Ephemerella subvaria (Henrickson) female dun.

In this picture: Mayfly Species Ephemerella subvaria (Hendrickson).

There's a stonefly nymph in the bottom right corner of this picture, but what's really interesting is those white blotches. They're pretty common in my Wisconsin home river river, stuck flat onto the rocks--lots of rocks have a speckled look as a result. They are microcaddis cases, made by larvae of the caddisfly family Hydroptilidae. These are made by larvae of the subfamily Leucotrichiinae, most likely the genus Leucotrichia. They spin little flat oval cases of silk tight and immobile against the rocks.

In this picture: Caddisfly Species Leucotrichia pictipes (Ring Horn Microcaddis).

Several caddis larvae cling in the current amongst the debris collected on an underwater alder branch.

In this picture: Insect Order Trichoptera (Caddisflies).

A big crayfish lurks under a log.

In this picture: Arthropod Order Decapoda (Crayfish).

Several well-camouflaged Ephemerella mayfly nymphs cling to this log, and a few cased caddisfly larvae cling to the plant in front of it.

In this picture: Insect Order Trichoptera (Caddisflies) and Mayfly Genus Ephemerella (Hendricksons, Sulphurs, PMDs).

An Ephemerella subvaria nymph clings to a white rock in the foreground, and there are other nymphs in the background.

In this picture: Mayfly Species Ephemerella subvaria (Hendrickson) and Insect Order Trichoptera (Caddisflies).

Here's a view through the stationary den of a type of netspinning caddisfly larva.

In this picture: Insect Order Trichoptera (Caddisflies).