View Full Version : Harlequin Shrimp Project

09/26/2014, 04:12 PM
Please see our other post on harlequin shrimp.

We now believe we have a system in place to rear larval harlequin shrimp to adults.

On 09/22/2014 we collected 1926 larvae from our breeding pair of harlequin shrimp
We set up 2 systems one with 326 and one with 1600. After 2 days we realized that we did not have enough food to raise that many. Rather than loose them all to starvation we kept 200 and released the rest in our greenhouse systems to fend for themselves.

10/08/2014, 06:00 PM
10/08/2014 day 16

We lost most of the last batch to an accident when someone decided they did not like our strainer because it clogged too quickly so they made their own and most of the shrimp either passed through and were filtered out or got stuck on the strainer. We still have about 20 left and they are doing great.

10/12/2014, 01:31 PM
Check our facebook page:


for updates on our research project on harlequin shrimp.
As of October 12 the last batch is 20 days old. We collected a new batch of 892 yesterday and split them with our research partner. We put them in the same system with the surviving members of the last batch.

Harlequin shrimp
captive raised
captive bred

12/12/2014, 10:33 PM
We set up 2 systems one with 326 and one with 1600. After 2 days we realized that we did not have enough food to raise that many. Rather than loose them all to starvation we kept 200 and released the rest in our greenhouse systems to fend for themselves.

12/15/2014, 05:32 PM

12/17/2014, 01:32 PM
check our face book page for updates

https://www.facebook.com/AquaticTechnologyOhio (https://www.facebook.com/AquaticTechnologyOhio)

Our research partner using the same procedures as us but with less human error has succeeded in rearing 50 plus larvae to adults.

To date we have not reared any to adults. Our losses have all been attributed to human error:
We did not have enough food
our water quality was poor
our salt level was too high
our strainers ripped several times

we now check and adjust water parameters 3x weekly

we now have 35 gallons of copepod cultures and can reach culture densities of up to 100 copepods per ml but
are still struggling with the food mostly culturing iso for the copepods

For our next batch we are going to install a second 100 micron strainer after the first one in case it tears

On another note,
we have plans for attempting to culture seahorses, cleaner shrimp, and blood red shrimp when our new coral system is up and running
possibly within the next month

03/09/2015, 09:03 AM
We have not been able to keep the larvae longer than about 21 days
I am not sure why.
Our current system has a 55 micron overflow screen. The water trickles into a 15 gallon sump from a 15 gallon bucket with a rounded bottom. We have 2 buckets a black one and a blue one
The sump has a constant height section with a filter sponge and a protein skimmer. Water is drawn through the filter sponge with an airlift

In the other section of the sump there is a phosphate reactor and a return pump which trickles the water back.
We have a heater which we have kept both in the sump and in the bucket. The water has been kept anywhere from 74 to 84 degrees.
The specific gravity is kept between 1.023 and 1.026

air is bubbled lightly into the bottom center of the bucket where it washes upwards over the overflow screen. We have also placed the sponge in the bucket at times. It doesn't appear to capture the larvae.

We tint the water daily with iso to lightly cloud it and feed rotifers and parvo initially and then add parvo daily to maintain 6-12 adults per ml.

The larvae just disappear over time

I make the strainers by drilling a bunch of holes in a 2" piece of pvc and gluing a 55 micron screen obtained from Florida Aqua Farms over it.

The screens have split many times and may be the culprit.
The screens are washed in a dilute bleach solution and rinsed in dechlor and
set aside to dry whenever they start to clog
when they split they are removed and a new one is glued on

03/16/2015, 03:02 PM
We collected about 72 larvae today March 16th.
It appears from the low number that they were born yesterday and we didn't notice them until today.

They went into a previously sterilized system with a blue 15 gallon bucket with rounded corners a heater, a stream of air bubbles in the center under the screened overflow with a new 55 micron screen.
The water is kept at 81 degrees. The heater is kept with the shrimp because it is much easier to regulate the temperature that way since the water from the sump just trickles back.

The 15 gallon sump has a constant height section with protein skimmer and a sponge. The other part of the sump houses a a phosphate reactor and a return pump.

03/21/2015, 07:42 AM
Cool project! Needs to be more of these efforts, but having the facilities and patience are taxing. Thank you for attempting this! Good luck and please keep this thread updated. Some of us refuse to open a FB account.

03/26/2015, 03:44 PM
I saw your set up. Good luck!

04/07/2015, 12:11 PM

On Easter Sunday we had a very large batch of Harlequin Shrimp larvae. Gregory and Wilson are shown in the photo. Gregory is collecting the larvae. In our previous attempts we think the larvae were getting stuck on the strainers so we redesigned them to hopefully avoid this and to make removing and replacing them much easier. We of course were caught off guard and our copepod culture count was a little low so we also gave them some fresh hatch baby brine. Wish us luck!

04/07/2015, 12:21 PM
Great project and I applaud you guys for doing it.

I totally agree that some people refuse to operate a Facebook page so relying totally on that is going to leave a lot of people out of the loop.. I have a Facebook and I still don't go to links requiring it just because every time I open Facebook it wants more personal info from me than I'm willing to comfortably give, I think others feel the same way. Just saying it may be better to keep both( Facebook and the largest reef forum in the world) an option if you want the most feedback or qualified opinions/praise.

Thanks for sharing

04/22/2015, 08:06 PM
excited to hear some good updates

04/23/2015, 03:35 PM
We appear to have lost the last batch.
We never found any dead ones on the bottom
We did not notice any dead ones on the strainer.
The new strainers work great
We will look at water movement on the next batch.

04/24/2015, 12:34 PM
The last batch appears to be gone.
We collected 373 larvae today, April 24th, 2015 and transferred them to a empty larval rearing system.
Everything is the same as last time except this time the tub is blue instead of black and the circulation is turned up higher.

04/29/2015, 11:02 AM
We keep killing them faster and faster. The April 24th batch appears to be gone. We did not have enough circulation.
The bubble ring kept producing less bubbles.
We have made a new bubble ring by melting the holes in it instead of puncturing them.

05/14/2015, 11:23 AM
On 5/13/2015 we collected 46
on 5/14/2015 we collected an additional 83

They are in a sterilized black tub with a new style strainer with a new bubble ring with enough circulation to keep them suspended, with a cycled sponge filter, protein skimmer, and phosphate reactor. Parvo density is kept at 6 + /ml
iso cultures are going good
parvo cultures are going good
all the stars are aligned
maybe this time

05/14/2015, 11:41 AM
What are you feeding the parents?

05/14/2015, 12:33 PM
asterina starfish and chocolate chip starfish

07/19/2015, 12:31 PM
We lost our male harlequin yesterday. He went to the great shrimp yard in the sky. We are now in search of a new pair. We have another female so 2 males would also work. If anyone local has a male they would like to trade for something let us know.

09/04/2015, 07:07 PM
Try to include blue linckia into diet.

Use a kreisel utilising water flow and not air.

A person good to consult would be Syd Kraul.

09/13/2015, 12:52 PM
The larvae don't settle for 45 plus days. It would be very difficult to build/maintain a Kreisel using a pump since the screens would clog from the small size of the food.

We don't have a Kreisel but by releasing air in the center of a round bucket you create a toroid which has the same effect. Many hatcheries use this method

The air does not SEEM to bother them but I guess you don't know until you try it

03/27/2016, 07:14 AM
Our first pair of harlequin shrimp has long since passed away
Their offspring are already sexually mature

Our second pair of harlequin shrimp released their first clutch of larvae on March 6th, 2016. They all died within a few days. They did not seem capable of staying in the water column. These are are not second generation They are another wild collected and obtained months apart from each other.

On March 26th they released their second batch of over a thousand
We have them in the same system used on all previous attempts.

I think we have our iso culture down. We hardly ever loose a culture.
Our parvo culture is also doing well.

I am thinking of making a Kreisel tank out of glass or acrylic so we can observe them better.

03/27/2016, 07:40 AM
yesterday the culture was fed iso to lightly cloud the water and enough parvo culture to obtain a density of 2.5 3 copepods per ml

This morning the density was down to near zero.
We added 4 600 ml portions or parvo
the density count went up to 4 per ml
the copepods did not appear to be full so we added more iso to the culture
We also strained the iso through a 200 micron felt filter bag (This is a new procedure)

We did not perform a density count on the larvae.
It would be very difficult to estimate their numbers.
They are capable of going wherever they want to and are not evenly distributed

04/14/2016, 09:51 AM
The last batch died at about 5 days
The air ring had come loose

We had a new partial release yesterday 4/13/2016 of about 100.
The rest were released this morning and we are collecting them now.

I think we need to come up with a better means of keeping them suspended
Any screens used need to be capable of being easily replaced and capable of keeping the copepods and larvae in without causing them to stick to it.

We are feeding parvocalanus and using a 55 micron screen.

05/02/2016, 05:49 PM
I have been thinking of making a new system to try. The last batch had all just died and we had another thousand plus released yesterday. I started with a 55 gallon tank and made 2 3 sided inserts to make an octagon with the water surface and tank bottom acting as 2 of the sides. All sides are 6.75 inches long
I positioned one vertical side 5 inches from one side of the 55
I made the inserts and then could not get them in the aquarium so I had to reheat them and bend them in the tank. Do not touch hot acrylic. I have a burn on my arm as a result of this. I cut out a 8 by 4 patch on the top of both sides and glued a 55 micron screen over the openings
I am calling the Kresiel the roundish area where the larvae are kept
In the water to the left of the Kreisel we have a very small pump that pumps water at a trickle to the right side of the tank.
In the right side of the tank we have 2 sponge filters a phosphate reactor and a protein skimmer
The skimmer is on a timer to go on from 11 at night to 11 in the morning so that it doesn't take phytoplankton out of the water
The tank is illuminated for 12 hours with a 36 watt LED bar
In the morning and at night we add isochrysis to tint the water and make the copepods more visible
The iso is strained through a 100 micron mesh bag.
We wait about 15 minutes and then perform a copepod density count and adjust it to about 8 copepods per ml.
circulation within the Kreisel is achieved by using 2 rigid airlines to release bubbles at the bottom of one vertical sides of the Kreisel.
A nice thing about the new system is that the larvae are much easier to see
They are capable of maintaining position in the water or moving.
Between feedings they eat about 4-5 copepods per ml

A little math:
The Kreisel area hold about 10 gallons of water
that is about 100 larvae per gallon
or 1 larvae per 38 ml
which means each larvae is eating 152 copepods per feeding 2x daily
if they do this in a 12 hour period they are consuming a copepod every 2.4 minutes

We are feeding parvocalanus copepods

05/06/2016, 04:17 PM
05/06 Everything is working great. It doesn’t appear that we have lost any larvae. They seem to be bigger and darker brown. Next week we will start taking pictures to document their growth

05/07/2016, 11:42 AM

Pictures taken May 7th 2016 in the Lab at Aquatic technology

05/07/2016, 12:04 PM
how do you sex these shrimp?

05/08/2016, 11:56 AM
Female harlequins are the larger of the two and have blue/purple spots under the tail.

Male harlequins are generally much smaller than the female and they lack the blue/purple spots under the tail

05/12/2016, 10:00 AM
There aren't that many left maybe 20
I cant attribute their deaths to anything in particular

They seem to release larvae every 13 to 18 days so they are due for a new release soon.

I am going to build 2 new systems with gasketed screens so we can easily clean them. That will allow us to flow more water through the Kreisel. I wont have all the parts I need until the 23rd so the next batch is going to go in the current system. In the meantime I am going to add a UV sterilizer.

05/23/2016, 01:01 PM
A few of the last batch made it to day 21 tying our record to date.
We had a new batch of 1000 plus born on the 19th of May. They are all going strong. as of day 4
We painted the bottom or the Kreisel white, added stick on black paper to the 2 open sides, raised the temperature to 80 and added a UV since the last batch.

We have plans to make at least 2 more systems in the next few months
The Kreisels will have removable gasketed screens, one side painted black, and we will probably try a black bottom on one. We may also experiment with lighting.

05/23/2016, 02:47 PM
This is really cool. Thanks for sharing with the ReefCentral community! Best of luck, I know raising saltwater fish and inverts is tough, but worth the effort when ultimately successful.

05/23/2016, 03:02 PM
If you have trouble with them being sucked onto the screens, make the screen area much larger, of course keeping the flow the same. That will decrease the face velocity through the screen and hopefully the larva will not be drawn onto the screen or hopefully can free themselves if they do.

05/26/2016, 02:57 PM
The new Kreisels have 2 roughly 8" by 4" screens. They take up the whole top section on both sides.

The next system will have easily removable gasketed screens. I just obtained some 50 micron stainless steel screen. It should be a lot easier to clean.

The screens clog mostly with copepod waste. The shrimp do not get stuck in them.

We haven't had much problem with clogged screens with the new system. If a screen gets dirty the water level on the small side reservoir drops and the pump slows down. The pump pumps water from the small reservoir over the Kreisel to the large reservoir where all the equipment is. When we see the water level is down we clean the screen by rubbing it. (We will be able to remove and clean it in the new Kreisels system if we drop the water level first)

Water circulation in the Kreisel is from air bubbles
The transfer pump just moves water from one reservoir to the other, where it flows back by gravity through the Kreisel. We probably get around 10 turnovers per day of the water in the Kreisel.

05/29/2016, 02:22 PM
Today is 10dph on the latest batch
They are doing great
We are struggling on feeding them
We are using around half a million copepods per day
Our iso culture is struggling to keep up
They keep eating more and more copepods which requires more iso
We probably need to scale our production to something larger than 5 gallon buckets and carboys

06/14/2016, 01:38 PM
Each day is a new record for us. Today is 26dph.
Here are some pictures taken yesterday:


The new system is working great but the screens are clogging. We are building some new systems with gasketed removable/replaceable screens and should have them on line next week.

06/20/2016, 04:48 PM
We made it to 30dph
We should have another batch in about a week
The new system is in place and has screens that can be swapped out
We built a stand for 8 systems but only have one set up so far.
Its expensive. We already have a blower but each system needs a stand, 55 gallon tank, 25 watt UV, a light, custom Kresisel, 2 sponge filters, protein skimmer, phosphate reactor, heater and 2 pumps. We have almost 1k in a system

We will probably take the system down we just used and sterilize it and modify it to be like the new one

The phyto cultures are all going strong
The parvo cultures are all going strong

I purchased a stainless steel 55 micron screen. It appears to work much better than the nylon screens but I wonder how safe it will be with larval shrimp

06/27/2016, 03:58 PM
The previous system has been repurposed for raising black perculas.
I moved it up front out of the clean room because I did not want rotifers to contaminate our copepod cultures.
I removed the Kreisel, tapped it for removable screens and replaced it. We should be getting a batch of eggs ready to hatch this week.
A customer who has been trying to raise them is providing the eggs to us.

We set up a new Kreisel system in the clean room
It is the same as the old one but it has removable screens and a black bottom instead of a white bottom.
The current screen is 55 micron stainless steel.

Yesterday our female harlequin shrimp released just a few larvae. This morning there were thousands. There were way more than we have ever collected. We collected them but due to the large number did not bother counting them. There are probably somewhere between 1 and 2 thousand.

07/09/2016, 12:13 PM
12dph update
harlequins doing fine
stainless screens suck
we received the clown eggs but only 4 hatched
they are doing fine

08/11/2016, 05:28 PM
We had poor success on the last 2 hatches
they only made it to around 18 days

We saved just 500 from a release of over 2000 on August 8 and 9 and have them in a Kreisel currently
Maybe we will have better luck with less competition for food

09/08/2016, 05:55 PM
Harlequin shrimp update 09/08/2016
still no success
We have a new system with an octagonal Kreisel built into a 55 gallon aquarium.
It holds about 8 gallons of water
It is much easier to see the larvae
The Kreisel is located about 8 inches from one side of the aquarium
at night water is pumped from one side of the aquarium to the other so the water flows through the Kreisel screens. Effectively changing the water daily.
We also only kept 500 of the last batch since food sometimes becomes an issue as they get older.
one side of the aquarium houses a uv filter, 2 sponge filters a protein skimmer and a phosphate reactor
We have removable 55 micron screens on both sides of the Kreisel
The current batch 08/29 is going strong Losses if any have been minimal

09/26/2016, 02:31 PM
Was just there yesterday and saw a few of those Harlequin Shrimp enjoying a nice tasty starfish.. It was the first time we have been to your place too, absolutely amazing selection I was amazed when I walked into Aquatic technology! Currently prepping for a new 30 gallon tank with 10 gallon sump and hope to get some fish from you when its ready!

09/27/2016, 05:13 PM
Today is 30dph
We have a lot of larvae left and they are bigger than 1/16 of an inch
Tomorrow will be a new record.

10/01/2016, 04:52 PM
35dph and going strong

10/14/2016, 08:38 PM
Good luck, I am appreciate your dedication

10/19/2016, 12:01 PM
51dph and we still have some going but none have settled yet
fingers crossed

10/21/2016, 09:39 AM
Awesome work!

10/25/2016, 05:23 PM
We Did IT !!!!!

After years of trying we finally succeeded in getting them to settle
52dph we had our first 2 settlers. There was something in the tank that ate them and the rest of their brothers but we managed to save one and move it to a different system. He is about 2mm long


11/23/2016, 05:48 PM
The last batch only made it to 3 days past settlement
something ate them

The current batch hatched on October 28th and are doing fine
They are half way there to settlement
In the next week or so we are going to move them to a new
identical sterile system
when/if they settle we will move them to another system with fresh asterina starfish

11/29/2016, 10:53 AM
today is 32dph for the current clutch
I set up another identical system and will transfer them and the sponge filters over tomorrow.
Doing this to avoid any buildup of bad things in the current tank.

11/29/2016, 12:52 PM
Great work.. We need more qualified people with your dedication to succeed.

11/30/2016, 04:59 PM
We moved them to their new home today
all 943 of them

12/13/2016, 10:00 AM
December 13th
500 plus have settled
many more on the way
If anyone is local we need asterina starfish

12/14/2016, 01:16 AM
Wow, that is amazing! I wish that I had starfish for you. These gorgeous little shrimp are the reason that I decided too start keeping a saltwater aquarium. I love how they look but I've been doing tons of research and they seem like they might be too much for me at first. I noticed you said you were going through half a million copepods a day? How big a system and how much time do you have too dedicate too suppy that many? Thanks from a noob.

12/14/2016, 04:28 PM
For copepod production we have 8 6 gallon buckets

12/14/2016, 04:30 PM
We have about 650 some that have settled so far

12/22/2016, 12:31 PM
We had 600 plus settle out
A few have died since settlement but we still have many many hundreds


12/22/2016, 01:13 PM
We had 600 plus settle out
A few have died since settlement but we still have many many hundreds

They are so beautiful....great job guys!!

Sent from my LGMS550 using Tapatalk

12/23/2016, 11:48 AM


video of 55ish of our 600 plus babies

Luke Schnabel
01/07/2017, 07:41 AM
Do you know when these will be for sale? I can also bring some starfish up when i stop out.

01/09/2017, 11:14 AM
We are not really pushing them, but we can sell them in our store now. The world's first commercially available captive reared harlequin starfish.
At their current size they are $39.99 each
We are not shipping them at this time. They are eating chocolate chip starfish and asterina starfish whenever we get any.

We have a huge amount of money invested in this project and will probably never recoup our investment, but it was worth it for what we learned about culturing that we can apply to other species.

We are working on training them to eat an alternative food.

01/30/2017, 08:06 PM
Awesome job!

02/01/2017, 01:22 PM
Feeding Trial January 31, 2017
time lapse video is just over 4 hours
shrimp are 54 days old in this video
we left the lights on for the video
they eat better at night

Alternative Food is proprietary


Thunder Goose
02/21/2017, 06:31 AM
Fantastic! I prefer captive breed critters whenever possible (and I'm willing to pay)!

02/21/2017, 11:13 AM
They are for sale in our store for local pick up $40.00 each

We are also offering them to wholesalers in 100 lots You must agree to advertise them

and to retailers with a store front in 5+ lots

call 440 236 8330 for details

03/30/2017, 09:19 AM
We have been gradually selling them
we still have 100 plus left.

We are working on getting them to eat food other than starfish and have had moderate success so far

05/07/2017, 11:01 AM
05/07/2017 update
We have a 100 plus left of the first 2 batches
they are getting pretty big
we have a batch of larvae in the Kreisel now
They are about half way to settlement
no problems so far

We obtained a pair of Hawaiian Harlequin shrimp
We lost the first spawn. We were not set up for it

We are waiting on another spawn from the Hawaiian harlequins

06/01/2017, 10:49 PM
What is standard lifespan of harlequin?

06/06/2017, 01:37 PM
probably around 4 to 5 years
You cant know for sure unless you raised them from settling.