 the macroinvertebrate key the macroinvertebrate key guides you through identification of a dragonfly larva or nymph using questions and photos the key begins with a quick check of other aquatic invertebrates to make sure you re on the right track with your specimen aquatic macroinvertebrates phylum  arthropoda  class insecta  we will focus on insects but there are other aquatic macroinvertebrates that are part of the phylum arthropoda such as subphylum crustacea for example crayfish phylum mollusca snails mussels clams phylum annelida leeches  if you re interested in identifying some of the other macroinvertebrates you might have found start here  aquatic macroinvertebrates that are insects and that inhabit north america include  anax junius lestes eurinus lestes eurinus prementum  enallagma civile ischnura verticalis callibaetis spp adult  callibaetis spp hydrometra spp belostoma flumineum tropisternus spp hydrophilus spp berosus spp family phryganeinae case family phryganeinae dragonflies order odonata suborder anisoptera  damselflies order odonata suborder zygoptera mayflies order ephemeroptera stoneflies order plecoptera true bugs order hemiptera dobsonflies fishflies alderflies order megaloptera water beetles order coleoptera caddisflies order trichoptera   mercury in watersheds  