Dealing with fish aggression, esp. damsels

[betareef]

One of the most annoying and disappointing things that can happen in an aquarium, is for fish to fight and bully. I have heard and read so many suggestions over the years, and for certain, they don't always (ever?) work. Nevertheless, I would love to have a community of damsels in a tank.

Years ago, I put 5 yellowtailed Blue damsels (the supposedly best natured type) in a 4 foot tank (with various other fish species, like a tang, tusk fish, wrasse, etc. This was following the theory of letting each damsel have it's own territory. They 5 found spots in the reef to call home, but over about 6 months, they were down to 3. They held at 3 for many years. So, should we conclude only 3 in a 4 foot tank?

Well, another theory is to have many damsels all together so any aggression is spread, territories are not formed, and one fish doesn't get picked on continually. I have had this work with freshwater fish, haven't tried it with damsels.

Also suggested, is many hiding places (not necessarily "territories" but plenty of caves and holes to disappear into when ne fish inevitably chases another).

Another suggestion often heard, is to buy groups in odd numbers, so you don't end up with pairing, and ganging up, so much. Combined often with adding them all at the same time, or rearranging the tank completely when a new fish is added.

Another method is to get a batch from the same breeding and raise them together, Again, not with damsels, but I have see this work, only until maturity starts, then they start picking off the weakest in the group, and one by one, you start losing them.

How about a group, on one of each different species that you obtain. With damsels, these days it is easy to come up with 6 or 8 or more types, of the less aggressive species. Maybe you could double up on some of the better behaved.

Another common one to combine with the above, is just keep them well fed, so they don't compete for food. Along with this, good water quality is also suggested, so well fed and good clean water, adds up to a good filtration and biological support system.


Maybe you can add other suggestions. How about those who try to keep a large group of green chromis, or ocellaris clowns. What works best?


Right now, I am considering (maybe in combination)

1. mixed damsels (species like talbot, yellowtailed blue, lemon, blue, vanderbilt - basically avoid bigger and/or more aggressive types)
2. larger numbers in smaller tank
3. numerous escape routes and hiding places
4. keeping them fat :)
5. maybe, depending on tank size, a few other types of fish that can cope, goby, wrasse, puffer


Lastly, I hope my thinking out loud here doesn't start a big argument.
Please be nice :)

 

[Savage Henry]

I don’t know the answer. I had a group of neon blue damsels together in a small tank and they just seemed to fight. You don’t get that effect you expect from Malawi cichlids.

One point about the group of five you had that became three. Do you know what the other two died of? Could have been old age, got stuck in a rock, or something else.

 

[slingfox]

I have a bunch of damsels in my tank and they all get along great:

- 2 DaVinci clownfish
- 7 blue-green chromis
- 2 neon damsels

I also have 3 Anthias. The male anthia helps keep the chromis in check.

My fish are fed 5 or 6 times day via auto feeder plus frozen and nori by hand. My chromis are like starving piranhas and like to join my tangs to pick at nori and wait for tidbits to go into the water column.

 

[betareef]

I don’t know the answer. I had a group of neon blue damsels together in a small tank and they just seemed to fight. You don’t get that effect you expect from Malawi cichlids.

One point about the group of five you had that became three. Do you know what the other two died of? Could have been old age, got stuck in a rock, or something else.

Could have been something else, but it is very suspicious as they were all bought together and the remaining three lived years after.

 

[betareef]

I have a bunch of damsels in my tank and they all get along great:

- 2 DaVinci clownfish
- 7 blue-green chromis
- 2 neon damsels

I also have 3 Anthias. The male anthia helps keep the chromis in check.

My fish are fed 5 or 6 times day via auto feeder plus frozen and nori by hand. My chromis are like starving piranhas and like to join my tangs to pick at nori and wait for tidbits to go into the water column.

Great to hear a success story like this. Yes, multiple feedings is something I am keen to include. Damsels certainly are avid feeders.

Interesting about the Anthia interaction with the chromis.

 

[slingfox]

Great to hear a success story like this. Yes, multiple feedings is something I am keen to include. Damsels certainly are avid feeders.

Interesting about the Anthia interaction with the chromis.

Many people report groups of chromis killing themsleves so that only 1 survives over time. I have had these exact 7 chromis for over 2 years without issue. They are well fed and they can’t expend the energy fighting each other when they have a male Anthia chasing them around every so often.

 

[betareef]

I don’t know the answer. I had a group of neon blue damsels together in a small tank and they just seemed to fight. You don’t get that effect you expect from Malawi cichlids.

One point about the group of five you had that became three. Do you know what the other two died of? Could have been old age, got stuck in a rock, or something else.

I meant to mention, around here, shops sell two completely different types of "yellowtailed Blue" or "neon" or electric blue" damsels, and they don't distinguish between them, but one is a Pomacentrus and the other is Chrysiptera.

The Pomacentrus are super aggressive, and the Chrysiptera are one of the more well behaved (IME).

 

[betareef]

Just had a thought about numbers of fish. I am thinking, with damsels in mind, the old old inch of fish per gallon (with all it's caveats) is applicable, especially as modern filtration and water flow is better than back when the saying came about.

That would mean, as a small example, I might think about 6 to 8, one inch, fish in a true 10 gallon tank.

Of course, this means, as fish grow, numbers might need to be reduced, so occasionally a fish might need to be removed from the group. So a second tank or two for the removals is needed.

 

[Savage Henry]

The damsels I kept were Pomacentrus Coelestis. I caught them myself. So, maybe they were the worst examples to test in a group as you’ve pointed out they are aggressive.

 

[betareef]

The damsels I kept were Pomacentrus Coelestis. I caught them myself. So, maybe they were the worst examples to test in a group as you’ve pointed out they are aggressive.

Yes, they deserve one of their common names, Blue Devils

 

[Sean Clark]

More fish regardless of type means the aggression is spread out. I have lots of damsels of various types in my tank and no aggression among them. I think the more, the marrier.

 

[betareef]

More fish regardless of type means the aggression is spread out. I have lots of damsels of various types in my tank and no aggression among them. I think the more, the marrier.

This is definitely my current plan. The experiment begins...

 

[StartingATank]

I would say only keep 1-2 types and only 2 of each. But if needby, then have a good amount in there and maybe they will act like a schooling damsel. But I would say the most pacifist of all damsels would be true springeri damsels

 

[betareef]

I would say only keep 1-2 types and only 2 of each. But if needby, then have a good amount in there and maybe they will act like a schooling damsel. But I would say the most pacifist of all damsels would be true springeri damsels

But that's only 4 fish. I feel you will need many more to spread the aggression.

 

[areefer01]

I'm not sure of the question. If it is can you keep multiple damsels in a display, happily, the answer is yes. You will, however, need to setup the display to manage this to include frequent feedings, small portions, several times a day.

They need space to sleep
They need space to spawn
They need tank maturity to break line of sight, chases
They need flow
They need reef structure
Hobbyist needs to stock accordingly
Hobbyist needs to add them last

Space to sleep, spawn, and retreat is a no brainer. This is reef structure, corals, and maturity. Depending on the type of damsels you buy they sort of mingle among the reef structure. I have 11 Lyretail Damsels right now and that is what they do. I have also kept 7 Sapphires which behaved similar. Same with my Azures. The only Damsel that was a bit different was a single Surge which was more open water.

Frequent feedings is easy. Use an auto feeder. Small portions throughout the day. I actually feed hourly but I understand some freak out over this. Point is frequent feedings, mix of dry food, means someone will have a chance to get something. I also add in a frozen feeding later in the evening. This gives me time to observe them. Again full belly, less fighting over food, fish have favorites, so someone will usually get something.

Why add last you might ask. Damsels for the most part when properly taken care of will form a pair and spawn. Some males are a bit aggressive in protecting the nest. Existing fish will know their spawning areas. New fish will not. Even if you turn off the lights the it won't know as it forages and there may be aggression.

These are just my opinions after keeping several of different types in my 210 gallon. I'm currently keeping 11 Lyretail's as I mentioned earlier with a few of them spawning. Keeps the reef active I must say as they are always out and about doing their thing. What is more fun is watching the Pink Square Anthia, dominate male, keep the damsels in check by diving bombing them so that the retreat into the reef only to turn around and come back out. Much like I see when scuba diving over a reef crest.

TL; DR - yes, you can have them. Setup is important. I would recommend adding them last. Feed often through out the day.

 

[betareef]

What is more fun is watching the Pink Square Anthia, dominate male, keep the damsels in check by diving bombing them so that the retreat into the reef only to turn around and come back out. Much like I see when scuba diving over a reef crest.

This is the second mention of having an Anthia to keep them in check. Interesting...

 

[areefer01]

This is the second mention of having an Anthia to keep them in check. Interesting...

I have nothing to go on other than what I have seen while scuba diving and what my Pink Square Anthias do. Maybe it is their size. Maybe the Anthias behavior or role. Honestly, no idea but it is what I see in my display which is rather interesting.

There are no torn fins. No bite marks. Just quick bursts of speed chasing and pushing them back into the reef structure. The Damsels scurry away, dart into their respected areas, and then turn around and are back out again. No harm, no foul.

/shrug.

 

[betareef]

I have begun an experiment along the lines discussed. See - https://www.reef2reef.com/threads/r...gal-after-power-outage.1130890/#post-13915806

 

[mcarroll]

More fish regardless of type means the aggression is spread out. I have lots of damsels of various types in my tank and no aggression among them. I think the more, the marrier.

I'm terrible at analogies usually, but this one just occurred to me.

Imagine our fish is a boxer – the sport, not the animal.

He has to box 1 or 2 fish every day, maybe no problem.

But you're his manager, and you're not happy with your cut yet, are you?? So he's gotta fight more.

6 fights a day. Still our boxer seems alright.

$$$

12 fights a day....now our boxer is *really* taking a beating with that number of fights, even if he's winning every fight.

"But it's a 75 Gallon boxing ring – there's room for more," you say!

24 fights a day. $$SCORE$$

But now your fighter can heal properly before fights and he's gonna start showing an overall wear pattern so he won't really be able to read or do math anymore.

Maybe that's where the analogy breaks down...

Anyway, more is not "a solution" where you're talking about a collection of aggressive reef fish.

First, the carrying capacity of a reef tank won't really support that...at least not with any reasonable margin for safety.

But also, as someone else observed, you do not get the effect folks look for out of (eg) "African Cichlids" – it's a different situation, IMO.

Neither do you get the "dither fish" effect because marine fish we keep really don't school like many freshwater fish do....not in little tanks, anyway.

On keeping Damsels, you can't just consider them all "Damsels" and imagine they're like Clownfish just because they're related. There are a ton of Damselfish species and each has at least somewhat unique life habits that will each be more or less easy to cater to in a reef tank – many just aren't really compatible with small tank life. For example, some like a branching coral head to call home base. Some like to garden algae. Is anyone going to sacrifice that big coral colony so they can have a colony of Damselfish instead? Is anyone going to let them "garden" a patch of hair/turf algae in the tank?? That's a couple of common ones, but read up on the specific habits of your target fish as much as possible.....don't assume they're "like other fish" if you don't have to. They might be, but maybe not – that's how folks wind up with hit-or-miss success! ;)

This is another great time to reach for some good reefing books.

 

[betareef]

This is another great time to reach for some good reefing books.

Books get out of date, or disagree with each other, just like information on the web as well. Over the years, I have often found it's best to discover it for yourself - after having found whatever agreement you can between books and online information, to get a head start.