Maccaffertium vicarium (March Brown) Mayfly Nymph Pictures

Mayflies

Caddisflies

Stoneflies

Classification

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Heptageniidae (March Browns, Cahills, Quill Gordons)

» Genus Maccaffertium (March Browns and Cahills)

» Species vicarium (March Brown)

I photographed this Maccaffertium vicarium nymph shortly after it molted to a new instar (Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.) in my holding container. Many nymphs take on drastically different coloration immediately after molting, and this species is no exception.

This mayfly was collected from the Beaverkill River on April 19th, 2006 and added to Troutnut.com on April 21st, 2006.

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Maccaffertium vicarium (March Brown) Mayfly Nymph from the Beaverkill River in New York

AuthorTroutnut

CameraCanon EOS 20D

View Full Size and Comment (2X larger)

AuthorTroutnut

CameraCanon EOS 20D

View Full Size and Comment (2X larger)

AuthorTroutnut

CameraCanon EOS 20D

View Full Size and Comment (2X larger)

AuthorTroutnut

CameraCanon EOS 20D

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Jargon Defined:

Instar: Many invertebrates molt through dozens of progressively larger and better-developed stages as they grow. Each of these stages is known as an instar. Hard-bodied nymphs typically molt through more instars than soft-bodied larvae.

Molting: When aquatic insects with hard exoskeletons (like mayfly and stonefly nymphs) grow bigger, their exoskeleton does not grow with them. Instead they grow a new, larger one underneath and shed the old one when it's too small. This process is called molting.

Nymph: The juvenile, underwater stages of mayflies, stoneflies, dragonflies, and damselflies and other aquatic insects whose juvenile stages are covered by hard exoskeletons. The word can also refer to the fishing flies which imitate these creatures, in which case it is used as a blanket term for flies imitating any underwater stage of an invertebrate (except for crayfish and leeches).