Common Misconceptions In the Hobby

[Paul B]

Lobster old friend,
I think you are correct about having much zooplankton in a tank. I do think though that if you have non photosynthetic animals you need to feed them. I usually target feed these animals rather than dosing the tank which just leads to pollution. This is the reason that we can't keep sea fans and have a hard time with certain corals. In the sea, even in the tropics there is always something to eat but in a tank especially with ultraviolet sterilizers, ozone, skimmers and filter socks there is basically nothing floating around.
But in your original statement I do think that zooplankton or even before that, phytoplankton which is tiny mostly one celled plants is the basis of the food chain. All animals in the sea depend on plankton, even tropical animals. If we could supply these in a tank we could keep the above mentioned animals, but unfortunately there are only poor, dead substitutes available.
I personally hatch brine shrimp every day and turn off the filters and pumps for an hour to feed most of my small gobies and anything else that wants to eat it. It is the closest I can come to plankton in the winter. Iw we want to attempt to keep these non photosynthetic animals we must mimic their natural food or condem these animals to a slow demise.
Now I must leave. My retirement party is in one hour.
Have a great day.
Paul

 

[Aquarist007]

<a href=showthread.php?s=&postid=11370745#post11370745 target=_blank>Originally posted</a> by LobsterOfJustice
Agreed paul.

But it seems that feeding phytoplankton would not promote fish, coral, or other invert spawning. So I would say that instead of dosing phyto, maybe having a mated pair of gobies/clowns, a few cleaner shrimp, or having a healthy population of other spawning critters such as stomatella, would be a better way of replicating nature and feeding our corals.

Perhaps what I should have said before is "I have yet to see a stable zooplankton population." All these events result in temporary surges of zooplankton availability, not self-sustaining populations (let alone ones which would require phytoplankton to survive and thrive).

Lobster---why the swing towards refugiums dedicated to producing a greater number and diversity of zooplankton--aka copopods. I have learned to believe that a refug can have either the function of added filtration or the function of greating a safe haven for growth of copopods etc-----each function a direct dependancy on the amount of flow through the refugium.
If there is no need for the latter then might as well crank up the flow through the refugium and let the cheato help with nitrates and phosphates.

 

[LobsterOfJustice]

The copepods and amphipods a refugium aren't really zooplankton - by definition, plankton drift around in the current, unable to propel themselves. The benthic mysid shrimp, amphipods, and copepods in our tank don't feed on phytoplankton, they feed on algae, bacterial films, detritus, etc, because these too are benthic.

 

[Aquarist007]

<a href=showthread.php?s=&postid=11371714#post11371714 target=_blank>Originally posted</a> by LobsterOfJustice
The copepods and amphipods a refugium aren't really zooplankton - by definition, plankton drift around in the current, unable to propel themselves. The benthic mysid shrimp, amphipods, and copepods in our tank don't feed on phytoplankton, they feed on algae, bacterial films, detritus, etc, because these too are benthic.

thanks I didn't realize that mysid could not move on their own

then the life forms that we see swimming around on their own in the cheato--are amphipods and copepods?

Other then fish are these not too big for filter feeding lps and soft corals?

 

[LobsterOfJustice]

I think you misunderstood - Mysid (and the other pods in our tanks) can propel themselves, so they are not zooplankton. Plankton are everything that drift in currents and can not propel themselves.

The mysids and pods in our tanks might act as food for corals, but dosing phytoplankton does not encourage growth of these mysids and pods because they eat other stuff.

 

[Tomoko Schum]

According to Beyond the Reef, a website associated with Autstralian museum,

Zooplankton are floating or weakly swimming animals that rely on water currents to move any great distance. Krill, copepods, various pelagic (free swimming) sea snails and slugs, salps, jellyfish and a small number of the marine worms are all part of zooplankton.

According to a number of other articles, copepods do eat phytoplankton.

Tomoko

 

[LobsterOfJustice]

"Copepod" is a generic term which does not refer to a single species. Oceanographers and other scientists usually use it to refer to planktonic orgamisms which would be considered zooplankton. These truly plaktonic copepods likely consume phytoplankton (what else could they consume?) because it too is free-floating (planktonic). Hobbyists however usually call the little critters they find crawling around on the glass or rocks copepods. These are not true plankton because they are not floating around in our water (planktonic) - they are crawling on substrate (benthic). Subsequently, they will eat foods which they find on the substrates they are on (which is not phytoplankton).

Basically, animals generally eat foods which live where they live. So the benthic (substrate-living) "pods" in our tanks probably won't benefit much from phytoplankton. This is supported by the fact that these "pods" in our tanks are coming in on live rock which is collected in tropical reef areas which are largely devoid of phytoplankton (as I have shown above).

 

[iwishtofish]

Happy retirement, Paul! Hope you can find something to do with your time!

 

[crpeck]

Interesting discussion.

Under which classification would you put things like rotifers? They're tiny enough to be eaten by a lot of corals but do survive off of phyto. They swim .... sort of ... but would be carried by current.

I've beeen thinking about culturing rotifers again. I had a culture going while raising some clown babies and used to throw the extra cull rotifers into my main tank. I had faster coral growth and better polyp extension at that time than I ever have, but it may be coincidence.

It takes such an incredible density of rotifers for baby fish to survive that I've always wondered how any babies ever survive in the wild since since the rotifers need dense phyto and the statitstics show no such density in phyto.

 

[LobsterOfJustice]

Rotifers would be plankton. The main difference is they exist in the water column. Which is why you need to culture them separately - you cant have a stable population in an established tank as far as I know.

Phytoplankton is certianly useful for culturing rotifers, but since we dont have rotifers just floating around in our tanks, adding it directly to the tank is kind of useless in my opinion.

 

[Aquarist007]

<a href=showthread.php?s=&postid=11376032#post11376032 target=_blank>Originally posted</a> by LobsterOfJustice
Rotifers would be plankton. The main difference is they exist in the water column. Which is why you need to culture them separately - you cant have a stable population in an established tank as far as I know.

Phytoplankton is certianly useful for culturing rotifers, but since we dont have rotifers just floating around in our tanks, adding it directly to the tank is kind of useless in my opinion.

sps reefers swear by it--another myth

 

[Aquarist007]

if I could ask a question in practicalities here:
This is what I was under the assumption(and many other reefers)

set up a refugium--use chaeto, deep sand bed rock rubble, cut the flow down to about 1/10 the main flow, feed it slowly back to the main tank via the sump but past any skimming

this will increase the amount and diversity of zooplankton and bacteria in the main tank--provide food for mandarine gobies ect that will only eat it.

if you want to address a nitrate level--then same situation only increase the flow drammatically so as to pass more water in contact with the cheato
This flow rate is at expense of the zooplankon population in the refug

finally feed phyto once a week to the zooplankon cause they eat it--not the main tank--esp lps and softies--they consume the zooplankton.

What is misconception about the above statements ?

 

[Paul B]

Capn, the idea of the refugium is sound. You will culture pods in there and they will be sent to the tank but the main advantage of this is more water volume. Pods will multiply in the tank on any surface anyway. Pods eat the bacterial slime that is on any surface along with some tiny green algae film that is also on all surfaces. If the tank is large enough and fed enough, there will be more than enough pods and more than enough food for them without dosing anything. I never dosed anything and I have pods all over the place. I also don't have a refugium or sump.
Lobster is correct there is very little zooplankton in an aquarium and the little there is will find enough food.
Iwishtofish, thanks, I am retired about an hour already.
Paul

 

[LobsterOfJustice]

Capn, I'll pick it apart, but understand I am not a marine biologist (quite yet... ). A lot of this is just my opinion or observations.

"This will increase the amount and diversity of zooplankton and bacteria in the main tank"

As I said before, the stuff we grow in refugiums are not zooplankton, because they live on rock and sand instead of drifting in the water column. In addition to that, I'm really not convinced that a significant amount of "critters" make it from the fuge to the main tank passively. I think a more effective way would be to swap out the rocks, or shake out the cheato in the main tank.

"This flow rate is at the expense of the zooplankton in the refug"

Not zooplankton - pods. I'm not sure these pods mind flow up to a certian point - I'm rather sure up to 10x the fuge volume per hour would not bother them at all (ie 200gph on a 20g fuge).

"feed phyto once a week to the zooplankton cause they eat it"

Zooplankton does eat phyto, but what we have in out tanks is not zooplankton - and thus won't benefit much from phyto.

 

[Aquarist007]

<a href=showthread.php?s=&postid=11377161#post11377161 target=_blank>Originally posted</a> by Paul B
Capn, the idea of the refugium is sound. You will culture pods in there and they will be sent to the tank but the main advantage of this is more water volume. Pods will multiply in the tank on any surface anyway. Pods eat the bacterial slime that is on any surface along with some tiny green algae film that is also on all surfaces. If the tank is large enough and fed enough, there will be more than enough pods and more than enough food for them without dosing anything. I never dosed anything and I have pods all over the place. I also don't have a refugium or sump.
Lobster is correct there is very little zooplankton in an aquarium and the little there is will find enough food.
Iwishtofish, thanks, I am retired about an hour already.
Paul

thanks Paul--next spring---lake ontario---down rigging--I'll take you out-----those lake trout and salmon are great fishing at that time of year. some of them take 3/4 of an hour to bring in--great fun

 

[Aquarist007]

<a href=showthread.php?s=&postid=11377430#post11377430 target=_blank>Originally posted</a> by LobsterOfJustice
Capn, I'll pick it apart, but understand I am not a marine biologist (quite yet... ). A lot of this is just my opinion or observations.

"This will increase the amount and diversity of zooplankton and bacteria in the main tank"

As I said before, the stuff we grow in refugiums are not zooplankton, because they live on rock and sand instead of drifting in the water column. In addition to that, I'm really not convinced that a significant amount of "critters" make it from the fuge to the main tank passively. I think a more effective way would be to swap out the rocks, or shake out the cheato in the main tank.

"This flow rate is at the expense of the zooplankton in the refug"

Not zooplankton - pods. I'm not sure these pods mind flow up to a certian point - I'm rather sure up to 10x the fuge volume per hour would not bother them at all (ie 200gph on a 20g fuge).

"feed phyto once a week to the zooplankton cause they eat it"

Zooplankton does eat phyto, but what we have in out tanks is not zooplankton - and thus won't benefit much from phyto.

Perfect--perfect--thanks-----deprogramming the misconceptions from a life prior to Reef Central has been an ongoing process for me and allowing to give back more correct information to other reefers on RC

 

[MiddletonMark]

<a href=showthread.php?s=&postid=11373906#post11373906 target=_blank>Originally posted</a> by LobsterOfJustice
"Copepod" is a generic term which does not refer to a single species.

I recall some copepod expert's talk at IMAC a few years ago stating that there are 1000's of copepod species.

As with almost everything we keep in our tanks, often the larger category spans a couple different major classifications. [planktonic/etc]

 

[Rosseau]

I typed out a big post here... and then took it away.

In short, I would guess that we do have many species of true zooplankton in our tanks. How significant are these plankton for the overall 'health' of our tanks? I don't know.

I'm going to run a fine filter sock and take the collection into my lab and throw it under a scope... I sure hope I see some Daphnia in there...

 

[Rosseau]

Copepoda is an order in bioloical nomenclature.

From Wetzel, 2001: Limnology, 3rd edition.
-Copepods are not defined as an order by whether or not they are planktonic
-There are 3 sub-orders
-Calanoida - Planktonic, rarely benthic
-Cyclopoida - benthic, a few species planktonic
-Harpacticoida - exclusively littoral (on vegiatation or sediments)

Since we're talking about the details of the definition, the point here is that 'copepod' does not necessarily mean a benthic or planktonic. Also, planktonic copepods do exist.

Wetzel defines zooplankton as "animals suspended in water with limited powers of locomotion; they are subject to dispersal by turbulence and other water movements."




Ultimately plankton is a tricky word as everything is ultimately subject to dispersal by water movements. What changes is how affected the organism is and how strong the water movement must be. So, a copepod in your sump may not be considered planktonic, however in your turbulent DT it may be...The same applies for reefs.

Forgive me if you feel this does not apply to this discussion however I believe it is important to at least agree on definitions.

 

[Paul B]

thanks Paul--next spring---lake ontario---down rigging--I'll take you out-----those lake trout and salmon are great fishing at that time of year. some of them take 3/4 of an hour to bring in--great fun

Capn, thanks, today i finished my Captains upgrade to 100 tonns.
Maybe I will take you out SCUBA diving.
Paul
:lol: