Iowa Fish
What
is a fish? Fish are animals that live their lives in water. Fish are
cold-blooded, which does not mean that their blood is cold but rather that
their body temperature changes with the temperature of the water around them.
Fish are also vertebrates - they have a backbone and an internal skeleton made
of cartilage or bone.
Since
fish are animals they must breathe oxygen just like other animals - but how do
they breathe oxygen under water? With their gills! Gills make it possible for
fish to breathe oxygen under water by absorbing the dissolved oxygen in water.
Fish
also have fins and scales. Fins are how fish move around in the water.
Different fish have different fin shapes and sizes. Scales cover fish and
protect them. Most fish have scales but some, like catfish, are covered with
tough skin.
There
are 148 species of fish in Iowa.
Creature Feature –
American Brook Lamprey (Lampetra
appendix)
American brook lamprey
are listed as THREATENED in Iowa.
American
brook lamprey are long, cylindrical fish averaging 5 to 8 inches long. They
have a long dorsal (upper) fin which is divided into two parts and extends
around the tail. They do not have fins on the sides of their bodies. Adult american
brook lamprey’s bodies are olive green to brown fading to lighter below. Immature
American brook lamprey are smaller and have lighter colored bodies.
American
brook lamprey are non-parasitic (until like many lampreys that use their mouths
to attach to hosts and live off of their blood).
American
brook lamprey live most of their life in their immature form, called
ammocoetes. Ammocoetes live in burrows in the sand and silt in small streams in
northeast Iowa. They eat small plants, animals, and bits of organic matter. Ammocoetes
mature into adults after 3 to 7 years at which time they will no longer have a
functioning digestive system and do not eat. Adult American brook lamprey spawn
and die shortly after reaching maturity.
During
spawning the male and female construct a small nest by picking up small pebbles
with their mouths and moving them to form a rim around a small depression on
the stream bottom. The female then deposits the sticky eggs in the nest and
they adhere to the sand and gravel.
American
brook lamprey are listed as threatened in Iowa. Their numbers are low due to
loss of spawning habitat due to siltation, and channelization.
Conservation Messaging
Use Aquatic WILD’s “Conservation Messaging” to
create a public service announcement informing the public about actions they
can take to conserve the American brook lamprey. Students should research
threats to the American brook lamprey, explain what can be done to conserve and
restore aquatic habitats, and use their research to create their PSA.
Extension
Focus on
other species. What other threatened or endangered Iowa wildlife species can
you create PSA for as a class?
Book List
Amdahl, P. 2000. The Barefoot
Fisherman: A Fishing Book for Kids. Clearwater Publishing.
Burger, C. 1960. All About
Fish. Random House.
Parker, S. 2005. Fish. DK
Publishing, Inc.
Schaefer, L.M. 2001. What Is a
Fish?. Coughlan Publishing.
Links
IDNR:
Fishes of Iowa
American brook lamprey
Wikipedia: Lampetra appendix
For
factsheets, activity sheets and MORE visit:
IDNR: Education – Classroom
Resources (go to the Document Library at the bottom of the page for fact sheets
and activity sheets!)
