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Macroinvertebrates home

Streams project

 

Shady Rill

These are the ten most common macroinvertebrates identified from the samples collected by the students of Montpelier High School and identified by students at Saint Michael's College. The samples were collected near Shady Rill Road in Middlesex, VT on August 8th 2008.

Click on images to zoom in. 

ORDER: Ephemeroptera
FAMILY: Baetidae 
GENUS: Baetis 

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. SMC

ORDER: Trichoptera
FAMILY:
Hydropsychidae
GENUS: Cheumatopsyche

Cheumatopsyche has a forked foretrochantin (as does Ceratopsyche). The foretrochantin is the projection at the uppermost portion of the front leg closest to the head. The leg may need to be pulled away from the body to expose this feature.

Cheumatopsyche have a small or inconspicuous pair of sclerites under the prosternal plate that are difficult to see.  Contrast that with the larger pair of sclerites found on CeratopsycheTo access sclerites, it's best to gently pull the pronotum and mesonotum in opposite directions. Note: the large single sclerite is the prosternal plate.

Cheumatopsyche have only 2 types of hair on the abdomen: long thin plain hairs and thicker club hairs, which are narrow close to the body and widen out at the distal end. Paired sclerites on the ninth abdominal segment are notched. SMC

ORDER: Diptera
FAMILY: Tipulidae
GENUS: Dicranota

Dicranota can be distinguished by the two tails and their comb feet. There are usually 5 pairs of prolegs on the abdomen with combs on them. In addition, the posterior portion of the abdomen often has a slight swelling. SMC

 

ORDER: Trichoptera
FAMILY:
Hydropsychidae
GENUS: Ceratopsyche

Ceratopsyche has a forked foretrochantin. The foretrochantin is the projection at the uppermost portion of the foreleg. The leg may need to be pulled away from the body to expose this feature.

Ceratopsyche have a large pair of sclerites underneath the prosternum. Note: the large single sclerite is the prosternal plate. SMC

 

 


Donald S. Chandler / Discover Life

ORDER: Trichoptera
FAMILY: Hydropsychidae
GENUS:
Arctopsyche

Caddisfly larvae from the Arctopsyche genus have a single long seta (hair) on segments above the gills, in sa2 and sa3 positions, as opposed to tufts. The ventral apotome, when looking at the head, narrows posteriorly.

 


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ORDER: Diptera
FAMILY: Tipulidae
GENUS: Pedicia

Creeping welts or broad tubercles are found on this Tipulidae. No spiracles are present, but the surface may appear roughened under the microscope.

ORDER: Ephemeroptera
FAM
ILY: Heptageniidae
GEN
US:
Epeorus

This is the only Heptageniidae genus present in this area with two tails!

 

Images are available from An Identification Guide to the Nymphal Mayflies of British Columbia

Images will be forthcoming

ORDER: Ephemeroptera
FAMILY: Siphlonuridae
GENUS: Parameletus
 

This family of mayflies have posteriolateral spines on segment 9 and the labrum does not have a deep notch. Maxillae do not have pectinate spines. The Parameletus genus is characterized by the lack of tubercules on the sterna of the thorax. Additionally, segments 5 - 9 of the abdomen are not greatly expanded.

 

ORDER: Plecoptera
FAMILY: Leuctridae
GENUS: Leuctra

This family of stonefly is fairly slender by stonefly standards.  The divergent wing pads are a helpful characteristic. Leuctridae  are similar in overall shape to the Capniidae; however, Leuctridae often do not have pleural folds. If they are present, they only extend from abdominal segments 1-7.  Leuctra  are recognized by abdominal terga with posterior fringes of short hairs and last few segments with longer hairs. NABS

 

PHYLUM: Annelida
CLASS: Oligochaeta

Aquatic earthworms lack legs and are characterized by having 20 or more segments. Unlike leeches, they lack a suction disk.

 

The images are not a substitute for keying, but should serve as an aid in identifying common macroinvertebrates in samples.

Feedback - Partner schools: send us specimens not included above.  Taxonomists: click to email: Declan McCabe
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