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View Full Version : Peacock Mantis feeds on Blue Ring Octopus


kalim
10/01/2004, 01:52 PM
Here's interesting stuff from studies done by Huffard and Caldwell about peacock mantis shrimps preying on Blue ring octopus.


Inking in a Blue-Ringed Octopus, Hapalochlaena lunulata, with a Vestigial Ink Sac
Christine L. Huffard and R. L. Caldwell


During laboratory studies on H. lunulata
obtained from Indonesia, we recorded seven
instances when adults released a single, poorly
defined cloud of brown ink. In each case, the
small puff of ink diffused in seconds. The oc-topuses
ejecting the ink did not jet from the
inked area. We observed no apparent direct
reaction to the ink by the other animals in-volved
in these situations.
Two adult octopuses (one male and one
female) inked as they attempted to escape
from an attack by a stomatopod, Odontodacty-lus
scyllarus (Linnaeus, 1758). Another male
inked as it jetted away from a nearby stoma-topod.
A female inked as she rejected the
approach of a male with which she had pre-viously
mated, and a brooding female inked
while a male mounted her, attempting to
mate. An adult male inked near the end of a
mating session initiated by the female (Cam-bridge
Studios 1998). Finally, a female inked
near the end of a long series of approaches
and aggressive interactions with another fe-
male (Figure 1). The two females had wrestled
intensely, released, reapproached with
arms and web spread, and touched distal por-tions
of the arms. The smaller female inked
and eventually retreated from the advances of
her opponent. The inkings we observed by H. lunulata
are not easily attributable to any of the usual
explanations of inking behavior mentioned
previously. Because the thin, transient cloud
of ink released neither impairs visibility nor
retains any shape in the water column, it does
not serve as a smoke screen or a pseudo-morph.
Cephalopod ink may irritate the
chemosensory systems of some animals (Gilly
and Lucero 1992), but it appears to offer no
protection from O. scyllarus. Attacking sto-matopods
continued to pursue, and eventu-ally
killed, the two octopuses that had inked.
Because the highly visual O. scyllarus may be
an effective predator even with dulled olfactory receptors, the ability of H. lunulata ink to
inhibit the approach of predators that rely
more on chemosensory information should
be investigated. In five of the seven situations,
ink was released after provocation by a con-specific.
No animal jetted immediately from
the area, as would occur in response to an
alarm.

kalim
10/02/2004, 01:16 PM
added to blueboard:
http://www.blueboard.com/mantis/logs/041001.htm

goblinsharkman
10/02/2004, 06:23 PM
Hmmm...i think ive heard that name Caldwell before....oh yea, Dr. Roy watsha gotta say?