Octoguard - O. Mercatoris

For feeding Octoguard, look for any dime sized small crab. Porcelain, mithrax and female fiddlers don't need claws disabled. A good test is if the crab can break your skin, the claw needs to be removed or broken. If you can find shore shrimp or any small shrimp and can get them on a skewer (they are too fast for the octo once the octo is adult), these re also usually accepted. I have had trouble getting the mercs to eat table shrimp and swore for years they would not take it but with the last one we found she would accept a small piece with the shell on but not with the shell off so that is also worth a try. I think I also mentioned they love hermits if you will take them out of the shell and offer them directly but this is difficult to do. I froze some larger ones to kill them in the most humane way I could come up with and then cracked the shells. With patience you can usually get them out in one piece. Kara mentioned that they accidentally left some out of the water once and the hermits evacuated their shells. I gave this a brief try without success but was concerned about them suffering a slow death by drying out and probably did not leave them out of the water long enough. If you try to remove them you will see why the octos often don't bother, even dead their tails are tightly ensconced in the shells and they do not remove easily.
 
Thank you for moving the thread. I set up the 30 tall and will be moving octoguard today or tomorrow. I was looking over my 90 and saw octoguard in a barnacle and snaped a pic. This might be a common thing with mercs, I think I read it somewhere but I dont have the time to look it up right now. he likes to pull things on him to cover himself up or hide.
 

Attachments

  • conv_300824.jpg
    conv_300824.jpg
    2.3 MB · Views: 265
this is not the first time he or she has done this. the first week I got him he did this. I got him to take and eat 2 frozen krill today. never would have thought that he would eat them but he did. I know he is a dwarf but wouldnt she be a little bigger then this? I mean the body is no bigger then my thumb nail. If you go back and look at the pic of where I have him out of the water hanging off the barnicale you can see my thumb at the top of the pic. I havent researched the sizes of a merc yet but if this is full size then damm there tiny.
 
I would guestimate the average mantle size for a mercatoris to be about the size of your thumb to the first joint.

We have seen a really large variance in the size of all species we have kept. LittleBit was tiny for a vulgaris (and one reason it took a long time to accept her species). I have kept O. hummelincki the size of an O. mercatoris and others with a mantle the size of O. briareus. Muctopus (Dr. Christine Huffard) has mentioned that their is a large in situ variation of A. aculeatus and discounted food availability. We have also seen quite a variation in appetites. For a long time I believed that you could use the size of O. briareus to get a feel for age but, that too has gone out the window.
 
I have to say I am a little worried. I have spent the evening reading about past octo keepers of mercs only having them for a very short time. most of the time 2 months or less. also how most of the other species do not living much longer. I know they have a very short lifespans but I sure hope I get more time with my octos them most are getting. When I had my volgaris for aprox 14 months I felt that was a little short of a life. and realize now that it was a good long life. it seems that the bigger species live longer. Is this true? I know there have been a few that have had long lifespans. What species tend to live the longest. I know its hard to get A particular species but I have the ability to get many. I have many crabber friends and also some offshore fishing buddys that get them all the time. This is for future referance. I am happy with the 2 I have. thanks
 
It seems that the bigger species live longer. Is this true?
Generally speaking, yes. The Giant Pacific Octopus has about a 4 year lifespan and there are reports (accuracy not clear) of at least one living 6 years in captivity. Of the ones you will have access to from the wild in FL the vulgaris will have the longest natural lifespan guestimated at about 18 months (a small egg species for age at capture even as a small animal has requires adding a month for drifting in the plankton, not possible to raise from egg so actual is hard to determine). As a rule of thumb, O. mercatoris live 8-10 months with some males raised in captivity exceeding 12, O hummelincki is small egged and hard to know the age at capture (again, it can't be raised from hatchling in a home aquarium) but the expectation is 12 months (I suspect it is a longer since I have kept a few over 7 months that appeared to be adult when they arrived but it is an odd species and may be more than one lumped together), O briareus is a confirmed 12 month (large egg species with a minimal amount of success being tank raised) norm with the males living a little longer and the females a bit shorter, brooding at around 8 months.

Most likely found in the crabbers traps will be O. briareus, O. mercatoris or O. vulgaris (in order of commonly bought by licensed collectors to resell but I don't know about actual frequency or if the location makes a major difference). It appears that O. briareus has had several very good hatching years and are quite plentiful (to the chagrin of crabbers). We have not seen many O. mercatoris for about two years but are now seeing them show up again. O. hummelincki for sale were most commonly purchased from collectors in Haiti but they are common to the Keys (not sure about north of there though and I suspect not). Since the earthquake, very few have been available. I was very lucky to have kept Octavia last year (in tank 9.5 months, captured in the FL Keys) and am hoping we will start seeing more of this species.

There is one other Caribbean (or new to the Caribbean) that I have had the honor of keeping. I am not sure of its lifespan (I kept him for 10 months and have no clue on the species but I keep trying to find out). I may have kept a female recently but she closed herself into a den within two days, would not eat and I expected hatchlings. She died without offspring and I could not tell if she ever laid eggs. The male was a wonderful animal and I was extremely excited to have had the chance with the female and majorly disappointed that she was not with me long and that I did not get to see if it was a small or large egg species. One way to id this one is the presence of a pair of circles (called ocelli or eye spots) below the eye on at the top of the web. O. hummelincki has a similar pair of eyespots but the outer ring is yellow and the inner a bright blue (when displayed) this one has a tan/brown outer ring (you can see it in some of the photos) and a brown to black (that may even reflect an almost midnight blue) center. I have no idea if this one invades the crabbers' traps or not :wink:

Colder water species (the GPO being one) may as much as double the warm water lifespan (again a generalization) . There may be evidence of some deeper water Pacifics also living longer and some of the very cold water animals (Alaska and Hydrothermal vent animals) are suspected of extended lifespans but they are just now being studied. There are only two Pacifics that we currently see in home aquariums. The most common is O. bimaculoides (commonly called bimac). We have seen a few of these live almost 3 years IF they are kept at temperatures below 68 degrees. At 70 degrees they may live between 12 and 18 months, much like vulgaris. At warmer temps, shorter but more active lives as long as the temps don't exceed about 72 degrees over any extended period. O. reubescens, the other common coldwater animal we occasionally see, needs even colder water just to survive and I don't know its lifespan.
 
Thanks again for all the info. I guess the biggest issue is getting a young animal. do they ship well? I know I read on one of your posts that you were going to get a different species but were afraid of the shipping. I guess what i am saying is if I was to get multiple octos would they ship ok. I would not want money accept for shipping costs. I see people asking where to get octos all the time. I know that I am not licensed to sell but if I was giving them away could I get in trouble? As you said the crabbers are really mad about the numbers of octos and would be happy to give me them. I would throw them a 12 pack. I guess my idea here is to help the octo keepers out there that eather pay to much or cant find them. I prob cant do this because of it being against the law. but if it isnt for profit.
 
As far as we know (most research is done in CA for bimacs and I don't know about FL laws and live animals - octos often don't count though) as long as you don't charge anything you should be fine. Timing is often an issue (when one is available, no ones tank is ready, when you don't have one 10 people are looking). If you don't have a commercial account, it can cost as much as $150 ($75 being more the norm) for shipping. FedEx is a bit sticky with live animals and doubles their charge if you want it guaranteed. If you ship Mon - Wed overnight and the recipient agrees to eat the cost if things go wrong, this can be avoided. Most suppliers (Live Aquaria guarantees everything but most others cannot afford this) do not include the cost of shipping in their guarantee and don't use the extra cost rate because of high reliability.

Shipping is stressful and I allow two full weeks before I breath comfortably about the success of the shipping and acclimation. They need to be shipped in lots of water and in oxygen, not air. Most survive arrival with good packing but we do lose a few in shipping, primarily from inking. Some suppliers will attempt to get the animal to ink early on the day of shipment (in a separate container and then a transfer to clean water). This is controversial as it does add stress to the animal (which can be lethal) and any advantage is anecdotal but my supplier has started doing this after I lost one that inked heavily in shipping and I suspect it does more good than harm.

If all that is not a dissuasion, probably the best way to aid a member is to PM someone you see looking and see what happens. Be sure to clearly state that these are crab trap rescues, you will do your best to ID the animal but can't guarantee species and that you are only being reimbursed for the freight. Joe-Ceph did this for me and another member with a pair of bimacs he found while tide pooling. He requested that we pay the freight directly (easily done by setting up an account with FedEx on-line) to avoid any possible questions about payment.
 
Thank you for all your advice on this. An update on octoguard. this morning he/she was in the same barnicle that hes been in for the last few days when I started thinking about what you said about hermit crabs. then remembered I had put about 6 hermits in the tank about 3 weeks ago and had not seen any in some time. So off to the lfs that had hermits for 99cents. I got 40 went back to the shop and was floating them. wile doing this I gave octoguard another krill and he took it. a few mins later I released the crabs. and walked away. a min later my employee told me the crabs were eating a shrimp. I looked and they had the krill. damm I thought octoguard lost out to the crabs. then I looked at octoguard and saw he had 2 hermits at one time lol PIGGY This was late in the day and I went home for the night. couple hours later I had to go back to the shop because I forgot something. I went in without turning on the lights and grabed my flashlight. turned it on but kept my hand over the light. I looked in his barnicle but he wasnt in there so looked around and he was out and moving around. I was so excited. This is the first time I have seen him out on his own. Funny how something so small can make me so happy. I got out my phone and snaped a couple pics of him. I guess she is not brooding. YAAAA
 
I got out my phone and snaped a couple pics of him.
Sooo where are the pictures :biggrin2:. Journals are particularly great for photos because they don't get lost and become a reviewable history.

He may or may not be eating the crabs (depends on the individual animal except for possibly O vulgaris who eats anything that moves) but will collect them for den doors. I have seen some pretty funny events with snails and crabs the oct had to keep retrieve the door. There is a video of LittlBit (O. vulgaris) slamming a shell on the rock outside her den but I don't think she was trying to open it, I think she was trying to rattle the snail's brain because his door kept trying to crawl away :biggrin2:

The little things bring big smiles! Locate a red flash light to keep near the tank or set up a shop light (the old fashioned kind that looks like a cone) with a red "party" light (available at Home Depot and Wal-mart) over the tank and leave it on all the time. With the overhead red light on, you won't have to hide the lighting and it will give you a tiny bit of walking light in the shop with the lights off. You can get fancier, but the clip on style is often the easiest to set up.
 

Shop Amazon

Shop Amazon
Shop Amazon; support TONMO!
Shop Amazon
We are a participant in the Amazon Services LLC Associates Program, an affiliate program designed to provide a means for us to earn fees by linking to Amazon and affiliated sites.
Back
Top