Jason,
As far as quantity, I wrote a recent monologue
that may be helpful is in
Tranny's journal.
As far a what (vs how much) to feed, a lot depends on the octopus and the age of the animal. Variation over the week appears to be beneficial.
Crab is always a good choice, unfortunately, we can't get it frozen in raw form. Neal and I visit our local Asian markets once a month or so and harvest loose crab legs when they have live blue crab. Where the whole crab cannot be frozen, the claws freeze well. Live fiddler crabs can be ordered on-line (
Paul Sachs is a reliable and reasonably priced supplier if you can't get them locally) and kept in a rubber maid type storage container (largish plastic bucket). They must have enough water to stay wet but they also need rocks to climb on as they are air breathers. I use regular saltwater but a diluted brackish water works too.
Regular frozen table shrimp is another food that is usually accepted by adults but may take some coaxing with very young and sometimes rejected by very old octopuses. I have had mixed luck with the dwarf, O. mercatoris eating it at all but it is a mainstay for my larger animals.
Some animals will eat snails. If you can find some without an operculum (the trap door found on most saltwater snails), they will be easier for the octopus to eat. Be sure you find saltwater snails if hunting in the Asian markets. Often the seller will not know so try a few in salt and a few in fresh to see if they survive (some with survive both) What you don't want are land snails. Most on-line and local pet stores that have saltwater animals will offer snails as a cleanup crew. If they are not eaten, they will help keep your tank clean.
For very young or dwarfs, I usually get a supply of shore shrimp (Paul also carries these as well as a number of other on-line vendors). I keep them live but feed freshly killed as they are difficult for the octopuses to catch. Some people have had luck feeding hermit crabs but, with one exception, I have had to kill and shell the hermits to use them as food.
As a treat and change of diet, clams (again from the grocery) are usually accepted. I will buy them and keep them in a bucket of saltwater overnight to be sure they are alive and to help purge whatever water they have been sitting in (they will have been kept on ice). These can be placed in the tank live and will work as a minor clean-up crew until eaten. I have had some live through several octopuses. Alternately, you can open one and offer the meat (on the half shell usually works). If it is not accepted, be sure to remove it quickly. Other mollusks (oysters, mussels) can be offered as well but they make a mess in the tank and I avoid them.
On a rare occasion (maybe once a month) you can offer a crawfish (crayfish, crawdads). These will not live long in the saltwater so you need to monitor to be sure it was taken before it dies. You can freeze the tails and claws and use for treats but, like crabs, freezing the whole animal may pollute the meat.
You might consider editing your profile to include your city and state. The software does not post this automatically and it is often helpful for directing acquisitions as well as meeting up with other members.
