Nature sez - 250-year-old worms

[Geoff Read]

> Charles Fisher, professor of biology at Pennsylvania State University, and 
> his team, interpret  marking experiments with tubes of a Lamellibrachia sp. 
> as indicating a 250 year life span for the animals.

I have now had a look at the data and wonder if the authors are being 
somewhat naive in their assumptions, and what a fisheries population 
analyst would make of the size-data set. It appears from the figure that 
about 40 or so animals of all sizes did not grow at all - clearly these are of 
infinite age!  It's all very well fitting a regression equation to the data, but 
there are no confidence limits given. 250 years plus or minus what - 100, 
200, 500, 1000 years?   

The authors state that  "even if it were assumed that individuals could 
maintain their maximum growth rate throughout their lives, the larger 
animals would still be over 80 years old." As the max is over 10 cm per 
year a 2 metre tube would be a mere 20 years old.

Not a "longevity record" yet. Sorry Nature. Sorry chaps.

Bergquist, Derk C. , Frederick M.  Williams, & Charles R. Fisher. 2000. 
Longevity record for deep-sea invertebrate. The growth rate of a marine 
tubeworm is tailored to different environments. -- Nature, 403(6769):499-
500. 

-- Geoff Read <g.read at niwa.cri.nz>  


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