Stomatopod kill

Roy Caldwell 4roy at socrates.berkeley.edu
Fri Nov 2 12:11:47 EST 2001


With respect to the recent report of mass mortality of stomatopods in 
the  Seychelles, I can offer the following guesses.

First, I suspect that from the numbers, size and color information, 
this is (these are) gonodactylids, probably Gonodactylus smithii, G. 
viridis or G. chiragra or some combination of green, low intertidal 
stomatopods.   I have seen three mass mortalities of stomatopods 
during my field work, one in Panama, one in Australia, and one in 
Guam.  There was also the report of a fresh water event in Kaneohe 
Bay by Kinzie.  In all three cases that I witnessed, there was an 
extreme low tide during the day (we are just past a full moon) 
coupled with heavy rain and then bright, hot sun.  This can cause a 
lens of very hot, oxygen poor, fresh water to develop on the exposed 
reef.   Stomatopods are tough, but when it gets hot, they often will 
leave their cavities and try to dig in under rocks, coral heads, etc. 
to reach cooler, more saline conditions.   If the tide is still out 
and there is enough hot fresh water on an exposed reef, this is 
fatal.  One slight variation on this theme that I one saw on a 
mudflat in Thailand was rain and bright sun at low tide.  As the tide 
came in, the hot, fresh water being pushed ahead was very hot - 44 C. 
Many of the burrowing squillids and lysiosquillids vacated their 
burrows when the hot water hit and most perished.

It is hard to tell from this report how wide spread the phenomenon 
was.  If it occurred over a wide area, then my scenario is unlikely. 
If it were on just a few adjacent islands, it is more likely.  I 
suppose a red tide or other biological explanation is possible, 
although I haven't ever heard of this effecting stomatopods on a 
massive scale.

I would be happy to help identify the species, etc. if more 
information can be provided.  Too bad there isn't an emergency fund 
to fly stomatopod biologists to such hotspots.

Roy
-- 
***************************************
Roy L. Caldwell
Professor of Integrative Biology
Department of Integrative Biology
University of California at Berkeley
Berkeley, CA  94720-3140
USA

Phone (office):  (510) 642-1391
Phone (lab):      (510) 643-5448
Fax:       (510) 643-6264
Email:     4roy at socrates.berkeley.edu
http://ib.berkeley.edu/faculty/Caldwell,RL.html
***************************************
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<div>With respect to the recent report of mass mortality of
stomatopods in the&nbsp;<font size="-1"> Seychelles</font>, I can
offer the following guesses.</div>
<div><br></div>
<div>First, I suspect that from the numbers, size and color
information, this is (these are) gonodactylids, probably Gonodactylus
smithii, G. viridis or G. chiragra or some combination of green, low
intertidal stomatopods.&nbsp;&nbsp; I have seen three mass mortalities
of stomatopods during my field work, one in Panama, one in Australia,
and one in Guam.&nbsp; There was also the report of a fresh water
event in Kaneohe Bay by Kinzie.&nbsp; In all three cases that I
witnessed, there was an extreme low tide during the day (we are just
past a full moon) coupled with heavy rain and then bright, hot sun.&nbsp;
This can cause a lens of very hot, oxygen poor, fresh water to develop
on the exposed reef.&nbsp;&nbsp; Stomatopods are tough, but when it
gets hot, they often will leave their cavities and try to dig in under
rocks, coral heads, etc. to reach cooler, more saline
conditions.&nbsp;&nbsp; If the tide is still out and there is enough
hot fresh water on an exposed reef, this is fatal.&nbsp; One slight
variation on this theme that I one saw on a mudflat in Thailand was
rain and bright sun at low tide.&nbsp; As the tide came in, the hot,
fresh water being pushed ahead was very hot - 44 C.&nbsp; Many of the
burrowing squillids and lysiosquillids vacated their burrows when the
hot water hit and most perished.</div>
<div><br></div>
<div>It is hard to tell from this report how wide spread the
phenomenon was.&nbsp; If it occurred over a wide area, then my
scenario is unlikely.&nbsp; If it were on just a few adjacent islands,
it is more likely.&nbsp; I suppose a red tide or other biological
explanation is possible, although I haven't ever heard of this
effecting stomatopods on a massive scale.</div>
<div><br></div>
<div>I would be happy to help identify the species, etc. if more
information can be provided.&nbsp; Too bad there isn't an emergency
fund to fly stomatopod biologists to such hotspots.</div>
<div><br></div>
<div>Roy</div>
<x-sigsep><pre>-- 
</pre></x-sigsep>
<div>***************************************<br>
Roy L. Caldwell<br>
Professor of Integrative Biology<br>
Department of Integrative Biology<br>
University of California at Berkeley<br>
Berkeley, CA&nbsp; 94720-3140<br>
USA<br>
<br>
Phone (office):&nbsp; (510) 642-1391<br>
Phone (lab):&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (510) 643-5448<br>
Fax:&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; (510) 643-6264<br>
Email:&nbsp;&nbsp;&nbsp;&nbsp; 4roy at socrates.berkeley.edu<br>
http://ib.berkeley.edu/faculty/Caldwell,RL.html<br>
***************************************</div>
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