source of photo: >>http://dnr.state.il.us/ctap/bugs/worms.htm
Phylum Platyhelminthes
Class Tubellaria
(flatworms)
source of photo: >>http://dnr.state.il.us/ctap/bugs/worms.htm
Phylum Rotifera (rotifers)
Phylum Annelida
Class
Oligochaeta* (bristle worms)
Interesting stuff about Tubifex worms >>http://rivers.msu.montana.edu/dlg/aim/annelid/whirl1.html
>>http://www.flyshop.com/News/10-96Whirlingupdate/tubifex.html
Class
Hirundinea* (leeches)
Phylum Mollusca
Class
Gastropoda* (snails)
Class
Pelecypoda* (clams and mussels)
Cyclonaias tuberculata, INHS 4078.
Source of photo: http://www.inhs.uiuc.edu:80/chf/pub/mussel_man/cover.html
List with lots of mollusk links
>>http://habanero.cb.uga.edu/GSC/images.html
Superclass Crustacea
- head and thorax "fused"
into a structure called a cephalothorax
- two pairs of antennae
- breath with gills
Order
Ostacoda - seed or clam shrimp
- minute crustaceans
with large head, its trunk reduced in size
- bivalve calcareous
carapace
- almost all are free-living,
both marine and freshwater forms
Order
Amphipoda* - scuds, side-swimmers
- bilaterally compressed
(narrow), look like tiny shrimp
- head and first segment
of thorax fused into a cephalothorax
- seven free thoracic
segments, with 2 pair of pleopods which beat to move water over the gills
- small tail plate
(telson)
- active at night
- benthic, primarily
scavengers of fine detritus, or shredders
- can be common, some
species adapted adapted to subterranean environments
- two common families
in Michigan - Gammaridae, Hyalellidae
Order
Isopoda* - aquatic sowbugs, isopods
- dorsoventrally
compressed (flat)
- head fused with first
and second segment of thorax into a cephalothorax
- seven other thoracic
segments each with a pair of legs (pereopods)
- four abdominal segments
fused to tail plate (telson)
- six pairs of abdominal
legs (pleopods, and 6th uropods)
- live just about everywhere
and often where other things cannot
- scavengers, hide
in accumulated vegetative matter in rivers and lakes
- one common family
in Michigan - Asellidae
Order Mysideacea - opossum
shrimp
- shrimp-like, with
large carapace, and stalked eyes
- live in deep lakes,
often have dramatic cycles of diurnal vertical migration
Order
Copepoda* - copepods
- mostly marine, but
significant numbers of species that are freshwater
- immature copepods
called "nauplius"
- cylindrical shape,
narrow abdomen, often conspicuous as females often are seen carrying egg
sacs
- laterally compressed,
with a single folded carapace
- very small (usually
<0.5-2.0mm), noticeably segmented bogy with numerous appendages on head
and thorax,
and setose caudal rami on posterior end of abdomen
- filter feeders, feed
on organic detritus and other smaller animals; some species parasitic on
fish
- of the free-swimming
species, three important suborders:
- Calanoida, planktonic species with long antennae, filter feeders - dominant
freshwater group
- Cyclopoida, littoral species with short antennae
- Harpacticoida, littoral species with very short antennae (largely a marine
group)
Order
Cladocera* - water fleas
- laterally compressed
(narrow), with a single folded carapace open at the bottom, doesn't cover
head
- 5-6 pairs of legs
- antennae (biramous
Y-shaped) chief locomotive organ
- primary consumers,
visual predators, majority feed on algae and cyanobacteria, use their legs
to filter feed
- often an important
link in aquatic food chains, widely preyed upon by insects and fish
- soon responds to
increases in productivity with turnover events
- reproduction parthenogenetic,
males produced in spring in response to crowding
- populations with
diel vertical migration, staying at depths during the day, rising to near
the surface at night
to feed
- found in most still
water, planktonic in lakes, in weedy lake margins, a few in bogs, along
lake bottoms
or in the
mud
Order Anostraca* - fairy shrimp
- elongated trunk
- many paired appendages,
swims on back
- stalked, compound
eyes
- carapace absent
Order
Decapoda* - crayfish and freshwater shrimp
- diverse marine and
freshwater order, some individuals attain the largest size of any of our
crustaceans
- most freshwater decapods
inhabit shallow lentic and lotic waters, also some inhabit terrestrial
burrows
that lead
to groundwater, and some are subterranean (caves)
- head and thorax combined
into a very prominent cephalothorax, which often has an anterior, elongated
projection
(rostrum)
- feathery gills in
a gill chamber underneath the legs
- females carry eggs
on pleopods
- several types of
crayfish borrow into the ground, making chimneys (response to drought)
- largely nocturnal,
omnivorous feeding
Family - Cambaridae - crayfish
- body cylindrical
- appendages modified
- 2 pairs of antennae
- 5 pair of legs used for walking and food handling (1st 3 are chelate,
1st a large forcept)
- 5 pair of pleopods on abdomen
Family - Palaemonidae - freshwater shrimp
- body laterally compressed (narrow)
- first 2 paris of legs are chelate, the rest are adapted for swimming
- generally found in macrophyte-rich littoral zones of lakes or similarly
macrophyte-chocked sections
of rivers and streams
Phylum Arthropoda - Superclass
Arachnida
Order Acari* - watermites
- larvae are
6-legged, adults are 8-legged
- complicated life
cycle - egg, sometimes parasitic larvae, sometimes parasitic deuteronymph
which
disperses,
and adult
- over 5,000 species,
probably very conservative number; over 1,500 described in North America
Phylum Arthropoda
Superclass*
Hexapoda
see above link to view images