From: cigliano@bu-bio.bu.edu (John Cigliano)
Newsgroups: rec.aquaria
Subject: Re: Octopus
Date: 2 Sep 92 21:37:24 GMT
Organization: Biology Department, Boston University, Boston, MA, USA

>In article <cburns-020992133506@end.chem.indiana.edu> cburns@ucs.indiana.edu (Chris Burns) writes:
>In article <1992Sep2.123028.5300@echo.philips.nl>, johanb@echo.philips.nl
>(Johan Slob) wrote:
>> 
>> 
>> Does anyone know anything about keeping an octopus in an 
>> aquarium?
>> 
>>   - size, temperature of aquarium
>>   - best sort of Octopus
>>   - recommended literature
>> 
>
>
>I've heard that they're very hard to keep.  Mostly because it's very
>difficult to keep them in the tanks.  No hole is too small, no cover too
>tight for them to get a tentacle in.  Getting them to eat (assuming it's
>still in the tank) is also supposed to be troublesome.  I've also heard
>that even some of the big Aquariums have troubles with octopuses.  There
>may be some species that are more suited for aquaria then others, I don't
>know about any of this though.
>
>Good Luck
>
>Chris

Octopuses are indeed difficult but not impossible to maintain. I have had
limited success maintaining octopuses in aquaria (my doctoral dissertation
is on octopus behavior and ecology). You must be aware of several facts
before deciding on whether to keep octopuses: (1) they do get out of aquaria
very easily. An octopus can get out a hole 1/4 the width of its mantle since
the only hard part is cartilage surrounding its brain - if it can get an arm
through the rest will follow. (2) they are voracious eaters and usually will
only eat live food. Crustaceans are their favorite but will eat fish and 
snails to a lesser extent (but they will not eat fish or snails exclusively).
Some species will eat mussels and clams. Be prepared for a major food expense
(unless you can collect the food yourself. (3) octopuses are very sensitive
to water quality changes and (4) they are semelparous, ie., spawn once then
die, and very short live. The species that can be kept in the average sized 
aquarium will live between 6 mos. to a year and (5) octopuses are nocturnal
(active at night) and tend to hide in their dens when not active (which is
about 70% of the time) so you would not see much of your octopus. Also, 
octopuses ink when startled or threatened and a medium sized species will
ink enough where you might need to do a water change.

With that said, I do encourage you to try to keep an octopus (don't try
to keep more than one in a tank since they will fight) if you don't mind
a challenge. They are extraordinary animals. I reccommend keeping the
Atlantic dwarf octopus (_Octopus joubini_) since it is small (they hide in
clam and whelk shells). I found that they relish fiddler crabs (about one a
day). You can purchase them from the Gulf Specimen Marine Laboratories, Inc.
(904) 984-5297. _O. bimaculoides_ (the mudflat octopus) is somewhat larger
and lives about twice as long (6 mos for O. joubini, 1 - 1.5 years for O.
bimaculoides). However, the only source that I know of is a collector from
S. Cal. Pet stores sometimes will have octopuses for sale. 

I hope I was of help.

John A. Cigliano

References on keeping octopuses:

Hanlon, R.T. & Forsythe, J.W. Advances in the laboratory culture of octopuses
for biomedical research. Laboratory Animal Science, 35(1):33-40.

Forsythe, J.W. & Hanlon, R.T. 1980. A closed marine culture system for 
_Octopus joubini_ and other large egged benthic octopods. Laboratory Animals,
14:137-142.
Newsgroups: rec.aquaria