Are there actually any Friendly Damsels? Yes there are .. the related Chromis

[albertthiel]

Very interesting article on Chromis species,and other of the same and related genera


http://www.reefkeeping.com/issues/2003-11/hcs3/


Albert

[az]

chromis may not be as bad to all other fish like damsels but they do kill each other a lot.

[albertthiel]

chromis may not be as bad to all other fish like damsels but they do kill each other a lot.

The Green Blue one is the safest IME ... Chromis viridis ... usually keep them in odd numbers like 3 or 5 ... and in say a 30 gallon tank with non aggressive fish and you should be ok

Albert

[az]

The Green Blue one is the safest IME ... Chromis viridis ... usually keep them in odd numbers like 3 or 5 ... and in say a 30 gallon tank with non aggressive fish and you should be ok

Albert

thats what we used to advise people about the green/blue but this is what they told us later;

started with 7 ended with 3, started with 5 ended with 2, started with 3 ended with 1, started with 15 ended with 6....and so on.

they actually behave better when there is some other aggressive fish in the tank, xxxx scared they start schooling needing each other for cover, but when they are not scared they start killing each other one by one.

[albertthiel]

thats what we used to advise people about the green/blue but this is what they told us later;

started with 7 ended with 3, started with 5 ended with 2, started with 3 ended with 1, started with 15 ended with 6....and so on.

they actually behave better when there is some other aggressive fish in the tank, xxxx scared they start schooling needing each other for cover, but when they are not scared they start killing each other one by one.

Not my experience but I do thank you for sharing it for the benefit of other readers

[Greatwhite]

I've never had a problem with chromis killing each other.. I've usually kept 5 at a time.. I DID have a problem with them jumping out though.  Perhaps it was murder, but the crime scene was always tainted by dogs before my CSI Fish group could get in for the investigation.

[JetJumper]

I have had similar experience to what AZ said and I am aware of someone else as well who has a 210G tank that most of them killed each other off. 

[albertthiel]

I have had similar experience to what AZ said and I am aware of someone else as well who has a 210G tank that most of them killed each other off. 

Thank you all for your input and it looks like we have 3 scenarios going on right now :

- they kill each other
- they disappear for some reason
- they jump and carpet surf and side

Each of those could indeed happen IMO ... it may depend on the tank and what else is in it and what its size is vs how many Chromis viridis are in the tanks'

just trying to recap ...

[Stussi613]

I posted on the Facebook group that I have also heard they will thin the herd out eventually as well.  I know a few people who have had the same experience of them eventually turning on each other.

I wonder if the theory of them needing to feel fearful and sticking together for protection holds true.

[JetJumper]

- they kill each other
- they disappear for some reason
- they jump and carpet surf and side

These are all related in my opinion

If Fish A scares the poop out of Fish B and Fish B swims to get away and goes up and out of the tank.. Thats essentially killing the other one

I have seen personally that when I had 5 chromis one would hide in the rocks and not move EVER.. he was scared of the other chromis.  This caused him not to eat.. and die.

[Greatwhite]

I think that the point is that the Chromis are GENERALLY friendly to the other tank inhabitants if kept in a small school... Sometimes they may be cranky at each other though.

[albertthiel]

I think that the point is that the Chromis are GENERALLY friendly to the other tank inhabitants if kept in a small school... Sometimes they may be cranky at each other though.

Yes that is a good way of putting it indeed

Albert

[Herstead]

What I have read is that they are less likely to kill other species of chromis if kept together. So you could keep a blue green with a blue reef and a yellow chromis w/o trouble.

Does anyone here have experience with this? I want to know because then I might try a mixed group.

- Jonathan

[albertthiel]

What I have read is that they are less likely to kill other species of chromis if kept together. So you could keep a blue green with a blue reef and a yellow chromis w/o trouble.

Does anyone here have experience with this? I want to know because then I might try a mixed group.

- Jonathan

I have seem reports of such a mix going both ways ... so let's see what others have to contribute if they have kept several species together, and what their experiences were.

IME though you can keep the blue/green ones in a group, in a sufficiently large enough tank, and in 99% of all cases everything will be fine, but as you know, in this bobby there are always exceptions, so at times, I have to agree, there will be infighting.

One point that I did not mention is that if you keep a group of them, they should all be introduced "at the same time", and as most posts/articles will tell you, they should be kept in odd numbers.

The exact reason for the "odd numbers" is not totally clear though, but that is the recommendation found most of the time to avoid issues with conspecific aggression.

Hopefully other readers will contribute to this  thread.

Albert

[Canoe]

I have a pair of clowns in a 48G bowfront. Added 9 very small blue/green chromis. They seemed to thrive, liking the upper water column. After a few weeks of the clowns being scardy-cats, the clowns seemed encouraged to leave their rocks and explore the upper waters. I had two auto feeders, one with crushed small pellets and the other with flake, so with the feeder outputs set very small, the tank was fed a tiny amount eight times a day. Everything seemed fine, apart from the female clown deciding to take the feather-duster apart.

The chromis grew quickly. Later, at night they'd hide from a spontaneous purchase big-eyed black-barred soldier fish, which was keeping them exercised during the day. This soldier fish had to go as it was obviously too strong of a swimmer to be happy once it grew (went to Big Al's former shark tank; it's huge now!). Some weeks after the soldier fish was removed, the chromis started disappearing, one at a time, around every three weeks. I'd got in the habit of counting them due to the soldier fish's antics, watching as they'd regroup from their various night's hiding places. One to two days after the count was off by one, the tank got meaningful skimmer output for two days, which was a dramatic signal as it was usually sparse except when I vodka dosed. Water params did not spike... Never found a body, not in the tank nor on the floor. Barebottom tank, rock was dead rock that was cultured from a bottle, so there shouldn't be any worms to remove remains? Never saw the hermits change their foraging behavior. I observed the chromis decline in numbers, but have no evidence of the cause or where they went, other than a very temporary increase in skimmer foam output.

I'd love to have that 'school' back, but without knowing they can thrive...

[albertthiel]

I have a pair of clowns in a 48G bowfront. Added 9 very small blue/green chromis. They seemed to thrive, liking the upper water column. After a few weeks of the clowns being scardy-cats, the clowns seemed encouraged to leave their rocks and explore the upper waters. I had two auto feeders, one with crushed small pellets and the other with flake, so with the feeder outputs set very small, the tank was fed a tiny amount eight times a day. Everything seemed fine, apart from the female clown deciding to take the feather-duster apart.

The chromis grew quickly. Later, at night they'd hide from a spontaneous purchase big-eyed black-barred soldier fish, which was keeping them exercised during the day. This soldier fish had to go as it was obviously too strong of a swimmer to be happy once it grew (went to Big Al's former shark tank; it's huge now!). Some weeks after the soldier fish was removed, the chromis started disappearing, one at a time, around every three weeks. I'd got in the habit of counting them due to the soldier fish's antics, watching as they'd regroup from their various night's hiding places. One to two days after the count was off by one, the tank got meaningful skimmer output for two days, which was a dramatic signal as it was usually sparse except when I vodka dosed. Water params did not spike... Never found a body, not in the tank nor on the floor. Barebottom tank, rock was dead rock that was cultured from a bottle, so there shouldn't be any worms to remove remains? Never saw the hermits change their foraging behavior. I observed the chromis decline in numbers, but have no evidence of the cause or where they went, other than a very temporary increase in skimmer foam output.

I'd love to have that 'school' back, but without knowing they can thrive...

Have you checked for any crabs in the tank that may only come out at night ...

Did you see the Chromis fighting with each other ? That would happen during the day ...

I have a feeling but cannot be sure that there is something else going on in that tank ...

Just saying

[Darth]

I personally bought  7 blue/green chromis about a year ago, maybe more, they were all the same size, today I have 6 left and you can see the hierarchy amongst them as the size is big to small, they get a little bigger as you compare each one, yet they were bought at the same time and same size, they are not aggressive towards each other until feeding and then it is just who gets it first. So my long winded post is started with 7 now at 6, I think I lost the 7th because of natural causes in the tank (aka being the runt or was sick) but over a year later no issues

[albertthiel]

I personally bought  7 blue/green chromis about a year ago, maybe more, they were all the same size, today I have 6 left and you can see the hierarchy amongst them as the size is big to small, they get a little bigger as you compare each one, yet they were bought at the same time and same size, they are not aggressive towards each other until feeding and then it is just who gets it first. So my long winded post is started with 7 now at 6, I think I lost the 7th because of natural causes in the tank (aka being the runt or was sick) but over a year later no issues

Thanks for sharing your experience and yes that hierarchy does eventually come about and I glad to read that you did not notice any infighting, rather that the one you lost may have been to other causes. that is also what has been my experience, but ... all need to be introduced at the same time and all need to come from the same tank at the dealer where they have been living / swimming together for some time.

Of course, there will always be exceptions but the norm is that many can indeed be kept in the same tank without any issues IME

Albert

[Canoe]

Have you checked for any crabs in the tank that may only come out at night ...
Did you see the Chromis fighting with each other ? That would happen during the day ...
I have a feeling but cannot be sure that there is something else going on in that tank ...
Just saying

I too had the feeling that something else was going on, but I never saw anything and I can't figure out what it could be.

The canister filters were out of commission and dry for half a year, then cleaned and soaked in bleach, and then many many rinses with water, then with RO/DI. The rock in the canister filters was synthetic rock, purchased new, as was the pad media. The live rock in the tank was a mix of rock taken from Florida over 25 years ago (sitting dry as ornaments since then), and dry rock taken from a system decommissioned for over a year. The tank was cleaned like the canisters and is barebottom, so no sand taken from anywhere. I cycled it with the bacteria-in-a-bottle from the LFS. I had a small HOB skimmer to start with, then replaced it with a HOB Deltec. Both skimmers where used and got the same treatment as the canister filters.

The soldier fish had been trying its best to catch them, trying to single one out from the "school", but it always failed. I saw regular half-hearted short-lived chases between the chromis, but rarely contact, and never when feeding. Once the soldier fish was removed, the frequency of this increased but was not the dominant behavior, although there was one smaller chromis that the largest chromis seemed to regularly chase to the far side of the school. I never saw damage.  They continued their morning reunion and "schooling", anxiously seeking each other out.

Along with the soldier fish, I got a small Clarkii, which I figured its colour would be different enough from my pair of Ocellaris. It was tolerated for weeks, then the female Ocellaris started nipping and one day after around a week it went postal and shredded or removed 90% of the fins of the Clarkii. Shortly after that, the female Ocellaris ripped the feather-duster apart. In a separate tank on top but with the water flow, the Clarkii actually regrew all its fins, looked great, and the LFS took it to find it a home.

There are small hermits in the tank. They were aggressive with each other until I put a supply of larger shells into the tank. I never saw them gather together as though on a carcass.

When I decommissioned the large canister filter (3e), I was surprised to find a short fat worm in the top, maybe two inches long.

With the rock dry for so long, the usual suspect for hitch-hikers isn't viable?
Possibly from the hermits, in/on the fish, frogspawn, pulsing xenia, feather-duster, or in the trace water than was transferred with those. But I do note that one worm of unknown pedigree.

[albertthiel]

I too had the feeling that something else was going on, but I never saw anything and I can't figure out what it could be.

The canister filters were out of commission and dry for half a year, then cleaned and soaked in bleach, and then many many rinses with water, then with RO/DI. The rock in the canister filters was synthetic rock, purchased new, as was the pad media. The live rock in the tank was a mix of rock taken from Florida over 25 years ago (sitting dry as ornaments since then), and dry rock taken from a system decommissioned for over a year. The tank was cleaned like the canisters and is barebottom, so no sand taken from anywhere. I cycled it with the bacteria-in-a-bottle from the LFS. I had a small HOB skimmer to start with, then replaced it with a HOB Deltec. Both skimmers where used and got the same treatment as the canister filters.

The soldier fish had been trying its best to catch them, trying to single one out from the "school", but it always failed. I saw regular half-hearted short-lived chases between the chromis, but rarely contact, and never when feeding. Once the soldier fish was removed, the frequency of this increased but was not the dominant behavior, although there was one smaller chromis that the largest chromis seemed to regularly chase to the far side of the school. I never saw damage.  They continued their morning reunion and "schooling", anxiously seeking each other out.

Along with the soldier fish, I got a small Clarkii, which I figured its colour would be different enough from my pair of Ocellaris. It was tolerated for weeks, then the female Ocellaris started nipping and one day after around a week it went postal and shredded or removed 90% of the fins of the Clarkii. Shortly after that, the female Ocellaris ripped the feather-duster apart. In a separate tank on top but with the water flow, the Clarkii actually regrew all its fins, looked great, and the LFS took it to find it a home.

There are small hermits in the tank. They were aggressive with each other until I put a supply of larger shells into the tank. I never saw them gather together as though on a carcass.

When I decommissioned the large canister filter (3e), I was surprised to find a short fat worm in the top, maybe two inches long.

With the rock dry for so long, the usual suspect for hitch-hikers isn't viable?
Possibly from the hermits, in/on the fish, frogspawn, pulsing xenia, feather-duster, or in the trace water than was transferred with those. But I do note that one worm of unknown pedigree.

Thank you for the description, very methodical indeed, of all the things you did and looked at yet found nothing that would have  caused what ahas  going on. Well actually I think your soldier fish was keeping things in check and sort of running the show and so all others kind of submitted and no territorial fights or activity was going on.

However when that Clarkii clown was introduced, and the Soldier fish gone, the other Clown decided that it was time to show who the boss was, so to speak, and that is when gradually it starting attacking the Clarkii Clown more and more, as you noticed ...

Clowns are very territorial and the Ocellaris are certainly some of the most, except maybe for the Maroon Clown (Premnas sp.). The Clarkii clowns are usually not that territorial and so the Ocellaris would have had fair game (well unfair really).

One the internal status quo is disturbed, the real nature of some of the fish will come out and they will tend to become the dominant ones and that is what I think happened in your tank.

Glad you removed the Clarkii and placed it in another home so it could recoup from getting beaten up  ...

It just goes to show that even making one change in a tank can upset things completely.

Glad you figured most of it out though

Albert

[Littorina]

Hi there!

     I'm interested in the blue/green Chromis for my first saltwater tank (possibly deciding on a 30 gallon cube).  I read here that they will kill each other, but I would only have 1 Chromis in my tank.  I looked at the article posted here, and it listed other fish species that Chromis can co-habitate with peacefully. However, clownfish are not in that list.  I plan on having 1-2 Ocellaris clowns in my tank as well, so does anyone know if Chromis and Ocellaris clowns would get along? 

Thanks! 

[albertthiel]

Hi there!

     I'm interested in the blue/green Chromis for my first saltwater tank (possibly deciding on a 30 gallon cube).  I read here that they will kill each other, but I would only have 1 Chromis in my tank.  I looked at the article posted here, and it listed other fish species that Chromis can co-habitate with peacefully. However, clownfish are not in that list.  I plan on having 1-2 Ocellaris clowns in my tank as well, so does anyone know if Chromis and Ocellaris clowns would get along? 

Thanks! 

As you weil know one can never be sure how the interaction between fish will develop as it depends on a number of factors and you mention two of them, which make me think that it may not be a good idea :

1. the tank is only 30 gallons
2. you plan to have two clowns in there

The combination of those two would IMO result in the Clowns chasing that Chromis as Clownfish can be very aggressive especially they have been in a tank for a good amount of time ..

Now since the Clowns are not in the tank already what you could do and what may work is to introduce all three fish at the same time and with all the lights out. Try to get small clowns and a medium size Chromis.

Hopefully in that manner you may not run into the typical problem but as you know their are never guarantees in this Hobby ...

However when a number of fish are added all at the same time and no territories have been established yet, the typical aggression may not happen.

Hope this helps ...

Albert

[Littorina]

Thank you for the advice! 

I don't HAVE to have 2 clownfish in my tank.  I don't actually have a tank yet (I'm in the planning and researching stage), so I'm building my "fish wishlist" and I wanted to make sure which fish were compatible. 

     Perhaps if I did have my heart set on a Blue Green Chromis, it should be my first fish in the tank, followed by the (single) clown.......I'd be buying a small clown regardless - most of the retailers around me seem to stock little clowns. 


Thanks again!  :-)

[albertthiel]

Thank you for the advice! 

I don't HAVE to have 2 clownfish in my tank.  I don't actually have a tank yet (I'm in the planning and researching stage), so I'm building my "fish wishlist" and I wanted to make sure which fish were compatible. 

     Perhaps if I did have my heart set on a Blue Green Chromis, it should be my first fish in the tank, followed by the (single) clown.......I'd be buying a small clown regardless - most of the retailers around me seem to stock little clowns. 


Thanks again!  :-)

Oh I see you don't have the tank yet ... well then give me a list of what your choices would be and I will try to narrow the list down for you and we can always talk when I come to Aquamania in early April ...

Albert

[Littorina]

     Oh, how lovely of you to offer your advice, thank you!!  I was told by another member that you are an expert on nano tanks, and to check out your threads.  :-)    And I am very excited for Aquamania.  It will be my first one!  I'm hoping to attend your lecture actually. 

      I don't want a tank with an external sump (2 small, active kids in the house!), so I'm either going with an 18 gallon CAD Lights tank, or possibly a 30 gallon Innovative Marine Nuvo.  I plan on having a reef tank with a few fish and inverts.  I only recently considered the 30 gallon instead, as I realized how limited the 18 gallon would be to stock.  30 gallons is the absolute maximum size I'd be willing to try as a first tank.  But I'm still on the fence about the size.....

     Corals would be basic LPS - mushrooms, zooanthids, frogspawn or hammer coral, open brain corals...for inverts, I love the banded coral shrimp, but someone recently told me it can eat snails and to avoid it.        Your thoughts?  Otherwise, I guess I'd get peppermint shrimp?  And snails of course, and some hermit crabs - I adore the electric blue hermit crab.  I'd love to have a brittlestar down the road, once my aquarium is established, or a lettuce nudibranch.....but again, depending on tank size, and what's already in there for bioload.

     My top fish choices are Ocellaris clowns, Blue Green Chromis, Kaudern's cardinal, citrine clown goby, green clown goby, yellow clown goby.  The first 3 fish listed are my top 3 favorites, but obviously that would rule out an 18 gallon aquarium.........second choices include some of the colorful dottybacks, maybe like the bicolor dotty, or orchid dotty.....I like the azure damselfish, but I've had several people tell me it's a bit too aggressive.  People have suggested the royal gramma, and wrasses as well.

[albertthiel]

     Oh, how lovely of you to offer your advice, thank you!!  I was told by another member that you are an expert on nano tanks, and to check out your threads.  :-)    And I am very excited for Aquamania.  It will be my first one!  I'm hoping to attend your lecture actually. 

      I don't want a tank with an external sump (2 small, active kids in the house!), so I'm either going with an 18 gallon CAD Lights tank, or possibly a 30 gallon Innovative Marine Nuvo.  I plan on having a reef tank with a few fish and inverts.  I only recently considered the 30 gallon instead, as I realized how limited the 18 gallon would be to stock.  30 gallons is the absolute maximum size I'd be willing to try as a first tank.  But I'm still on the fence about the size.....

     Corals would be basic LPS - mushrooms, zooanthids, frogspawn or hammer coral, open brain corals...for inverts, I love the banded coral shrimp, but someone recently told me it can eat snails and to avoid it.        Your thoughts?  Otherwise, I guess I'd get peppermint shrimp?  And snails of course, and some hermit crabs - I adore the electric blue hermit crab.  I'd love to have a brittlestar down the road, once my aquarium is established, or a lettuce nudibranch.....but again, depending on tank size, and what's already in there for bioload.

     My top fish choices are Ocellaris clowns, Blue Green Chromis, Kaudern's cardinal, citrine clown goby, green clown goby, yellow clown goby.  The first 3 fish listed are my top 3 favorites, but obviously that would rule out an 18 gallon aquarium.........second choices include some of the colorful dottybacks, maybe like the bicolor dotty, or orchid dotty.....I like the azure damselfish, but I've had several people tell me it's a bit too aggressive.  People have suggested the royal gramma, and wrasses as well.

To keep this simpler, what I am going to do is send you a free copy of my latest book the "Nano-Reef Aquariums" in e-Version, but to do so I need your email address, so please send that to me at and include your full name and screen name so I know who it is coming from.

You can get an idea of what is in the book by going to www.nanoreefs.info (the book is 448 pages and takes you through everything you should know about the set up, the filtration, etc,  and the fish and the corals and much much more ...)

I will also subscribe you for free to the Newsletter and our web server will send you a login and password message. After you get that go to the drop down menu at the top left. One of the sub menus is called Newsletter archives and you can download them all but only download Volume 2 as I will send you a link to the entire Volume 1 in a single PDF also via Dropbox ... after you read the book esp the first 110 pages or so you will have a good idea of how to set the filtration up and what you can use ... etc ...

I think that will be easier and then after you have read that and have specific questions, post your messages here.

Albert

[Littorina]

Hi there!

     Well, I plowed through your nanoreef book last night and this morning.  Very informative, thank you!  :-)     I was a little overwhelmed with the chapter on various filtration methods - the chemical filtration methods more specifically- but I will continue to read about them and decide what I'd like to do. 

     As for fish stock.....well, looks like if I really have my heart set on a clownfish, or 2,  in a nanotank, I am pretty much looking at stocking clowns only, or perhaps 1 other fish.  I didn't realize they are so aggressive!  Although... since gobies inhabit the sand bed and live in burrows, and clowns swim up in the water column, can they perhaps co-exist a little better?   It sounds like the yellow and green clown gobies are more of a sand bed fish than the citron goby.  Or is this not true?   

     I will certainly take your advice and not stock hermit crabs in my tank. 

Thanks again.  Lots to think about!

[albertthiel]

Hi there!

     Well, I plowed through your nanoreef book last night and this morning.  Very informative, thank you!  :-)     I was a little overwhelmed with the chapter on various filtration methods - the chemical filtration methods more specifically- but I will continue to read about them and decide what I'd like to do. 

     As for fish stock.....well, looks like if I really have my heart set on a clownfish, or 2,  in a nanotank, I am pretty much looking at stocking clowns only, or perhaps 1 other fish.  I didn't realize they are so aggressive!  Although... since gobies inhabit the sand bed and live in burrows, and clowns swim up in the water column, can they perhaps co-exist a little better?   It sounds like the yellow and green clown gobies are more of a sand bed fish than the citron goby.  Or is this not true?   

     I will certainly take your advice and not stock hermit crabs in my tank. 

Thanks again.  Lots to think about!

Indeed the filtration section is quite large because I wanted to include as many options as possible that hobbyists have and can consider, but of course no one needs to use all of them ... one picks the ones that one is most comfortable with.

And on the fish ... if you go with the Clowns then a Shrimp Goby would probably be best ... with its shrimp as they will dig a burrow and remain sat the bottom ... just make sure that you feed them or the clowns will grab all the food you add ... so spot feed them.

The Gobies you mentioned live in SPS corals and are not IMO the ones you want to pick for your tank if you are going to put two Clowns in it.

Albert