Ah well, I guess it is about time I weigh in here, having been around in
Hartman's lab for quite a few years. Dr. Hartman preferred to study mature
individuals, and some of the statements about "small" and "large" were
supposed to refer to that (not always by any means). A second issue in
this whole debate about the cirratulids and one which the two of us kept
debating, was when and how the cirratulids "differentiated" into the
crowded front and rears and the beaded middle. We sort of came to the
conclusion that the issue was one of allometry: As the worm added more
segments (always from the posterior end of course) it maintained more or
less a certain fraction of the anterior end with crowded segments, and in
cases with the flattened, beaver-tails, a certain fraction in the beaver
tail. As Mary Petersen pointed out, getting too hooked up in counting
segments is probablly not a very good idea: Worms start with few segments
and then keep on adding. At this point in time, I believe that most
species have a sort of normal upper limit of segments, but I refuse to get
pinned down very precisely. There may be good rules of thumb on this, but
it appears to be both family and size dependent,, so may be useful only in
a very limited sense.
May I suggest that we attempt to settle all issues about polychaetes this
coming August, preferably over a beer or two in Curitiba? I assume that
beer is served in Brazil, never having been there, I do not actually know,
of course, but I feel confident we will be able to find a suitable
substitute!
Kristian Fauchald
<FAUCHALD.KRISTIAN at NMNH.SI.EDU>
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