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Scientific Name

Match	Scientific Name
	Animalia

This common name refers to only one kingdom.

Animal Kingdom Animalia

These are pretty much always called Animals.

Metazoa is the kingdom of animals. Worms are metazoans and so were the dinosaurs. Trout and mayflies are metazoans. You are probably a metazoan.

See Arthropoda for most of the invertebrates trout eat, or skip straight to the insect orders Ephemeroptera (Mayflies), Trichoptera (Caddisflies), or Plecoptera (Stoneflies), which are the three most important.

The non-arthropod classes are listed on this site only to hold pictures, so far, and I haven't put much information up yet about them.

Platyhelminthes (Flatworms) Flatworm

View 5 PicturesThis specimen is in the subphylum Turbellaria, a non-parasitic flatworm.

Collected June 13, 2019 from in
Added to Troutnut.com by on June 15, 2019

Baetisca obesa (Armored Mayfly) Mayfly Nymph

View 12 Pictures

Collected May 6, 2007 from in
Added to Troutnut.com by on May 10, 2007

Corydalus (Dobsonflies) Hellgrammite Larva

View 27 Pictures

Collected May 29, 2007 from in
Added to Troutnut.com by on June 4, 2007

Female Ephemera guttulata (Green Drake) Mayfly Dun

View 16 PicturesIt's about time I got a green drake on this site!

Collected June 1, 2007 from in
Added to Troutnut.com by on June 4, 2007

Male Ephemerella aurivillii Mayfly Spinner

View 15 PicturesThis spinner molted from a dun after being photographed, and the dun form is listed here as a separate specimen. I've rarely found a more cooperative and photogenic mayfly.

Collected July 10, 2011 from in
Added to Troutnut.com by on July 16, 2011

Rhyacophila (Green Sedges) Caddisfly Pupa

View 11 PicturesI collected this pupa and several like it from the same stream and on the same day as this larva. I suspect they're the same species. Every pupa I collected was in a brown casing like the one shown in one of the pictures below. I cut this pupa out of its case after a picture so you can see more details. It is close to but not fully developed.

Collected June 5, 2005 from in
Added to Troutnut.com by on May 25, 2006

Cambaridae Crayfish Juvenile

View 2 Pictures

Collected January 13, 2004 from in
Added to Troutnut.com by on January 25, 2006

Hydropsyche aenigma (Spotted Sedge) Caddisfly Adult

View 18 PicturesThese big caddisflies were tempting trout as they wriggled out of their shucks (

View Full Size

Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.), while others skated across the water at a medium pace, probably egg-laying.

Collected May 15, 2007 from in
Added to Troutnut.com by on May 18, 2007

See 1243 more specimens...

Jargon Defined:

Dun: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.

Larva: Many classes of aquatic insects, such as caddisflies, midges, craneflies, dobsonflies, alderflies, and many more, are known as "larvae" rather than "nymphs" in their juvenile stages. They have mostly soft bodies rather than hard exoskeletons. These insects also advance through a "pupa" stage before reaching adulthood.

Pupa: Any insect which spends most of its juvenile lifetime as a larva first becomes a pupa for a time before emerging as a fully grown adult. Depending on the species, the pupal form can be very important for fly fishermen to imitate.

View Full Size

Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shucks: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.

Spinner: There are two winged stages of adult mayflies. They emerge from the water as duns, molt on land (usually) into their fully mature stage, spinners. As spinners, they mate, lay eggs, and die.