Daphnia ambigua
U.S. Geological Survey
Daphnia ambigua is
the scientific name for a species belonging to a group of
animals known as "Water Fleas." Daphnia ambigua is
one of the most common Daphnia in our area, although Daphnia
are not fleas at all. They are Crustaceans,
cousins of crayfish and shrimp. Daphnia live in lakes,
ponds, and slow-moving streams. Daphnia ambigua,
which is one of the smallest Daphnia, grows up to almost one
and a half milimeters. Daphnia ambigua has a spiny,
helmet-shaped head, and long antennae. It uses its
antennae
to swim. By thrusting the antennae downward, the Daphnia
pushes itself towards the surface of the water. It pauses
after each push and floats back downward. As it drops, the
Daphnia breathes and collects food with its ten legs.
Daphnia eat algae
and protozoans. Rowe, C.L. and Hebert,
1999 Cladoceran Web Site Rowe, C.L. and Hebert,
1999 Cladoceran Web Site <Male Female> Rowe, C.L. and Hebert,
1999 Cladoceran Web Site The way in which
Daphnia swim so jerkily is probably how they got
the nickname "Water Flea." Daphnia
ambigua has a hard outer shell which protects
it from some predators.
However, even with its tough covering, Daphnia are
food for many small fish, tadpoles,
salamanders, newts, and aquatic
insects. Daphnia are very
important because they take nutrients
from algae into their bodies and pass those
nutrients on to their predators. As other predators
eat the fish or other animals which ate the
Daphnia, the nutrients get passed on again. This
means that Daphnia are an important part of the
food chain, even to people, who don't eat Daphnia
directly. Rowe, C.L. and
Hebert, 1999 Cladoceran Web Site
