248 
THE CORAL TRIANGLE: HEARST BIODIVERSITY EXPEDITION 
On exhibit, we have not seen 
the ‘stilting’ or ‘rolling’ behav¬ 
iors with eoeonut shells that have 
been observed in the wild, nor 
have we observed the bipedal 
loeomotion that has also been 
doeumented for Amphioctopus 
(Finn et al. 2009). We have 
observed Amphioctopus defend¬ 
ing food from its tank mate, the 
ehoeolate ehip starfish. Protore¬ 
aster nodosus. After a eoeonut 
oetopus had been fed a Manila 
elam, the starfish was attracted to 
the open clam and attempted to 
take it. The coconut octopus 
responded by using one of its 
arms to push the starfish away 
while using the remaining seven 
arms to stabilize itself on the bot¬ 
tom, secure itself in its den (small 
glass bottle) and hold on to the 
open clam shell. Ultimately the 
starfish was repelled and the 
octopus was able to feed in 
peace. 
Observations of mating 
behavior and captive breeding 
were limited, as we were almost 
exclusively displaying single specimens in our exhibits. On one instance, we did attempt to put two 
animals together for mating. The larger specimen quickly engulfed the smaller in its arm webbing. 
These two individuals were allowed to stay in this position until we observed inking, at which point 
they were separated. On display and in holding, three Amphioctopus marginatus each laid a single 
clutch of eggs; two of these three were fertile. Unfortunately, hatchings were not observed, so we 
did not have an opportunity to attempt to raise the paralarvae. 
Amphioctopus marginatus is an ideal candidate for public aquarium display. It is an engaging 
species with minimal space needs, and most facilities will be able to meet the minimum require¬ 
ments for successfully caring for the animal for the duration of its natural lifespan. It is popular 
with guests due to its interesting behaviors and it has a tendency to be active during daylight hours. 
The major challenges with this species surround acquisition. It will likely remain difficult to 
acquire specimens through regular commercial collectors and exporters. We have developed col¬ 
lecting techniques that minimize stress and eliminate mortality. Future research is needed to devel¬ 
op captive-breeding and larval-rearing protocols, and to examine whether populations within the 
Philippines are robust enough to support repeated collections of aquariums specimens in a sustain¬ 
able manner. 
Figure 8: Amphioctopus marginatus on display in the “lookout” pose. 
Note the use of a clay flowerpot as a den, and a coral skeleton as an operable 
“door” to the den. Photo by Richard Ross. 
