I suspect that the trumpetfish was trying to initiate shadow-hunting,
something they very much like to do - and are very good at.  Find a
largish fish - preferably a grazer or at least something which will not
spook the prey the trumpetfish is most interested in - glue close and
try to sneak up on prey under cover of the harmless friend.  I've seen
a lot of trumpetfish engaged in this behavior, which appears related to
nuclear hunting (when piscivores of different species hunt
cooperatively together).  Of all reef fish, trumpetfish are probably
the most likely to engage in shadow-feeding.  There's a nice picture in
Deloach and Human's Reef Fish Behavior (on page 66) of a trumpetfish
and a coney hunting with a goldentail moray.  Somewhere I've got a
picture -but not a very good one - of a trumpetfish glued to the side
of a batfish, who didn't seem as upset as yours.

Frogfish (Robert Delfs)

On Wed, 11 Jul 2001 05:10:58 -0400, Krazy Kiwi wrote:

>While diving off a steep wall in the open ocean off Tufi Resort, PNG I
>witnessed a grey coloured trumpetfish trying its best to literally latch
>itself on to a large batfish. The batfish was going berserk doing its best
>to shake off the unwanted attentions of this trumpetfish .. but the
>trumpetfish kept up the chase. They were going in circles & zig-zagging all
>over the place, which was quite entertaining for me as I'd never seen
>anything like it before (unfortunately had macro gear on the camera so no
>pics .. but it would have made a hilarious video). Everytime the
>trumpetfish touched the batfish it would turn itself towards the reef wall
>as if to rub off the persistant pest. Eventually the trumpetfish got the
>big hint to bug off & zapped over to another unsuspecting fish for a chance
>to tango.
>While diving around Layang-Layang Island it was a common sight to see
>yellow trumpetfish madly cruising beside another yellow coloured fish. Not
>sure if that was for protection or if it was the colour of their newly
>acquired travelling companion that was the attraction.
>


Robert Delfs
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