Strange shrimp/pod type critters?

[daveoirl]

Hi!
I have noticed tiny shrimp/pod type critters in a piece of rock.
- they are really small. Roughly same size as munnid isopods
- they stay in holes in the rock, and dart put every now and then to grab food?
- not sure if they are eating the actual pods that crawl over the rock
- they have multiple long antennae
- they have bright white markings on their body

I have attached some videos, and a picture highlighting some of the holes they live in.
I am also wondering what the other critter is I point out with the yellow arrow.

Critter ID 1

youtube.com

Critter ID 2

youtube.com

Critter ID 3

youtube.com

Thanks all!
Dave

 

[loganzielke]

amphipods i think. there harmless

 

[daveoirl]

amphipods i think. there harmless

Thanks Logan. They do seem pretty different to amphipods to me. Mainly in terms of their behaviour, staying in their own holes and only darting in and out. Especially compared to the other amphipods I have in the tank. Which are bigger and crawl around the rocks much more. Just want to make sure they aren't gonna cause me issues as they grow and/or multiply!

 

[Tired]

Those are amphipods, but a different species than the usual. The two white stripes are interesting. More than likely harmless- amphipods generally are. Though they can bother corals if you have a lot and no fish to eat them.

The thing with the yellow arrow looks like probably a barnacle. Does it periodically stick out sort of a fan/antenna/hand arrangement and wave? If so, that's a barnacle. If not, that's a dead barnacle.

 

[daveoirl]

Thanks Tired, for confirming the pod ID from Logan. I do have a lot of pods in the DT, but almost all are munnid isopods. I will eventually get a dragnet of some sort, but even though there are a lot of pods the tank is still only 4 months old. So want to hold off getting one until I am sure it is mature and has a sustainable population of pods to feed it.

The other thing is interesting. It doesn't have any sort of "appendage" it sticks out, that I have noticed. However it does move. Those two round/protruding parts sort of open/swell a little, and if anything comes near it does react by shrinking/closing them.

 

[elysics]

Thanks Tired, for confirming the pod ID from Logan. I do have a lot of pods in the DT, but almost all are munnid isopods. I will eventually get a dragnet of some sort, but even though there are a lot of pods the tank is still only 4 months old. So want to hold off getting one until I am sure it is mature and has a sustainable population of pods to feed it.

The other thing is interesting. It doesn't have any sort of "appendage" it sticks out, that I have noticed. However it does move. Those two round/protruding parts sort of open/swell a little, and if anything comes near it does react by shrinking/closing them.

The thing with an arrow is a tunicate, that white compass pattern around the edge of the tube is rather distinct, as is your description of the vents swelling, thats how they feed

 

[daveoirl]

The thing with an arrow is a tunicate, that white compass pattern around the edge of the tube is rather distinct, as is your description of the vents swelling, thats how they feed

Thanks for the ID elysics!

 

[Tired]

Ah, I see it now- I was thinking just the vent was the animal. Yeah, that's a tunicate. Neat animals. They're chordates, which means they're our closest non-vertebrate relatives.

 

[ying yang]

Very interesting.
I got exact same looking spider acting pod things and started a thread last month.will try find it.
Couldnt get exact id though but so far no harm came to my lobo that they in and around

 

[ying yang]

Lobo with hole in skeloton and creature inside

Hi all,hope your well. one my wrasse dive bombing sandbed then coming straight out the sand and him and his fishy friends eating all the micro fauna so decided last night to glue/epoxy to main rockwork sticking out in hope it grew new head on side facing upto the light, but weight of itself...

www.reef2reef.com

 

[ying yang]

This video at 1.10 minutes shows it best i believe

 

[Tired]

Oh, that looks like the same animal species, all right. The two white marks are there.

They look to me like comically long-legged amphipods. Probably they're darting out looking for detritus.

 

[ying yang]

Oh, that looks like the same animal species, all right. The two white marks are there.

They look to me like comically long-legged amphipods. Probably they're darting out looking for detritus.

What i observed is they stay at entrance to a rock and sit and wait and dart out and grab smaller copepods plus i think pieces of floating particles

 

[ying yang]

Look at 2.25 minutes,large pod catching small pod.
Its a poddy pod world ha ha

Different pods than op but still interesting

 

[Tired]

Oh, that's actually a thing that the typical amphipods do, too. They aren't super predatory, but they'll definitely catch and eat other, smaller pods if they get an opportunity.

I think that critter getting eaten in your video is a munnid isopod. Harmless algae-eater. Cool video.

 

[ying yang]

Oh, that's actually a thing that the typical amphipods do, too. They aren't super predatory, but they'll definitely catch and eat other, smaller pods if they get an opportunity.

I think that critter getting eaten in your video is a munnid isopod. Harmless algae-eater. Cool video.

Yeah i read munnid isopods are rare to have in reef tanks but i have many of them.well many of lots different small and some HUGE pods everywhere and i never bought any pods.they just came with the 5 coral frags i bought,even after dipping the corals.
Lots them spiromid worms probably hundreds but they extra food for my cbb and silver nelly wrasse and i probably get more enjoyment when lights are off in tank and all the small critters come out to play ha ha