Brewster River

From WikiEducator
Jump to: navigation, search


Streams logo web.jpg Brewster River
Basin:Lamoille River
State or Province:Vermont
Country:USA
School:Johnson State College


The following are the most common invertebrates collected from this stream site.

Chironomidae

Chironomidae.jpg
Order
Diptera
Family
Chironomidae


Common name
Nonbiting midge
Tied fly
Griffith's Gnat
Midge larvae tend to be the most common macroinvertebrate at our sites. As with other Diptera, there are no true jointed legs. Chironomidae do have a pair of prolegs at each end and preserved individuals tend to curl into a 'C'. Identification past family requires slide-mounted heads. We have seen philopotamid caddisflies misidentified with the chironomids and we suspect that that happens when samples are being sorted from trays. Under a microscope, six prominent legs can be seen on members of the caddisfly family Philopotamidae.

More information on Philopotamidae.




Baetis

Baetis.jpg
Order
Ephemeroptera
Family
Baetidae
Genus
Baetis


Common name
The Little Olive
Tied fly
Sawyer Pheasant Tail Nymph
This mayfly has three "tails" and a unique head shape. Its gills are oval shaped and insert dorsally. More mature nymphs have long, dark wing pads.

Image of the long, dark wing pads.




Helicopsyche

Helicopsyche.png
Order
Trichoptera
Family
Helicopsychidae
Genus
Helicopsyche


Common name
snailcase caddisfly
This caddisfly genus has one local species. It looks rather like a snail but has lots of sand grains covering it's 'shell' which is really a case. The anal claws have closely-spaced teeth, much like a small comb.

Image of the closely-spaced teeth



Baetidae

Baetis.jpg
Order
Ephemeroptera
Family
Baetidae


Common name
Small minnow mayfly
Tied fly
Tiny blue-winged olive
This mayfly has either two or three cerci ("tails") and a unique head shape. Its gills are oval shaped and insert dorsally. Commonly encountered genera include Acerpenna, Baetis and Pseudocloeon.

More information on the genera:

Acerpenna

Baetis

Pseudocloeon




Drunella

Drunella Whole.jpg
Order
Ephemeroptera
Family
Ephemerellidae
Genus
Drunella


Tied fly
Bluewinged Olive Dun
The mayfly Drunella is distinguished by its large femoral “biceps;” these femora have tubercles on the leading margins. Gills are present on segments 3-7.



Psephenus

Psephenus.jpg
Order
Coleoptera
Family
Psephenidae
Genus
Psephenus


The true "water penny" is commonly found in the waters sampled. Psephenus has a rounded shape with relatively smooth edge. The false water penny, whose edges are serrated, has a more oval appearance. The gills on the ventral surface are found only in the true water pennies.

Another genus encountered in this family is Ectopria.



Antocha

Antocha 11162010.jpg
Order
Diptera
Family
Tipulidae
Genus
Antocha


This small dipteran in the cranefly family is quite common. It is distinguished from most other dipterans we found by the 'creeping welts' that appear as prominent dark stripes along the abdomen. The dark head is usually partly exposed; however, it can be pulled back into the thoracic cavity during preservation.



Perlodidae

Oncoperla (of Perlodidae) whole side.jpg
Order
Plecoptera
Family
Perlodidae


Stoneflies in the Perlodidae family do not have branching gills from leg bases. When observing their mouthparts, the glossae and paraglossae form a large three-pronged notch, or opening. The hind wing pads are divergent. Cerci, or "tails," are as long or longer than the abdomen.

Images of mouthparts, thehind wing pads and the ventral view.




Capniidae

Capnia left whole.jpg
Order
Plecoptera
Family
Capniidae


Common name
winter stonefly
Capnia stoneflies have hind wing pads that are are broad as they are long. An important distinction of the Capniidae family is the membranous pleural folds that run down the posterior abdomen segments 1-9. These look like two lines running parallel down the back of the abdomen. Capnia are distinguished by femurs and tibia of forelegs with less than 20 fine hairs and no dorsal femoral fringe hairs.

Ventral and dorsal views are seen here.




Epeorus

Epeorus.jpg
Order
Ephemeroptera
Family
Heptageniidae
Genus
Epeorus


Common name
The Quill Gordon
Tied fly
Quill Gordon
This is the only Heptageniidae genus present in this area with two tails!