Troublesome Brook

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Streams logo web.jpg Troublesome Brook
Stream code:BRX_TrbBrk_99
Basin:Bronx River
State or Province:New York
Country:USA
Latitude:40.957167
Longitude:-73.827667
School:DeWitt Clinton High School


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

Gammaridae

Gammarus roeselii.jpg
Order
Amphipoda
Family
Gammaridae


The body of this scud is flattened side-to-side. It has seven pairs of walking legs and two pairs of antennae. On third third antennal segment, there is a segmented flagellum.

Images of the body flattened side-to-side, and the segmented flagellum.




Lymnaeidae

Lymnaeidae.jpg
Family
Lymnaeidae


Members of the family Lymnaeidae belong in the class of Gastropoda. Members contain a single, coiled shell with a right-handed spiral. Differing from those of Planorbidae, members of Lymnaeidae have a larger opening. Respiration in these snails are through lung-like structures. Preferred habitats include those with slow streaming waters and heavy vegetation.

Images of the family Lymnaeidae and the class Gastropoda.




Oligochaeta

Oligochaeta.jpg



Common name
aquatic earthworms; black worms
Aquatic earthworms lack legs and are characterized by having 20 or more segments. Unlike leeches, they lack a suction disk. We collect members of two or more orders in this class as small numbers of stream sites and they are rarely numerous. They are more common at pond and lake sites.

Image of the 20 or more segments.




Corbiculidae

Corbiculidae.jpg
Family
Corbiculidae


On this shell, the hinge ligament is visible from the outside as a leathery bulge. On the inside, three cardinal teeth are visible, and on either side of those, there are two rows of lateral teeth. Corbiculids, also called Asian clams, are invasive and not currently found in Vermont waters, although they have been found just two locks below Lake Champlain. We have seen them in samples from Puerto Rico and The Bronx NY. .

Images of the hinge ligament, and the teeth.

For more information on preventing exotic introductions, visit VT DEC's Aquatic Invasive Species site





Hyalellidae

Amphipoda Hyalellidae.jpg
Order
Amphipoda
Family
Hyalellidae


The body of this scud is flattened side-to-side. It has seven pairs of walking legs and two pairs of antennae. The first pair of antennae is shorter than the second pair in members of this family.




Asellidae

Isopodaasellidae2.jpg
Order
Isopoda
Family
Asellidae


Common name
sow bugs
These aquatic sow-bugs have seven pairs of legs and a dorso-ventrally flattened body. They have two pairs of antennae; one pair is much longer than the other pair.

Images of the body and the two pairs of antennae.



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.




Cheumatopsyche

Cheumatopsyche.jpg
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 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.




Hirudinea

Leech blutegel.jpg



Common name
leeches
Leeches have bodies with 20 or more segments and a ventral suction disk on at least one end, though sometimes on both ends. They are segmented worms (Phylum Annelida) in the Class Hirudinea. Most of the leeches we sample come from ponds and lakes but they are also commonly found in streams.

Image of the ventral suction disk.




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