Hello everyone.
    I recently conducted growth experiments on squid at two different
temperatures.  The squid which were placed into 15 degree Celsius water from
an ambient of about 22 Celsius had a band in their statoliths (analagous to
fish otoliths) which was obvious as a transparent band in incident light but
almost invisible in transmitted light.  Squid which went into 20 Celsius
water in the lab (from 22 Celsius ambient) showed no similar band.  There
was a strongish check visible at the start of the band but the increments
thereafter looked no different to those laid down before that check.
     I've looked in the squid statolith literature but the only reference to
zones are the darker vs lighter ones seen commonly in squid statoliths and
widely reported.
     I've looked in the fish literature too.  I know that temperature can
produce very visible checks in fish otoliths.  And that different zones have
been explained as due to metamorphosis or a habitat shift - again all seen
in transmitted light.
     My squid were kept at a constant temperature in my experiment for about
100 days and the band is visible for about 1/3 of that period and is then
less evident, but the optical properties are still tending more towards
transparency vs opacity.
     Has anyone seen a similar band(s) in incident light in otoliths or
statoliths?  Can anyone offer any explanation?  Might there be a chemical
explanation in the way that calcium is deposited to have different optical
properties (total stab in the dark here?!)
     Hope someone can offer some words of wisdom for me.

     Thanks

     Emma

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