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Macroinvertebrates home

Streams project

 

Schoolhouse Ponds: Nari, Joni, and Fran

These are the 17 most common macroinvertebrates identified from samples from the Schoolhouse Ponds.  We have also seen leeches collected by children in the summer camp program and would anticipate seeing back swimmers, water boatmen, and giant water bugs.

Click on images to zoom in. 

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.  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 family Philopotamidae.

ORDER: Ephemeroptera
FAMILY: Caenidae
GENUS: Caenis

These mayflies are characterized by  square-shaped operculate (plate-like) gills on the second abdominal segment.

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.

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: Coleoptera
FAMILY: Haliplidae
GENUS: Peltodytes
 

Both larvae and adults of this family of beetle can be found in ponds. The abdomen of the larvae end in 1-2 long filaments, and long filaments are also found protruding for elsewhere on its body. The adults are characterized by their hind coxae which are greatly expanded and cover the first couple abdominal segments.

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: Odonata
SUB-ORDER: Anisoptera
FAMILY: Libellulidae
 

These dragonfly larvae (sub-order Anisoptera) can be distinguished from damselfly larvae (sub-order Zygoptera) by their more robust bodies and an abdomen that ends in five 'spikes' as opposed to three gills. The family Libellulidae is characterized by their spoon-shaped mouthparts. They are distinguished from the other family with this trait, Cordulegastridae, by the small, rounded teeth on the edges of their palpal lobes.

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.

 

ORDER: Hemiptera
FAMILY: Pleidae
 

This family of Hemiptera has a small, convex body and a 'beak' with 3-4 segments.

 

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.

 


ORDER: Diptera
FAMILY: Ceratopogonidae

Members of this family look like very straight Chironomidae. They are very long and thin with a distinct head capsule and no prolegs.  Some in the lab call them 'bamboo sticks with eyes.' SMC

 

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: Hemiptera
FAMILY: Pleidae
 

This family of Hemiptera has a small, convex body and a 'beak' with 3-4 segments.

 

ORDER: Coleoptera
FAMILY:
Gyrinidae
 

Don't let the paired tarsal claws and the filaments on the abdominal segments make you think Megaloptera; it is in fact a 'whirligig beetle.' On the 10th abdominal segment, it has 2 pairs of hooks. Adults stand out from others in that they appear to have 2 pairs of eyes. They don't, actually- it's just that its eyes are divided on the exterior by its exoskeleton.

 

ORDER: Coleoptera
FAMILY: Hydrophilidae
 

This beetle has one tarsal claw at the end of each leg. It is characterized by conspicuous mandibles and also by several simple eyes instead of compound eyes.

 

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!

 

Photo Source:

http://commons.wikimedia.org/wiki/File:Leech_blutegel.jpg

Phylum: Annelida
CLASS: Hirudinea
 

Leeches have bodies with 20 or more segments and a ventral suction disk on at least one end, though sometimes on both ends.

 

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
This site is supported by Vermont EPSCoR grant from the National Science Foundation (EPS #0701410).
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