» Phylum Arthropoda (Arthropods)
This is page 3 of specimens of Arthropoda. Visit the main Arthropoda page for:
- The behavior and habitat of Arthropoda.
- 122 underwater pictures of Arthropoda.
- 4 streamside pictures of Arthropoda.
Pictures of 1058 Arthropod Specimens:
Male Nixe inconspicua Mayfly Dun
View 13 PicturesThis pretty little dun was part of a sparse midsummer evening hatch on a large Catskill river.
I could not identify it by following a species key step by step, but I tentatively keyed it to the genus Nixe, and based on distribution maps and physical descriptions the most likely species is Nixe inconspicua.
Argia Damselfly Nymph
View 3 PicturesMy friend Willy captured this early 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.) damselfly nymph and brought it to me for identification. It is more robust and stocky at this early stage than the spindly appearance of the later instars (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.), and its appearance is less familiar. Male Rhithrogena virilis Mayfly Spinner
View 12 PicturesI'm fairly sure this is a specimen of Rhithrogena virilis based on closeup examination of the reproductive anatomy under the microscope (not shown in photos). The other other species of Rhithrogena this large is Rhithrogena flavianula, but the key in Needham's Biology of Mayflies mentions annulation in the abdomen (visible in some images on bugguide.net) more distinct than that on this specimen.
The body and front wing were both about 15.5 mm long, while the cerci (Cercus: The left and right "tails" of an insect are known as the cerci or caudal cerci. The middle tail of a three-tailed insect is not.) were 40 mm long.
Hydropsyche aenigma (Spotted Sedge) Caddisfly Adult
View 18 PicturesThese big caddisflies were tempting trout as they wriggled out of their shucks (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.