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FAQs about Sea Slugs, the Opisthobranchs, Behavior

Related Articles: Sea Slugs, Nudibranchs,

Related FAQs: Seaslugs 1, Seaslugs 2, & FAQs on: Seaslug Identification, Seaslug Compatibility, Seaslug Selection, Seaslug Systems, Seaslug Feeding, Seaslug Disease, Seaslug Reproduction, & Marine Snails 1Marine Snails 2Marine Snails 3 Nudibranchs, Nudibranchs 2, Nudibranch Identification, Nudibranch Behavior, Nudibranch Compatibility, Nudibranch Selection, Nudibranch Systems, Nudibranch Feeding, Nudibranch Disease, Nudibranch Reproduction, Berghia Nudibranchs, Snail ID 1, Snail ID 2, Snail ID 3

Take your time... they "do" a bunch. Chromodoris magnifica.

How old and how big 1/24/10
Hello there. I was just wondering what the longest time was for a sea hare to live in a home aquarium.
<At least years. Some Aplysia California for a decade or more reportedly>
I am also wondering what the longest Pajama Cardinal grew to be in a home aquarium.
<Four inches, ten cm.s or so>
I think I may have some record breaking specimens, but would like to know the answers to the above questions before I do anything else.
Thank you for your time!
Austin Rice
<Bob Fenner>
Re: How old and how big 1/24/10
4 inches and 10 cm...from tip of the face to tip of the tail, or tail not included? Thanks.
<Not standard length (SL) as in fisheries, ichthyology, but overall length as in pet-fish. B>

Weird behaviour on sea hares... need to read   9/27/08 I have noticed very weird behaviour on the sea slugs. <Mmm, there are tropical and non-tropical species sold in the trade...> I bought them because I have a massive algae problem, which I haven't been able to solve, lights are ok, levels are in 0, I have a phosphate reactor, <Do you have life that needs soluble phosphate?> sump with Caulerpa, <Mmm, toxic itself to degrees> etc. It perhaps magnesium is low and I am fixing it, but there's so much algae that algae predators were needed. <Mmmm, not so sure. Likely other issues... lack of competition, nutrient abundance, imbalance...> Well a long time ago I had a small algae problem and I bought a 4 inch sea hare, the thing was an algae eating machine and it ate all the algae and then died in the powerhead. I have shut down the powerhead now in order to not have this problem again. So 1 year after that incident and with a major algae problem, I bought a new one and it was about 2 inches, it didn't move much, it seemed to sleep most of the day and it apparently died since left no trace and no poop and no algae devoured. So after 4 months I bought 6 sea hares of the spotted variety, <... what species?> they behave very weird, they are 1.5 inches in size, 1 of them spends the whole time upside down, barely moves, I think its dead, other 4 seem to sleep most of the time, I don't see them eat much, and 1 is moving everywhere and eating a lot this one is also the biggest one. I don't know what to think of the ones that sleep a lot or the one upside down, any ideas? <Either incompatible for the system, or the algae present isn't palatable most likely> If they actually get to eat all of the algae, which would take a while, can they feed on Caulerpa?, <Some species some species> I got some feather Caulerpa invading the main tank. Can they be given Nori to eat? <Ditto> Is it true that they only live 2 years at most? <Most, yes. I'd be reading on WWM re Caulerpa, Algae control in general and Aplysiids... for this last here: http://wetwebmedia.com/seaslugcomp.htm and the linked files above... Get reading. Bob Fenner>

Spitting Sea Slugs 1/21/04 Hello Chaps and thanks for a wonderful website. <Hello from the left side of the pond!  Glad you enjoy WWM.> I have a 40 gallon tank with loads of Fiji live rock, two true tank bred clowns, two green Chromis and a tank bred flame angel. The tank has been running for a few months with no problems, thanks to lots of reading of your site. I have a slight concern over what seems to be a group of sea slugs in my tank. They generally appear after the lights go out . I have seen about three of them together so I assume there must be more. I noticed the other night that they occasionally spit some sort of brown fluid. They are about  1.5 cm long and dark brown. Do you have any idea what these sitting creatures are and should I remove them? They don't seem to spit at anything in particular but your advise would be greatly valued. <A picture is worth a thousand words or more.  ID is difficult without one.  If they are surviving in your tank, they are getting food.  Many are herbivorous, some are carnivorous.  I don't know what the "spitting" is, but it is probably just excrement, but could be spawning material.  There are some internet sited dedicated to sea slugs and Nudibranchs.  Perhaps you can find a match there.  Best Regards!  Adam> Thanks again.  David

See here... Sea hare 5/3/04 Tube Anemone Good evening my wonderful reefers! lol <live it, swim it, smoke it... er, well.. two of those things at least> I won a Aplysia dactylomela the other day at a raffle.  I won it on purpose out of sympathy, I didn't want it to end up with some poor bloke w/out a clue where it would starve to death. <interesting... perhaps a polite mention to the club/donors to be more conscientious about submitting items of challenging needs for random win/purchase by others> After a bit of hunting around my tank for some red algae (which proved non-existent, the info on the specific type of algae these guys eat is rather lacking, a lot of authors say they eat red algae they just don't specify what kind! I think it must also take them a while to adjust their diet to green algae) <I do not spy it quickly at hand... but we have a link in our bibliography for our Reef Invertebrates book to a web page that lists the exact foods for many species of opisthobranchs> I tried putting in some red/purple Nori by Two Little Fishies (Julian Sprung & Co) and my guy started to chow down. Since then all it does is eat and sleep. hehe <Ahhh... good to hear> I was wondering if you could tell me approx how long this sea hare lives?  I've read from 1-2 years is all.   <hmmm... I am not certain, although I recall the larger temperate  species living somewhat longer than the typical 24 months or less> Do they live longer if they don't mate?   <nope... not to my knowledge. There is precedent to support this in other mollusks (like the famous octopuses with a defined lifespan, breed or no)> It's funny, I live in Miami and went snorkeling the other day and saw a mated pair of Dactylomelas.  I didn't know mine was the same even though I've seen them many times when I snorkel. Also, treading into dangerous waters... are there any colorful Nudi's that can be easily kept in a reef tank or is this a lost cause? <hmmm... sort of. The key to any Nudibranch is identifying and supplying their food source. Many will keep and breed easily if you can do this. I keep an active colony (several hundred!) of beautiful blue Berghia (Aiptasia eaters). Other folks keep and breed Elysia sp algae eaters... some folks even dabble with the Zoanthid eating species. The problem with keeping in reef tanks is that most such systems have excessive powerheads and overflows. If you plan well though, you can keep some beauties> I always feel so bad when I see these really amazing looking, doomed Nudi's at the LFS.  There should be a campaign on to stop the collection of specialized feeders such as these. <no formal campaign is needed. Educated aquarists simply vote with their dollars and do not buy them. They die in the dealers tank, and when it happens enough times, the dealer stops ordering them <G>. You might help this along with  a polite mention of the reality (supported by a helpful list of web links or photocopied documents) that you give to the LFS. If that doesn't work... tell us their name and we'll post them on the wall of shame <G> Ha!> Oh, about how big will a tube anemone get in a reef tank?   <it won't... because it does not belong in a reef tank and will never be placed there by a conscientious aquarist. If you know of anybody tempted to the contrary, please direct them to our extensive archives at wetwebmedia.com for an explanation why not <G>> Will I need meters of sand eventually? lol I hope not. ( <8-12" would work nicely... let it mature for 6-12 months before putting a Cerianthus in a species specific tank (no corals or other anemones unless you intend to sacrifice some)> Ah, the pot calling the kettle black I know, but I'm going to try and provide for it) It's only 3 inches long at the moment and eating fine. <sigh... disappointing> Thanks for all your help! Love you guys, Morgan <sob...sob... another anemone destined to be a statistic. Anthony :p>

Missing Nudibranch Hi guys, hope you're all doing well... << I am. >> Was hoping you might shed some light on a new addition gone MIA. I added 2 lettuce Nudibranchs to my tank a couple days ago as part of a two-fronted attack on hair algae (finally got an RO/DI-- Kent Maxxima-- fertilizer-free water changes to come!), but one of the fellows has gone missing during the 1st night. << Are you sure.  They may hide well. >> No signs of it stuck against a power head (all are screened off), & no sign of him in the overflow compartment either. I'm wondering if a tankmate may have eaten him. << Possible, but I'll say unlikely. >> Basically my inhabitants are currently a Mandarin Dragonet, 2 Green Chromis, a Lysmata amboinensis shrimp, a Spiny Brittle star, a Favia brain coral, some Discosoma & Rhodactis mushrooms, assorted red & blue legged hermit crabs + one scarlet reef hermit, & some Astraea & turbo snails. My 1st suspect is the brittle star-- I'm thinking that with his long searching arms it may have come across it & probably could have caught it pretty easily. I don't think this guy is actively predacious, but could be opportunistic?
<< Doubtful. I wouldn't think of him as the problem. >> My next suspect is the scarlet reef hermit. The only reason I really even consider him is because I had caught him eating a "Red Footed Conch" that I had (never was able to truly id this guy). << Well, that is possible as well, but hermits are more of scavengers and are more likely to eat it something that has already died. >> The hermit would pry open the conch's little 'door' & was picking out matter from inside. I removed the conch & put him in the fuge, but it didn't make it. I haven't caught the hermit assaulting any of the Astraea or Astro, but one wonders... My last suspicion is the Rhodactis mushrooms. One of them is about 4 inches across, & I have seen them close up on morsels that drift onto their surface. I wonder if the Nudibranch could have floated onto one accidentally & been consumed before he could high-tail it off? << Doubtful again. >> What do you think the likelihood of any of these scenarios seem to you? Are the lettuce Nudibranchs 'distasteful' enough that these shouldn't be a concern? << I would bet he simply just died.  They aren't that hardy and being transitioned into a new aquarium may have just been too much.  They often get blown around by powerheads into the rocks and things like that.  I wouldn't think it was predation, so much as unfortunate circumstances. >> I'm trying not to assume the worst, & bearing in mind that he could have just gotten into the rockwork somehow & not being plainly visible, but I'm also thinking that because these guys are partly photosynthetic, that they should hang out in the light, on rocks' surfaces, more or less, right? Thanks for any insight you can offer... << I'd probably not try another.  If you are having a hair algae problem I'll assume you have a water issue problem.  I don't like adding delicate items to a system with water problems. >> Pete Cushnie <<  Blundell  >>

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