Cleaner Shrimps and Bright Lighting

[Quinn]

Has anyone done any research into why some cleaner shrimps hide under rocks from bright lighting? I bought two on Saturday and am finding that, like Canadian Man's and Dez's, they hide in relatively dark areas all day. From what I know, Delphinus' do not, and are out and about even under his halides. Mine are moving all over, eating flake food and so on, but generally hanging out upside down away from the lights.

[Beverly]

Originally Posted by teevee

Mine are moving all over, eating flake food and so on, but generally hanging out upside down away from the lights.

Can't say for sure, Quinn, but I'll bet their hiding behaviour is for self-preservation. Being in the light makes them easy prey, even when no predators are around. It's like the crabs in my reef. They don't come out during the day either ... which reminds me - it's lights out. Maybe I'll see one of the little beggars

[Son Of Skyline]

I never see my cleaner shrimp while the lights are on! The only time they ever come out is when I feed the tank. Other than that I can only see them come out in the dark. I guess that's just the way most of them are.

[Chad]

Mine was like that when I first got him.. would only hide in the rocks etc. but now he is everywhere..

[Michael]

Another thing to consider is that they are not hiding from the light, but any possible predators. I know my tang always goes nose to nose with my peppermint shrimp (when they are out in daylight) just to let the shrimp know who is boss.
-I have 2 peppermint shrimp, and one always hides under a rock, and the other is moving about at all hours.
(I'm kinda assuming cleaners and peppermints would both apply to this topic)

Michael

[sumpfinfishe]

Noctournal maybe

[Delphinus]

I never had shrimp come out into the open until I had four of them together. The group dynamics of four is so amazingly different than just one or two it does not cease to amaze me (whatsoever). These guys have far more complex behaviours than I think we give them credit for.

I should mention that although I've had four shrimp before, it wasn't four of the same. I.e., two peppermint, two cleaners. And in those cases both pairs stayed nice and hidden throughout the day. So it's something about the fact there are four (4 cleaner shrimp that is) in their social group that makes the difference.

I first had one shrimp in the 75g. I never saw him, day or night, he was so amazingly hidden. I then put in three (it was a mistake actually, I don't remember the details but I think I only meant to order two. I wanted two, and I thought I had lost the one I had, so I meant to order two, but I was somehow stuck on the thought "but there might be another one so that makes three" and I told J&L "send me 3." Whooops, well, whatever, three came, and I just put them in together.) Even after the three were established, I didn't see the original for a while, and then gradually I saw more and more. But it was easily a full month before I saw a group dynamic of "four" as opposed to a group dynamic of "three plus a loner." Even now, I still see times where I see three together, and a fourth off to the side.

The other thing that I find possibly anomalous is their complete lack of fear when they molt. They molt right out in the open (I've now witnessed it several times), and then they go into a brief mating frenzy, and then the "molt-ee" then goes up to one of the upper corners to rest up for about a day. This I find extraordinary. Most of the times they're shy when they're about to molt (presumably because they're vulnerable), and their espescially shy right after a molt because they're soft shelled for a little while, it's in their best interests to hide. Not stand right out in the open like that.

And the one last tidbit I want to share: when I had a pair, both of them were always covered in eggs. Now that there are four, there is only ever one at a time who carries eggs. Sometimes two, but only very seldom. But never more than that. I don't know if I'm reading too much into what could just be a coincidence, but still I find it somewhat noteworthy. Given the orgies they get into right after a molt, I would have thought they'd all carry eggs. But it seems they stagger their molting. I have no idea what this means, but one thing I intend to follow up on now is I am going to start tracking iodine levels just to make sure everything is on the up-and-up on that one.

If I stare at them long enough I can usually start to differentiate the individuals on a day-to-day basis (until one of them molts, and then I have to start over).

[Quinn]

Mine moved to the left side of my tank yesterday, the side that is easily viewable without risk of being burnt on my MH ballast, and both show no fear of me or anything, but they are still avoiding the light. As soon as the lights went off, they began to wander around in the open. I do plan to add two more soon, so hopefully they will be as out and out as Tony's.

I should note that one (the smaller of the two) molted in the bag on the way home from Edmonton.

[Chad]

Yesterday I had my hand in the tank to move a coral after it had fallen over ( still don't know how that happened since it had secured itself, maybe it intended to move ), and my cleaner shrimp went right up to my hand and then right onto it and started to "clean" it. Even after I had moved my hand to get it off it would come right back. Was funny.. wish I had gotten a picture of it.

Chad

[AJ_77]

From your pal Mr Fenner at wetwebmedia.com, "All Cleaner Shrimp species prefer subdued lighting, plenty of rocky cover, nooks and crannies..."

Also notice that their cleaning stations or favourite hangouts are places where fish present themselves occasionally for a going-over, and are fairly vulnerable while in this position. It makes sense to be discreet...

Like when the masseuse sets up her table in your living room, and you draw the blinds for privacy.