[reefcouple]

Thanks Eric, good post..

[rlcline76]

Originally Posted by ejwsr

Google for Ocean Pods.

Only somewhat interesting? More information can be found on Google Scholar, look up copepods. One author Adelaide Rhodes PhD does research on 'pods and sells Ocean Pods. I have bugged her to death for some information and have read all of the articles I could find.

What makes this really complex and a challenge for me is all of the variables for sustaining a population. First is the generation v. life cycle and predation pressure math. Next is the nasty habit that copepods have delaying gestation if there is an upset condition.

What got me really interested in this is that I was keeping a mandarin dragonet in a 12 gallon micro reef. The clowns would eat the tigger pods and the dragonet was always picking at something. I got a 10x loupe and examined an area close to the glass that she had been grazing. I was amazed at the amount of microfauna, like 60 per square centimeter. I have distinguished at least for species of pods in my tank.

This has changed the way I deal with water changes and sand cleaning. Now I use a powerhead to stir up the gunk in the tank and keep it stirred up in an effort to get the gunk into the fine filter and allow the pods to resettle in the sand. I also siphon water from downstream of the filter to reduce the number of pods removed from the system.

The dragonet? I had her for 9 months and not only was her stomach full, she was also getting ready to spawn. Then the male died, poisoning her in the process, and I am waiting for suitable replacements to become available.

Anyway, Dr. Rhodes wrote her dissertation on pods and is very helpful in answering questions.

Eric,
I say somewhat because it depends on what crowd you are talking to. I would be interested in the "size does matter" theory of pods when talking about pod predacious fish. I think it might be something that hobbyists don't think too much about. We say "pods" and leave it at that. So I will be googling. I just gave a presentation on food for the local MAS, and if I look at one more article on food before...tomorrow or Tuesday, I am gonna flip. I need at least 24 hours to stare at the wall.

[ejwsr]

LOL!!!

I know what you mean. I am a certified Fire Service Instructor and just "love" the research process.

Opinion: Size matters based on predation style.

Column feeders need larger masses to be energy effective. They are fighting a current or need to chase their prey, expending energy to get more.

Grazers or stationary source feeders expend their energy on a relatively flat curve, so smaller masses that are slow moving or stationary meet their needs well. I think the density of the population, while linked to numbers, is important.

Here is an experiment for you to try. Make a mix of distinctly different size foods. Throw them in the tank and watch. Ever see an ocellaris clown work over a large piece of krill?

Some of this I learned trout fishing. I only catch and release now.

[ejwsr]

Becky,
I guess I should have italicized Only. Joke, no offense meant or taken. I know that this is rather dry for most people.

[ejwsr]

Almost forgot: Harpacticoid copepod species of interest;

Tigriopus
Nitokra
Tisbe

Listed in order largest to smallest.

[thelastmucci]

Becky, how did I know you would chime in on this one hehe.

Eric, believe it or not I'm actually kinda interested in this stuff too..I love learning about different aspects of reef keeping and any sort of "diffrences" I love to digest. I knew there were different types of pods but never knew their name of the size of them. And you bring up very good points about how bigger ones should be used to feed bigger fish. I intend to have a fuge in the back of my tank so all this information is very useful to me...at least for now.

[ejwsr]

Thanks Marine!

Before this goes into the library I'd like to have the chance to re-research this, get it reviewed by you, my peers, and shoot any holes in it.



Semper Fi!

[rlcline76]

Originally Posted by ejwsr

LOL!!!

I know what you mean. I am a certified Fire Service Instructor and just "love" the research process.

Opinion: Size matters based on predation style.

Column feeders need larger masses to be energy effective. They are fighting a current or need to chase their prey, expending energy to get more.

Grazers or stationary source feeders expend their energy on a relatively flat curve, so smaller masses that are slow moving or stationary meet their needs well. I think the density of the population, while linked to numbers, is important.

Here is an experiment for you to try. Make a mix of distinctly different size foods. Throw them in the tank and watch. Ever see an ocellaris clown work over a large piece of krill?

Some of this I learned trout fishing. I only catch and release now.

Trout is $7/lb here. I eat what I catch!
Thanks for the listing, makes my search much easier.

[ejwsr]

Apparently I have too much time on my hands...

I have been giving it some thought and believe that it is time for a paradigm shift. When we speak of copepods we usually use terms that are population based ( I got a billion pods in the tank!!) I suggest that we try to think in terms of mass. One gram of Tigger pods weighs as much as one gram of T. furcata or N. lacustris, but the populations and generation rates are very different.

How about "fast mass", "middle mass" and "slow mass"? And a self sustaining population with predation pressure is a "critical mass"?

I may play with the math a bit and see if I can simplify the concept....

[ilovemash]

I do not understand your logic.

[ejwsr]

Here is where my train of thought is running...

T. californicus is 2mm long. N. lacustris and T. furcata are 50 to 150 um long. Now for the rudimentary math. (u for micro)
1 mm =.001 meters
1 um = .000001 meters
or
1 mm = 1000 um

Here is where I need to do some work to get the ratios right, but for the sake of argument;
Given that 100 T.californicus = 1 gram
If N. lacustris is 10% the mass of T. californicus, then 1000 N. lacustris = 1 gram
If T. furcata is 5% the mass of T.californicus, then 5000 T. furcata = 1 gram

If one coral polyp consumes .001 grams of copepods/day, one dragonet consumes 2 grams of copepods/day, etc.... How many grams of biomass is needed to maintain a net zero population growth if the face of the predation pressure and natural cause loss?

T. californicus has a 28 day generation rate, is large and attractive to larger fish. The others are smaller and have a 4 to 8 day generation rate. So, part of the question is how long does it take for a particular species to generate 1 gram of biomass? Once you know that and can estimate consumption rates, it might make it easier to manage.

Then the other question is what is a reasonable density of pod biomass per liter of water....

See what I mean about too much time?

[thelastmucci]

I love the way your mind works Eric. I've learned allot from this thread the most important thing I think that there are more than one type(s) of pods. As I've stated I don't have my tank yet but plan too get it some time this year. All I knew about pods was that they were good, mandarins eat them, and they produce in a refugium. What you've told me helps tremedously in trying to figure out what all these "white things" will be covering the walls of my 'fuge. I also plan on buying some "super premium" LS that is supposed to have pods already in them. Now wheather they survive the trip and or the cycle is a different story but at least now I know that there is more than one type and that means I can get more than one type of I ever want to get a mandarin...which I probably won't due to the fact that it's such a hard fish to keep...but it would be nice to know if I can do it or not.

[reefcouple]

i loved the mandarins we had, what a great fish.. just loved it.

[ejwsr]

That is the beauty of pods. They will and do survive the initial cycle, are amazingly resilient and are found in very questionable water qualities. They are detrivores cleaning at the level where others lose interest.

Opinion- Seeding your tank with a variety of pods at the beginning of the cycle is a very good thing.

I too love the mandarin, which is why I give this a lot of thought. In fact another thought just hit me.....

Since mandarins excrete a toxic mucus when stressed:
What is the toxin?
What is the LD50?
What is the half-life or detox curve look like?
What is the detox mechanism?
How much water and what kind of filtration rate does it take to keep the toxin level very low?

Hypothesis - Biomass of copepods/liter can be easily achieved and sustained at low volumes, but toxin concentration increases inversely proportional to the volume of water.

Ahhh, the mind of a well trained nutcase....

[reefcouple]

Let me ask ya this Eric, is it necessary to have a refugium to keep ocean pods? would they survive if just added to the tank?

Thanks

[ejwsr]

That is not an easy question to answer. The questions I have are:

What animal population is in the tank?
What is the substrate formation? Large v small rocks, or surface area that is inaccessible to predators?

Food sources for the pods isn't an issue, but an area or volume where they can breed without predation is key. A refugium is isolated from the predators and feed the tank by pods getting pumped into the tank. A tank is less sheltered, but I think sufficient volume can be created with a rubble pile of live rock or coral pebbles.

With appropriate shelter, yes.

[reefcouple]

90 gallon, 1OOlbs LR 120lbs LS

1 Blue Hippo
1 Flame angel
1 Lubbocks Fairy wrasse (small wrasse)
1 scooter blenny.

The fish i would like to add in the near future is

1 sand sifting goby (yellow head)
1 powder brown Tang
1 royal gramma



I hope this answers your questions...

also behind the reef is alot of smaller rocks that would add for shelter..

[thelastmucci]

I have a comment about the fish you currently have vs. the fish you want. The only problem I see is your wrasse (granted I have no idea what it looks like) however I have read, I think on this site..the problems people had with their 6 line wrasses and royal grammas. From what I read (and yes I'm reiterating what I read) wrasses seem to be a semi-aggressive fish when it comes to grammas. However I don't know how big/small their tanks were therefore I don't know if there was any territory issues. I would read up on them more and see what kind of information you can find.

[reefcouple]

my 6 line and my royal are both gone now, i dont think i'll get another 6 line.. just a gramma in the future..

I have a couple issues to deal with prior to adding any more fish..

oh, and the lubbocks fairy wrasse is probably one of the smallest and docile of the wrasse family.. very timid, but cool looking... you can see it behind the frogspawn if you look closely..

[ejwsr]

Sorry for the delay, but I needed to research your fish a bit.

What I believe is the jawfish, the ocellated dragonet (aka scooter blenny) and the wrasse are your primary pod predators in the tank. The angel and tangs are primarily herbivorous, but won't pass up a large protein snack. In all cases, feeding from the water column is opportunistic, their main style is grazing.

The corals appear to be mainly to be photosynthetic symbiotes and will feed on protein as the chance arises.

The anenome may not notice pods at all.

Do you use a sump or a canister filtration system. Dump 'em in the sump and they'll be fine.
If you are using a canister, I would guess part of the pods are collecting there, but not edible or otherwise available to the tank.

Add pods to your tank when it is dark. They will have a better chance of surviving.

[reefcouple]

Thanks Eric, your feed back was most helpful, i'll add some more rubble behind the reef to ensure a safe place for reproduction, and add them to the tank in the evening.... my blenny is getting hungry lol

[ejwsr]

Glad I could help!

[starboy]

Pods in a tank enviroment seem to go through phases nomatter what feeding you apply to the system.They seem to naturally drop in numbers then increase again.
Personally i keep 2 mandarins.A spotted picture mandarin in a small tank which he shares with a blueline pipefish and a blue mandarin in a 3 ft tank with various other peaceful fish.I very much doubt my mandarins are surviving on pod life especially the picture mandarin in the small tank.Both however are fat and healthy because i feed them frozen foods which they eat daily.You should never buy this fish if it is dependant on pods and is not taking other foods because they just won't live long term.

[reefcouple]

Starboy-

Saying "never" buy a fish dependant on what its main diet is and expecting a long healthy life is a no no imo.

We have had multiple mandarins (dragonettes) and eventually they will die if there isnt a good pod population. Ours were fat and happy at one time as well eating frozens along with the rest. but up and died for no apparent reason, (water was spot on)....

So if you do have dragonettes you should be providing some occasional pods.....

[starboy]

We have had multiple mandarins (dragonettes) and eventually they will die if there isnt a good pod population. Ours were fat and happy at one time as well eating frozens along with the rest. but up and died for no apparent reason, (water was spot on)....

Then mine must be eating some pods.I havn't got much liverock in the small tank with the picture mandarin and i've never seen a pod in there.My blueline pipefish,which shares the tank, also eats frozen foods a favorite being lobster eggs.Both my mandarins love eating earthworms, chopped up very small which i've been told is an excellent diet along with various frozen.Recently i bought a candycane coral which was crawling with little flatworms and the blue mandarin ate the lot of them.
I've had my blue mandarin for 7 years and my picture mandarin for 5 years.I've often thought about buying a partner for each of them but decided against this incase they don't get on together.Does anyone know how long these fish live?