06/13/01

Students,

The use of the word "Metazoa" came up in yesterday's discussion (see thePPT slides on website); some of you commented that you never heard theword before (even in fresh biology), others said it might be outdated.

Here is what I found out after researching some old and new college biology texts.

In my college freshman biology book: Life, An Introduction to Biology, by Simpson et al, 1957, publisher Harcourt, Brace, New York, 845 pp. On page 552 in a footnote: "The Kingdom Animalia is sometimes subdivided into three subkingdoms: (1) the unicellular Protozoa; (2) the Parazoa; and (3) the Metazoa."

In a biology book in Dr. Norris' office: Biological Science (2nd Ed) by Keeton, 1972, publisher WW Norton and Co., New York. On page 837 is a listing of Kingdom Animalia, with three subkingdoms listed, including Subkingdom Metazoa. Some phyla listed are: coelenterata (hydras, jellyfish, sea anemones, and corals), ctenophora (jellyfish); many other phyla listed containing marine organisms.

In a biology book in my office: Biology, by Goodman et al., 1986, publisher Harcourt, Brace and Janovich, Orlando, 878 pp. On page 826: Only Kingdom Animalia is mentioned. In the book's index there is no mention of metazoa.

In your college biology textbook used at Florida Tech (provided by Abe from our class): Biology, by Cambell et al., 1999. Table 32.1. is a table showing the Organization of Animal Phyla According to "Major features of Body Plans". Listed under Category in the table is Kingdom Animalia (Metazoa)", that is the word Metazoa is in parenthesis, followed by a list of 4 groups and associated phyla.

Finally, if you go to Webster's New World Dictionary (2nd edition) by Guralnik (ed.), 1982, you will see the following definition of metazoa: " any of the very large subkingdom (Metazoa) made up of all animals whose bodies, originating from a single cell, are composed of many differentiated cells arranged into definite organs. "Conclusion: Metazoa can substitute for the word Kingdom Animalia; but in all biology books I consulted, Kingdom Animalia is the primary heading.

We (us humans) as well as possibly all or most marine animals belong to the Metazoa: you, me, everyone started from a single cell which differentiated to contain organs etc).

To avoid further confusion on this issue, I have relabeled all the PPT slides: ftp://duedall.fit.edu/ocn1010/Spring2000/11aprilbio2.ppt shown yesterday from "Metazoa" to "Kingdom Animalia (Metazoa)".