Pod population explosion, feasting on my zoas?

[Pastronomer]

I know this is a potentially controversial question but I'm still new enough in this hobby to be finding things out myself.

A night time peak in my tank has revealed an enormous pod population, running rampant all over the sand, rocks and corals. I've also recently lost a few zoa colonies and this evening spotted one pod very happily burying it's way into my now non existent rasta zoa.

Water quality is good so I'm not blaming that for coral issues (35ppt, 8dkh, 450 cal, 1400 mag, 10 no3), but many seem a bit grumpy, as does my BTA. Could the pods be causing my corals to become irritated? Can they actually eat my zoas?

Any tips on control apart from cutting down feeding (I feed sparingly as it is). Tank is a 20g cube with 2 clowns and a goby, so a bit small to house more fish, as much as I would looovvveee a mandarin.

When I say rampant, I mean I can't actually imagine how they all manage to hide in the day as there are that many.

Thanks!


Rasta Zoa Vs Amphipod

 

[Mr. Mojo Rising]

A copepod is the size of this period. They are harmless to your corals, in fact, corals munch on pods. If a pod climbs onto a coral polyp it’s a free snack.

Sorry but what are you trying to show in the picture? Can you show a full tank pic?

 

[Pastronomer]

A copepod is the size of this period. They are harmless to your corals, in fact, corals munch on pods. If a pod climbs onto a coral polyp it’s a free snack.

Sorry but what are you trying to show in the picture? Can you show a full tank pic?

I was assuming they were amphipods? I've got copepods on the glass and I'm happy for them existing, but these are like tiny shrimp, maybe 3mm or 1/8" long, thousands of them.

In that pic, if you tap it and zoom in you'll see one of them face first in what was a Zoa.

 

[taricha]

I've had amphipods eat my polyps. If you have no fish that eat them they can become a problem. Just one fish that hunts amphipods made my population much more well-behaved

 

[DanyL]

Maybe these are isopods and not amphipods?

They look similar to each other, but one can be predatory while the other (at least to my knowledge) not.

 

[BZOFIQ]

This is second thread this week complaining about pods - that everybody else would love to have a tank full.

Is it just me?

 

[DanyL]

This is second thread this week complaining about pods - that everybody else would love to have a tank full.

Is it just me?

I mean, pods is a general name for probably hundreds of different species, and some can indeed be predatory.

Chances for having predatory pods in the tank is likely to be low, and you are correct that often times it’s just a “new reefer” panic rather than an actual problem.
But I wouldn’t dismiss this possibility straight away.

 

[Pastronomer]

Got a better photo of the pod I'm dealing with. As you can see there are the standard copepods which I'm happy about for scale, and a bumblebee snail shell.

At a guess I'd say whatever this thing is 5-8mm long not including antennae, and there are thousands of them.

It's an isopod of some sort, but wondering if it's the type that is irritating my corals.

 

[Reefkeepers Archive]

Got a better photo of the pod I'm dealing with. As you can see there are the standard copepods which I'm happy about for scale, and a bumblebee snail shell.

At a guess I'd say whatever this thing is 5-8mm long not including antennae, and there are thousands of them.

It's an isopod of some sort, but wondering if it's the type that is irritating my corals.

I can't tell you if that's an isopod or amphipod, but definitely not a "pod"

@ISpeakForTheSeas?

 

[ISpeakForTheSeas]

I can't tell you if that's an isopod or amphipod, but definitely not a "pod"

@ISpeakForTheSeas?

This critter is surprisingly ambiguous, but I'm leaning toward amphipod. OP, any chance you could get a clear, side shot of the front limbs or a top-down shot of the tail of one of these?

Also, for those wondering, the term "pods," even if only applied to amphipods and copepods (not including isopods, ostracods, etc.) would apply to literally over twenty thousand species.

 

[Jay'sReefBugs]

That 100% a amphipod and it's more then likely just eating algea or dead flesh from around the base of the zoa . People get confused by this thinking they are eating the zoas . Can they irritate zoas yes eat them no . Theres another issue in your tank going on a key factor is your bta not doing well . I would run a ICP test because theres alot more to it then just cal,mag,kh ,no3,po4

 

[Tony Thompson]

I have observed amphipods eating corals. It is a thing.

There is also data available on this available in academic publications.

The word "pods" can be used for Amphipods, Copepods and Isopods, "Pods" on its own it just means foot or feet.

The one in the photo looks like a amphipod due to its shape. Isopods are generally vertically flatter.

 

[ISpeakForTheSeas]

I have observed amphipods eating corals. It is a thing.

There is also data available on this available in academic publications.

Genuinely curious here - do you have any references to these academic publications that show this? I wouldn't be surprised if some did, but I haven't been able to find any info on it so far.

 

[Jay'sReefBugs]

Genuinely curious here - do you have any references to these academic publications that show this? I wouldn't be surprised if some did, but I haven't been able to find any info on it so far.

Same here I've seen Zero studies done from an actual academic or scientific source over the years . If you can please link theses as I would love to read them

 

[Tony Thompson]

Same here I've seen Zero studies done from an actual academic or scientific source over the years . If you can please link theses as I would love to read them

There are a certain species of amphipoda that live in specific coral species including anemones. These species have been classified as faculative corallivores.

Just do a search on researchgate if one has an academic logon there are papers available.

There has also been extensive reports in the aquarium hobby including public aquariums of faculative corallivore amphipods.

As a quick reference (but not exclusive) here is an article from the Journal of Crustacean Biology.

https://doi.org/10.1093/jcbiol/ruaa061

Group 2 is the one to read.

My personal experience of observing corralivore amphipods was in a 16L fishless aquarium with discosoma spp. species. I observed them very closely as the aquarium was on my office desk. I watched them devour a whole discosomma right before my eyes.

There are a wide range of amphipods that east various Cnidarians including anthazoa.

 

[Jay'sReefBugs]

There are a certain species of amphipoda that live in specific coral species including anemones. These species have been classified as faculative corallivores.

Just do a search on researchgate if one has an academic logon there are papers available.

There has also been extensive reports in the aquarium hobby including public aquariums of faculative corallivore amphipods.

As a quick reference (but not exclusive) here is an article from the Journal of Crustacean Biology.

https://doi.org/10.1093/jcbiol/ruaa061

Group 2 is the one to read.

My personal experience of observing corralivore amphipods was in a 16L fishless aquarium with discosoma spp. species. I observed them very closely as the aquarium was on my office desk. I watched them devour a whole discosomma right before my eyes.

There are a wide range of amphipods that east various Cnidarians including anthazoa.

Great read thanks for the info but definitely not the same spices as he has as majority in this report come from artic conditions. What OP pictured is a common amphipod in the marine industry in the U.S . I did a quick search on researchgate but yielded no results on tropical anthazoa eating amphipods. If you have a link please repost it as I'm now down the rabbit hole as I've never seen this information like this before and I'm fully intrigued lol . Thanks a Ton for posting I Learn something new every day in this hobby it's great ! For reference these images are from the report posted

 

[ISpeakForTheSeas]

There are a certain species of amphipoda that live in specific coral species including anemones. These species have been classified as faculative corallivores.

Just do a search on researchgate if one has an academic logon there are papers available.

There has also been extensive reports in the aquarium hobby including public aquariums of faculative corallivore amphipods.

As a quick reference (but not exclusive) here is an article from the Journal of Crustacean Biology.

https://doi.org/10.1093/jcbiol/ruaa061

Group 2 is the one to read.

My personal experience of observing corralivore amphipods was in a 16L fishless aquarium with discosoma spp. species. I observed them very closely as the aquarium was on my office desk. I watched them devour a whole discosomma right before my eyes.

There are a wide range of amphipods that east various Cnidarians including anthazoa.

Great read thanks for the info but definitely not the same spices as he has as majority in this report come from artic conditions. What OP pictured is a common amphipod in the marine industry in the U.S . I did a quick search on researchgate but yielded no results on tropical anthazoa eating amphipods. If you have a link please repost it as I'm now down the rabbit hole as I've never seen this information like this before and I'm fully intrigued lol . Thanks a Ton for posting I Learn something new every day in this hobby it's great ! For reference these images are from the report posted

From what I've found (using the link posted as a springboard), it seems that there are a few (mostly deep sea [bathypelagic] and super coldwater) amphipods that do live in corals (primarily octocorals) and other hosts; it's expected (but not studied that I've found) that at least some of them are parasitic or will evolve into parasitic species in the future:

Life Cycle and Life History Strategies of Parasitic Crustacea

Different parasitic life strategies are described including four new life cycles: complex rebrooding, micro-male, mesoparasite and prey-predator transfer. Four new life cycle behaviours are named: nursery hiding, mid-moult stage, positive precursor (intraspecific ...

www.ncbi.nlm.nih.gov

https://www.semanticscholar.org/paper/A-new-gammaridean-amphipod%2C-Pleusymtes-symbiotica%2C-Gam%C3%B4-Shinpo/ca395759cf967b544b1fed53edc37fbf06025860

 

[Jay'sReefBugs]

From what I've found (using the link posted as a springboard), it seems that there are a few (mostly deep sea [bathypelagic] and super coldwater) amphipods that do live in corals (primarily octocorals) and other hosts; it's expected (but not studied that I've found) that at least some of them are parasitic or will evolve into parasitic species in the future:

Life Cycle and Life History Strategies of Parasitic Crustacea

Different parasitic life strategies are described including four new life cycles: complex rebrooding, micro-male, mesoparasite and prey-predator transfer. Four new life cycle behaviours are named: nursery hiding, mid-moult stage, positive precursor (intraspecific ...

www.ncbi.nlm.nih.gov

https://www.semanticscholar.org/paper/A-new-gammaridean-amphipod%2C-Pleusymtes-symbiotica%2C-Gam%C3%B4-Shinpo/ca395759cf967b544b1fed53edc37fbf06025860

Same here but I thought they didn't eat live tissue at all so I was dead wrong on that aseptic even if they are cold water species. With that said I've only been in the biodiversity industry for 4 years now so I still have alot to learn

 

[Tony Thompson]

Great read thanks for the info but definitely not the same spices as he has as majority in this report come from artic conditions. What OP pictured is a common amphipod in the marine industry in the U.S . I did a quick search on researchgate but yielded no results on tropical anthazoa eating amphipods. If you have a link please repost it as I'm now down the rabbit hole as I've never seen this information like this before and I'm fully intrigued lol . Thanks a Ton for posting I Learn something new every day in this hobby it's great ! For reference these images are from the report posted

Hi, I had no intention of identifying the particular species in the posters comments, neither was my intention to link that posters species to the article.

My intention is to show that there is evidence of coral predation by certain species of Amphipods, more detailed as corallivore tendency. In fact there are a number of coral parasitic species of Copepods, Amphipods and Isopods.

I simply grabbed the first article I could find to lead into the conversation. "Are there Amphipod species that eat coral" My opinion based on "historical research" is yes.

Also I have personally witnessed this predation first hand.

It is a very long time ago that I researched the subject so have no links to mind. However when searching for information on such a diverse group especially with reference to corals or Anthazoa, in specific. It was helpful to broaden the search topic to a larger group such as Cnideria, the information is often hidden in the depth of related research.

Why are there so many reports of amphipods eating coral tissue in the hobby? This in itself lead me to carry out my own investigation quite a few years ago.

If there is evidence that identifies at least one species of amphipod (such as the article linked) that predate on coral tissue, then in my mind the answer to the question do some amphipods predate on coral tissue? the answer would appear to me be "yes" I would also theorise that there are species that feed on Zoanthids.

 

[Tony Thompson]

I would also like to add to the conversation, the exploration of the theory that certain species of animals adapt to the closed systems of aquariums. An animal behaviour including feeding behaviour may be influenced by variation in availability and competition.

As a general observation many of the anecdotal evidence I have read in the hobby have a common thread of large populations of amphipods. This was also the case in my own aquarium mentioned earlier. I had no natural predators of the amphipods in my tank as it was fishless, also very little detritus. Maybe this trait of eating coral tissue is one of opportunity and necessity. ?

Also certain species of amphipods have been described as having certain immunity from nematocysts.