About Calanoid Copepods

About Calanoid Copepods

Postby Luis A M » Mon May 14, 2007 4:10 pm

Calanoids are the pelagic organisms that constitute mainly the ocean´s plankton.Immense biomass of them drifts in the sea,like insects on land and air.They feed on phytoplankton and they are eaten by small fish.Their larvae,called nauplii, are the natural food for larval fish and crustacea.They have the perfect size,shape,movements,nutrients and even self digesting enzimes to make them the best larval food,both in the oceans as in our tanks.
In this thread we will discuss what they are,how to get them,culture them and it´s use as larval food.
I started culturing them some years ago,and since 2001 I keep a thriving colony of Acartia tonsa.So I can share how I do it which is a mix of different scientific methods and my practical hobby based experience with them.
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Postby KathyL » Mon May 14, 2007 7:26 pm

I'll allow myself one breath, while I wait for the rest!
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Calanoids vs Harpacticoids

Postby Luis A M » Tue May 15, 2007 3:23 pm

It is VERY important that we understand that these are two different kinds of copepods and that they must not be confused.
HARPS are benthic,adults and nauplii both crawl on tank substrates,lke glass,rocks and sand.Both adults and nauplii hide away from light into dark crevices.They assist as microdetritivorous in the breakdown of food leftovers and other organic material.Mandarins feed on them but few other fishes take them,I heard some small labrids do.

CALANOIDS are pelagic,both adults and nauplii spent their lives swimming in the water column where they are the 2nd trophic level of the food chain,so they are the basic resource all life in the sea consume,directly or indirectly.
They are the natural food of our larvae and planktivorous fish.They,and not the others,are what we need for larval rearing.
Adults swim with their antennae spread in a 90º angle,like a "tee".Nauplii and adults swim in the open and are atracted to the light.

So remember,don´t use any copepod...Use CALANOIDS,"Cokepods"(the real thing) :lol:
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Re: Calanoids vs Harpacticoids

Postby mpedersen » Tue May 15, 2007 4:08 pm

Luis A M wrote:HARPS are benthic,adults and nauplii both crawl on tank substrates,lke glass,rocks and sand.Both adults and nauplii hide away from light into dark crevices.They assist as microdetritivorous in the breakdown of food leftovers and other organic material.Mandarins feed on them but few other fishes take them,I heard some small labrids do.


I don't believe this is entirely accurate. Tigriops (aka. "Tiggerpods" as sold by Reed Mariculture / Reef Nutrition), one of the most common copepods in hobbyist culture (in the US), are Harps that do swim occasionally, and do not "hide away" constantly. It is also my understanding that their nauplii stages are free swimming?

I've seen "antenna length" cited as the main way to easily ID Harps from Calanoids, but where do Cyclops fit into the picture?

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Postby KathyL » Tue May 15, 2007 5:54 pm

Matt, stop arguing with the man. :roll: Let him tell us more!

Gasp! :oops:

More please!
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Re: Calanoids vs Harpacticoids

Postby BaboonScience » Tue May 15, 2007 10:40 pm

mpedersen wrote:I've seen "antenna length" cited as the main way to easily ID Harps from Calanoids, but where do Cyclops fit into the picture?

Class Crustacea
SubClass Copepoda (7 Orders, 3 common) Most visually notable characteristics.
Order Calanoida: Generally free living and Planktonic adults
First antennae long, usually longer than the body length.
Second antennae short and biramous (splits into two sections)
Order Cyclopoida Generally free living and Planktonic adults, some benthic forms. Note many are parasitic at some stage in their lives.
First antennae conspicuous but shorter than the body length.
Second antennae short and uniramous (does not split)

Order Harpacticoid Generally Benthic and many interstitial (live in the open spaces between sediment particles)
First antannae very short (shorter than body width) and uniramous.
Second antennae very short and biramous.

All are sexual. All have 5-6 nauplius instars (stages) before five copepodid instars. Copepodid instars resemble the adult.
Hatch to adult can take as little as one week or as long as one year.

Interestingly, copepod eggs can be dessecated and rehydrated to hatch. Wonder if anyone has tried this?
"The exact contrary of what is generally believed is often the truth" Jean De La Bruyère (1645-1696)
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Re: Calanoids vs Harpacticoids

Postby Luis A M » Wed May 16, 2007 1:35 am

mpedersen wrote:
Luis A M wrote:HARPS are benthic,adults and nauplii both crawl on tank substrates,lke glass,rocks and sand.Both adults and nauplii hide away from light into dark crevices.They assist as microdetritivorous in the breakdown of food leftovers and other organic material.Mandarins feed on them but few other fishes take them,I heard some small labrids do.


I don't believe this is entirely accurate. Tigriops (aka. "Tiggerpods" as sold by Reed Mariculture / Reef Nutrition), one of the most common copepods in hobbyist culture (in the US), are Harps that do swim occasionally, and do not "hide away" constantly. It is also my understanding that their nauplii stages are free swimming?

I've seen "antenna length" cited as the main way to easily ID Harps from Calanoids, but where do Cyclops fit into the picture?

Matt

LOL Thanks Kathy for coming again to the rescue and John for the info.
We have discussed this same subject in pms before.
My description is as accurate as biological things could be.Of course harps swim and show occasionally.And yes,some very few species,like Tisbe holothuriae produce swimming nauplii that might be useful as larval food.
And there is also a harp that is fully pelagic,small and very productive:Euterpina acutifrons,which could find a place in larviculture.
But those are exceptions to the rule.It would be great if you find some good use for your harps.
Other than that,breeding harps is an exercise in futility,because IMHO they are good for nothing.
Of course everything can be assayed and tested as always something unexpected could be found.But here I want to offer a good tool for larval raising which is the topic of this thread;calanoids,the real thing. :wink:
Cyclopoids don´t fit in this picture because they are FW.With some exceptions,like Oithona,which was one of the species Frank B.used to rear Centropyge.It can be treated as a calanoid for all practical purposes.
The aim with my previous post was that everybody understands the difference between calanoids and "the others".Please tell if it is yet not clear.Otherwise,I can return to the topic 8)
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Postby BaboonScience » Wed May 16, 2007 1:55 am

Yep, Please proceed.
Agreed, marine cyclopoids can be treated the same as calanoids.
Benthics are good for reef type systems as they are interstitial in the sand bed and are always producing young. Potential resource?
The other thought is that the time to maturity gives some species a limited usefulness. Species selection for culture purposes is important because you need the shorter life cycle to build cultures in a reasonable time frame.
"The exact contrary of what is generally believed is often the truth" Jean De La Bruyère (1645-1696)
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Postby KathyL » Wed May 16, 2007 8:39 am

t
u
r
n
i
n
g

b
l
u
e

:shock:
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Re:

Postby Luis A M » Wed May 16, 2007 1:05 pm

KathyL wrote:t
u
r
n
i
n
g

b
l
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:shock:


Concerned about Kathy´s hematosis,I will start an "about harps"thread so we can keep in track with calanoids here.Digressions concerning "the others"will be sent there and Kathy will keep breathing all the time :D
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Re: Calanoids vs Harpacticoids

Postby Luis A M » Wed May 16, 2007 2:00 pm

BaboonScience wrote:Interestingly, copepod eggs can be dessecated and rehydrated to hatch. Wonder if anyone has tried this?

Never heard about that,could you tell more?
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Re:

Postby KathyL » Wed May 16, 2007 2:30 pm

Luis A M wrote:Concerned about Kathy´s hematosis,I will start an "about harps"thread so we can keep in track with calanoids here.Digressions concerning "the others"will be sent there and Kathy will keep breathing all the time :D


Starting a new harp thread is great, as long as you do it AFTER writing more about the Calanoids, please kind sir. We must not let you be distracted from the important task at hand.

I am uncertain how much longer I can last:!: :oops: :roll: This information may be critical to the survival of my acartia tonsa culture....
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Which ones?

Postby Luis A M » Wed May 16, 2007 2:56 pm

OK,now that we know how good calanoids are and want to start culturing them,we must choose which of the thousands of species to start with.
Basically any planktonic species filter feeding on phyto will do but there are some things we must consider when making the choice:

A-it must be a tropical species or a tropical temp.tolerating temperate species.Cold water species are too complicated and their nauplii wouldn´t survive long in larval tank´s warm water.
B-Life cycle (egg to egg,or adult to adult)must be brief.
C-They should be prolific enough
D-They must be hardy,easy to culture.

Additionally,it is convenient that our selected calanoid is an egg broadcaster and not an egg carrier,if we plan to collect/store eggs from them.

I suggest Acartia tonsa as a first calanoid to try.Most of my experience was with them.They are one of the favorite research lab species,and it is kind of "semi domesticated".I keep my stocks running since 2001.
A.tonsa inhabits estuaries and coastal lagoons all around the world.Therefore it can thrive under extreme temperatures and salinities,making it very hardy.It has a short life cycle of about 9 days,and a good nauplii production.This depends on cultural conditions,of course.The nauplii of A.tonsa are pretty small,suitable for most small fish larvae.
It´s only drawback is that they are cannibalistic,feeding on their own nauplii.This problem can be handled with a good culture management,however.

There are smaller species,mostly in the paracalanids,such as Parvocalanus,Bestiolina,(and Oithona,mentioned before),whose wild collected nauplii were instrumental in Frank B.first success with Centropyge.

As a general rule,calanoids living in lagoons/estuaries are the hardest,but those living in coastal waters are hardy enough.Deep sea species are the most delicate and are seldom cultured.
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Postby KathyL » Wed May 16, 2007 4:39 pm

Ahhhhh, I am turning pinker, but still a bit hypoxic.

Thank you so much for that, and now may we continue?
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Postby KathyL » Thu May 17, 2007 8:28 am

What is good culture management?
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Re:

Postby Luis A M » Thu May 17, 2007 2:15 pm

KathyL wrote:What is good culture management?

Wait,that subject belongs to "season II"scheduled to start on April 2009. :evil:
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Postby KathyL » Thu May 17, 2007 2:38 pm

Oh, Noooooo
I feel a blueness overcoming me......... :shock: :(

I'll never last that long. So depressed..... :(
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How to obtain calanoids?

Postby Luis A M » Thu May 17, 2007 4:39 pm

So if we´re ready to start keeping calanoids we need to have our initial breeding stock.We can get them from people keeping them,or collect them ourselves.
Some people imagine calanoids could be found in reef tanks,collected and cultured.Unfortunately,this is not the case,it won´t happen.So let´s consider ordering and collecting.

ORDERING CALANOIDS
Until recently there was virtually no place offering calanoids.Some few commercial firms offering "copepods"only had harps in their lists.I tried many times to convince them that they should carry calanoids,suggesting the more convenient species,but got no success.The silly thing is that these people have access to TONS of microalgae,the key ingredient in calanoid production.
Then there is a firm that offers live plankton,containing wild calanoids.I once ordered that from them and obtained a pure rotifer culture!
There was also a firm in UK which supplied (expensive!) A.tonsa for toxicity tests.But sending live things across borders is not easy either.
Some universities and public aquariums which keep calanoid cultures can also be contacted but that´s not easy for the regular hobbyist.
Things might finally improve.A new firm,which also produces microalgae is making A.tonsa available to anybody.This is where Kathy got hers from,though indirectly (and not knowing).This is good news,this people will probably raise other calanoids as well.And they are considering the production/sale of millions of A.tonsa eggs, so commercial hatcheries (and hobbyists)can keep them in the fridge until needed like IA.And then we won´t need to bother breeding them!
Next option is:

CALANOID HUNTING
Try this next time you visit the seashore.It´s easy and you don´t need expensive equipment like plankton nets,boats,etc.
You need:
a small 200 mic.sieve.
a funnel
a bucket (with a 2L mark)
several 2L soda bottles
some microalgae (other than NAN)
air pump,airlines,valves.
Take the sieve and the bucket and wade weist deep in a spot without rough waves.Fill the bucket and strain thru the sieve,up to ten times.Put 2L in the bucket and rinse the sieve in there.Now go to the shore and fill a bottle, close and mark the location.Move to other location with a different biotope (lagoon,river mouth,mangrove swamp) and repeat.
Back at home,or at the Hotel,feed the bottles some algae and bubble some air in them.
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Postby KathyL » Thu May 17, 2007 8:02 pm

I think we have a mystery novel here, with cliff hanger chapters....

Will the copepods grow? Will there be better copepods from the lagoon or the rivulet mouth, or the penisula bay? Will they eat the Isochrysis, or the Tetraselmus? Will they lay eggs? Will they survive in the Coke bottle at room temperature? Can we take them home?

When can we get to the next chapter?
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How to keep stock cultures.

Postby Luis A M » Sat May 19, 2007 3:56 pm

Here´s a "how to"description of my method for keeping calanoid stocks indefinitely.It is very simple and demanding very little work or materials.
It is in fact so easy that I see no excuse why cultures of many different calanoid species are not being kept and starter cultures available for interested parties,which I´m sure are many.
If we keep in the "recipe"style,here are the ingredients:

Plastic gallon jars,wide mouthed and made of clear PET.I don´t know if they are found anywhere.They are very practical,I also use them for rearing larval shrimp (future thread).
53,100 and 200 micron sieves.I make mine out of clear sections of acrylic pipe,8x6cm.This size fits in Petri dishes and under a diss.microscope,which comes very handy for observations.
Live algae.T-ISO works fine and is very easy to grow.Same for TET.
RHO is said to be better,but a little more touchy.Since this is the most limiting factor,I tried to find if they can be reared with frozen TET paste.It can be done but is very difficult,I failed 9 of every 10 times.
Air pump,valves,tubing
ASW.I use IO

Fill a jar with one of the collected bottles and fill up to 3 L with ASW of the same salinity.For estuarine species,such as A.tonsa,I use 1.010.
Provide gentle air bubbling.
Feed 100 ml of a dense algal culture every day.
That´s it.Simple,huh? :)

If you started with purchased calanoids or eggs,it is just the same,you put them in the jar and fill up to 3L.

Well cared cultures seem to last indefinitely,never seem to get old as most other cultures we know.But they can crash sometimes,so 3-4 jars of each species must be kept at all times.

In wild cultures,usually only one species from each bottle (location) develops,but occasionally we can have two or more species together in culture.This is not a problem and in the long run only one species prevails.
In certain times and locations,barnacle nauplii,clam veliger larvae and other such planktonic organisms come in our wild stock bottles,and thrive in our cultures until they settle and can be removed.
Culture contamination with Artemia and rotifers can always happen in the fish room and we must be very careful to avoid it.Artemia is not a big problem, they will grow and can be removed later.But rotifers will quickly outgrow and kill a calanoid culture.If you see one or two rotifers when checking for nauplii (explained later),you must act immediately and drastically,or you´ll lose all your stocks.You must dispose of the contaminated jar,and wash thoroughly.If it is your only culture and you want to save it,it can be done.You must flush the culture in a 200 mic.sieve with at least 20 L of water everyday for one week,moving to a clean jar.After that,keep watching until you are sure they were erradicated.
Cultures don´t need any direct light and can be kept at normal fish room temperature.
To check the calanoids best way is with a flashlight playing obliquely from above,against a black background.
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Postby KathyL » Sat May 19, 2007 5:54 pm

Thank you Luis,
Do the cultures need water changes eventually?
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Re:

Postby Luis A M » Sat May 19, 2007 7:36 pm

KathyL wrote:Thank you Luis,
Do the cultures need water changes eventually?


Yes,stock culture mantainance is as follows:
As you are adding 100 ml every day,eventually the jar will be filled completely.
Now you pour part of it thru a 53 mesh sieve,so that 1/2 of the original volume (1.5L) remains.The sieve is then rinsed back in the remaining water,returning all calanoids back to the jar.And now top up to the 3L mark with new water.

MAKING NEW CULTURES
I check the cultures for nauplii twice a week,recording how many nauplii are found in a 2ml sample.This gives an idea of the culture´s health,as well as the presence of unwanted alliens,as explained before.
If you need to start a new culture,choose the old culture showing more nauplii in the 2ml sample,and strain half of the volume but this time thru a 100 mic.mesh.The strained water goes into a new jar and is your new culture.The sieve is back washed in the old jar,as before,and both jars are topped up with new water.
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Postby KathyL » Sat May 19, 2007 9:59 pm

Are they square jars or round ones?
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Postby aomont » Sat May 19, 2007 11:01 pm

How many A. tonsa broodstock /L (stocking density) you keep in those jars Luis ?
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Postby Luis A M » Sat May 19, 2007 11:45 pm

Round,Kathy.Not common there?.Need a pic?
As many as they come,Anderson,they somehow control their population.I haven´t counted the adults,but nauplii occur at variable densities from 0 to 15 /ml.
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