Iowa's invertebrates

This is an entirely arbitrary grouping on my part. There are a number of phyla that are not considered as complex as the arthropods, for example, and I will deal with them here.

Really, when talking about invertebrates in Iowa and the study of them, we need to mention the work of Charles Drewes. He was a professor at Iowa State University who did a lot with invertebrates. Unfortunately, he died suddenly a few years ago, but not before leaving a great web site dealing with Iowa's invertebrates. That web site can be found here:

http://www.eeob.iastate.edu/faculty/DrewesC/htdocs/

By looking at the Illinois list (see the introduction to the biological diversity section), we might get some ideas about the number of species we have here.

Phylum Porifera: We do have freshwater sponges in Iowa. Illinois has 14 species. We probably have a few less. Dr. Drewes had photos on his web site.

Phylum Cnidaria: This group includes the salt water jellyfish and corals. The Illinois list has 10 species of hydra and one species of jellyfish. We do have freshwater jellyfish in Iowa according to Dr. Drewes' web site, and we probably have a smaller number of hydra than does Illinois.

Flatworms, Phylum Platyhelminthes: Illinois lists 400 species. I don't know of an Iowa list.

Phylum Nemertina, Ribbon worms: Illinois lists one species. I do not know if it is found in Iowa as well.

Phylum Nematoda, Round worms: The Illinois list does not give an estimate. I don't know of an Iowa list. There is a huge number of species, and they can be both important pests of crops and important predators of crop pests.

Phylum Nematomorpha, Horsehair worms: The Illinois list has two species. Iowa has at least one. These worms are internal parasites of grasshoppers and crickets which emerge from the insect near water. They look like a hair that can swim.

Phylum Acanthocephala, Spiny-headed worms: The Illinois list has 27 species. I am not aware of any information for Iowa.

Phylum Gastrotricha: The Illinois list has 60 species. I am not aware of any information for Iowa.

Phylum Rotifera: The Illinois list for this group of microscopic animals has an estimate of 150-175 species. I am not aware of any information for Iowa.

Phylum Entoprocta: The Illinois list has one species. I am not aware of any information for Iowa.

Phylum Annelida: The Illinois list has 170 species. The list includes earthworms, leeches, "suction feeding worms", and crayfish worms. I am not aware of any Iowa specific information.

Phylum Tartigrada, Water bears: 13 species for Illinois, I have no information for Iowa.

Phylum Mollusca: The Illinois list has 170 species of snails and 104 species of bivalves--mussels and clams. I have included a treatment of the Iowa snails--50 aquatic species and 134 species of terrestrial snails in subsequent pages. (There is some overlap of aquatic and terrestrial snails). There is a list of mussels of Iowa, and it has 48 species. A link can be found at:

http://www.ag.iastate.edu/centers/wrg/mussels/mussels.html

Phylum Ecotprocta: Bryozoans: The Illinois list has 9 species. Dr. Drewes has photos of some on his web site. I don't know of any Iowa specific information.

The photographs were of some kind of worm that I found under some wet tree bark. I was attempting to photograph other organisms at the time, and did not realize how strange they were. I have not identified them for sure yet, but the eyes (visible on the lower left photo) look a lot like the "land planarian" (Platyhelminthes) on Dr. Drewes' web site.