Date:  03/27/1998  02:01 pm  (Friday)
      From:  Roland Anderson
        To:  conch-L
   Subject:  More shell dissolution
 
Paul M. wrote:
 
 As I read your post, a few questions came to mind, some
more serious than others:
How do you define an "occupied bottle" - does it actually have
to have an octopus in it when you find it to qualify as occupied?
YES
 I'm kind of confused by the terminology here, because you
speak of relative numbers of shells in occupied vs. unoccupied
bottles. Presumably the presence of any shells indicates that
the bottle was occupied at some point?
YES
If the octopus favor brown and encrusted bottles, presumably
darkness is the condition they seek?
YES
 Is this therefore a shallow  water species?
YES, DOWN TO ABOUT 200 M
Where did this species live before beer bottles arrived on the
scene?
UNDER ROCKS AND IN SHELLS, IN ROCK CREVICES
Do they still live there?
YES
 Is the species found in areas that are not littered with bottles?
YES, BUT IN SMALLER NUMBERS, ESPECIALLY ON
SANDY BOTTOMS
 Are there enough "naturally occurring" (so to speak) beer
bottles to support the population, or did you have to "seed" an
area for the sake of the study?
THERE WERE PLENTY ENOUGH BEER BOTTLES FOR MY
STUDY, BUT WE PUT OUT "NEW" BEER BOTTLES ALSO
AS A COMPARISON
In your 6-month experiment, will your final examination for
deterioration be based on weight loss, or just visual evidence?
IT WILL HAVE TO BE VISUAL EVIDENCE, SINCE I DIDN'T
TAKE A WEIGHT BEFORE STARTING
 Could the dissolution of shells in occupied bottles be due to, or
accelerated by, acids resulting from:
(1) waste products of the octopus (anybody know the pH of
octopus poop?)
YES.
(2) carbonic acid formed from CO2 produced by the respiration
of the octopus in such a small, restricted space?
YES.
(3) decomposition of snail tissues not thoroughly removed from
the shells by the octopus?
YES, BUT NOTICE THESE ARE ALL ARTIFACTS FROM THE
OCTOPUS.
THESE ARE ALL GOOD THOUGHTS, PAUL, I APPRECIATE
YOUR HELP.
 
Roland
 
 
Roland C. Anderson, Puget Sound Biologist
The Seattle Aquarium
1483 Alaskan Way
Seattle, WA 98101 USA
206-386-4346
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