Mysid shrimp on doctors, surgeons and tangs

[MikeJacobs]

A few months ago I saw my first "growth" on a blue tang... I was sure I was wrong, but it looked just like a small lobster tail growing out of the gill.

Though here for a year now I hadn't really noticed how many of these fish have small riders. According to Reef Creatures they're not parasites, even though they are permanently attached and lose their ability to swim.

And there are LOTS of them! My impression is that they're more common on solo fish than in schools, so maybe either these fish are groomed by one another or ostrasized once they pick up a mysid shrimp.

Some are quite large, and I wonder if they hamper the fish's ability to escape preditors. I haven't seen two on one fish yet, but the book says that mating pairs find one another on-board, and can even change sex if they're both the same!

Well, just thought I'd share... anybody else look for these?

 

[ScubaRon]

Mike,

I think what you saw was an isopod. Mysid shrimp are only 1-2 mm long and to my knowledge do not attach themselves to fish.
ScubaRon

 

[MikeJacobs]

ScubaRon once bubbled... I think what you saw was an isopod. Mysid shrimp are only 1-2 mm long and to my knowledge do not attach themselves to fish.ScubaRon

lol I'll take your word for it; they say they're mysid shrimp in Reef Creatures, and the pics are the same. But regardless, they've become a real favorite of mine. I can almost pick out the 'brooding females' now that I've seen so many and can sort of differentiate.

 

[Gibbon]

These little guys and galls are verry cool.
I take care of fish (aquariums), and the fish will sometimes practically for a line to be serviced (cleaned) by the shrimp.

 

[ScubaRon]

MikeJacobs once bubbled...
...they say they're mysid shrimp in Reef Creatures, and the pics are the same. ...

Now you got me curious, so I yanked out my Reef Creatures (1993 version) and on page 183 it shows both the isopod (on top) and the mysid shrimp (middle). They really are very different.

Here are some web pages of the isopod and mysid shrimp .

Gibbon, you are referring to so called cleaner shrimp which are again totally different. They are not parasitic, but actually clean parasites, e.g. small isopods, from the fish. I have several in my reef tank and if you stick your hand in they will try to clean it too.
ScubaRon

 

[MikeJacobs]

ScubaRon once bubbled... Now you got me curious, so I yanked out my Reef Creatures... SNIP...

Your links didn't come through very well, but I did see the same creature. Is an isopod a parasite?

 

[MikeJacobs]

Gibbon once bubbled... These little guys and galls are verry cool. I take care of fish (aquariums), and the fish will sometimes practically for a line to be serviced (cleaned) by the shrimp.

Yes, cleaners are a trip! We have them on our reef, as well as little neon blue fish that hang around brian coral and wait for a chance to clean something.

The shrimp are more adventurous hand-cleaners than the fish, which are more careful. It looks as though they WANT to come clean my hand, but can't get their courage up. Then again, maybe I'm too impatient.

But ScubaRon's right, Gibbon, these are two completely different animals.

 

[Former FLL Now MSP Diver]

After reading these posts - I grabbed my book too. I think the confusion comes from the way the page is laid out. Both names are at the top, and both pictures appear on the pages.

I believe ScubaRon is correct. The isopod hangs on the fish's bodies. The mysid are the tiny shrimp that look like fry.

My book says that the isopods are symbiotic versus parasitic. They don't feed off the fish, but rather capture stray particles that drift near from the fishes mouth.

It still looks nasty.

Marc

 

[Scuba_Jenny]

Wow! Thanks for the lessons guys! I always wondered what those things were hanging off the fish (isopod) and now I know. Always wondered if they beneficial or not. Its nice to know they aren't like the blood suckers they have up north (ewwyuk).
I agree, they look nasty...

 

[ScubaRon]

scuba_jenny once bubbled...
Its nice to know they aren't like the blood suckers they have up north (ewwyuk)...

Actually many isopods are blood suckers and some types will kill a fish in hours!
And some of them grow quite large too: giant isopod !

The good part is that these large ones only live a few thousand feet deep.
ScubaRon