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Macroinvertebrates home

Streams project

 

Fox Meadow Brook (BRX_FxMdBrk_155)

These are the most common macroinvertebrates identified from samples from Fox Meadow Brook in Westchester County, New York.

Click on images to zoom in. 

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.

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.

PHYLUM: Annelida
CLASS: Oligochaeta

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

ORDER: Diptera
FAmily: Tipulidae
Genus: Tipula
 

This genus of Tipulidae is rather large as compared with other genera. Tipula larvae are generally dark brown and have creeping welts.

ORDER: Isopoda
FAMILY: Asellidae
 

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

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: 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

 

 

ORDER: Odonata
SUB-ORDER: Zygoptera
FAMILY: Coenagrionidae
 

These damselfly larvae (sub-order Zygoptera) can be distinguished from dragonfly larvae (sub-order Anisoptera) by their more slender bodies and the presence of three leaf-like gills at the end of the abdomen, seen here and here. The family Coenagrionidae is characterized by its distinctly shaped labium, which may or may not be extended.

CLASS: Gastropoda
FAMILIES: Physidae, Lymnaeidae, and Planorbidae
 

Three families from this class are commonly found here. Members of the family Planorbidae are found in flattened shells. Those belonging to Lymnaeidae are found in "right-handed" shells, in which the spiral goes clockwise. Members of Physidae  are called "left-handed" as the spiral of the shell goes counterclockwise. Remember, these only count if there is an individual in the shell; don't count empty shells in your data!

ORDER: Odonata
SUB-ORDER: Anisoptera
FAMILY: Aeshnidae
 

Like other Odonata, members of this family have four wingpads. Like members of the sub-order Anisoptera, the abdomen terminates in five points. The prementum and palpal lobes of this dragonfly are flat when viewed from the side.

ORDER: Coleoptera
FAMILY: Dytiscidae
GENUS: Dytiscus

Top picture (adult): Adult Dytiscidae have streamlined bodies and hind-legs modified for swimming. They are characterized by the division of the first abdominal segment by the hind coxae, seen here.

Bottom picture (larva): Don't let the paired claws and prominent 'tails' tempt you to think 'stonefly'; these tails are far less segmented than Plecoptera tails. The head and jaws are also unlike those of stoneflies. SMC

ORDER: Diptera

Pupae from the order Diptera are typically found in small numbers at every site. These can be identified further, but we do not.

 

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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