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Baldwin Creek

These are the ten most common macroinvertebrates identified from samples from Baldwin Creek.

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. The wing pad shape is an obvious characteristic. More mature nymphs have long, dark wing pads. SMC

ORDER: Ephemeroptera
FAM
ILY: Heptageniidae
GEN
US:
Epeorus. 

A mayfly with two 'tails'!  This family of mayflies has distinctly flattened heads, and this particular genus has two tails and a unique gill arrangement.
NABS

ORDER: Diptera
FAMILY: Chironomidae

 Midge larvae tend to be the most common macroinvertebrate at our sites.  As with other Diptera, there are no true jointed legs.  Chironomids 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 the philopotamids.

ORDER: Diptera
FAMILY: Simuliidae

What's not to like about blackflies?  Our second most common dipteran.  Rather like a bowling pin with hands attached at the head end.  We have not identified them past family at this point, but it is in the long-term plan.
NABS

ORDER: Ephemeroptera
FAMILY: Ephemerellidae
GENUS:
Drunella


The mayfly Drunella is distinguished by its large femoral “biceps” on the front legs. The body rests in one plane with the biceps at the same level as the head and junction with the thorax.

 

 

ORDER: Trichoptera
FAMILY:
Philopotamidae
GENUS: Chimarra

Chimarra are distinguished from the other Philopotamidae by a prominent asymmetrical notch in the frontoclypeus as well as a prominent process on the femora which bears a single hair, called setae. SMC

ORDER: Plecoptera
FAMILY: Leuctridae
GENUS: Leuctra

Among our most common stoneflies, this family 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

ORDER: Trichoptera
FAMILY: Philopotamidae
GENUS: Dolophilodes

Dolophilodes stands out in the Philopotamidae family due to its slightly asymmetrical frontoclypeus on the anterior margin and its distinguishable projecting foretrochantin.

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.
NABS

ORDER: Plecoptera
FAMILY: Perlidae
GENUS: Acroneuria

Acroneuria are reasonably common in our samples.  Acroneuria always have three ocelli.
 

 

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


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