Mud CreekThese are the ten most common macroinvertebrates identified from samples from Mud Creek. |
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ORDER: Trichoptera 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
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This family of net-spinning caddisflies is
very abundant at several sites. They are important filtering
collectors and are quite common at urban and agricultural sites where particles
of organic material can be important food resources. Genus-level identification is
possible for mature specimens and we will include the genera we found at
your site if possible. In general we commonly find
Cheumatopsyche,
Ceratopsyche, and
Hydropsyche. |
ORDER: Diptera
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: Coleoptera 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. SMC
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ORDER: Ephemeroptera
This family of mayfly is characterized by
antennae longer than the width of their head and a notch in their labrum. The most
common genus we found was Baetis. |
ORDER: Trichoptera 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 Ceratopsyche. To 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:
Ephemeroptera This mayfly has unique long hairs on its forefemora as the main distinguishing characteristic (allowing anyone keying to move through quickly). Carefully observe the limbs because such hair can be matted down and therefore hidden in preserved wet specimens. The body of Isonychia is slim and "minnow-like" when observed dorsally. In specimens we collected, they were commonly brown and substantial, in length and width as compared to the very common Baetidae.
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ORDER: Diptera The majority of fly larvae in the Tipulid family were found to be from the genera Antocha and Molophilus.
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ORDER: Ephemeroptera Heptagenia are easily characterized by their flat head. The claws have just one basal tooth and no denticles (serrated edges). The gill on abdominal segment 7 has multiple fibrils at is base (thread-like structures) and has a single tooth on its claws but is smooth otherwise. Gills on segment 7 are similar to those on all other segments, but may be smaller in size.
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Images are available from An Identification Guide to the Nymphal Mayflies of British Columbia Images will be forthcoming ORDER: Ephemeroptera 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.
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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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