» Phylum Arthropoda (Arthropods)
Common Name
This is page 8 of specimens of Arthropoda. Visit the main Arthropoda page for:
- The behavior and habitat of Arthropoda.
- 122 underwater pictures of Arthropoda.
Pictures of 1244 Arthropod Specimens:
Brachycentrus (Grannoms) Caddisfly Pupa
View 10 PicturesThe green blob contained in this case is a pupa in the early stages of transformation from larva to the final stage we generally picture and imitate. This specimen and several like it were fixed to a rock I picked up, and each one had the front of its case sealed off, protecting the helpless pupa from predation. It's neat to see the insect part-way through such a radical transformation.
It was very hard to extract this thing from its case, so there's a bit of extra goo near the head from where I accidentally punctured it. 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. Female Amphinemura (Tiny Winter Blacks) Stonefly Adult
View 5 PicturesA few of these tiny stoneflies were among the only species of aquatic insect adults in the air on this particular afternoon, with most of the action coming from a species of Epeorus mayfly. I somehow forgot to photograph this one on the usual ruler, but I recall it was very, very small, with an abdomen no more than 1mm in girth and the body, not counting the wings, probably just 5-7mm long.