This cuttlefish is flamboyant on special occasions only!

Date:
August 19, 2020
Source:
Marine Biological Laboratory
Summary:
The flashy Flamboyant Cuttlefish is among the most famous of the
cephalopods (octopus, squid, and cuttlefish) - but it is widely
misunderstood by its legions of fans. A new article sets the
record straight.



FULL STORY ==========================================================================
The flashy Flamboyant Cuttlefish is among the most famous of the
cephalopods (octopus, squid, and cuttlefish) -- but it is widely
misunderstood by its legions of fans.


==========================================================================
A new paper from the Roger Hanlon laboratory at the Marine Biological Laboratory, Woods Hole, sets the record straight.

"This animal is well known in the Internet community, has been on TV
many times, and is popular in public aquariums," Hanlon says. "In almost
all cases, [its skin] is showing this brilliantly colorful flamboyant
display." But Hanlon's field studies in Indonesia, reported here,
tell a different and richer story. "It turns out in nature, flamboyant cuttlefish are camouflaged nearly all of the time. They are nearly
impossible to find," he says. In the blink of an eye, they can switch
from some of "best camouflage known in the cephalopods" to their dazzling flamboyant display. But they only use this display on certain occasions:
For elaborate male courtship rituals; or when males are fighting over a
female; or to flash briefly at a threatening object when it approaches
too close, presumably to scare it away.

"The flamboyant display is common when a diver approaches close enough
to photograph, which is why the public may think this species always
looks so colorful," Hanlon says. "But it is rare to see this species in flamboyant display in the wild." A Flamboyant Courtship The courtship
displays by male flamboyant cuttlefish (Metasepia pfefferi) are among the
most elaborate of all cephalopods! This study reveals new observations
about the sex life of the flamboyant cuttlefish -- from courtship to
mating to egg laying -- gleaned from hours of video taken during many
SCUBA dives in Indonesia with teams of volunteers.



========================================================================== Males, which tend to be significantly smaller than females, approach
and court a camouflaged female with flamboyant displays and elaborate
rituals, which include "waves" (rapidly waving three pairs of arms while displaying "passing cloud") and "kisses" (male darts forward and briefly, gently touches his arms to hers).

Females generally ignore males while they are courting; they stay
camouflaged and motionless or just keep on foraging and hunting. Male
courtship goes on non-stop for prolonged periods (6 to 52 minutes observed
in this study).

In three observations, two males competed simultaneously for a
female. Males can display flamboyant courtship signaling on one side of
the body while flashing white (signaling aggression) on the other side
toward the rival male.

In one case, male competition ended abruptly when one of the males,
while facing the female and waving and kissing, backed into a camouflaged scorpionfish and was eaten! "Sex can have a real cost," Hanlon notes.

Females were choosy and often rejected courting males. Female receptivity
was obvious when she widely spread her first three pairs of arms (while standing on the fourth pair of arms). The male would then swim within
the arm crown and quickly deposit spermatophores in the buccal region
where the seminal receptacle is located. Average duration of mating was
only 2.89 seconds.



========================================================================== After fertilization, the successful male guarded the female for a
while but not, curiously, up to egg laying, as is common with other
cuttlefish. When another male was present, mate guarding was aggressive.

The female lays her eggs while camouflaged and staying still. She then
pushes her eggs under a coconut shell and affixes them to the inside of
the shell.

When the hatchlings exit the egg case and jet away, they are fully formed
and capable of camouflage and signaling.

Flamboyance for Secondary Defense The primary mode of defense for
both male and female Metasepia pfefferi is camouflage, and they remain camouflaged almost all the time. If a predator or threatening object
(such as a diver) comes too close, though, the cuttlefish will flash
the flamboyant display -- switching from camouflaged to flamboyant in
700 milliseconds! Elaborate Dynamic Signaling Rivaling That of Any
Vertebrate The vibrant colors (white, yellow, red and brown) of the
flamboyant display are combined with apparent "waves" of dark brown color
that produce a dazzling and dizzying kaleidoscope of motion, color, and patterning. The fast neural control of many thousands of chromatophore
organs in the skin enable this unique signaling capability -- all turned
on or off in less than a second, and changed depending on the behavioral context of the courtship, or in the case of defense, the fish predators
that discover them.

"Birds are renowned for highly evolved visual displays that depend partly
on dramatic postural changes (with wings of different color and pattern,
in particular), yet this invertebrate cuttlefish species has evolved
equally dramatic and complex displays mainly with its skin coloration,"
Hanlon says.

Video: https://www.youtube.com/watch?v=bwhO5qkTpiI&feature=emb_logo

========================================================================== Story Source: Materials provided by Marine_Biological_Laboratory. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Roger T. Hanlon, Gwendolyn McManus. Flamboyant cuttlefish behavior:
Camouflage tactics and complex colorful reproductive behavior
assessed during field studies at Lembeh Strait, Indonesia. Journal
of Experimental Marine Biology and Ecology, 2020; 529: 151397 DOI:
10.1016/ j.jembe.2020.151397 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200819170221.htm

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