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MOFIB Copepod Cultivation Paper


Almon

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(edited)

Originally posted on the MOFIB website in this thread What would you like to know about live feeds?.

 

MOFIB Copepod Cultivation Paper

Compiled by Jim Welsh (“JimWelsh” on MOFIB)

Draft

 

Introduction

One of the most important food sources available to the marine breeder is the copepod. Copepods are small crustaceans in the class Maxillopoda, and the subclass Copepoda. There are many different types of copepods, but the ones of interest to marine breeders for cultivation as food sources are the Calanoid, Harpacticoid, and Cyclopoid types, in the orders Calanoida, Harpacticoida, and Cyclopoida, respectively.

 

This paper will attempt to briefly describe some of the copepods of interest to the marine breeder, list some sources for obtaining them, and provide some protocols for culturing and harvesting them.

 

Giving credit where it is due, the information in this paper was largely drawn and heavily edited from posts on MOFIB. Many people have contributed information that can be found here, but by far, the most prolific contributor was Dr. Luis Magnasco (“Luis A M” on MOFIB).

 

Types of Copepods

There are basically three types of copepods of interest to the marine breeder. These are the Calanoids, Harpacticoids, and Cyclopoids. In most cases, the breeder is interested in copepods as a food source for pelagic fish larvae. The best copepods for this purpose are those with pelagic nauplii. The term “pelagic” simply means swimming in the water column, as opposed to “benthic”, which means tending to live on the bottom or other surfaces. The term “nauplii” refers to the younger, smaller developmental life stages. The adults are usually too large to serve as appropriate food sources for larval fish.

 

Generally speaking, calanoid copepods are pelagic, and/or have pelagic nauplii. While many cyclopoid copepods are parasitic on fish, there are some types of cyclopoids that are safe to use as food sources, and are commonly cultivated for this purpose, that also have pelagic nauplii. For the purpose of this document, these cyclopoids should be grouped together with the calanoids. Most harpacticoid copepods are benthic in nature, although a few do have pelagic nauplii, and some are entirely pelagic. Benthic copepods are still a useful food source for certain marine animals, such as more fully developed fishes like mandarins, seahorses, pipefishes, and others.

 

Copepod Sources

There are basically two ways of obtaining copepod cultures: Collecting wild specimens, and purchasing or obtaining starter cultures from a commercial vendor or another marine breeder.

 

Collecting Wild Specimens

For those with easy access to the ocean, one way to get a copepod starter culture is to collect it directly from the ocean. You will need a plankton sieve of around 200 microns mesh size, a bucket, a funnel, and several clean 2 liter beverage bottles. Take a bucket and your sieve and wade out until you are waist deep in a relatively calm spot in the ocean. Fill the bucket and pour it through the sieve several times. It can take quite a bit of water — up to 10 buckets — to get a good “catch”. Then put about 2 liters of water in the bucket, and rinse the sieve into that water. Back on shore, pour the collected copepods in their 2 liters of water into a clean 2 liter beverage bottle. Label the bottle with the location where you collected the copepods. Move on to another location with a different biotope, such as a different lagoon, river mouth, mangrove swamp, etc. and repeat the process. When you return home, feed the copepods some phytoplankton such as T-Iso or Tetraselmis, but don’t use Nannochloropsis. Provide light aeration.

 

Usually, over time, only one species of copepod will dominate your wild-collected culture, and will prevail. It can be very difficult to identify which species of copepod you have when dealing with wild-collected specimens. Identification usually requires careful examination of very small body parts under a dissecting microscope, and is the special realm of the copepodologist.

 

A good way to collect harpacticoid copepods in an aquarium is to put several pieces of PVC pipe in there. Harpacticoids congregate in them looking for dark places. The pipes are lifted after some time covering both ends and their content emptied in Petri dishes.

Stock cultures can also kept in Petri dishes. Keep them separated by species. If more than one is collected, pipette some egg carrying females of each species to start pure cultures.

 

Starter Cultures

There are several vendors that sell copepod starter cultures. This is a good way to get a healthy culture of a known species, or at least a known genus. The following is a list of a few commercial sources of copepod starter cultures, and the species available as of this writing (Wednesday, March 03, 2010). Note: I am still looking for commercial sources outside of the United States. If anybody has any sources to provide me, please PM JimWelsh on MOFIB. This list will be updated as new sources become available or I learn about them.

 

Aqua-Tech

Aquatech PMB# 126

1153 S. Lee St.

Des Plaines, IL 60016-6503

Phone: 888-387-9979

Fax: 888-387-9979

 

Producers of Phyto2 and Zoo2

http://www.phyto2.com/

 

Harpacticoid:

Euterpina acutifrons (pelagic harpacticoid – special order item)

Tigriopus californicus

Tisbe spp.

 

Calanoid:

Pseudocyclops

 

Essential Live Feeds

Essential Live Feeds

800 5th Ave. #101-173

Seattle, WA 98104

1-866-328-PODS

 

Producers of Ocean Pods

http://www.essentiallivefeeds.com/

 

Harpacticoid:

Ammonardia sp. (Not recommended for larval fish, only adults.)

Micoarthridion sp. (Cold water species.)

Tigriopus californicus "Southern California strain"

Tigriopus californicus "Washington State strain"

(Note: You should not mix these two strains. It will result in population depression.)

Tisbe sp. (Three different species available.)

 

Calanoid:

Acartia tonsa "Gulf of Mexico strain"

Pseudodiaptomus pelagicus (Only available on Special Request and with written nondisclosure / noncompete agreement with provider.)

 

Cyclopoid:

Oithona sp.

Apocyclops sp.

 

Reed Mariculture

Reed Mariculture Inc.

871 E Hamilton Ave, Suite D

Campbell, CA 95008

Toll Free: 1-877-Seafarm (877-732-3276)

Voice: 1-408-377-1065

Fax Number: 1-408-884-232

 

Producers of Tigger-Pods

http://www.tigger-pods.com/

 

Harpacticoid:

Tigriopus californicus

 

Seahorse Source

Seahorse Source, Inc.

4028 Greenwood Dr.

Ft. Pierce, FL 34982

Toll Free 877-465-2401

Voice 772-462-2401

Fax 772-462-2402

 

Resellers of Algagen products

http://www.seahorsesource.com/

 

Harpacticoid:

Tisbe spp.

 

Calanoid:

Acartia tonsa

 

Life Stage Sizes

An important part of feeding larval fish is providing food items of an appropriate size for the larvae in question. This section provides some information about the sizes of various species at various life stages.

 

Acartia tonsa:

Nauplii width 145 Microns

Adult length 1000 Microns

 

Euterpina acutifrons:

Nauplii width 70 Microns

Adult length 700 Microns

 

Nitokra lacutris:

Nauplii length 100 microns

Gravid female average length 620 microns

 

Cultivation Protocols

Harpacticoids

Mass cultures of harpacticoids can kept in trays. Any tray will do, such as old photography processing trays. They have a convenient spout for emptying them. Feed ground flake food. Keep several trays. When one is ready to harvest, pour the water thru a 53 micron sieve and refill the tray with new water. No aeration is necessary.

 

Many people find that their harpacticoid cultures multiply more rapidly if they are fed small amounts of T-Iso (Isochrysis, Tahitian strain) or Tetraselmis. Others supplement the feeding with small amounts of Cyclop-Eze. Tigriopus are reported by many to multiply more rapidly at temperatures under 70º F.

 

Calanoids

Ingredients

• Plastic gallon jars, wide mouthed and made of clear PET.

• 53, 100 and 200 micron sieves. These can be purchased or made out of clear sections of acrylic pipe, 8x6cm. This size fits in Petri dishes and under a dissecting microscope, which comes very handy for observations.

• Live algae. T-Iso (Isochrysis, Tahitian strain) works fine and is very easy to grow. Same for Tetraselmis. Rhodomonas is said to be better, but a little more touchy. Others used include Chateoceros and Platymonas. Nannochloropsis is generally not considered a good food for copepods.

• Air pump, valves, tubing.

• Artifical Salt Water. Many use Instant Ocean.

 

Startup protocol

Fill a jar with a starter culture and fill up to 3 L with ASW of the same salinity. For estuarine species, such as A. tonsa, use a specific gravity of 1.010. Provide gentle air bubbling.

 

Daily protocol

Feed 100 ml of a dense algal culture every day. Sustaining dose is 33ml/L/day of a dense culture. Minimum cell size is T-Iso. The larger the cell size, the better. For A. tonsa, to address the problem of cannibalism, you can use an acrylic cylinder with a 200 micron mesh bottom, which fits into a bucket. A. tonsa are cultured there. Every day, the cylinder is lifted and moved to a new bucket. Water in the old bucket is now strained thru 53 microns and eggs collected for use or storage.

 

Weekly protocol

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 aliens. 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

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 micron 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.

 

Collecting and Storing Eggs

Eggs should be collected and stored periodically. This serves two purposes:

 

1. Provide a back-up. If for some reason we lose all our cultures, you can start again with them.

2. Work like a saving account, delivering a lot of nauplii when the need arises.

 

How to Collect and Store Eggs

This can only be done with the egg broadcasters, which release their eggs in the water column. They sink to the bottom, and hatch in 48hrs.if left there.

Other calanoids keep their eggs in egg sacs attached to their bodies, like harpacticoids and cyclopoids. With them this technique can not be applied.

 

To collect eggs, the culture water must remain still for some time to allow eggs to sink to the bottom, and then they are siphoned out with as little water as possible. The eggs, copepods and detritus can be processed by screening it thru 100 micron mesh, which removes the large debris and copepods and then thru 53 micron mesh, which holds the eggs free of smaller particles. Some people go to the extreme of concentrating them making them float in hypersaline media (like for parasites egg screening). You can use a simpler approach: First, choose the egg donor flask as the one showing more nauplii/ml. Every day, siphon all the bottom debris with a little water in a 1L pitcher. Put the pitcher in the fridge. Repeat every day until the pitcher is full, then take it out of the fridge, let it stand for a while, and then siphon the debris and eggs from the bottom into a 100 ml.vial, taking care not to stir the debris while doing so. The vial must be filled up to the rim and closed tightly. Then date it and keep it in the refrigerator.

 

Eggs so treated can be kept some time, up to six months, perhaps more. When stored eggs are needed, select the older ones, so as to keep the egg pool as young as possible. To hatch eggs, just take a vial from the fridge and pour its contents in one of our gallon jars, prepared as explained before. Check for nauplii 48 hours later. If you don’t see any nauplii, put another vial in the jar and repeat every 48 hours, until you find nauplii. Then stop adding eggs and start feeding.

 

It is advisable to start a culture with stored eggs every periodically to keep cultures pure, healthy, and free of contaminates.

 

Continuous Culture -- "The Copepod Machine"

Use three buckets (best if graduated and translucent but any bucket will do). Two are filled with culture water. I use 10 L at 1.010. Start with a culture from the jars. Every day the culture is lifted into another bucket, and the water strained thru 53 micron mesh into the empty bucket. One L of this water is discarded. One L of phytoplankton is added to the culture, bringing volume to 11L.

 

Growing Phase

Put the collected nauplii and eggs in a 4L Jar. Each jar takes 2 days’ worth of production. 4 jars are used. After 8 days, the 1st jar is added to the main culture and a new jar is started. This follows until a dense population of adults is reached and a good daily production of nauplii. Then we move to the Production Phase.

 

Production Phase

Now, the 53 micron mesh is simply rinsed in the larval tank. The Machine keeps working fine for a month or more, and then usually production starts to decrease. Surprisingly, nauplii are always collected, even if eggs take 2 days to hatch and we strain the culture every day. Sometimes contamination with harpacitoids or rotifers occurs, but the nature of this technique keeps them in check. When you want to collect eggs with this technique, rinse the 53 micron sieve into a narrow tall chemistry container (graduated clinder), and allow it to settle under a light that attracts the nauplii to the surface. Then siphon all the water except the last 150 ml, which goes into a storage vial, as described.

 

The Copepod Machine, using 1L of phytoplankton per day, produces enough nauplii for an average larval run. If phytoplankton is not limited, more machines could be created, or larger ones be designed.

 

Dealing with Contamination

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, as 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, you must act immediately and drastically, or you´ll lose the culture.You must dispose of the contaminated jar, and wash thoroughly. If it is your only culture and you want to save it, this can be done. You must flush the culture in a 200 micron sieve with at least 20 L of water every day for one week, moving to a clean jar. After that, keep watching until you are sure they were eradicated.

Edited by Almon
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that is OUTSTANDING!!!

 

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All credit goes to Jim Welsh for compiling this information. He originally posted this paper in a thread on the MOFIB website.

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  • 1 year later...

This is an excellent article. I've been thinking about trying to Cultivate Copepods for my seahorses that keep breeding like rabbits to maybe improve my survival rate. Does anyone know if there is a good source for graduated and translucent containers and the necessary mesh sizes? Right now I've got green water, rotifers, and brine shrimp cultivating but if I can find some room away from all of that to precent contamination I think I may give it a try.

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